WO2025073011A1 - Biomass pyrolysis system - Google Patents

Abstract

A pyrolysis system using three different sections combined in series, of a vertical drying and gas scrubbing section, 2, a transitional section 3, and an extended horizontal high temperature reactor zone 4 based on top of a step grate furnace. The system is to efficiently convert various biomass materials into high Fixed Carbon material, clean syngas and valuable condensates by controlling feed down the vertical drying & gas scrubbing section in a packed bed-counter flow heat exchange arrangement where residence time and gas volume can be controlled through 3 feeding rate, 5 air injection, 6 & 14 recirculating gas injection. Radiant heat at 12 provides additional energy for drying the wet feed material.

Description

BIOMASS PYROLYSIS SYSTEM

Field of the Invention

[1 ]The present invention relates to a biomass pyrolysis system.

[2]The invention has been developed primarily for thermochemical transformation of biomass and will be described hereinafter with reference to this application. However, it will be appreciated that the invention is not limited to this particular field of use.

Background of the Invention

[3]A biomass pyrolysis system using standard pyrolysis techniques provides a process of converting biomass material into char, gas and condensate. This process, called pyrolysis, has been in use for hundreds or even thousands of years. Fundamentally, it includes heating biomass material to around 400-800C, with limited or no oxygen for an amount of time.

[4]There are two main ways used to achieve this - Direct or Indirect. This basically identifies the method the material is heated: a. Indirect - material is usually heated through a sealed reactor chamber or wall b. Direct - material is heated through direct contact, usually by hot gases (other heating methods are also available)

Both of these options pose different challenges with regards to scaling.

[5] There is the well proven “biomass stoker grate furnace” or “stepped reciprocating grate furnace” technology that is extensively used throughout industry for more than 100 years to combust wood chips, usually for boiler operations.

[6] Grate firing is a type of industrial combustion system used for solid fuels. It is now used mainly for burning waste and biomass, but also for smaller coal furnaces.

[7] Capacities are in the range of 0.3 to 175 MWh in industry and combined heat and power (CHP). Fuel fired per grate area generates 1 -2 MW/m², with maximum grate area of 100 m².The general concept of a stepped reciprocating grate within a furnace is well known and this remains very active in the field of alternative methods of renewable energy production. [8]An example, shown in Fig 1 , is the GTS Energy Reciprocating Grate Combustion System technology which is utilised by Detroit Stoker Company in Medium-Density Fiberboard (MDF), Oriented Strand Board (OSB) and other particleboard plants. The system uses inclined reciprocating grates that push the fuel down the length of the grate through distinct drying, gasification, combustion and burn-out zones. However high alloy material is used so it is capable of operating at high temperatures so air cooling is sufficient. The feed material is completely combusted and therefore the products are heat, ash and flue gases only. Therefore, the output and throughput does not upscale to produce high char output.

[9]The features of a stepped grate are shown in numerous patent publications, including various iterations in US Patent No. 4471704, US Patent No. 2431415 and US Patent No. 4656956.

[10] While the prior art showing the general concept of a stepped reciprocating grate is not new, various improvements such as materials used, air openings in grate plates, different arrangements of plates and movement are needed to improve the efficiency of heating.

[1 1 ] A fundamental problem with the current pyrolysis systems is the scale. Most of the new pyrolysis technologies introduced over the past 20 years are below 0.5 tonnes/hour in processing capacity. It is necessary to scale the product output to overcome fixed operating costs and to reduce the overall cost per tonne of product. Each technology's robustness/reliability also has a large performance impact on “up time” and “expected life” of the equipment. For example, many new technologies utilising screw augers and reactors made from metals exposed to high temperature cycling and high torques, have serious weaknesses in this area.

[12] It can be seen that the known prior art for a biomass pyrolysis system has one or more of the following problems of: a. not being readily scalable b. not operationally robust c. being highly complex machinery that sets limitations on production rates and scalability d. not capable of processing high moisture organic materials with high carbon yields without external energy sources needing technology robustness

[13]The present invention seeks to provide a biomass pyrolysis system, which will overcome or substantially ameliorate at least one or more of the deficiencies of the prior art, or to at least provide an alternative.

[14] It is to be understood, if any prior art information referred to herein, such reference does not constitute an admission that the information forms part of the common general knowledge in the art, in Australia or in any other country.

Summary of the Invention

[15] According to the first aspect of the present invention, a biomass pyrolysis system is provided for thermochemical transformation of biomass, comprising a biomass infeed, a grate transfer system downstream from the biomass infeed and a furnace/reactor chamber which receives biomass via a transitional drive system, wherein the system includes gas flow substantially in the opposing direction to the flow of biomass.

[16] Within the reactor there is included a reciprocating step grate system driven by a grate motor, which distributes the biomass infeed evenly thereover for exposure to heat in different zones, and transfers the biomass through the furnace to a carbon material receiving exit, wherein the gas flow is provided partly by an air injection port beneath and another above the reciprocating step grate system, whereby oxygen reacts with volatile gases emitted from the heated biomass.

[17] Preferably the biomass infeed is: a. a ligneous material such as wood chips from sawmills or b. biomass materials such as agricultural residues either with up to 50% moisture and size of approximately 100mm or lower.

[18] Biomass enters the drying and pre-heating section through an airlock system that prevents gas escape or unwanted air ingress into the system.

[19] In a first mode, gas can flow in a pathway on top and up the step grate, through the incoming feed material to a condenser and is condensed and liquids, known as pyroligneous acid, are collected, and wherein the reciprocating grate urges infeed biomass along the steps and conversion of the biomass to carbon material collected at the reactor exit. Preferably, part of the gas after condensing the liquids out can be injected back into the reactor system near the char exit to enhance thermal efficiency and drying of biomass, particularly for high moisture feeds.

[20]The thermochemical reaction transforms organic biomass materials in a controlled manner into carbon material (char), pyroligneous acid (wood vinegar) and syngas products.

[21] In a second mode, gas can flow in a second pathway on top and up the step grate to a recycle flue and is aerated and collected and fed to a boiler, and wherein the reciprocating grate urges infeed biomass along the steps and conversion of the biomass to carbon material collected at the reactor exit.

[22] Preferably, gas flows are primarily focused on operation in the first mode on which gas is drawn off through the woodchip.

[23] The biomass pyrolysis system provides the heating of biomass material to around 400-800C with limited oxygen for an amount of time.

[24] The stepped reciprocating grate can comprise a plurality of grate plates of general configured to be reciprocatingly linked to distribute thereon and urging travel of an infeed of biomass through heating zones towards an exit. The feeding section of the air flow can be an upper point above the stepped grate.

[25]The reciprocating step grate motor is preferably driven through a large reduction box and transfers the biomass infeed material through the furnace from the top step to the bottom exit, with the speed controlling material “residence time” inside the furnace hot zone. However, the reciprocating step grate can also be driven through a controlled hydraulic actuator system and transfers the biomass infeed material through the furnace from the top step to the bottom exit, with the speed controlling material “residence time” inside the furnace hot zone.

[26]The reaction chamber is formed by a channel above the stepped grate causing reaction gases to flow adjacent and up and above the stepped grate to be extracted from an upper section.

[27] Heat is generated in the system by injecting a small amount of air at varying rates by controlling an air blower and controlling entry of this air injected through an isolation or proportional valve and wherein the injected air flows through the material bed via holes in one or more of the step grates. Pre-heated air is injected under the grate section. The rate is controlled through programmable logic controller (PLC) software to maintain predetermined processing conditions required for feed properties and product specifications. [28] Oxygen (from air) reacts with volatile gases coming out of the heated biomass and the gases produced travel upwards through the feed material entry region and through the gas exit settler where a pump acts as a spray cooler and collects the condensables out of the gas while cooling it further. The condensed product can be weighed by load cell.

[29]A biomass pyrolysis system where the material is heated to 400-800C before it gets to the end of the step and is fully carbonised, typically with 90-95% Fixed Carbon content, and the solid carbon material falls off the bottom step into a conveyor system to be removed through an airlock device to prevent gas escape. Before removal, the solid material can be cooled (below 100°C) by injecting dry gas to reduce heat loss and the heated gas assists with drying moist feeds.

[30] It can be seen that the invention of this biomass pyrolysis system provides the benefit of the novel and inventive modification of changing the feeding section, reaction chamber and gas pathway built "on top" of the step grate and passing through the feeding section, which are different to all other step grate furnaces.

[31] In one formulation the invention provides a biomass pyrolysis system with one or more of the following benefits: a) improvements in structure and assembly including construction in order to maximise efficiency b) improvements over traditional furnace designs in the utilisation of a novel gas pathway concept c) feeding materials in and out that can use off-the-shelf components such as rotary valves or airlock systems d) automated process control that can vary production rate, material bed depth, process temperatures, product yields and gas composition e) machinery that is not constrained and does not need pre sizing or drying of feed f) a unique gas offtake system that does not strip dust from the incoming material which could otherwise block cyclones, etc. g) a unique gas cooling in the infeed column and the condensing system (gas temperatures reducing to around 80°C and 30°C respectively), looping the condensates to ensure a cleaner gas product h) the ability to independently vary feed rate and “residence time” i) allows ready control of injection volumes of air and combustion gas within the reactor independent of feed material j) only allows unreactive gases in direct contact with feed material k) can use gas product composition as a control variable l) can process high moisture feed materials without external energy sources m) allows space for expansion and is not constrained by pressure increases.

[32]The method uses high temperature combustion conveying equipment (moving grate furnaces) which can be easily scaled to large capacity compared to currently available pyrolysis equipment (e.g., auger based) and changing its internal gas pathway.

[33]The gas pathway is optimised for the purposes of high thermal energy efficiency, collection of valuable pyroligneous acid product, to maximise high-quality low-volatile char product, and to provide clean syngas (exiting at around 30°C after condenser) that does not need further cleaning or scrubbing.

[34] It can be seen that the invention of this biomass pyrolysis system provides the benefits of taking a known proven combustion technology and altering it to be used at low char making temperatures (e.g., 400-600°C), including modifying the gas pathway and control logic to produce the required products at scalable quantities, which was not possible previously. Modifying gas pathway and control logic can further distinguish this invention with wood vinegar collection and cleaner gas emissions than possible with the existing wood chip furnaces.

[35]The modifications, operating methods and controls are novel and inventive technology, while utilising the benefits of the proven furnace grate equipment. This allows for the custom design of a larger scale unit that was previously unavailable.

[36] Other aspects of the invention are also disclosed.

Brief Description of the Drawings

[37] Notwithstanding any other forms which may fall within the scope of the present invention, preferred embodiments of the invention will now be described, by way of examples only, with reference to the accompanying drawings in which:

Fig. 1 is a reciprocating step grate furnace of the prior art showing limited gas flow and thereby controlled thermochemical transformation of biomass.

Fig 2 is a diagrammatic view of thermochemical transformation of biomass using a modified reciprocating step grate furnace with controlled gas flow for improved scaling and efficiency in accordance with a preferred embodiment of the present invention.

Fig. 3 is a diagrammatic view of the processes at various locations of the modified reciprocating step grate furnace for conducting thermochemical transformation of biomass of Fig 2 in accordance with a first embodiment of the present invention.

Fig 4 is a diagrammatic view of the key process parameters for control of biomass material and gas flow, and for temperature and pressure control, of the modified reciprocating step grate furnace for conducting thermochemical transformation of biomass of Fig 2 in accordance with the present invention.

Fig 5 is a diagrammatic view of [0095] Temperature Profiles and Residence Times of Examples A and B respectively;

Figs 6 and 7 are graphical views showing temperature of different zones of the system of the invention over the invention process of Examples 1 and 2 respectively.

Fig. 8 is a diagrammatic view of the processes at various locations of the modified reciprocating step grate furnace for conducting thermochemical transformation of biomass of Fig 2 in accordance with a second embodiment of the present invention.

Fig 9 is a diagrammatic block view of the steps of a method of pyrolysis for improved scaling and efficiency in accordance with a preferred embodiment of the present invention.

Description of Preferred Embodiments

[38] It should be noted that in the following description like or the same reference numerals in different embodiments denote the same or similar features.

[39] Pyrolysis is the thermochemical decomposition of organic material at temperatures of around 600C in a limited oxygen environment. Material such as wood is converted into solid carbon material, liquid products and syngas.

[40] Referring to the drawings, there is shown thermochemical transformation of biomass in a biomass pyrolysis system. There is a biomass infeed to a grate transfer system downstream, from the biomass infeed leading to a furnace/reactor which receives biomass infeed in the grate transfer system. In this way the system includes gas flow substantially in the opposing direction to the flow of biomass.

[41] Referring to Fig 2, the reciprocating step grate furnace has a method for material conveying. The “green” gas pathway is normal operation (Mode 1) and the “orange” gas pathway is modified operation (Mode 2).

[42]The stepped reciprocating grate comprises a plurality of grate plates configured to reciprocate in order to distribute thereon and urge travel of an infeed of biomass through heating zones towards an exit.

[43] Mode 1 - Char, Wood Vinegar and clean syngas for external use (L1 - green pathway)

• Dashed red line - pathway closed

• No or Minimal over bed air

• Gas sucked through incoming moist feed

• Gas condensed, wood vinegar collected, and the gas used for external uses applications like electricity generation burnt through syngas burner

• Exhaust from syngas burner drafted through boiler or used for other external processes

• Grate speed and air adjusted for required energy/char ratio.

[44] Mode 2 - Char and Heat (L2 - orange pathway)

• No sucking of gas flow through feed

• Over fire air and more air for complete combustion of gases

• Syngas burner not operating - could be secondary fuel burner to help with emissions and peak heat requirements

• Draft blower to suck hot flue gases through boiler • No condensates collected

• Grate speed and air adjusted for required energy/char ratio

[45]The reciprocating step grate furnace has a method for material conveying. The "green" gas pathway (L1 ) is normal operation (Mode 1) and gas flow follows the “orange” pathway (L2) in modified operation (Mode 2).

1461 Method 1

[47] Referring to Fig 3, at 1 , suitable biomass with up to 50% moisture and 100mm or lower in size enters the drying and pre-heating section through a suitable airlock system that prevents gas escape or air ingress into the system. The feed entry is controlled by a level sensor through PLC software.

[48]At 2, the feed travels down the vertical section to the top of a moving floor furnace mechanism. This feed is fed into a sealed reactor section through a variable cross section area and feeding mechanism such as augers or pusher rod. The feed rate is controlled by PLC software, independently of the floor speed.

[49]The reciprocating grate is shown at 3, 4 and 5, wherein at 3 the feed travels down the moving floor furnace in a suitably dimensioned and sealed reaction chamber at a variably controlled speed to control “residence time” and increase material temperature. The material is heated by hot gases/air injected through the floor section and from radiant heat of the reaction chamber walls and roof. As the reciprocating grate approaches 4 the material is heated to 400-800C and by the time it gets towards the end of the step the material is fully carbonised, typically with 90-95% Fixed Carbon content.

[50] At 5, the solid carbon material falls off the bottom step into a conveyor system to be removed through another airlock device to prevent gas escape. A liquid can be injected at this point to change the gas composition through the water gas reaction, or a dry cool gas can be used to cool the carbon material.

[51] Air is injected under the grate section at 6. The rate is controlled through the PLC software to maintain pre-determined processing conditions required for the feed properties and product specifications.

[52] Depending on feed material properties and processing conditions a further gas/air injection can also be made in section 7.

[53]The syngas travels from the sealed reaction chamber section through variable geometry at section 2 and then vertically up the full feed column by way of a vacuum pump. The vertical feed column is designed (large enough) to cool the gases sufficiently and the dimensions and angles in section 8 help settle any dust components contained within the gas and a further condensate system is injected into the gas stream.

[54]The cooled and clean gas exits through section 9 at around 80C, and through an external condenser system where valuable condensate products are removed and the gases cooled further to around 30C, with any excess gas available for external use such as combustion for process heat or electricity generation.

[55] Pyrolysis as the predominant reaction in this reactor system is achieved by not fully combusting gas by controlling air injection. This gas travels countercurrent to incoming feed (instead of direct to a heat exchanger). The control process modifies grate speed, and air injection volumes and locations, so that it operates at lower temperatures with limited air, than a standard combustion furnace. This allows straightforward production and collection of the pyroligneous acid product and to produce and collect char product - instead of combusting to ash.

[56]The step grate section is modified by the uniqueness of changing the feeding section, reaction chamber and gas pathway built "on top" of this step grate which is different to all other step grate furnaces. This is different to the current running grate stoker furnaces in that our plant operates in pyrolysis mode (not gasification/combustion) and incorporates countercurrent material/gas flows and all of these allowing for easy scale-up. All existing "new pyrolysis technologies" have major constraints regarding scaling.

[57]The system also has much superior emissions (than wood chip furnaces) due to the clean, cool gas the reactor produces and also with the use of a new low NOx syngas burner. Not needing expensive gas cleaning arrangements, robust equipment with longer uptimes and lifespan, and the use of a simple countercurrent process (much lower energy requirements) to collect pyroligneous acid product - all lead to make char at significantly lower price per tonne compared to other available technologies.

[581 Operational apparatus of Method 1

[59] Referring to Fig 4 there are key process parameters for control of biomass material and gas flow, and for temperature and pressure control, of the modified reciprocating step grate furnace for conducting thermochemical transformation of biomass of Fig 2 and Fig 3.

[60] Solid Material Flow

[61] The process uses woody biomass such as wood chips from sawmills.

[62]The material is sized and loaded into a “feed hopper” mounted on load cell “WT025” and conveyed to the feed entry hopper by MT01 - this conveyor is switched on based on the output from vibration sensor switch “VIB001”.

[63]“AT21 ” is a CO meter measuring and alarming for any escaping gases from the reactor as feed is entering through the lock hopper.

[64]There is a double flap valve air lock system, or other devices like rotary valves or screw type feeders, allowing material to enter into the reactor without gas escaping; “SGV01” and “SGV02” are activated by vibration sensor switch “VIB002” indicating material level inside reactor. These slide gates run in a “loop” through PLC sequence to ensure there is always one valve shut. The gas blower “MT07” is in a FID loop to “PT35”, controlling pressure near the flap valves to just below ambient to ensure any gas transfer is inwards.

[65]A material agitator “MT02” is allowed to run to level material and prevent any bridging or rat holing as it falls downwards. “Torque” value can be used on this to trigger an alarm of low material if “VIB002” fails.

[66]The material falls onto a live floor hopper base with “MT03” driving three parallel augers through a reduction gearbox and chain/sprocket transmission. The speed of these augers relative to “MT04” step grate transfer speed control material “bed height” inside the furnace.

[67]The reciprocating step grate motor “MT04” driving through a large reduction box transfers the material through the furnace from the top step to the bottom exit. The speed of “MT04” controls material “residence time” inside the furnace hot zone.

[68]The char solids are cooled before leaving the system through an external water spray from “PUMP1” control valve “V010”. The material is carried out of the furnace by char conveyor driven by “MT05” and then exits the system through a similar double flap valve arrangement as the feed entry, where “SGV03” and “SGV04” are in a control loop activated by vibration sensor switch “VIB003”.

[69] There is a safety CO meter “AT23” at the char exit to ensure no gas is escaping and the exiting char material weighed by load cell “WT027”.

[70] Gas Pathway

[71] Using modified technology specific reactor chamber dimensions and geometry, modified gas pathway, and well-designed control logic, products of different combinations and characteristics can be made. The process is fundamentally pyrolysis, but with modified structure and process and ability to successfully automate the modified reactor system. Low value of feed materials and the ability to easily scale the processing equipment, give additional flexibility to optimise product yields and specifications at low risk to commercial feasibility.

[72] [0070] Heat is generated in the system by injecting a small amount of air at varying rates by controlling air blower “MT06”. This air is injected through the isolation valve “VO11 ” and flows through the material bed via holes in the step grate.

[73] Oxygen reacts with the volatile gases coming out of the heated material and travels upwards towards the feed material entry region and through the gas exit settler where “PUMP2” acts as a spray cooler and collects the condensables out of the gas while cooling it further. The condensed wood vinegar product is weighed by load cell “WT026”.

[74] Gas flow is controlled by the gas blower (“MT07”) suction speed which is linked to “PT35” to maintain a slightly negative pressure (to prevent escaping of gases). There is another safety CO meter located near the gas blower (“AT22”).

[75]The gas is pumped to a separate gas burning equipment where another combustion air blower is driven by “MT08”.

[76] Gas pathway can be selected (Mode 1 or 2) and optimised for the purposes of: high thermal energy efficiency, collection of valuable pyroligneous acid product, maximise high-quality low-volatile char product, and clean syngas that does not need further cleaning or scrubbing.

[77]Traditional step grate furnace designs do not utilise this novel gas pathway concept.

[78] Feeding of materials (in and out) can use components such as rotary valves or airlock systems. The automated process control allows to vary production rate, material bed depth, process temperatures, product yields and gas composition. The machinery is not constrained as with other technologies and does not need pre sizing or drying of feed.

[79]The system uses a unique gas offtake system that does not strip dust from the incoming material to block cyclones or other gas treatment or combustion devices. There are unique gas cooling and condensing systems looping the condensates to ensure a cleaner gas product.

[80]The reactor system allows independent varying of feed rate and “residence time”. This also allows for control of injection volumes and combustion of gas within the reactor independent of feed material.

[81] In the reactor system, only non-reactive gases come into direct contact with feed materials and therefore gas composition can be used as a control variable.

[82] Temperature and Pressure I/Os

[83]We have space for gas expansion and are not constrained by pressure increases in the reactor. All of the temperature sensors and pressure transducers, except for “PT35” which is in PID loop with gas blower (MT07), are there for monitoring and data collection to better understand process fundamentals. We incorporate key reactor temperatures (e.g., TT03) in a PID loop with material feed rate and/or air flow rate as a method for process control. Also, some of these monitored parameters will be system critical and required to be linked to alarming and possible system shut down (basically turn off air blower “MT06” to stop further heat generation).

[84]Alarming

[85] Included are sensors linked to critical alarms

[86] Pyrolysis conditions

[87] Biomass materials used during the trials were predominantly hardwood chips, with sizes in the range of 5 to 50 mm (also consisted of smaller and larger sizes). Their moisture content varied within 20 to 45% depending on the weather conditions (they were stored in the open).

[88]The primary control variables in our biomass pyrolysis system were - material feed rate into the reactor, residence time (in step grate) and air injection rate and locations in the reactor. These variables were controlled to perform pyrolysis at different temperatures, with the aims of achieving complete charring, characterising char yield (the percentage char produced from dry feed) and other product yields, and characterising product qualities.

[89] The key considerations in the biomass pyrolysis system were:

[90] Reactor temperatures - temperatures measured in the gas phase (above step grate) were used for process control. TT03 is measured near the middle of the step grate and indicates maximum gas phase temperature. TT02 is measured near the end of the step grate before char dropped into the conveyor. TT02 and TT03 varied within 400 to 700°C, and the temperatures measured on the step grate could be as high as 800°C.

[91]The biomass pyrolysis system was designed to allow the products to leave the system at low temperatures and this contributes to higher thermal efficiency, increased product yield and higher quality products. Char leaves the system at around 100°C (TT01 ) and the heat recovered by the syngas (recirculated, dry and cold) during char cooling is used to enhance drying of moist feed.

[92]The gases cool down significantly as they go up the feed column before exiting (at 9) and the gas exit temperature (TT07) was around 80°C for all run conditions. Such low temperature is key for gas cleanliness as it allows for condensing and eventual cracking of long chain hydrocarbons. The gas then goes through an external condenser where pyroligneous acid and a small amount of tar are condensed out, and the gas is cooled (TT08 of around 30°C) and cleaned, before the gas is used for generating thermal energy.

[93]Temperature profiles (4 hour) of two examples are shown below. Example 1 is for 40% moisture feed - reactor temperatures (gas phase) of 500 to 600°C, with a residence time of 20 min. Example 2 is for 25% moisture feed - reactor temperatures (gas phase) of 400 to 450°C, with a residence time of 13 min. Step grate temperatures for these two examples were around 800°C and 650°C respectively.

[94] Temperature Profiles and Residence Times

[95] Referring to Fig 5, Examples A and B show two different temperature profiles and residence times (with the corresponding graphs showing real time data) noting that these examples are not the limitation of what the invention can do.

[96]The invention can cater for different feed materials, moisture contents and production rates by changing processing temperatures through varying air/gas injection rates, residence times by varying grate speeds and material bed heights by varying feed rate through transition section from vertical to horizontal [97] Noting that the vertical drying section temperature profile can be controlled independently of the horizontal pyrolysis reactor chamber to enable drying of varying moisture feed materials by varying recirculated gas flows and radiant energy into this column (even with the lower horizontal reactor temperatures and faster residence times on Example B, the vertical drying temperature profile remained the same for both Examples A and B).

[98]As the biomass travels through the horizontal reactor section, it is initially heated and turned into char material, and this char material is continued to be exposed to heat for extended periods without further gasification of the material, leading to improved yields, in particular more volatiles are removed to produce a higher Fixed Carbon char product.

[99] Both the gas exit and char exit temperatures are below 100°C corresponding to better thermal efficiency and higher product yields.

[100]The automated control system can adjust and cater for different feed materials, and processing parameters, with the capacity to change the end product specifications (e.g. char or gas quantities and qualities) to match what is required for an application.

[101] Referring to Fig 6, there is shown Example 1 for hardwood chips (40% moisture) - 500 to 600°C reactor temperature (gas phase) and 20 min residence time and 20% char yield (dry basis).

[102] Fig 7 shows Example 2 for hardwood chips (25% moisture) - 400 to 450°C reactor temperature (gas phase) and 13 min residence time and 25% char yield (dry basis).

[103] It can be seen therefore that the reactor system of the present invention can handle high moisture feed materials (e.g., 40% moisture content) without the need for pre-drying or external energy sources. This was not possible in prior art systems that required a drying step prior to pyrolysis and/or external energy input to sustain the process.

[104] Char

[105] Char yields were typically in the range of 20% (Example 1 ) to 25% (Example 2), which could account for 35 to 40% of the biomass energy. Char yield, proximate analysis and calorific values of char from the examples are presented below.

[106] Lower char yield in Example 1 (20%) is possibly due to the additional energy needed from the biomass to evaporate excess feed moisture (40%), and the higher Fixed Carbon in Example 1 (95%) can be attributed to the higher degree of carbonisation (higher reactor temperatures and longer residence times).

[107]The data show the possibility of making char with different yields and product characteristics as per the requirements (different for industrial and agricultural applications).

[108] Characteristics of char

[109] Wood Vinegar

[110]The water-based condensate is typically 50% of the feed weight and once feed moisture is removed from consideration, the yield is around 20-30%.

[11 1 ]The liquid condensate is readily refined into wood vinegar through a settling process, which leads to the separation of oil and tar fractions. Tar could account for about 5% of the condensate volume and has significant value as a by-product.

[112] Wood vinegar is acidic (pH of 2-3), with main constituents of acetic acid (typically 5%) and phenols (0.1 -0.3%). There are also tens of naturally occurring organic acids in trace amounts, which contribute to its special properties and beneficial uses in agricultural applications.

[113]WV Contents (volume %)

[114] Syngas

[115]Syngas is the third significant product of the biomass pyrolysis system. This is the remainder once char and wood vinegar yields and the biomass used to sustain the process is accounted for.

[116] Product gas composition measurements were generally within a narrow range. An example is shown below with primary combustibles (CO, H2 and CPU) and the energy density. Among the non-combustibles, CO2 is typically 1 1 -13% and N2 is around 50 to 55%. N2 is from the injected air and contributes to the dilution of the product gas.

[117] Product Gas Composition

"“Calculated from gas composition

[118]The Energy Density of the gas (6.2 MJ/m³) is modest partly due to the diluting effect of N2 (e.g., 50%) in the gas mixture. However, the volumes of air used and syngas produced were substantial, leading to the estimation that syngas accounted for 35-40% of the biomass energy - a significant input towards industrial heat and/or electricity generation.

[119] It should be noted that the long chain hydrocarbons (C_mH_n) in the gas mixture was only 0.86% (always lower than 1 %), indicating the effectiveness of the reactor system in achieving gas scrubbing and cracking of larger gas molecules.

[120] Mass and Energy Balance

[121 ] Indicative Mass & Energy Balance for hardwood woodchips (1 tonne basis) is given below

[122] Mass Balance Mass Balance (for 1 tonne of woodchips)

[123] Energy Balance

Energy Balance (for 1 tonne of woodchips)

[124] Nearly 90% of the biomass energy is accounted for in the products, showing an exceptionally high energy conversion rate, owing to the novel and innovative design concepts adopted in the technology.

[125] Feed flexibility

[126] In testing, first at an arborist site and then at a sawmill, nearly 200 runs have been conducted, involving thousands of hours of successful operation, including continuous automated 24 h, 50 h and 100 h campaigns. Most of these runs have been with waste woodchips. There were also many successful runs processing a wide variety of feed materials, proving the versatility of the technology, as well as setting the scene for future expansion of its application. A few such feed materials which were processed are:

[127] The technology of the present invention has been successfully trialled to show it is also capable of processing various other feed materials such as macadamia shells, almond hulls, engineered timbers, and building and demolition waste.

[128] Optimisation of air injection to lower reactor temperatures and maximise char yield or increasing char yield from approximately 20% to 24% for a particular high moisture feed. The reduction in step temperature caused by new air mix (underbed and overbed air combination) is the reason for this increase.

[129] Air injection solely below the step grate and a combined mode of air injection below and above the step grate have notable differences in the temperature profiles of the material passing through (the later can be controlled to achieve lower step grate temperatures of 500 to 600°C, compared to the typical 650 to 850°C) and this resulted in greater than 20% improvement in char yield. This outcome is possible only with the novel and innovative engineering aspects incorporated into the design of the reactor of the invention.

[130] Method 2

[131] Referring to Fig 8, this is a pyrolysis system using three different sections combined in series, a. A vertical drying and gas scrubbing section, 2, b. A transitional section 3, and c. An extended horizontal high temperature reactor zone 4 based on top of a step grate furnace.

The system is to efficiently convert various biomass materials into high Fixed Carbon material, clean syngas and valuable condensates.

[132] Suitable biomass with up to 50% moisture and 100mm in size enters 1 , the drying and gas scrubbing section, through a suitable airlock system that prevents gas escape or air ingress into the system. The feed entry is controlled by a level sensor through PLC software.

[133] The feed travels down the vertical drying & gas scrubbing section in a packed bedcounter flow heat exchange arrangement where residence time and gas volume can be controlled through 3 feeding rate, 5 air injection, 6 & 14 recirculating gas injection. Radiant heat at 12 provides additional energy for drying the wet feed material.

[134] This dried feed is fed at transitional section 3 into a separate sealed reactor section through a variable cross section area and feeding mechanism such as augers or pusher rod. The feed rate is controlled by PLC software independently of the grate floor speed to adjust material bed height.

[135] The feed travels down the moving step grate furnace 4 in a suitably dimensioned and sealed reaction chamber at a variably controlled speed to control residence time and increase the material temperature.

[136] The material is heated by air injected through various locations below, through and above the feed at section 5 - this reacts with combustible volatile gas from the biomass to generate heat: a. directly on the biomass surface, b. below the step grate / biomass and above the biomass material, and c. additional radiant heat through the reaction chamber walls and roof 1 1 .

[137] The reaction chamber geometry is designed to increase gas residence time, allow for gas expansion volumes without exceeding pressure limitations and for extended material exposure to radiant heat without gasifying or combusting the char product to achieve high char yields with high Fixed Carbon.

[138] The material is heated to a maximum temperature in the range of 400 to 800°C (as per the process requirement), before it gets to the end of section 5 in the step.

[139] Volatile gases are further removed from the char material due to the extended time biomass is exposed to high radiant heat without generating unwanted gasification, combustion or ash, while producing a fully carbonised material with high Fixed Carbon (95%) and low ash.

[140] The reactor system has no external energy input to drive the process, and all energy requirements (drying, pyrolysis and heat losses) are provided by the feed material itself (depending on the feed and processing conditions this could be in the range of 5 to 20% of the feed energy). Our unique design allows for low processing temperatures (e.g., 450°C) on wet feed materials (e.g., 40% moisture content) without external energy input.

[141] The solid carbon material falls off the bottom step into a conveyor system to be removed through another airlock device at 6 to prevent gas escape.

[142] A liquid can be injected at this point into the char at exit 6 to change the gas composition through the water gas reaction.

[143] Further, dried syngas can be injected through direct contact with char material before the exit point 6 to cool the char and to capture thermal energy for the process.

[144] A combination of pre-heated syngas/oxygen containing gas (gas/air) is injected under the grate, through the material and above the material at section 5. The rate and mixture ratio is controlled through the PLC software to maintain pre-determined processing conditions required for feed properties and product specifications.

[145] The control of various gas/air injection points directly on the material or below and above is designed to maximise energy efficiency and optimise char yields - a 20% increase in char yield has been achieved using the same residence time by limiting air injection through the material and instead by combusting gas/air below and above the material in the gas space - predominantly radiant heat instead of conductive heat.

[146] Depending on feed material properties and processing conditions further gas/air injection can also be made in this section on either side of section 5.

[147] Radiant heat is also provided by an external combustion chamber through refractory walls at sections 1 1 and 12. The temperature/energy can be controlled through burner 10.

[148] The syngas travels from the sealed reaction chamber section through variable geometry at section 3 and then vertically up the full feed column 2 by way of vacuum pump 9.

[149] This transitional section 3 can control the material bed height through the reactor zone (step grate) 4 and also the gas residence time, reactor pressure and gas velocity entering the lower vertical drying section 2.

[150] As the hot gases pass through the incoming feed travelling countercurrent in section 2 it both dries the feed material and cleans the gas by removing the heavy hydrocarbon fractions by filtering and condensing on the cooler feed material.

[151] These heavy hydrocarbons travel on the material back into the high temperature reactor zone for further cracking into simpler and cleaner gas composition (minimal heavy hydrocarbons).

[152] Additional dried and preheated gas can be injected at varying rates into the bottom of the drying section 14 or char exit 6 to cater for different moisture feed loads.

[153] The gas travelling through section 2 towards exit 7 is cooled through the incoming moist feed material, stripping out heavy hydrocarbon fractions through both a filtering and condensing process provided by the moving packed biomass bed. The bed height and moisture content is controlled to capture all the thermal energy in this gas for beneficial use in the process, allowing wet feeds to be processed without a separate feed drying equipment. The gas exit temperature at section 7 is kept below 100C and more preferably around 80C.

[154] The dimensions of the vertical section 2 are designed to keep the cooling gas velocity for optimum heat exchanging efficiency, without stripping out finer dust materials into the gas stream. That is as the gas cools the cross-sectional area of the vertical section is reduced to maintain velocity of gas to prevent laminar flow.

[155] The volume of gas flow through the vertical drying section is controlled on processing requirements by adjusting volumes and/or temperature of gas flows through section 5, 6, and 14.

[156] The gas flow and reactor pressure are controlled automatically through control software algorithms of gas blower 9 to keep the reactor at a slight negative pressure around, preferably minus 150 pascals, to prevent gas leaks at material entry and exit points.

[157] The drying section also has additional thermal energy provided through the refractory wall at section 12, the temperature or energy of this radiant heat can be controlled through burner 10.

[158] The cross-sectional dimensions and baffle angles into the feed material at section 7 are critical for settling any dust components contained within the gas flow by reducing the velocity at this exit point below 6m/s.

[159] The cooled and clean gas exits through condenser section 8 at around 30°C via gas pump 9 to remove the valuable condensate products before being used at either section 6, 10 and/or 14, with any excess gas available for external use such as combustion for process heat or electricity generation at 15.

[160] Gas/air is injected through a separate combustion chamber burner 10 to allow for radiant heat to be provided into the char reactor section 1 1 and vertical drying section 2. The exhaust gas from this combustion exits through section 13.

[161] This burner 10 temperature can be controlled through the PLC to assist with faster cold start and additional heat load required for various processing conditions. It can minimise the amount of nitrogen (air) injected into the system for a higher energy density syngas product.

[162] Other embodiments of the invention would be understood by a person skilled in the art and are included within the scope of this invention.

[163] Method

[164] Referring to Fig 9 there is shown method of forming a biomass pyrolysis system including the steps of” a. provide reciprocating grate b. The reaction chamber is formed by a channel above the stepped grate causing reaction gases to flow adjacent and up and above the stepped grate to be fed off from an upper section c. Provide gas pathway on top and up the step grate to a condenser and is condensed and collected d. the reciprocating grate urges infeed biomass along the steps and conversion of the biomass to carbon material collected at the reactor exit e. part of the gas after condensing the liquids out can be injected back into the reactor system near the char exit to increase drying of high moisture feeds.

[165]Some beneficial Features of the Invention

[166]The invention provides one or a combination of one or more benefits of: a. the ability to make low volatile, high Fixed Carbon (95%) char from high moisture biomass in a single process without external energy sources. This is achieved by the modified process of pyrolysis and conducted at a relatively low temperature by limiting air injection - unlike gasification - and making a much higher char yield than a gasification process. b. Continuous char making processes of the prior art using wet feed material typically have lower char yields due to increased gasification or require additional external energy sources to remove the moisture in the feed material before pyrolysis. c. The combination of direct conduction heat transfer from combusting a small percentage of volatile gas directly on the feed material surface for fast charring times and radiant heat source (in the furnace) for higher char yields. d. The vertical drying/gas cleaning section transitioning into a high temperature horizontal pyrolysis chamber linked through continuous material flow (bed thickness being accurately controlled). e. The separate high temperature horizontal step grate furnace section gives extended residence time the biomass is subjected to the higher temperatures arising from radiating refractory walls and roof, 8-20 minutes residence time giving higher quality low volatile, high Fixed Carbon (95%) char with higher yields than possible by injecting greater volumes of air into a restricted space in a vertical kiln. f. Having a gas expansion space above the material liberating gases in the high temperature reactor zone controlling gas residence time to finalise chemical reactions, and reducing expansion pressures in the reactor chamber. g. The control of the transitional zone from high temperature reaction zone to vertical drying section with the ability to impact on production rates via adjusting material bed heights, gas velocity exit from reactor controlling gas residence time at temperature through variable area adjustments. h. The ability to run the process at low temperatures of 400 to 500°C without external energy sources on 50% moisture biomass - all this flexibility gives the ability to maximise char yield and efficiency. i. Significant volumes of clean gas with high energy (around 6 GJ/tonne of woody feed processed) remain after drying the wet feed and charring process to use for external processes such as electricity generation. j. Gas flow is controlled by a blower to keep the reactor at a slightly negative pressure compared to the ambient environment. k. The ability to automatically change process controls to cater for various types of biomass material, size and moisture contents on a continual basis. l. Recirculating of dry gas at varying rates to allow for extra drying capacity. m. Capturing the specific heat in char before exit by direct injection and contact of dried and cooled syngas for further beneficial use in the vertical section. n. Highly thermally efficient process with all products exiting below 100°C (thereby using the majority of heat in the process). o. The ability to change gas composition and calorific value based on various air, syngas, liquid injection rates alongside external radiant heat sources. p. No external energy requirement for the process - typically 5 to 20% of the biomass energy is used for drying, pyrolysis and to account for losses (high moisture feeds near the high end). q. The process is focussed on maximising char yield (25% and more) - which is unrealistic for vertical updraft gasification processes. Typically 40% of the biomass energy is contained in the char. r. Gas is clean and rich in energy for a high char making pyrolysis process. Again, close to 40% of the energy in the biomass material is contained in the gas. s. Highly efficient process where typically 80% or more energy is accounted for in the products.

[167] An important element of the invention is in separating the reaction chamber effectively into two discrete sections both from a process perspective and geometrically (with a transition arrangement): - drying/gas cleaning and pyrolysis/heat generation. There is no precedent in the prior art for that. That separation has allowed for maximum beneficial impact for both groups of processes and has given enormous possibilities for optimising both separately inline.

[168] In particular, in the horizontal reaction chamber, different sources of air/gas injection/heat source, thickness of the layer, time-temperature profiles - it is these combinations that make high char and cumulative energy yield possible (that is minimising combustion and gasification, and maximising pyrolysis).

[169] In the vertical drying/gas cleaning chamber, varying gas flow rates and temperatures by recycling syngas. The separation of processes allows different conditions to prevail in each section. That is, in the drying section maximum contact and therefore heat exchange is achieved between the cool, incoming feed and hot, outgoing gas, while controlling gas velocity to eliminate stripping of dust from the biomass feed. In addition, in the reactor section air, containing oxygen, is directed through a biomass bed of controlled depth, allowing oxygen to react efficiently with pyrolysis gas on the surface of the biomass, below the biomass and above the biomass, driving the pyrolysis process. Also, the large reaction chamber volume in the reactor above the step grate allows longer gas residence times causing further cracking of pyrolysis products and providing space to absorb extra gas volumes thereby avoiding high pressures.

[170] When all functions are attempted in one vessel, huge challenges are introduced that are both process and engineering related. The current invention allows for solving these challenges through its unique structure and processes while maintaining a continuous one step process. [171] Benefits compared with Prior Art

[172] In known pyrolysis process, such as with comparison to DE 2930256 A1 (BALSTER HUGO DR) 19 February 1981 , the known process is characterised in that in a shaft-shaped box the material slides over grates from top to bottom and is heated by a heat source located underneath, so that the material is slowly heated to the temperature necessary for carbonization during the slide from top to bottom and is discharged as ash at the lower discharge of the device; the gas generated by the carbonization process leaving the device at the top. However, they have comparative limitations including:

• Balster hugo are taking gas off at much higher temperature for a separate cleaning process.

• Our process carries out the complete gas scrubbing within the reactor and drying section with a gas exit temperature below 100C for better thermal efficiency and a cleaner gas.

• Known vertical reactor design does not have the cross-sectional area exposed to high temperature, compared to the invention’s drawn out horizontal section, so difficult to scale.

• The known design does not allow the long residence time exposed to high temperature (it is only at the bottom of vertical kiln), compared with radiating roof section and space for gas expansion and extended gas residence time in our design.

• The known reactor design - the gas velocity through the vertical column does not allow for cooling of gas and velocity compensation.

• Grates are not in the same reciprocating motion and are in completely different arrangements.

• They are passing oxygen through ash.

• The cooling of char in known designs is indirect through the grate holder pipes and not direct contact with a gas medium.

[173]The present invention, cooling is through direct contact with the char material itself which then allows this energy to continue through the drying phases - once again through direct contact with the materials so as to not lose efficiency of using external heat exchangers. [174]The technology of the present invention has a vertical column of feed material allowing for direct contact of hot gases from the furnace with incoming feed materials allowing efficient heat exchange between gas and incoming feed material. As a result of efficient heat exchange, the gas exiting the system is below 100°C. Balster Hugo does not cool gas to the same extent and the feed moves down alternating slopes, not allowing the same efficient heat exchange between hot gas and incoming feed material as in the present invention.

[175]The vertical feed column also allows for scrubbing of gas as heavy molecules are deposited on the cooler incoming feed. Balster Hugo does not have the same level of interaction between hot dirty gas and packed bed of incoming feed.

[176]The invention’s technology uses a grate feed transfer system at the base of the vertical drying and gas scrubbing section and a step grate furnace, where air is injected to generate heat via combustion, for the heating and charring of the feed material. Balster Hugo injects air at the bottom of the single shaft furnace for heat and combustion which passes upwards in the same shaft furnace. The invention’s technology uses discrete parts of the equipment for different operations: The step grate furnace generates heat by air injection, chars the feed material and cracks high molecular weight chemicals. The feed transfer system transfers feed from the vertical drying section to the furnace. The vertical drying system continuously heats and dries the incoming feed material while cooling and scrubbing the gas.

[177] Ultimately the Balster Hugo patent is about a vertical column for combustion/gasification with limited scope for heat exchange. The present invention, on the other hand, exposes materials at high temperatures (e.g., 500°C) for extended periods (e.g., 20 min) which are crucial for char making and high char yields and this would be unachievable with a simple vertical column (temperature at the bottom combustion point would be much higher) - a key objective of the present invention’s process (together with gas cleaning, etc., described above).

[178] With comparison to WO 2012/154133 A2 (KIV KOVINSKA IND VRANSKO D D et al.), the comparative differences of the invention include:

• They are a “gasification and combustion process” where we stop at pyrolysis which is difficult for a self-energy system on wet feed material

• They do not collect carbon material - charcoal • They are fully combusting gases in section 10, 11 - we do not and have extra gas for use in external processes

• The gas through the feed section is not fully obstructed and gas leaves hot and dirty

• They do not extract liquids from gas stream - burn it all (no pyroligneous acid extraction)

• They talk about using steam injection for energy source (gasification)

• We do not have two outlets for different chambers - ours has to flow through in series

• Our vertical drying section is not positioned above the grate, but with a transfer section between the two zones and is fed by the feed transfer system. This feed transfer system ensures that the correct amount of feed is delivered to the grate without blockages.

• Their patent was about gasification (producing energy rich gas for use) and combustion (fully combusted for energy) on top of the step grate - two separate chambers for each reaction (instead of both happening in one chamber) - that was the innovation.

• Char is not a product; gases leave hot - for gasification or combusted.

• We stop at low temperature pyrolysis where char is our main product - accounts for about 40% of the biomass energy.

[179] With comparison to US 2018/0208852 A1 (BRITISH COLUMBIA BIOCARBON LTD) the comparative differences to the present invention include:

• The reactor of the present invention can run from 400-800°C - the disclosed prior art can’t go below 650°C.

• Their gas exit temperature is 250°C and above and then tar is condensed at 110- 150°C. Our gas exit temperature is 80-100°C and then condensed to 30°C.

• The prior art disclosure is simply about an updraft (material down/gas up) pyrolyser and then the char is ground and mixed with tar (condensed from the gas) - recombination of the two to form briquettes (all the focus was on briquette making).

• Only commonality is the counter flow of solids and gases in pyrolysis but does not show the novel air/gas flow path or control of the air flows. [180] With comparison to CN 104152184 A (HARBIN INST OF TECHNOLOGY) 19 November 2014, the comparative differences to the present invention include:

• This system is about “suspension” meaning the material needs to be very small.

• It appears to be similar to a fluidised bed process in which the particles are kept in suspension in the pyrolysis gases and/or air.

• This is a gasification process and not pyrolysis

• Higher gas velocity

• This is about a new gasification method where fine biomass particles produce very fine char particles (in suspension) - which is combusted for energy (800 to 950°C) and the resulting CO2 reacts with char to make CO.

• This is gasification where the product is relatively energy-rich gas. Char is not even a product.

[181] With comparison to US 2012/0079762 A1 (SCHOTTDORF BERND), the comparative differences to the invention include:

• They do not inject air/gas under pressure to multiple different zones - rather just air gets sucked through an adjustable vent

• They do not recirculate gas

• They use larger material and longer residence times

• They do not have the critical free space above the air injection zone for expanding gases

• They do not have radiating refractory roof section over charing area for extended time at temperature

• Restricted on scaling single reactor due to vertical arrangement not having cross sectional area exposed to hot face, this is minimal compared to our 8-20 min time

• Lower yields as the air entry is always through the charring material - combusting more of the material into gas

• The present invention chars a bed of material at a set thickness and speed, whereas these shaft style furnaces do not have the same degree of control over the furnace or pyrolysis zone. • A vertical reactor with counter flow of gases and solids. But much restricted in scope and possibilities for scaling up and required multiple units.

[182] The design of the present invention effectively breaks the process into two - a vertical section for drying and gas cleaning, and a much-expanded horizontal section that allows for large volume gas flow (no pressure effect), multiple possibilities of air/gas injection and highly precision control of temperature-time profile. The possibilities for process outcomes and the ease of scalability are many fold more than provided in the prior art.

[183] Other differences and benefits of the present invention would be understood by a person skilled in the art and recognize the novelty and inventiveness of the present invention.

Interpretation

Embodiments:

[184] Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment but may. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner, as would be apparent to one of ordinary skill in the art from this disclosure, in one or more embodiments.

[185] Similarly, it should be appreciated that in the above description of example embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the claims following the Detailed Description of Specific Embodiments are hereby expressly incorporated into this Detailed Description of Specific Embodiments, with each claim standing on its own as a separate embodiment of this invention. [186] Furthermore, while some embodiments described herein include some but not other features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention, and form different embodiments, as would be understood by those in the art. For example, in the following claims, any of the claimed embodiments can be used in any combination.

Different Instances of Objects

[187] As used herein, unless otherwise specified, the use of the ordinal adjectives “first”, “second”, “third”, etc., to describe a common object, merely indicate that different instances of like objects are being referred to, and are not intended to imply that the objects so described must be in a given sequence, either temporally, spatially, in ranking, or in any other manner.

Specific Details

[188] In the description provided herein, numerous specific details are set forth. However, it is understood that embodiments of the invention may be practised without these specific details. In other instances, well-known methods, structures and techniques and have not been shown in detail in order not to obscure an understanding of this description.

Terminology

[189] In describing the preferred embodiment of the invention illustrated in the drawings, specific terminology will be resorted to for the sake of clarity. However, the invention is not intended to be limited to the specific terms so selected, and it is to be understood that each specific term includes all technical equivalents which operate in a similar manner to accomplish a similar technical purpose. Terms such as "forward", "rearward", "radially", "peripherally", "upwardly", "downwardly", and the like are used as words of convenience to provide reference points and are not to be construed as limiting terms.

Comprising and Including

[190] In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary implication, the word “comprise” or variations such as “comprises” or “comprising” are used in an inclusive sense, i.e., to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention. [191] Any one of the terms: including or which includes or that includes as used herein is also an open term that also means including at least the elements/features that follow the term, but not excluding others. Thus, including is synonymous with and means comprising.

Scope of Invention

[192]Thus, while there has been described what are believed to be the preferred embodiments of the invention, those skilled in the art will recognize that other and further modifications may be made thereto without departing from the spirit of the invention, and it is intended to claim all such changes and modifications as fall within the scope of the invention. For example, any formulas given above are merely representative of procedures that may be used. Functionality may be added or deleted from the block diagrams and operations may be interchanged among functional blocks. Steps may be added or deleted to methods described within the scope of the present invention.

[193] Although the invention has been described with reference to specific examples, it will be appreciated by those skilled in the art that the invention may be embodied in many other forms.

Industrial Applicability

[194] It is apparent from the above that the arrangements described are applicable for industries to conduct thermochemical transformation of biomass.

Claims

Claims The claims defining the invention are as follows:

1 . A biomass pyrolysis system, for thermochemical transformation of biomass comprising of high Fixed Carbon char, clean syngas and valuable condensates, the system including: a. A biomass infeed; b. A vertical drying and gas scrubbing section c. A feed transfer system downstream from the vertical drying and gas scrubbing section d. A step grate furnace/reactor which receives biomass infeed from the transfer system; wherein the system includes a gas flow substantially in the opposing direction to the flow of biomass.

2. A biomass pyrolysis system according to claim 1 wherein the step grate furnace includes an extended horizontal high temperature reactor zone with gas expansion space above the feed material that fluidly connects to the vertical drying and gas scrubbing section through a transitional section.

3. A biomass pyrolysis system according to claim 2 wherein the transitional section includes variable cross section area and feeding mechanism such as augers or pusher rod allowing the feed rate and gas velocity to be controlled by PLC software independently of the grate floor speed to adjust material bed height.

4. A biomass pyrolysis system according to claim 2 or 3 wherein the horizontal section is suitably dimensioned and moves at a variably controlled speed to control residence time and increase material temperature.

5. A biomass pyrolysis system according to claim 2, 3 or 4 wherein the horizontal section is configured such that the separate high temperature horizontal step grate furnace section gives extended residence time for the biomass to be subjected to higher temperatures from radiating refractory walls and roof for a period of about 8 to 20 minutes.

6. A biomass pyrolysis system according to claim 5 wherein providing higher quality low volatile, high Fixed Carbon (95%) char with higher yields (25% and more) than possible by injecting greater volumes of air in a vertical kiln.

7. A biomass pyrolysis system according to any one of the preceding claims wherein within the reactor there is included: a. a reciprocating step grate system is driven, which distributes the biomass infeed evenly thereover for exposure to heat in different zones, and transfers the biomass through the furnace to a carbon material receiving exit; b. wherein the gas flow is provided partly by an air injection port beneath adjacent or through and above the material on the reciprocating step grate system, whereby oxygen reacts with volatile gases emitted from the heated biomass.

8. A biomass pyrolysis system according to claim 7 wherein a. Additional energy is also provided through radiating refractory walls above the reactor zone and adjacent to the vertical drying section; and b. the high temperature reactor section is insulated and refractory lined and transfers heat to the material through radiation, convection and conduction with hot gas contact.

9. A biomass pyrolysis system according to any one of claims 1 to 8 wherein the biomass infeed is a ligneous infeed such as wood chips from sawmills.

10. A biomass pyrolysis system according to any one of claims 1 to 8 wherein the biomass infeed includes biomass materials such as agricultural residues.

1 1 . A biomass pyrolysis system according to claim 9 or 10 wherein the biomass contains up to 50% moisture and approximately 100mm or lower in size.

12. A biomass pyrolysis system according to any one of the preceding claims wherein the biomass enters the drying and pre-heating section through an airlock system that prevents gas escape or unwanted air ingress into the system.

13. A biomass pyrolysis system according to any one of the preceding claims a. wherein there is provided a first mode gas flows in a first pathway on top and up the step grate to a condenser and is condensed and collected, b. and a second mode gas flows in a second pathway on top and up the step grate to a recycle flue and is aerated and collected and fed back to boiler wherein gas flows on top and up the step grate prior to being directed as per the selected mode of operation and wherein the reciprocating grate urges infeed biomass along the steps and conversion of the biomass to carbon material collected at the reactor exit.

14. A biomass pyrolysis system according to claim 13 wherein part of the gas after condensing the liquids out are reheated and injected back into the vertical drying gas scrubbing section to effect the drying of high moisture feeds.

15. A biomass pyrolysis system according to claim 13 or 14 wherein the thermochemical reaction transforms organic biomass material into carbon material, pyroligneous acid and syngas products.

16. A biomass pyrolysis system according to claim 7 wherein biomass travelling along the horizontal reactor section is exposed to high temperature of about 400 - 800°C heat through radiation, conduction and/or convection for extended time periods of the order of 8 to 20 minutes allowing larger scale production and higher Fixed Carbon char with low volatiles.

17. A biomass pyrolysis system according to any one of the preceding claims wherein the heating of biomass material is to around 400-800°C with limited oxygen for an extended time.

18. A biomass pyrolysis system according to any one of the preceding claims including the stepped reciprocating grate comprising: a. a plurality of grate plates of general frustoconical configuration b. reciprocating linked to distribute thereon and c. urge travel of an infeed of biomass through heating zones towards the exit.

19. A biomass pyrolysis system according to claim 18 wherein the feeding section of the air flow is in multiple zones to optimise the pyrolysis reaction and allow for only the radiant heat past the char zone to remove volatiles without burning char and generating ash.

20. A biomass pyrolysis system according to claim 18 or 19 wherein the reciprocating step grate motor is driven through a large reduction box and transfers the biomass infeed material through the furnace from the top step to the bottom exit with the speed controlling the material “residence time” inside the furnace hot zone.

21 . A biomass pyrolysis system according to claim 18, 19 or 20 wherein the reciprocating step grate motor is driven through a controlled hydraulic actuator system and transfers the biomass infeed material through the furnace from the top step to the bottom exit with the speed controlling the material “residence time” inside the furnace hot zone.

22. A biomass pyrolysis system according to any one of claims 18 to 21 wherein the reaction chamber is refractory lined with maximum distance from the material of 0.5m and a gas volume above the grate steps of about 0.5m³ for about every 1 m² of grate area increasing gas residence time and reducing pressures from expansion then the gas is forced to flow through the vertical feed material section.

23. A biomass pyrolysis system according to any one of claims 18 to 22 wherein heat is generated in the system by i. injecting a small amount of air at varying rates by controlling air blower and controlling entry of this air injected through an isolation valve and wherein the injected air flows below, through, or above the material bed via holes in one or more of the step grates and ii. radiant heat from the reactor roof section generated by externally combusting a portion of the syngas generated in the process.

24. A biomass pyrolysis system according to claim 23 wherein a combination of preheated syngas/air mixture is injected adjacent or through or above the grate section wherein the rate and mixture ratio are controlled through a PLC software to maintain pre-determined processing conditions required for feed properties and product specifications.

25. A biomass pyrolysis system according to claim 23 or 24 wherein the oxygen (from air) reacts with the volatile gases coming out of the heated material and travels upwards towards and through the vertical drying gas scrubbing section, both drying the feed material and condensing the hydrocarbons in the gas stream, then through the entry region and through the gas exit settler where a pump acts as a spray cooler and collects the remaining condensables out of the gas while cleaning and cooling it further to 30°C or lower, and the gas cooled in such a manner producing lower than 1 vol% of long chain hydrocarbons (CmHn) and the rest being primary combustibles of CO, H2, and CF (and nitrogen).

26. A biomass pyrolysis system according to claim 25 wherein the condensed product is weighed by load cell.

27. A biomass pyrolysis system according to any one of claims 23 to 26, wherein the material is heated to 400-800°C before it gets to the end of the step and is fully carbonised, wherein the solid carbon material falls off the bottom step into a conveyor system to be removed through an airlock device to prevent gas escape.

28. A biomass pyrolysis system according to claim 27 wherein before being removed the solid material is cooled (below 100°C) within the reactor chamber by injecting dry gas to reduce heat loss from the system and the recovered heat assists with drying of moist feeds.

29. A pyrolysis system according to claim 27 or 28 that processes 50% moisture content feed material without any external energy sources or pre-drying required and all the drying and process related energy and heat losses are provided by the biomass itself, typically of 5 to 20% of the biomass energy depending on the feed moisture.

30. A pyrolysis system according to claim 27, 28 or 29 that has greater than 25% char yield while processing and using wet materials which also is the only energy source.

31 . A pyrolysis system according to any one of claim 27 to 30 that exposes char material to extended periods of high temperature without further gasification or combustion, only to remove the volatiles in the char to produce a higher Fixed Carbon (95%) material.

32. A single pyrolysis system according to any one of claim 27 to 31 that can control the vertical drying section and reactor chamber gas flow conditions separately.

33. A pyrolysis system according to any one of claim 27 to 32 that has a clean syngas gas product with lower than 1 vol% of long chain hydrocarbons (CmHn), without further external scrubbing processes required.

34. A pyrolysis system having: a structure comprising a. A vertical drying and gas scrubbing section b. A transitional section and c. An extended horizontal high temperature reactor zone having a step grate furnace feeding material towards an outlet.

Wherein the structure is configured to a. receive biomass b. dry and control the feed of the biomass to the step grate furnace c. and feed air into a gas pathway including to the biomass on the step grate furnace and wherein a PLC control system automatically controls a. the infeed of biomass material b. the infeed of air flow is provided partly by an air injection port beneath adjacent, through or above the material on the reciprocating step grate system, whereby oxygen reacts with volatile gases emitted from the heated biomass. c. the time of the biomass in the extended horizontal high temperature reactor zone to increase gas residence time, expansion volumes without pressure limitations and for extended material exposure to high temperature without gasifying or combusting the char product to achieve high char yields with high Fixed Carbon

35. A pyrolysis system according to claim 34 wherein the infeed material is heated to a maximum temperature in the range of 400 to 800°C

36. A pyrolysis system according to claim 35 wherein the hot gases pass through the incoming feed travelling countercurrent it both dries the feed material and cleans the gas by removing the heavy hydrocarbon fractions by condensing on the cooler feed material which then travels back into the reactor and have more chances at cracking into lighter fractions, producing gas with lower than 1 vol% of long chain hydrocarbons.

37. A pyrolysis system according to claim 36 wherein volatile gases are further removed from the char material due to the extended time biomass is exposed to high radiant temperature without generating unwanted gasification, combustion or ash, while producing a fully carbonised material with as high as 95% Fixed Carbon and low ash.

38. A pyrolysis system according to claim 37 wherein the gas is cooled through the incoming moist feed material, stripping out heavy hydrocarbon fractions through both a filtering and condensing process provided by the moving packed biomass bed wherein the bed height and moisture content is controlled to capture all the thermal energy in this gas for beneficial use in the process, allowing wet feeds to be processed without a separate feed drying stage and wherein the gas exit temperature is kept below 100C and more preferably around 80°C.

39. A pyrolysis system according to claim 38 wherein the gas flow and reactor pressure is controlled automatically through control software algorithms of the gas blower to keep the reactor at a slight negative pressure around, preferably about minus 150 pascals, to prevent gas leaks at material entry and exit points.

40. A pyrolysis system according to claim 34 that recirculates dried syngas into different locations (reactor chamber and drying section) at varying rates to control the drying performance in the vertical section and match the required demand of moist feed materials.

41. A pyrolysis system according to claim 34 that controls convection, radiant and conduction heat sources, to increase productivity rates, yields (reducing gasification and combustion) and provides high Fixed Carbon content char material.

42. A pyrolysis system according to claim 34 that uses convection heat transfer by combustion of a small amount of gas emitting directly on the biomass material surface.

43. A pyrolysis system according to claim 34 that uses conduction heat transfer by hot gases passing through biomass material.

44. A pyrolysis system according to claim 34 that uses radiant heat transfer through high temperature refractory material roofs and walls.

45. A pyrolysis system according to claim 34 that has a gas residence time in the horizontal reactor section greater than 2 seconds to allow time for chemical reactions to take place, improving gas composition and char quality.

46. A single continuous flow pyrolysis system according to claim 34 that can control heat and gas flow through both the vertical drying and horizontal pyrolysis sections independently of each other.