WO2023028679A1 - Thermo-dehydration oven, carbonized powder production method, carbonized powder and electric energy production method - Google Patents

Abstract

The present invention relates to a dehydration oven which receives residues from a drying process and subjects them to a temperature of 800° in the absence of oxygen for approximately 50 minutes, dehydrating the residues and transforming them into a carbonized powder having identical properties to vegetable coal. This product has a stabilized moisture content and heat value and provides when burned a uniform heat for steam generation and conversion into electric energy. During the dehydration process, the residues release synthesis gas that is captured and used to feed back the oven, meaning that the equipment produces its own fuel. The present invention further relates to a more efficient electric energy production method, owing to the thermo-dehydration oven.

Description

THERMAL-DEHYDRATION OVEN, CARBONIZED POWDER PRODUCTION PROCESS, CARBONIZED POWDER AND ELECTRIC ENERGY PRODUCTION PROCESS

FIELD OF THE INVENTION

[001] The present invention refers to a dehydrating oven that, when receiving waste after the drying process, subjects them to a temperature of 800° in the absence of oxygen for approximately 50 minutes, dehydrating these wastes and transforming them into a carbonized powder with characteristics identical to those of charcoal.

[002] This product contains stabilized moisture content and calorific content and promotes uniform heat during burning for steam generation and conversion into electrical energy. During the dehydration process, the waste releases synthesis gas, which is captured and directed to retrofeed the furnace, which means that the equipment produces its own fuel.

[003] The present invention also refers to a more efficient process of producing electricity due to the presence of the thermo-dehydrator oven.

BACKGROUND OF THE INVENTION

Biomass is the term used to define the biological mass, detritus of living or decomposing organisms, used in the production of electrical energy. This biological mass can be of animal or vegetable origin, such as food scraps, fruit peels, wood, among others. Electricity generation from biomass takes place through thermoelectricity:

There are some technologies used to transform biomass into electricity. All of them convert the raw material into an intermediate product that will be used in a driving machine that will produce the mechanical energy that will drive the electric power generator. The two main technologies are: Combustion and Gasification, the third: Thermo Dehydration is the technology that was developed by USITRAR. The main difference between them is in EFFICIENCY.

Combustion: the direct burning of biomass in boilers carried out at high temperatures in the abundant presence of oxygen, producing high pressure steam that is used to drive turbines and electric generators. Its energy efficiency is in the range of 20 to 25%.

Gasification: the biomass is heated in the absence of oxygen, resulting in a flammable gas as the final product. Gasification does not require high temperatures, making the biomass result only in biogas, which is either used as mechanical energy that activates a generator or in boilers for direct burning or in cogeneration of thermal energy. Its energy efficiency is in the range of 25 to 40%.

Thermo Dehydration: Thermo dehydration in a combined cycle, is the technology that was developed by USITRAR using existing equipment on the market that has been improved to enable the combination of the use of COAL obtained through the dehydration of the biomass together with the SYNTHESIS GAS obtained during the biomass transformation process in charcoal. Its energy efficiency is in the range of 60 to 65%.

[004] WO 2012/004739 describes a plant for the production of electricity from biomass based on the use of a heat exchanger between the biomass burner and the power generation unit. The process described in this document is said to be more efficient than those in the prior art and uses air as the working fluid.

[005] The present invention differs from this document by not requiring the use of air for the carbonization of biomass.

[006] Documents WO 2008/049059 and WO 2016/118067 describe biomass burning processes, but the processes described there do not exemplify a pre-dehydration step followed by a burning step, in the absence of oxygen as described in the present invention . [007] Therefore, there is still a need for processes to burn biomass and generate energy more efficiently.

SUMMARY OF THE INVENTION

[008] It is an object of the present invention a dehydrator oven that dehydrates the raw material in the absence of oxygen, transforming them into a carbonized powder with characteristics identical to those of charcoal.

[009] In a preferred embodiment, the dehydrating oven comprises a) a mechanical seal that allows the passage of the raw material and prevents the entry of oxygen. b) an anterior chamber for partial dehydration of the raw material; and c) a main chamber for heating the raw material in the absence of oxygen; d) means for capturing generated synthesis gas; e) means for directing all or part of the generated synthesis gas for heating the raw material;

[0010] It is an additional object of the present invention a carbonized powder production process comprising the steps of: a) admitting the raw material into the anterior chamber; b) dehydrate the raw material at temperatures ranging from 200°C to 380°C so that it loses at least 80% of its moisture; c) admit the raw material from the previous stage into the main chamber; d) heating the raw material to at least 750°C; e) remove carbonized dust from the main chamber.

[0011] It is an additional object of the present invention a carbonized powder produced by the above process, with characteristics identical to those of charcoal, and with stabilized moisture content and calorific content, which promotes uniform heat during its burning for steam generation and conversion in electrical energy.

[0012] It is an additional object of the present invention an electric energy production process comprising the steps of: a) admission of a carbonized powder into a boiler for steam generation; b) conversion of thermal energy into mechanical energy; and c) conversion of mechanical energy into electrical energy.

BRIEF DESCRIPTION OF THE FIGURES

[0013] Figure 1 shows a perspective view of an example of an electric power generation plant comprising a dehydrator oven according to the present invention.

[0014] Figure 2 shows the dehydrator oven of the present invention, where: A - input conveyor; B - driving gear; C - carbonization drum; D - oven roll; E - gearbox.

DETAILED DESCRIPTION OF THE INVENTION

[0015] The following description is intended only to exemplify some of the numerous ways of carrying out the invention, and should not be seen as limiting the scope of the present invention.

[0016] The dehydrator oven is the main part of this invention and receives the raw material for a drying process to then subject it to a temperature of at least 750°C, preferably 800°, in the absence of oxygen for an adequate time , preferably for 50 minutes.

[0017] The dehydrator oven of the present invention is illustrated in Figure 2 and comprises the following parts: a) a mechanical seal that allows the passage of the raw material and prevents the entry of oxygen. b) an anterior chamber for partial dehydration of the raw material; and c) a main chamber to heat the raw material in the absence of oxygen; d) means for capturing generated synthesis gas; e) means for directing all or part of the generated synthesis gas for heating the raw material; [0018] In the chamber before the dehydration oven, the raw material is subjected to temperatures of 200°C to 380°C, preferably from 260° to 360°C, and lose at least 80%, preferably 85% of its moisture to enter in the main chamber of the humidity-regulated dewatering furnace. This equipment uses residual heat that returns from the dehydration oven, therefore it does not use any type of additional fuel for the purpose of dehumidifying and drying the residues in the process that precedes dehydration, this makes the process much cheaper from the point of view of the operational cost of the machine.

[0019] This thermal stress provides the dehydration of the raw material and transforms it into a carbonized powder with characteristics identical to those of charcoal. The carbonized powder contains stabilized moisture content and calorific content and promotes uniform heat during burning for steam generation and conversion into electrical energy. During the dehydration process, the raw material releases synthesis gas, which is captured and directed, in whole or in part, to retrofeed the furnace. This means that the equipment produces its own fuel.

[0020] The raw material of the present invention is preferably biomass. Biomass is the term used to define the biological mass, detritus of living or decomposing organisms, used in the production of electrical energy. This biological mass can be of animal or vegetable origin, such as food scraps, fruit peels, wood, among others. In a preferred embodiment, the raw material is urban solid waste.

[0021] The electrical energy production process of the present invention is based on the use of carbonized powder to generate steam in a boiler, transforming this steam into mechanical energy by suitable means, such as a turbine, and finally transforming that energy mechanical energy into electrical energy by suitable means, such as a generator. Figure 1 presents a perspective view of an electric power generation plant according to the present invention. [0022] The process presented below contains several equipment that have been improved to obtain greater energy efficiency with lower pollutant emissions and better use of biomass, absorbing a much greater diversity of waste that can be used, these units can be assembled in capacities to process 120, 240 or 480 tons per day generating between 60% and 65% of energy.

[0023] 01 — Waste Conveyor: The conveyor transports the waste after separating all recyclable products to the entrance of the dehydrator oven, the conveyor belt is equipped with a sensor to detect the correct moment of stops, as well as speed control for adequacy of the time required for each waste dehydration cycle and its subsequent transformation into charcoal.

[0024] 02- Waste Entry: In this part of the equipment, the waste is loaded into the inside of the furnace through a helical screw system, which turns it into a MECHANICAL SEAL to prevent the entry of oxygen and the consequent combustion of waste . Due to this MECHANICAL SEAL and the absence of oxygen, the residues do not combust, they only undergo a dehydration process.

[0025] 03 - Dryer: In the chamber before the dehydration oven, the waste is subjected to a temperature of 260° to 360° and loses 85% of its moisture to enter the dehydration oven with regulated humidity, this equipment uses waste heat that returns of the dehydration oven, therefore it does not use any type of additional fuel for the purpose of dehumidifying and drying the residues in the process that precedes the dehydration, this makes the process much cheaper from the point of view of the operating cost of the machine.

[0026] 04 - Exhaust fan: This equipment is manufactured exclusively by USITRAR as it uses a system of internal fins that serves both to direct the residual heat and all gases from the thermal process, which prevents any particulate matter from being released into the atmosphere before to be treated, and to direct enough heat to the dehumidifier to dry the residues before the dehydration process without any additional cost regarding the generation of the necessary heat for this stage of the operation.

[0027] 05 - Dehydrator: The dehydrator oven is the main part of this set of equipment, receives the waste after the drying process and submits it to a temperature of 800° in the absence of oxygen for approximately 50 minutes, this thermal effort provides dehydration of the residues and transforms them into a carbonized powder with characteristics identical to those of charcoal, this product contains stabilized moisture content and calorific content and promotes uniform heat during burning for steam generation and conversion into electrical energy. During the dehydration process, the waste releases synthesis gas, which is captured and directed to retrofeed the furnace, which means that the equipment produces its own fuel.

[0028] The remainder is bottled to supplement the heat in the thermal system during the power generation process.

[0029] 06 — Coal Outlet: After dehydration, the residues already transformed into coal are unloaded through this outlet to be conducted by the conveyor belt to the boiler.

[0030] 07 - Coal Conveyor: The conveyor transports the coal to the boiler inlet for steam production and turbine activation.

[0031] 08 - Coal Inlet: The coal reaches the boiler grate system through this inlet, here it will be dosed through sensors that assess the temperature and inject the sufficient and adequate volume for the balance of temperature and stability of the steam and of the pressure.

[0032] 09 - Boiler: the boiler is the equipment responsible for transforming fuel (coal) into steam to obtain the necessary pressure to drive the turbine, this boiler was developed using pressure and counterpressure technology that feeds back the boiler and increases the 30% efficiency, providing great fuel savings and greater safety, as it works at 75% of the pressure of a conventional boiler.

[0033] 10 - Turbine: turbine is the equipment responsible for converting thermal energy (heat/steam) into mechanical energy to drive the generator and convert mechanical energy into electrical energy. An example of a turbine is a turbine built with ULTRA LOW-PRESSURE technology, using a bidirectional steam and counter-steam system to increase its mechanical efficiency. This turbine model uses only 52% of the necessary pressure to generate the same volume of energy that a conventional turbine would use 92%.

[0034] 11 - Reducer: The reducer makes the turbine rotation (3,600Rpm) compatible with the generator rotation (900Rpm), the self-lubricating gear system does not require the use of an oil box, and the axial model is shown much more efficient in reducing friction, noise and wear.

[0035] 12 - Generator: The generator is responsible for converting mechanical rotation into electricity, preferably the generator operates at low rotation which provides a quieter system, operates at lower temperatures and produces less vibration and friction, as well as drastically reducing the need for maintenance.

[0036] 13 - Gas scrubber: The gas scrubber processes all the gaseous product generated during the process, both from the dehydration of waste and from the burning of coal during the energy generation process, this equipment processes the gases through spraying of micro particles of liquid solution developed specifically for this purpose, this reduces the emission of particulates by 95%, leaving only volatile gases that go to the filter where the gas cleaning process is complemented by 99.5%

[0037] The process of the present invention provides the use of various types of biomass, including urban solid waste, one of the main problems in the world, enabling its conversion into clean, low-cost electricity, preferably for remote areas and needy populations, proving that it is possible to combine technology and sustainability, respecting the environment, and generating wealth for people.

Claims

1. Thermo-dehydrator furnace characterized by comprising: a) a mechanical seal that allows the passage of raw material and prevents the entry of oxygen; b) an anterior chamber for partial dehydration of the raw material; and c) a main chamber for heating the raw material in the absence of oxygen; d) means for capturing generated synthesis gas; and e) means for directing all or part of the generated synthesis gas for heating the raw material. 2. Thermo-dehydrator oven, according to claim 1, characterized in that the raw material is biomass. 3. Thermo-dehydrator oven, according to claim 2, characterized in that the biomass comprises urban solid waste. 4. Thermo-dehydrator oven, according to claim 1, characterized in that the anterior chamber operates at temperatures from 200°C to 380°C. 5. Thermo-dehydrator oven, according to claim 1, characterized in that the anterior chamber removes at least 80% of the moisture from the raw material. 6. Thermo-dehydrator oven, according to claim 1, characterized in that the main chamber heats the raw material to at least 750°C. 7. Thermo-dehydrator oven, according to claim 1, characterized in that it uses residual heat taken back from the dehydration oven, and does not use additional fuel to dehumidify and dry the raw material. 8. Carbonized powder production process characterized by comprising the steps of: a) admitting the raw material into the front chamber of a thermo-dehydrator oven as defined in any one of claims 1-7; b) dehydrate the raw material at temperatures ranging from 200°C to 380°C so that it loses at least 80% of its moisture; c) admit the raw material from the previous stage into the main chamber; d) heating the raw material to at least 750°C; e) remove carbonized dust from the main chamber. 9. Process for producing carbonized powder, according to claim 8, characterized in that it uses residual heat taken back from the dehydration oven, and does not use additional fuel to dehumidify and dry the raw material. 10. Charred powder characterized by having characteristics identical to those of charcoal. 11. Carbonized powder, characterized in that it is obtained by a process as defined in any one of claims 7 or 8. 12. Electricity production process characterized by comprising the steps of: a) admission of a carbonized powder as defined in claims 10 or 11 in a boiler for steam generation; b) conversion of thermal energy into mechanical energy; and c) conversion of mechanical energy into electrical energy. 13. Electricity production process, according to claim 12, characterized in that the carbonized powder is prepared by a process as defined in any one of claims 8 or 9. 14. Electricity production process, according to claim 12, characterized by step b) using a turbine that uses a bidirectional steam and counter-steam system. 15. Electricity production process, according to claim 12, characterized by step c) using a generator that operates at low speed.