WO2016141432A1

WO2016141432A1 - Apparatus, system and method for treating lignocellulosic material

Info

Publication number: WO2016141432A1
Application number: PCT/AU2016/050164
Authority: WO
Inventors: Alex Baker; Marc Sabourin
Original assignee: Leaf Sciences Pty Ltd
Current assignee: Leaf Sciences Pty Ltd
Priority date: 2015-03-09
Filing date: 2016-03-08
Publication date: 2016-09-15
Anticipated expiration: 2017-09-09

Abstract

A reactor apparatus and reactor system for treating a lignocellulosic material is provided, said apparatus and system including a reactor which is switchable between a first mode for producing a first reaction product including a partially hydrolysed lignocellulosic material and a second mode for producing a second reaction product suitable for conversion into a cellulosic pulp. Also provided is a method of operating a reactor system for treating a lignocellulosic material, which includes selecting between first and second modes of operation of a reactor, wherein the first mode is adapted to produce a first reaction product comprising a partially hydrolysed lignocellulosic material and the second mode is adapted to produce a second reaction product suitable for conversion into a cellulosic pulp.

Description

TITLE

APPARATUS, SYSTEM AND METHOD FOR TREATING LIGNOCELLULOSIC

MATERIAL TECHNICAL FIELD

THIS INVENTION relates to a hybrid apparatus and system for producing one or more useful products, such as pulp for paper or other fibre based products and/or fermentable sugars, from a lignocellulosic material. BACKGROUND

Lignocellulosic material can be used to produce a cellulosic material, such as a cellulose pulp, that may be amenable to various downstream uses such as paper, cardboard and textile production. Additionally, lignocellulosic material can be treated to produce a partially hydrolysed lignocellulosic material that can be used in downstream applications to produce fermentable sugars and/or bioproducts including biofuels. The lignocellulose processing conditions, however, generally dictate the characteristics of the processed lignocellulosic material produced therefrom, and therefore, its applicability for certain end uses.

For the efficient production of a cellulosic material or pulp from lignocellulosic material, a proportion of the lignin and/or hemicellulose components of the lignocellulosic material typically need to be removed. This is generally achieved by degrading the lignin and/or hemicellulose into smaller compounds that are readily solubilized and subsequently separated from the cellulose fibres without depolymerizing the cellulose fibres. Alkaline liquors are most commonly used in combination with pressurized digestion at desired temperatures and retention times to produce a given pulp-type. Pulps produced using weaker chemical liquors and more moderate digestion conditions tend to have higher yield, bulk and stiffness properties; whereas pulp produced at higher liquor concentrations and more severe digestion conditions tend to be lower in yield, higher in pulp strength and less bulky. The end product requirements typically dictate the chemistry and digestion requirements.

Alternatively, lignocellulosic material can be used to produce biofuels (e.g., bioethanol) and biochemicals. For efficient biofuel production from lignocellulosic materials, the cellulose and/or hemicellulose components of lignocellulosic material are preferably converted to monosaccharides (i.e., monosugars) that are capable of being fermented into ethanol or butanol for example. In this regard, the production of fermentable sugars from lignocellulosic material typically initially involves a chemical and/or physical pretreatment to disrupt the natural structure of the lignocellulosic material, followed by enzymatic hydrolysis of the cellulose and hemicellulose components into monosugars. The severity of the pretreatment required typically dictates the severity of the chemistry and digestion conditions.

Thus, there exists a need for a reactor apparatus and system for treating a lignocellulosic material that is relatively inexpensive to run, yet is highly versatile, enabling its user to elect to produce a plurality of different products from the lignocellulosic material, such as a cellulosic pulp and a partially hydrolysed lignocellulosic material.

SUMMARY

An object of the present invention is to provide a reactor system and/or apparatus that is switchable between different modes of operation so as to be capable of producing either fermentable sugars or a cellulosic pulp for paper, cardboard or other fibre based production as required by the user. A preferred object of the present invention is to provide a reactor system and/or apparatus that can be adapted or otherwise integrated or incorporated into a paper or pulp processing facility.

In a first aspect, the invention provides a reactor apparatus for treating a lignocellulosic material comprising: a reactor comprising a first treatment chamber, the reactor switchable between a first mode for producing a first reaction product comprising a partially hydrolysed lignocellulosic material and a second mode for producing a second reaction product suitable for conversion into a cellulosic pulp.

In a second aspect, the invention provides a reactor system for treating a lignocellulosic material comprising:

a reactor comprising a first treatment chamber, the reactor switchable between a first mode and a second mode, wherein the first mode comprises a first set of reaction conditions adapted to produce a first reaction product comprising a partially hydrolysed lignocellulosic material and the second mode comprises a second set of reaction conditions adapted to produce a second reaction product suitable for conversion into a cellulosic pulp.

Suitably, the reactor system and/or apparatus may be adapted or otherwise integrated or incorporated into a paper or pulp processing apparatus, system or facility.

In a third aspect, the invention provides a method of operating a reactor system for treating a lignocellulosic material including the steps of:

selecting between first and second modes of operation of a reactor comprising a first treatment chamber, wherein the first mode comprises a first set of reaction conditions adapted to produce a first reaction product comprising a partially hydrolysed lignocellulosic material and the second mode comprises a second set of reaction conditions adapted to produce a second reaction product suitable for conversion into a cellulosic pulp; and optionally

producing a cellulosic pulp from said second reaction product and/or from another source of lignocellulosic material.

In an embodiment, the reactor of the above aspects further comprises a pretreatment chamber in communication with the treatment chamber.

In an embodiment, the reactor of the above aspects is connectable with or to a pulp processor. In a particular preferred embodiment, the pulp processor is part of a kraft pulp mill facility, a neutral sulfite semichemical pulp mill facility, a caustic carbonate semichemical pulp mill facility and/or a thermochemical pulp mill facility. In another embodiment, the pulp processor is a stand alone or purpose built pulp processor.

In an embodiment, the reactor of the above aspects:

(i) further comprises a pretreatment chamber in communication with the treatment chamber; and

(ii) is connectable with or to a pulp processor.

Suitably, when operating the reactor apparatus, the reactor system or the method in the first mode: (i) the pretreatment chamber and/or the first treatment chamber are for treating the lignocellulosic material with an acid; and/or (ii) the first treatment chamber is for treating the lignocellulosic material with a chemical agent.

The chemical agent can be any chemical known in the art including a solvent that enhances process efficiency.

Suitably, when operating the reactor apparatus, the reactor system or the method in the second mode, the pretreatment chamber and/or the first treatment chamber are for treating the lignocellulosic material with an alkali, a sulphide, a sulphite, a carbonate, and/or water.

In particular embodiments, the reactor of the above aspects further comprises a refiner and/or a separator. In one embodiment, the refiner is an attrition device with at least one rotating disc. In a further embodiment, the reactor comprises, consists or consists essentially of the treatment chamber and the separator.

In certain embodiments, the pulp processor referred to in the above aspects comprises one or more of a second treatment chamber, a washing chamber, a screen, a bleaching chamber and a concentrator.

Suitably, the reactor system, reactor apparatus or method are adapted to transfer the second reaction product from the reactor to the pulp processor. Preferably, the reactor and the pulp processor are in communication so as to facilitate transfer of the second reaction product from the reactor to the pulp processor. In one preferred embodiment, the second reaction product is transferred from the refiner and/or the separator of the reactor to the washing chamber, the screen and/or the bleaching chamber of the pulp processor.

Suitably, the reactor system is adapted to transfer one or more reactants, agents and/or byproducts of the first and/or the second set of reaction conditions from the reactor to the pulp processor. Preferably, the reactor and the pulp processor are in communication so as to facilitate transfer of the one or more reactants, agents and/or byproducts from the reactor to the pulp processor. In one preferred embodiment, the one or more reactants, agents and/or byproducts are transferred from the reactor to the concentrator of the pulp processor.

Suitably, the second treatment chamber is for treating the lignocellulosic material with an alkali, a sulphide, a sulphite and/or a carbonate to produce a third reaction product. Preferably, said system or apparatus are adapted to transfer the third reaction product from the pulp processor to the reactor. More preferably, the reactor and the pulp processor are in communication so as to facilitate transfer of the third reaction product from the pulp processor to the reactor.

In one embodiment, the third reaction product is transferred from the second treatment chamber, the washing chamber, the screen, and/or the bleaching chamber of the pulp processor to the pretreatment chamber, the first treatment chamber and/or the refiner of the reactor, and wherein the reactor is operating in the second mode for treatment of the third reaction product by the second set of reaction conditions. In another embodiment, the third reaction product is transferred from the washing chamber, and/or the screen of the pulp processor to the pretreatment chamber and/or the first treatment chamber of the reactor, and wherein the reactor is operating in the first mode for treatment of the third reaction product by the first set of reaction conditions. Preferably, the first and/or second set of reaction conditions are substantially performed without contacting the third reaction product with a further chemical agent, such as an alkali, a sulphide, a sulphite, a carbonate, an acid and/or a solvent, in the reactor.

Suitably, the reactor apparatus or reactor system of the invention further comprise a power supply for providing power and/or steam to the reactor and the pulp processor.

Throughout this specification, unless otherwise indicated, "comprise", "comprises^'" and "comprising" are used inclusively rather than exclusively, so that a stated integer or group of integers may include one or more other non-stated integers or groups of integers. Conversely, the terms "consist", "consists" and "consisting" are used exclusively, such that a stated integer or group of integers are required or mandatory, and no other integers may be present. The phrase "consisting essentially of indicates that a stated integer or group of integers are required or mandatory, but that other elements that do not interfere with or contribute to the activity or action of the stated integer or group of integers are optional.

It will also be appreciated that the indefinite articles "a" and "an" are not to be read as singular indefinite articles or as otherwise excluding more than one or more than a single subject to which the indefinite article refers. For example, "a" solvent includes one solvent, one or more solvents or a plurality of solvents.

BRIEF DESCRIPTION OF THE DRAWINGS

By way of example only, an embodiment of the invention is described more fully hereinafter with reference to the accompanying drawings, in which:-

Figure 1 is a schematic of a reactor system with a reactor operating in a first mode according to a preferred embodiment of the invention;

Figure 2 is a schematic of a reactor system with a reactor operating in a second mode according to a preferred embodiment of the invention;

Figure 3 is a schematic of a reactor system with a reactor operating in a first mode according to a further preferred embodiment of the invention.

DETAILED DESCRIPTION

The present invention arises, in part, from the identification of a novel and versatile reactor system for producing, from a lignocellulosic material, a plurality of useful products, including a cellulosic pulp for use in paper-based products and a partially hydrolysed lignocellulosic material for the production of fermentable sugars. Furthermore, economic modelling suggests that such a reactor system may significantly reduce the costs associated with cellulosic sugar production, particularly when integrated or incorporated into an existing paper or pulp processing facility.

Accordingly, the apparatus, system and/or method disclosed herein provides a reactor system configured in a "first mode" to not only produce a partially hydrolysed lignocellulosic material, but which can also be switched to operate in a "second mode" for producing a cellulosic pulp, such as a kraft pulp or semichemical pulp for example. The reactor switchable between the first and second modes may be operable as a "satellite" system integratable or otherwise operable in communication with a pulp and paper processing facility, such as a Kraft pulping facility. Accordingly, the apparatus, system and/or method disclosed herein can provide users with an additional revenue stream via the production of such a material suitable for use in bioproduct production. Additionally, when circumstances require, such as periods of high demand, the reactor system inclusive of its satellite reactor, may function to produce only a cellulosic pulp. Advantages of the apparatus, system and/or method include: a satellite reactor switchable by a user between two treatment modes; a single stage continuous process; a common recycling stream for reagents, agents and byproducts; and a common source of power and steam.

Accordingly, in one aspect, the invention provides a reactor apparatus for treating a lignocellulosic material comprising: a reactor comprising a first treatment chamber, the reactor switchable between a first mode for producing a first reaction product comprising a partially hydrolysed lignocellulosic material and a second mode for producing a second reaction product suitable for conversion into a cellulosic pulp.

In a related aspect, the invention provides a reactor system for treating a lignocellulosic material comprising:

a reactor comprising a first treatment chamber, the reactor switchable between a first mode and a second mode, wherein the first mode comprises a first set of reaction conditions adapted to produce a first reaction product comprising a partially hydrolysed lignocellulosic material and the second mode comprises a second set of reaction conditions adapted to produce a second reaction product suitable for conversion into a cellulosic pulp. Suitably, the reactor system and/or apparatus may be adapted or otherwise integrated or incorporated into a paper or pulp processing apparatus, system or facility.

In a further aspect, the invention provides a method of operating a reactor system for treating a lignocellulosic material including the steps of:

Preferably, the reactor of the above aspects further comprises a pretreatment chamber in communication with the treatment chamber.

The statements which follow apply equally to the aforementioned aspects of the invention.

The terms "lignocellulosic" or "lignocellulose", as used herein, refer to material comprising lignin and/or cellulose. Lignocellulosic material can also comprise hemicellulose, xylan, proteins, lipids, carbohydrates, such as starches and/or sugars, or any combination thereof. Lignocellulosic material can be derived from living or previously living plant material (e.g., lignocellulosic biomass). "Biomass", as used herein, refers to any lignocellulosic material and can be used as an energy source.

The source of the cellulosic material may dictate the cellulose fiber characteristics, and therefore, the fiber's applicability for certain end uses. In this regard, lignocellulosic material (e.g., lignocellulosic biomass) can be derived from a single material or a combination of materials and/or can be non-modified and/or modified. Lignocellulosic material can be transgenic (i.e., genetically modified). Lignocellulose is generally found, for example, in the fibers, pulp, stems, leaves, hulls, canes, husks, and/or cobs of plants or fibers, leaves, branches, bark, and/or wood of trees and/or bushes. Examples of lignocellulosic materials include, but are not limited to, agricultural biomass, e.g., farming and/or forestry material and/or residues, branches, bushes, canes, forests, grains, grasses, short rotation woody crops, herbaceous crops, and/or leaves; energy crops, e.g., corn, millet, and/or soybeans; energy crop residues; paper mill residues; sawmill residues; municipal paper waste; orchard prunings; chaparral; wood waste; wood chip, logging waste; forest thinning; short-rotation woody crops; bagasse, such as sugar cane bagasse and/or sorghum bagasse, duckweed; wheat straw; oat straw; rice straw; barley straw; rye straw; flax straw; soy hulls; rice hulls; rice straw; tobacco; corn gluten feed; oat hulls; corn kernel; fiber from kernels; corn stover; corn stalks; com cobs; corn husks; canola; miscanthus; energy cane; prairie grass; gamagrass; foxtail; sugar beet pulp; citrus fruit pulp; seed hulls; lawn clippings; cotton, seaweed; trees; shrubs; wheat; wheat straw; products and/or by-products from wet or dry milling of grains; yard waste; plant and/or tree waste products; herbaceous material and/or crops; forests; fruits; flowers; needles; logs; roots; saplings; shrubs; switch grasses; vegetables; fruit peels; vines; wheat midlings; oat hulls; hard and soft woods; or any combination thereof.

As would be appreciated, the lignocellulosic material for use in both the reactor and pulp processor may be the same or from the same lignocellulosic source. By way of example, bagasse may be the lignocellulosic material treated upon operation of both the reactor and the pulp processor. Alternatively, the lignocellulosic material for treatment by the reactor may be different or from a different source to that of the pulp processor. By way of example, bagasse may be treated in the reactor and wood chip may be treated in the pulp processor. Further, the lignocellulosic material for treatment in the reactor may be the same or may differ between the first and second modes of operation. Preferably, the first, second and/or third set of reaction conditions are adapted to suitably treat the particular lignocellulosic material selected for treatment thereby. For example, certain lignocellulosic materials may require "harsher" treatment conditions (e.g., higher temperatures, pressures and chemical concentrations) than others.

For the present invention, the lignocellulosic material may have been processed by a processor selected from the group consisting of a dry grind ethanol production facility, a paper pulping facility, a tree harvesting operation, a sugar cane factory, or any combination thereof.

Suitably, the lignocellulosic material used in the apparatus and system described herein is derived from softwood fibre, hardwood fibre, grass fibre and/or mixtures thereof.

By "hydrolysis" or "hydrolysed" is meant the cleavage or breakage of the chemical bonds that hold the lignocellulosic material together. For instance, hydrolysis can include, but is not limited to, the breaking or cleaving of glycosidic bonds that link saccharides (i.e., sugars) together, and is also known as saccharification. Lignocellulosic material, in some embodiments, can comprise cellulose and/or hemicellulose and/or lignin. Cellulose is a glucan, which is a polysaccharide. Polysaccharides are polymeric compounds that are made up of repeating units of saccharides (e.g. , monosaccharides or disaccharaides) that are linked together by glycosidic bonds. The repeating units of saccharides can be the same (i.e. , homogenous) to result in a homopolysaccharide or can be different (i.e. , heterogeneous) to result in a heteropolysaccharide. Cellulose can undergo hydrolysis to form cellodextrins (i.e., shorter polysaccharide units compared to the polysaccharide units before the hydrolysis reaction) and/or glucose (i.e. , a monosaccharide). Hemicellulose is a heteropolysaccharide and can include polysaccharides, including, but not limited to, xylan, glucuronoxylan, arabinoxylan, glucomannan and xyloglucan. Hemicellulose can undergo hydrolysis to form shorter polysaccharide units, and/or monosaccharides, including, but not limited to, pentose sugars, xylose, mannose, glucose, galactose, rhamnose, arabinose, or any combination thereof. Lignin is a complex heterogeneous polymer of aromatic alcohols known as monlignols. Lignin is covalently linked to hemicelluloses and crosslinks with many different plant polysaccharides. Generally, the goal is to break many of these crosslinks to release the wood lignin, otherwise they will remain attached to the polysaccharides.

The apparatus, system or method of the present invention may function, such as when operating in a first mode, to partially hydrolyse the lignocellulosic material. A "partially hydrolysed lignocellulosic material", as used herein, refers to a lignocellulosic material that has undergone a hydrolysis reaction to cleave or break less than 100% of the chemical bonds that hold the lignocellulosic material together. Preferably, the partially hydrolysed lignocellulosic material is suitable for conversion into one or more sugars using a microorganism and/or an enzyme known in the art.

In this regard, the hydrolysis reaction may cleave or break less than 100% of the glycosidic bonds of the cellulose and/or hemicellulose present in the lignocellulosic material. In some embodiments, the partial hydrolysis reaction can convert less than about 20%, 15%, 10%, or 5% of the cellulose into glucose. Further, the partial hydrolysis reaction can convert less than about 20%, 15%, 10%, or 5% of the hemicellulose into monosaccharides. Examples of monosaccharides include but are not limited to, xylose, glucose, mannose, galactose, rhamnose, and arabinose. Additionally, the partial hydrolysis reaction may result in the recovery of greater than about 80%, 85%, 90%, or 95% of the glucan present in the modified cellulosic material compared to the amount of glucan present in the lignocellulosic material before treatment with the reactor system or apparatus described herein.

In some embodiments of the present invention, the partial hydrolysis reaction can result in the recovery of less than about 40%, 35%, 30%, 25%, 20%, 15%, 10%, or 5% of the xylan in the modified cellulosic material compared to the amount of xylan present in the lignocellulosic material before treatment with the reactor system or apparatus of the present invention.

As described herein, the apparatus may function to break down and/or remove the lignin present in the lignocellulosic material, such as to produce a partially hydrolysed lignocellulosic material, a cellulosic pulp or one or more reaction products convertible thereinto (e.g., a second reaction product for conversion into a cellulosic pulp). As used herein, "cellulosic pulp" refers to that material resulting from the treatment of the lignocellulosic material which has been treated (e.g. , hydrolysed, cooked, washed, bleached etc) in accordance with the present disclosure, so as to remove or reduce, at least partly, the lignin content therein. Preferably, the cellulosic pulp is a kraft pulp.

Lignin may be removed from the lignocellulosic material by hydrolysis of the chemical bonds that hold the lignocellulosic material together. Accordingly, in some embodiments of the present invention, use of the reactor system or apparatus results in the removal of about 100% or less (e.g., about 100%, 95%, 90%, 85%, 80%, 75%, 70%, 65%, 60%, 55%, 50%, 45%, 40%, 35%, 30%, 25%, 20%, etc.) or any range therein of the lignin in the cellulosic pulp or partially hydrolysed lignocellulosic material compared to the amount of lignin present in the lignocellulosic material prior to the treatment with the reactor system or apparatus. In particular embodiments, the cellulosic pulp described herein has had at least about 75%, and even more preferably at least about 85% and yet even more preferably at least about 95% of the lignin present in the lignocellulosic material prior to the treatment with the reactor system or apparatus removed therefrom.

In some embodiments, the reactor system or apparatus results in the recovery of about 20% or more (e.g., about 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, etc.) or any range therein of the lignin in the treated lignocellulosic material compared to the amount of lignin present in the lignocellulosic material prior to treatment with the reactor system or apparatus of the present invention.

In particular embodiments, lignin that has been removed from the partially hydrolysed lignocellulosic material is recovered and/or sold as a co-product of the treatment.

Furthermore, the system or apparatus described herein may affect the structure of the lignocellulosic material. For instance, the system or apparatus may result in the dissociation of fibres in the lignocellulosic material, increase the porosity of the lignocellulosic material, increase the specific surface area of the lignocellulosic material, or any combination thereof. In some embodiments, the system or apparatus reduces the crystallinity of the cellulose structure by, for example, changing a portion of the cellulose from a crystalline state to an amorphous state.

As used herein, "treat", "treating" or "treatment" may refer to, for example, contacting, soaking, steam impregnating, spraying, suspending, immersing, saturating, dipping, wetting, rinsing, washing, submerging, and/or any variation and/or combination thereof.

Suitably, for the first set of reaction conditions the lignocellulosic material is treated with an acid and/or a chemical agent, such as a solvent. Preferably, for the first mode, the pretreatment chamber and/or the first treatment chamber are for treating the lignocellulosic material with the acid and/or the first treatment chamber is for treating the lignocellulosic material with the chemical agent. The chemical agent can be any agent known in the art used to enhance the efficiency of the hydrolysis process.

In alternative embodiments, the first set of reaction conditions are performed substantially in the absence of an acid. By way of example, the lignocellulosic material may have been previously treated, such as with an alkali in the pulp processor, which may allow for a lower intensity treatment or digestion conditions in comparison to raw or untreated lignocellulosic material.

The skilled person would readily understand that the term "acid", as used herein, refers to various water-soluble compounds with a pH of less than 7 that can be reacted with an alkali to form a salt. Examples of acids can be monoprotic or polyprotic and can comprise one, two, three, or more acid functional groups. Examples of acids include, but are not limited to, mineral acids, Lewis acids, acidic metal salts, organic acids, solid acids, inorganic acids, or any combination thereof. Specific acids include, but are not limited to hydrochloric acid, sulfuric acid, phosphoric acid, hydrofluoric acid, hydrobromic acid, hydroiodic acid, nitric acid, formic acid, acetic acid, methanesulfonic acid, toluenesulfonic acid, boron trifluoride diethyletherate, scandium (III) trifluoromethanesulfonate, titanium (IV) isopropoxide, tin (IV) chloride, zinc (II) bromide, iron (II) chloride, iron (III) chloride, zinc (II) chloride, copper (I) chloride, copper (I) bromide, copper (II) chloride, copper (II) bromide, aluminum chloride, chromium (II) chloride, chromium (III) chloride, vanadium (III) chloride, molybdenum (III) chloride, palladium (II) chloride, platinum (II) chloride, platinum (IV) chloride, ruthenium (III) chloride, rhodium (III) chloride, zeolites, activated zeolites, or any combination thereof.

Preferably, the acid is selected from the group consisting of sulphuric acid, hydrochloric acid, phosphoric acid, hydrofluoric acid, hydrobromic acid, nitric acid, acid metal salts and any combination thereof.

Even more preferably, the acid is sulphuric acid.

Suitably, for the second and/or third set of reaction conditions the lignocellulosic material is treated with an alkali, a sulphide, a sulphite, a carbonate and/or water. Preferably, in the second mode, the pretreatment chamber and/or the first treatment chamber are for treating the lignocellulosic material with an alkali, a sulphide, a sulphite, a carbonate and/or water.

As would be readily understood by the skilled artisan, "alkali", as used herein, refers to various water-soluble compounds with a pH of greater than 7 that can be reacted with an acid to form a salt. By way of example, an alkali can include, but is not limited to, sodium hydroxide, potassium hydroxide, ammonium hydroxide, magnesium hydroxide and alkali metal salts such as, but not limited to, sodium carbonate and potassium carbonate.

Preferably, the alkali is selected from the group consisting of sodium hydroxide, potassium hydroxide, ammonium hydroxide, alkali metal salts and any combination thereof.

Even more preferably, the alkali is sodium hydroxide.

In certain embodiments, the lignocellulosic material is treated in the first set of reaction conditions with: (a) an acid alone; (b) sequentially with an acid and then an alkali; or (c) sequentially with an alkali and then an acid. These embodiments may further include treatment of the lignocellulosic material with the chemical agent, such as a solvent.

For the purposes of the present invention, the terms "sulphide " , "sulphite " and "carbonate " respectively refer to those sulphides, sulphites and carbonates which are suitable for treating a lignocellulosic material in the second set of reaction conditions so as to produce a reaction product able to be converted to a cellulosic pulp through one or more processing steps.

By way of example, the sulphide may be one typically present in a kraft liquor, such as sodium sulphide or sodium hydrosulphide. Preferably, the sulphide is or comprises a metal sulphide. In one preferred embodiment, the sulphide is or comprises sodium sulphide.

Suitably, the sulphite is or comprises one that is used in any neutral sulphite semichemical pulping process known in the art. Preferably, the sulphite is or comprises sodium sulphite, magnesium bisulphite, calcium bisulphite, potassium bisulphite or ammonium bisulphite.

Suitably, the carbonate is or comprises a metal carbonate, such as that used in the caustic carbonate pulping process known in the art. Preferably, the carbonate is or comprises sodium carbonate.

Suitably, the second set of reaction conditions in the reactor {i.e., treatment with an alkali, a sulphide, a sulphite and/or a carbonate) are adapted to produce a second reaction product suitable for conversion into a cellulosic pulp. Preferably, such conversion occurs in the pulp processor. Accordingly, in one embodiment, the reactor system or apparatus is adapted to transfer the second reaction product from the reactor to the pulp processor. Preferably, the reactor and the pulp processor are in communication so as to facilitate transfer of the second reaction product from the reactor to the pulp processor. In particular embodiments, the second reaction product is transferred from the refiner and/or the separator of the reactor to the second treatment chamber and/or the washing chamber of the pulp processor.

In one preferred embodiment, the pretreatment chamber is adapted to steam impregnate the acid, alkali, sulphide, sulphite and/or carbonate of the first and/or second reaction conditions into and/or onto the lignocellulosic material. In this regard, the lignocellulosic material may be first pre-steamed before steam impregnating the acid, alkali, sulphide, sulphite and/or carbonate so that it is wetted and preheated by the steam. Pre-steaming typically causes cavities within the lignocellulosic material, such as the capillaries within wood chips, to become at least partly filled with liquid. The steam treatment may further cause air within the lignocellulosic material to expand and be, at least partly, expelled therefrom. Subsequently steam impregnating the pre-steamed lignocellulosic material may then result in the liquid within the cavities of the lignocellulosic material being replaced with the acid, the alkali, the sulphide, the sulphite and/or the carbonate. Alternatively, steam impregnation of the acid, the alkali, the sulphide, the sulphite and/or the carbonate may be performed without first pre- steaming the lignocellulosic material.

In particular embodiments, the first treatment chamber, when operating in a first mode, is for treating the lignocellulosic material with a chemical agent, such as a solvent. In embodiments where a chemical agent is used, it would be understood that the chemical agent may vary depending on, for example, the type of lignocellulosic material to be processed, the severity of treatment or digestion desired, and the downstream processing requirements thereof. Preferably, the chemical agent is a solvent. In particular embodiments, the solvent is a polyol.

The term "polyoF as used herein refers to an alcohol containing multiple hydroxyl groups. Examples of polyols of the present invention include, but are not limited to, 1,2-propanediol, 1,3-propanediol, glycerol, 2,3-butanediol, 1,3-butanediol, 2-methyl- 1,3 -propanediol, 1,2-pentanediol, 1,3-pentanediol, 1,4-pentanediol, 1,5- pentanedial, 2,2-dimethyl- 1,3-propanediol, 2-methyl- 1,4-butanediol, 2-methyl- 1,3- butanediol, 1,1,1-trimethylolethane, 3-methyl-l,5-pentanediol, 1,1,1- trimethylolpropane, 1,7-heptanediol, 2-ethyl-l,6-hexanediol, 1,9-nonanediol, 1,11- undecanediol, diethylene glycol, triethylene glycol, oligoethylene glycol, 2,2'- thiodiglycol, diglycols or polyglycols prepared from 1,2-propylene oxide, propylene glycol, ethylene glycol, sorbitol, dibutylene glycol, tributylene glycol, tetrabutylene glycol, dihexylene ether glycol, trihexylene ether glycol, tetrahexylene ether glycol, 1,4-cyclohexanediol, 1,3-cyclohexanediol, or any combination thereof.

Preferably, the polyol is selected from the group consisting of glycerol, ethylene glycol and any combinations thereof.

Even more preferably, the polyol is glycerol.

In one particularly preferred embodiment, the pretreatment and the first treatment chambers when operating in the second mode are for treating the lignocellulosic material with a white liquor. For the purposes of the present invention, the term "white liquor" refers to an aqueous Kraft liquor containing active lignocellulose cooking chemicals. White liquor typically contains sodium hydroxide and sodium sulphide, which are two active lignocellulose treating chemicals. These chemicals may be present in the range of, for example, from about 70 to about 120 g/L of sodium hydroxide, and from about 20 to about 50 g/L sodium sulphide. White liquor may also contain other inactive chemicals, such as sodium carbonate in amounts of from about 11 to about 44 g/L, and small amounts of sodium sulfate, sodium sulhite, sodium thiosulphate, sodium chloride, and other inorganic salts.

Suitably, treatment of the lignocellulosic material in the pretreatment chamber is carried out at a temperature from about 20 to 99°C, or any range therein, such as, but not limited to, about 20°C to about 90°C or about 25°C to about 80°C. In particular embodiments, treatment in the pretreatment chamber is carried out at a temperature of about 21°C, 22°C, 23°C, 24°C, 25°C, 26°C, 27°C, 28°C, 29°C, 30°C, 31°C, 32°C, 33°C, 34°C, 35°C, 36°C, 37°C, 38°C, 39°C, 40°C, 41°C, 42°C, 43°C, 44°C, 45°C, 46°C, 47°C, 48°C, 49°C, 50°C, 51°C, 52°C, 53°C, 54°C, 55°C, 56°C, 57°C, 58°C, 59°C, 60°C, 61°C, 62°C, 63°C, 64°C, 65°C, 66°C, 67°C, 68°C, 69°C, 70°C, 71°C, 72°C, 73°C, 74°C, 75°C, 76°C, 77°C, 78°C, 79°C, 80°C, 81°C, 82°C, 83°C, 84°C, 85°C, 86°C, 87°C, 88°C, 89°C, 90°C, 91°C, 92°C, 93°C, 94°C, 95°C, 96°C, 97°C, 98°C and 99°C. Preferably, treatment in the pretreatment chamber is carried out at a temperature from about 25°C to about 75°C.

Suitably, treatment in the first and/or second treatment chambers is carried out at a temperature from about 100°C to about 220°C or any range therein, such as, but not limited to, about 120°C to about 200°C, about 140°C to about 180°C, or about 150°C to about 170°C. In particular embodiments, treatment in the first and/or second treatment chambers is carried out at a temperature of about 100°C, 101°C, 102°C, 103°C, 104°C, 105°C, 106°C, 107°C, 108°C, 109°C, 110°C, 111°C, 112°C, 113°C, 114°C, 115°C, 116°C, 117°C, 118°C, 119°C, 120°C, 121°C, 122°C, 123°C, 124°C, 125°C, 126°C, 127°C, 128°C, 129°C, 130°C, 131°C, 132°C, 133°C, 134°C, 135°C, 136°C, 137°C, 138°C, 139°C, 140°C, 141°C, 142°C, 143°C, 144°C, 145°C, 146°C, 147°C, 148°C, 149°C, 150°C, 151°C, 152°C, 153°C, 154°C, 155°C, 156°C, 157°C, 158°C, 159°C, 160°C, 161°C, 162°C, 163°C, 164°C, 165°C, 166°C, 167°C, 168°C, .169°C, 170°C, 171°C, 172°C, 173°C, 174°C, 175°C, 176°C, 177°C, 178°C, 179°C, 180°C, 181°C, 182°C, 183°C, 184°C, 185°C, 186°C, 187°C, 188°C, 189°C, 190°C, 191°C, 192°C, 193°C, 194°C, 195°C, 196°C, 197°C, 198°C, 199°C, 200°C, 201°C, 202°C, 203°C, 204°C, 205°C, 206°C, 207°C, 208°C, 209°C, 210°C, 211°C, 212°C, 213°C, 214°C, 215°C, 216°C, 217°C, 218°C, 219°C, 220°C, or any range therein. In certain preferred embodiments, treatment in the first and/or second treatment chambers is carried out at a temperature of about 160°C.

Treatment in the pretreatment chamber is preferably performed or carried out for a period of time from about 5 minutes to about 30 minutes or any range therein, such as, but not limited to, about 5 minutes to about 25 minutes, or about 10 minutes to about 15 minutes. In certain embodiments, treatment in the pretreatment chamber is carried out for a period of time of about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30 minutes, or any range therein. In particularly preferred embodiments, treatment in the pretreatment chamber is carried out for a period of time of about 10 minutes.

Treatment in the first and/or second treatment chambers is preferably performed or carried out for a period of time from about 5 to about 120 minutes or any range therein, such as, but not limited to, about 15 minutes to about 60 minutes, or about 20 minutes to about 40 minutes. In certain embodiments, treatment in the first and/or second treatment chambers is carried out for a period of time of about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120 minutes, or any range therein. In particularly preferred embodiments, treatment in the first and/or second treatment chambers is carried out for a period of time of about 30 minutes.

Suitably, the second treatment chamber is for treating the lignocellulosic material with an alkali, a sulphide, a sulphite and/or a carbonate to produce a third reaction product. In one embodiment, the reactor system or apparatus are adapted to transfer the third reaction product from the pulp processor to the reactor.

In this regard, a portion of the treated lignocellulosic material (i.e., the third reaction product) produced in the second reaction is fed into the reactor for additional processing. In one embodiment, the reactor system or apparatus are adapted to transfer the third reaction product from the pulp processor to the reactor. Preferably, the reactor and the pulp processor are in communication so as to facilitate transfer of the third reaction product from the pulp processor to the reactor.

Suitably, the third reaction product from the pulp processor can be sourced from multiple locations including following treatment, washing or bleaching. In one embodiment, the third reaction product is transferred from the second treatment chamber, the washing chamber, the screen and/or the bleaching chamber of the pulp processor to the pretreatment chamber, the first treatment chamber and/or the refiner of the reactor. In one particular embodiment, wherein the reactor is operating in the first mode, the third reaction product is transferred from the washing chamber and/or the screen of the pulp processor to the pretreatment chamber and/or the first treatment chamber of the reactor. In a further embodiment, wherein the reactor is operating in the second mode, the third reaction product is transferred from the second treatment chamber, the washing chamber, the screen and/or the bleaching chamber of the pulp processor to the pretreatment chamber, the first treatment chamber and/or the refiner of the reactor.

Once transferred to the reactor, the third reaction product may undergo treatment as hereinbefore described. In one embodiment, further treatment of the third reaction product does not comprise contacting the product with a further chemical agent, such as an alkali, a sulphide, a sulphite, a carbonate, an acid and/or a solvent.

Accordingly, in this embodiment, the third reaction product receives little or no further chemical treatment in the reactor.

In one embodiment of the present invention, the reactor further comprises a refiner. Typically, the refiner is adapted to physically or mechanically separate the cellulose fibres of the treated lignocellulosic material. Generally, a refiner comprises ridged metal discs called refiner plates and the refiner may or may not be able to be pressurized.

Preferably, when operating in a first mode there will be little or no refining of the treated lignocellulosic material (e.g., first reaction product). By way of example, the treated lignocellulosic material may pass through the refiner with the refiner plates fully backed off to eliminate any effective refining action, other than turbulence, or a small amount of specific energy can be applied, typically less than 50 kWh/ODMT. In one embodiment, the refiner is bypassed altogether.

Preferably, when operating in a second mode, the treated lignocellulosic material (e.g., the second reaction product) is refined at a high consistency, such as from 18% to 35% solids, with an application of specific energy from about 200 kWh/ODMT to about 800 kWh/ODMT.

In certain embodiments, the treated lignocellulosic material of the reactor and the pulp processor (e.g., the first, second and/or third reaction products) is washed before and/or after refining, separation, filtering or screening therein. In this regard, washing may be carried out with a wash solution and/or water. The treated lignocellulosic material may be washed with water and/or a wash solution one or more times, such as 2, 3, 4, or more times. Preferably, if the lignocellulosic material has been treated with an acid then washed with an alkaline wash solution (i.e. pH greater than 7) and/or water thereafter. Preferably, if the lignocellulosic material has been treated with an alkali it is then washed with an acidic wash solution (i.e. pH less than 7) and/or water thereafter. Additionally, the lignocellulosic material may be washed with water one or more times after treatment with an acid and/or an alkali, then the lignocellulosic material is washed with a alkaline or an acidic wash solution respectively one or more times, followed by optionally washing the lignocellulosic material again with water one or more times. Washing may also include leaching, such as diffusion and desorption, wherein dissolved solids and/or chemicals in the interior of the treated lignocellulosic material diffuse into the surrounding liquor for removal.

It would be appreciated that two basic pulp washing techniques include dilution/extraction and displacement washing. Generally, pulp washing equipment is based on one or both of these principles. In dilution/extraction washing, the treated lignocellulosic material is typically diluted and mixed with a weak treatment solution or water, which is then extracted by thickening the pulp, such as by filtering or pressing. In displacement washing, the treatment solution in the treated lignocellulosic material is displaced with a weaker treatment solution or water.

In one embodiment of the present invention, the pulp processor comprises a washing chamber for washing the treated lignocellulosic material as described herein. In particular embodiments, the washing chamber of the pulp processor is or comprises a diffusion washer, a rotary vacuum washer, a horizontal belt washer, a wash press and/or a rotary pressure washer. As would be appreciated, a used or spent treatment solution, such as a black liquor, which is a byproduct of the treatment process during the production of a cellulosic pulp may be removed by one or more washing steps in the washing chamber. As described herein, the treatment process of the pulp processor digests a lignocellulosic material into cellulose fibers (from which, for example, paper may be made), hemicellulose, lignin fragments and other organic compounds. The used treatment solution (e.g., black liquor) may comprise an aqueous solution of lignin residues, hemicellulose and other by products of the treatment process, as well as other inorganic wood pulping chemicals used in the treatment process. By way of example, a black liquor may comprise a total dissolved solids level of about 50% or less (for example, about 45% or less), a residual sulphide (e.g. , Na₂S) level of about 3 g/L to about 35 g/L, and an alkali (e.g., NaOH) level of about 1 g/L to about 25 g/L.

Suitably, the pulp processor comprises a concentrator for facilitating chemical recovery or recycling of a used treatment solution, such as from a black liquor. For the purposes of the present invention, one or more reactants, agents and/or byproducts of the first and/or the second set of reaction conditions from the reactor may also be recovered or recycled in the concentrator. Accordingly, in one embodiment the reactor system is adapted to transfer one or more reactants, agents and/or byproducts of the first and/or the second set of reaction conditions from the reactor to the pulp processor. Preferably, the reactor and the pulp processor are in communication so as to facilitate transfer of the one or more reactants, agents and/or byproducts from the reactor to the pulp processor. The one or more reactants, agents and/or byproducts will typically be present in the liquid stream or hydrolysate formed after separation in the separator of the first reactor. In one preferred embodiment, the one or more reactants, agents and/or byproducts are transferred from the reactor to the concentrator of the pulp processor. It would be readily appreciated that the reactants, agents and or byproducts from the reactor may be mixed with the used treatment solution (e.g., black liquor) from the pulp processor, such as in storage tanks, prior to feeding the concentrator.

As would be understood by the skilled person, the liquid stream or hydrolysate or a portion thereof from the reactor, particularly when operating in a first mode, may alternatively go on for further processing, such as hydrolysis of any polysaccharides therein into shorter polysaccharides and/or monosaccharides. Typically, the liquid stream or hydrolysate of the reactor operating in a first mode will be rich in hemicellulose C5 polysaccharides.

Important to the production of a cellulosic pulp is the subsequent chemical recovery or recycling, and in particular recovery or recycling of those reagents that delignify the lignocellulosic material (e.g. , sodium hydroxide and sodium sulphide), such that they may be re-used in the treatment process described above. By way of example, a used treatment solution from the washing chamber may contain about 15% solids and may be concentrated in the concentrator, such as by evaporation, up to about 65-80% solids. In one embodiment, the concentrator is a multiple effect evaporator.

Once concentrated, a number of byproducts or reactants of the treatment process, such as rosin soap, may be removed. The concentrated used treatment solution may then be transferred to a power plant, such as a chemical recovery boiler, for burning. In one preferred embodiment, the reactor apparatus or system comprises a power supply for providing power and/or steam to both the reactor and pulp processor.

By way of example, green liquor is a pulping liquor which is formed from the inorganic ash recovered from concentrated black liquor burned in a chemical recovery furnace or power plant where the sulphur compounds are reduced to sodium sulphide, and which are then dissolved in water to form the green liquor. Green liquor contains primarily sodium carbonate (e.g., in amounts of about 98 to about 155 g/L), sodium sulphide (e.g., in amounts of about 28 to about 55 g/L) and sodium hydroxide (e.g., in amounts of about 13 to about 21 g/L). Green liquor may be further converted into white liquor by contacting the green liquor with calcium hydroxide (for example, as quick lime or calcium oxide) in water. This process converts sodium carbonate (Na₂C0₃) into sodium hydroxide (NaOH), and is also referred to as recausticizing. In one embodiment of the present invention, the pulp processor further comprises a causticizer.

Suitably, for the reactor apparatus, reactor system or method provided herein, the reactor further comprises a separator and/or the pulp processor comprises a screen or a filter. In this regard, following treatment and/or washing the treated lignocellulosic material may be separated, screened and/or filtered from a liquid fraction or hydrolysate by any means known to those skilled in the art. Methods of separating the lignocellulosic material from the liquid fraction may include, but are not limited to, vacuum filtration, membrane filtration, sieve filtration, partial or coarse separation, centrifugation, a screw press or any combination thereof. The separating step can produce a liquid fraction (i.e., filtrate or hydrolysate) and a solid residue fraction (i.e., the first, second or third reaction product). In some embodiments of the present invention, water is added to the treated lignocellulosic material before and/or after separation. Thus, the first, second and/or third reaction products may include the chemical agent, residual acid, residual alkali, residual sulphide, residual sulphite, residual carbonate and/or by-products from the treatment process, such as, but not limited to, polyol(s), glycerol residue, and products produced from the treatment process.

In particular embodiments, the reactor comprises, consists or consists essentially of the treatment chamber and the separator.

Suitably, the pulp processor provided herein comprises a bleaching chamber.

In this regard, the treated lignocellulosic material of the pulp processor (e.g., the third reaction product) may be further delignified by one or more bleaching steps, such as in the bleaching chamber provided herein. Bleaching of kraft pulps typically takes place across multiple stages with washing and extraction steps following several of the bleaching steps. Examples of bleaching agents include, but are not limited to, chlorine, hypochlorite, chlorine dioxide, oxygen, ozone and hydrogen peroxide. The amount of bleaching required will typically vary depending on the end use of the cellulosic pulp. For example, in a plant designed to produce pulp to make brown sack paper or linerboard for boxes and packaging, the cellulosic pulp may require little or no bleaching. Accordingly, in one embodiment, the bleaching chamber is bypassed. Conversely, in a plant designed to produce writing paper or the like, the cellulosic pulp may require significant bleaching to achieve a high brightness. As would be understood, the cellulosic pulp may require further washing after bleaching.

In particular embodiments, the pulp processor is an existing or established pulp and paper processing facility, such as a Kraft pulp mill facility, a neutral sulphite semichemical pulp mill facility, a caustic carbonate semichemical pulp mill facility, a soda pulp mill facility, a thermochemical pulp mill facility, a chemi-mechanical pulp mill facility or any combination thereof. Preferably, the pulp processor is part of an existing pulping facility, such as one of those hereinbefore described, or is a stand alone or purpose built pulp processor.

As would be appreciated by the skilled artisan, expansion of production capacity at an existing or established pulp and paper processing facility can be very capital intensive and often prohibitively expensive. For example, the recovery boiler and/or power supply of the existing processing facility may be limited in capacity and the cost of a new recovery boiler is too expensive for the potential production gains therefrom. As such, adding or integrating a "satellite" reactor (i.e., the reactor) to such a pulp and paper processing facility allows for increased production capacity and the versatility to produce an alternative product if desired typically with less capital investment than that required to upgrade an existing facility. For efficiency, the reactor is suitably integrated and/or in communication with the existing or established pulp and paper processing facility chemical treatment processes, power supply and recovery and effluent systems.

Accordingly, in certain embodiments, the cellulosic pulp described herein may, with or without further modification, be used in the production of paper-based products including, but not limited to, paper, cardboard, paperboard, fibreboard, tissue, towel, and napkin. In one particular embodiment, the modified cellulosic material described herein is used in the production of a corrugating medium and/or a corrugated fibreboard.

As would be readily understood by the skilled person, the reactor apparatus, reactor system and/or method hereinbefore described may make the lignocellulosic material more susceptible to enzymatic digestion or hydrolysis compared to lignocellulosic material not subjected thereto. Thus, enzymatic hydrolysis at the same enzyme dosage of the partially hydrolysed lignocellulosic material may be increased by two, three, four, five, six, seven, eight or more times compared to enzymatic digestion of lignocellulosic material not treated by the method described herein. Alternately, lower doses of enzymes can be used to obtain effective rates and yields at lower cost.

An enzyme can be microbially produced and/or plant produced, and can include, but is not limited to, a cellulase, a hemicellulase, a xylanase, a ligninase, a pectinase, a protease, an amylase, a catalase, a cutinase, a glucanase, a glucoamylase, a glucose isomerase, a lipase, a laccase, a phytase, a pullulanase, a xylose isomerase, or any combination thereof. The enzyme compositions can be prepared as a liquid, a slurry, a solid or a gel.

Accordingly, in particular embodiments, the partially hydrolysed lignocellulosic material described herein may, with or without further modification, be used in the production of one or more fermentable sugars.

"Fermentable sugar " as used herein, refers to oligosaccharides and/or monosaccharides that may be used as a carbon source by a microorganism in a fermentation process. Examples of fermentable sugars include glucose, xylose, arabinose, galactose, mannose, rhamnose, sucrose, fructose, or any combination thereof.

It would be apparent to the skilled artisan that the fermentable sugars produced from the lignocellulosic material that has undergone treatment by the reactor apparatus, reactor system and/or method described herein may then be converted to useful value-added fermentation products, non-limiting examples of which include amino acids, such as lysine, methionine, tryptophan, threonine, and aspartic acid; vitamins; pharmaceuticals; animal feed supplements; specialty chemicals; chemical feedstocks; plastics; solvents; fuels or other organic polymers; lactic acid; butanol and/or ethanol, including fuel ethanol and/or fuel butanol, as examples of biofuels; organic acids, including acetic acid, citric acid, succinic acid and maleic acid; microbial lipids or oils, which may be used, at least in part, for biodiesel production; and/or industrial enzymes, such as proteases, cellulases, amylases, glucanases, lactases, lipases, lyases, oxidoreductases, transferases and xylanases. Accordingly, the partially hydrolysed lignocellulosic material may be further contacted (e.g., fermented) with a microorganism, including, but not limited to, an ethanologenic bacteria, a yeast or a combination thereof.

A preferred embodiment of the reactor system is shown in Figures 1, 2 and 3. In referring to Figures 1 to 3, the system 10 comprises a reactor 100 and a pulp processor 200, each reactor adapted for treating or digesting a lignocellulosic material. In the embodiment provided, the reactor 100 has been designed so as to be in communication and integrated with an existing Kraft pulping facility, which includes the pulp processor 200, a power supply 300 and a causticizer 400.

For the reactor 100, the lignocellulosic material first enters a pretreatment chamber 110. Preferably, the pretreatment chamber 110 is capable of physically pressing (e.g., a screw press) so as to facilitate compaction and destructuring of the lignocellulosic material prior to chemical treatment. As demonstrated in Figures 1 to 3, any liquid or pressate produced as a result of this pressing by the pretreatment chamber 110 may be removed therefrom. Optionally, the pretreatment chamber 110 is designed to apply low pressure steam to thereby pre-wet and pre-heat the lignocellulosic material. The pre-wetted and pre-heated lignocellulosic material is then subsequently impregnated with a treatment agent or solution.

As can be seen from Figures 1 to 3, the particular treatment agent to be impregnated into the lignocellulosic material depends upon the mode of operation of the reactor 100, which is switchable therebetween as specified by the user. In Figures 1 and 3, the reactor 100 is operating in a first mode and an acid is impregnated into the lignocellulosic material in the pretreatment chamber 110, whereas in Figure 2, the reactor 100 is operating in a second mode, wherein an alkali and a sulphide are now impregnated into the lignocellulosic material in the pretreatment chamber 110. Optionally, alternative or additional chemical agents or aqueous applications may be used.

In Figures 1, 2 and 3, the reactor 100 is shown to further comprise a first treatment chamber 120 for treating or digesting lignocellulosic material under user specified temperatures and/or pressures. Further, additional chemical agents may be added to the lignocellulosic material in the first treatment chamber 120, which may depend upon the mode of operation of the reactor 100. For example in Figure 1, when the reactor 100 is operating in a first mode, a chemical agent, such as a solvent like glycerol, may be added to the first treatment chamber 120 to assist in digesting or hydrolysing the lignocellulosic material. Although not shown in Figure 2, additional agents, such as more alkali and/or sulphide, may also be added to the first treatment chamber 120, when operating in a second mode.

Preferably, the first treatment chamber 120 is adapted to digest or treat the lignocellulosic material at a low liquids to solids ratio and may include rotating drums with baffles. In this regard, the first treatment chamber 120 may include a number of nozzles for spraying liquid, such as glycerol, onto the lignocellulosic material. It will also be appreciated that the lignocellulosic material may be gravity fed between successive chambers or alternatively it may be transferred or moved by conveyors such as belt conveyors or screw augers that facilitate movement of the lignocellulosic material therebetween.

As can be seen from Figures 1 to 3, the reactor 100 further includes a refiner 130, such as a disc refiner, which is adapted to facilitate the mechanical separation of cellulose fibres of the treated lignocellulosic material. In this regard, the refiner 130 comprises a series of refiner plates and is capable of being pressurized. When operating in a first mode, little or no refining of the treated lignocellulosic material is typically required and optionally the refiner 130 may be bypassed altogether. Conversely, when operating in a second mode, significant refining of the treated lignocellulosic material in the refiner 130 is usually required to produce a useable pulp material.

Figures 1, 2 and 3 demonstrate that the reactor 100 further includes a separator 140 configured to promote separation of the treated lignocellulosic material from any remaining liquid fraction, such as by physically pressing the treated lignocellulosic material. Following passage through the separator 140, the treated lignocellulosic material may be at least partly separated from any agents (i.e., the liquid hydrolysate), particularly liquid agents such as acid, alkali, sulphide and/or other chemical agents including glycerol, or additional water added to the lignocellulosic material in the pretreatment chamber 110 and treatment chamber 120.

As shown in Figures 1 and 3, a portion of the liquid hydrolysate from the reactor 100 when operating in a first mode may go on for further processing, including hydrolysis of any polysaccharides therein into shorter polysaccharides and/or monosaccharides.

Although not demonstrated in Figures 1 to 3, a conveyor is used to move the lignocellulosic material at a desired rate through and between the aforementioned chambers of the reactor 100, including the pretreatment chamber 110, the first treatment chamber 120; the refiner 130; and the separator 140. Further, the conveyor may operate at a user-defined rate so as to achieve the required retention time in each chamber before moving the lignocellulosic material on to the next chamber.

In one embodiment, as shown in Figure 2, the treated lignocellulosic material may be used for subsequent paper, cardboard or corrugating medium and paperboard applications or low freeness pulps for specialty or bio specialty applications.

In another embodiment, the treated lignocellulosic material may be transferred to a pulp processor 200. The pulp processor 200 may preferably be a component of a Kraft pulping facility or may be a purpose-built or stand alone pulp processor 200. This latter option may apply when the production of treated lignocellulosic material by reactor 100 exceeds the capacity of the pulp processor 200 of the Kraft pulping facility. In some instances, the pulp processor 200 may have additional equipment to handle the extra treated lignocellulosic material supplied from the reactor 100. For example, the pulp processor may have an additional screen 230 to handle the increased pulp throughput.

Referring to Figures 1 to 3, generally for the pulp processor 200, lignocellulosic material (i.e untreated lignocellulosic material) first enters a second treatment chamber 210. The lignocellulosic material then enters the washing chamber 220, is then screened by screen 230 and is then bleached in bleaching chamber 240. Similar to the first treatment chamber 110 of the reactor 100, the second treatment chamber 210 may optionally pre-wet and pre -heat the lignocellulosic material with steam or pre-impregnate with a treatment solution. As can be seen in Figures 1 to 3, the pulp processor 200, regardless of the mode of operation of the reactor 100, receives a treatment solution including an alkali and a sulphide (e.g. , a white liquor) which can be impregnated or added directly in the digester treatment 210. The second treatment chamber 210 is adapted to treat or digest lignocellulosic material under user specified temperatures and/or pressures in batches or in a continuous manner.

In referring to the particular embodiment provided in Figure 3 wherein the reactor 100 is operating in a first mode, a portion of the unbleached cellulosic pulp produced from the pulp processor 200, particularly following treatment in the second treatment chamber 210 and subsequent washing in the washing chamber 220, is transferred to the reactor 100 for at least partial hydrolysis therein. Preferably, the pulp is transferred after washing, such as multiple stage brown stock washing, in the washing chamber 220 so as to at least substantially remove the alkali therefrom. The washed unbleached pulp can then proceed with acid pretreatment in the pretreatment chamber 110, digestion in the first treatment chamber 120, refining in the refiner 130 and separation in the separator 140 to produce a solids fraction comprising partially hydrolysed lignocellulosic material and a liquid hydrolysate, as hereinbefore described.

With regard to this embodiment, the treatment process of the pulp in the reactor 100, and indeed the reactor 100 itself, may be simplified given that the lignocellulosic material has already been subjected to an alkali treatment reaction in the second treatment chamber 210 of the pulp processor 200. By way of example, the refiner 130 may be bypassed or impart little refining energy. Furthermore, the pretreatment chamber 110 may no longer require a screw press or the like to facilitate compaction and destructuring of the unbleached cellulosic pulp prior to chemical treatment in the first treatment chamber 120. Moreover, the acid application requirement and digestion severity conditions, such as temperature, pressure and retention time, may be less than that required to treat raw or untreated lignocellulosic material in the reactor 100. In particular embodiments, the pretreatment and/or treatment steps in the pretreatment and first treatment chambers 110, 120 respectively are performed substantially without an acid. This may also allow for simplifying the pretreatment chamber 110, or in certain embodiments, removing it altogether. Additionally, the size of the first treatment chamber 120 may also be reduced.

In light of the above, the reactor of Figure 3 may include a first treatment chamber 120 and a separator 140 in its simplest form. This embodiment typically represents the lowest cost of capital expenditure required to produce a partially hydrolysed lignocellulosic material suitable for the production of fermentable sugars. This embodiment also requires that the pulp mill simply takes a stream of unbleached cellulosic pulp from its existing pulp processor 200 (i.e., after the washing step in the washing chamber 220) and transfers it to the reactor 100. As such, the pulp processor 200 may even increase production to provide the additional stream of cellulosic pulp for treatment in the reactor 100. Alternatively, the pulp processor 200 may simply divert a portion of its existing pulp production to the reactor 100.

Furthermore, for this embodiment shown in Figure 3, the pulp processor 200 is preferably one or more of a high yield kraft mill pulp processor, a neutral sulfite semichemical mill pulp processor, a caustic carbonate semichemical mill pulp processor and a thermochemical pulping mill pulp processor. With respect to a thermochemical pulping mill pulp processor, the pulp may be removed following treatment in the primary refiner, preferably after a relatively mild amount of specific energy (<200 kWh/ODMT) has been applied in the primary refiner. For high yield kraft mill pulp processors, the degree of reaction or digestion is typically less than for a low yield kraft mill from which the degree of reaction may be too progressed or severe for the cellulosic pulp derived therefrom to be suitable for conversion to fermentable sugars. In this regard, a high yield kraft mill pulp processor typically runs at less than 40 minutes retention time in the second treatment chamber as compared to several hours for a low yield kraft mill pulp processor.

In referring particularly to Figure 2, when operating the reactor 100 in a second mode, in one embodiment, treated lignocellulosic material from the reactor 100 may be added to the washing chamber 220, the screen 230 and/or the bleaching chamber 240 of the pulp processor 200 (i.e., rather than entering the second treatment chamber 210). To this end, the treated lignocellulosic material may be transferred from the reactor 100 to the pulp processor 200 by any means known in the art, such as gravity fed or conveyors.

As previously described, the treated lignocellulosic material may be transferred to the washing chamber 220, screen 230 or bleaching chamber 240 rather than entering the second treatment chamber 210. Preferably, the treated lignocellulosic material is transferred to the washing chamber 220 and then sequentially passes through the screen 230 and then the bleaching chamber 240.

When the treated lignocellulosic material is transferred to the washing chamber 220, the used treatment solution comprising the alkali, the sulphide and/or other byproducts and reactants of the treatment (e.g. , digested lignin) are separated therefrom. Preferably, the washing chamber 220 comprises a plurality of washing stages in series. The used treatment solution (e.g., black liquor) is then transferred to a concentrator 250 so as to undergo an evaporation operation, such as by a multiple effect evaporator. In addition to the used treatment solution (e.g., black liquor) of the pulp processor 200, pressate from the pretreatment chamber 110 and/or liquid hydrolysate from the separator 140 when the reactor 100 is operating in either a first or second mode may also be transferred to the concentrator 250. The liquid pressate and/or hydrolysate may be transferred from the reactor 100 and mixed with the used treatment solution (e.g. , black liquor) in storage tanks of the pulp processor 200 by any means known in the art, including by pumping. Typically, the used treatment solution (e.g. , black liquor) therein is concentrated from about 15% solids in one or more steps in the concentrator 250 to about 65% to about 80% solids. Figures 1 to 3 do not illustrate the used treatment solution (e.g., black liquor) storage tanks that feed the concentrator 250, however this would be well understood by one skilled in the art.

As demonstrated in Figures 1, 2 and 3, this concentrated used treatment solution in then transferred to the power supply 300, where it is typically burned to facilitate recovery and/or recycling of one or more agents of the treatment solution (e.g. , the sulphide). This burning in the power supply 300 may also facilitate the generation of power and/or steam. The power supply 300 functionally is required for steam generation, electricity generation from steam feeding turbines and treatment solution recovery or recycling. Preferably, the power supply 300 provides power and/or steam to both the reactor 100 and the pulp processor 200 of the reactor system 10. Following combustion, an inorganic smelt is diluted and then transferred to a causticizer 400 for further recovery and/or recycling of one or more agents of the treatment solution (e.g. , the alkali). This is achieved by recausticization, so as to produce a recycled treatment solution comprising primarily of an alkali and a sulphide suitable for use in the pretreatment chamber 110 of the reactor 100 and/or the treatment chamber 210 of the pulp processor 200. In the Kraft process, the rejuvenated liquor is predominantly sodium hydroxide and sodium sulphide.

When the treated lignocellulosic material enters the screen 230, this promotes removal of any contaminants or large debris, such as large shives, knots and dirt. Typically, the filter 230 may comprise different types of sieves, filters and/or screens, centrifugal filtration and/or vacuum filtration. It is quite common to have a screen 230, such as a knotter earlier in the process and even before washing 220.

When the treated lignocellulosic material enters the bleaching chamber 240, at this point the treated lignocellulosic material comprises a small amount of residual lignin (e.g., less than 5% residual lignin). Accordingly, the treated lignocellulosic material may be further delignified in the bleaching chamber 240 by contacting it with one or more bleaching agents in one or more bleaching steps in combination with alkali extraction washing steps, as defined by the user. Typically, the amount of bleaching performed on the treated lignocellulosic material will depend on the required brightness of the resultant cellulosic pulp.

Once produced, the cellulosic pulp from the pulp processor 200 may be used for various downstream purposes, such as paper and/or cardboard production. Additionally, as demonstrated in Figure 2, a portion of the cellulosic pulp produced by the pulp processor 200 (particularly when the pulp processor is part of a Kraft pulping facility) may be transferred to the pretreatment chamber 110 of the reactor 100 when operating in a second mode so as further digest and/or refine the cellulosic pulp therein. In this regard, the cellulosic pulp may be added separately or in combination with further lignocellulosic material. The cellulosic pulp may be transferred from the pulp processor 200 to the reactor 100 by any means known in the art, such as gravity fed or conveyors.

Claims

1. A reactor apparatus for treating a lignocellulosic material comprising a reactor comprising a pretreatment chamber in communication with a treatment chamber and/or comprising a treatment chamber connectable to a pulp processor, the reactor switchable between a first mode for producing a firstreaction product comprising a partially hydrolysed lignocellulosic material and a second mode for producing a second reaction product suitable for conversion into a cellulosic pulp.

2. A reactor system for treating a lignocellulosic material comprising: a reactor comprising a pretreatment chamber in communication with a treatment chamber and/or comprising a treatment chamber connectable to a pulp processor, the reactor switchable between a first mode and a second mode, wherein the first mode comprises a first set of reaction conditions adapted to produce a first reaction product comprising a partially hydrolysed lignocellulosic material and the second mode comprises a second set of reaction conditions adapted to produce a second reaction product suitable for conversion into a cellulosic pulp.

3. A method of operating a reactor system for treating a lignocellulosic material including the steps of:

selecting between first and second modes of operation of a reactor comprising a treatment chamber, wherein the first mode comprises a first set of reaction conditions adapted to produce a first reaction product comprising a partially hydrolysed lignocellulosic material and the second mode comprises a second set of reaction conditions adapted to produce a second reaction product suitable for conversion into a cellulosic pulp; and optionally

4. The reactor apparatus of Claim 1, the reactor system of Claim 2, or the method of Claim 3, wherein the reactor comprises a pretreatment chamber in communication with the treatment chamber

5. The reactor apparatus, reactor system or method of any one of the preceding claims, wherein the reactor is connectable with a pulp processor.

6. The reactor apparatus, reactor system or method of Claim 5, wherein the pulp processor is part of a kraft pulp mill facility, a neutral sulfite semichemical pulp mill facility, a caustic carbonate semichemical pulp mill facility and/or a thermochemical pulp mill facility.

7. The reactor apparatus, reactor system or method of Claim 5, wherein the pulp processor is a stand alone or purpose built pulp processor.

8. The reactor apparatus, reactor system or method of any one of the preceding claims, wherein for the first mode, the pretreatment chamber and/or the first treatment chamber are for treating the lignocellulosic material with an acid.

9. The reactor apparatus, reactor system or method of any one of the preceding claims, wherein for the first mode, the first treatment chamber is for treating the lignocellulosic material with a chemical agent.

10. The reactor apparatus, reactor system or method of any one of the preceding claims, wherein for the second mode, the pretreatment chamber and/or the first treatment chamber are for treating the lignocellulosic material with an alkali, a sulphide, a sulphite, a carbonate and/or water.

11. The reactor apparatus, reactor system or method of any one of the preceding claims, wherein the reactor further comprises a refiner and/or a separator.

12. The reactor apparatus, reactor system or method of Claim 11, wherein the reactor comprises, consists or consists essentially of the treatment chamber and the separator.

13. The reactor apparatus, reactor system or method of any one of Claims 1 to 12, wherein the pulp processor comprises one or more of a second treatment chamber, a washing chamber, a screen, a bleaching chamber and a concentrator.

14. The reactor apparatus, reactor system or method of any one of Claims 1 to 13, wherein the apparatus, system or method is adapted to transfer the second reaction product from the reactor to the pulp processor.

15. The reactor apparatus, reactor system or method of any one of Claims 1 to 14, wherein the reactor and the pulp processor are in communication so as to facilitate transfer of the second reaction product from the reactor to the pulp processor.

16. The reactor apparatus, reactor system or method of Claim 15, wherein the second reaction product is transferred from the refiner and/or the separator of the reactor to the washing chamber, the screen and/or the bleaching chamber of the pulp processor.

17. The reactor system of any one of Claims 1 to 16, wherein the reactor system is adapted to transfer one or more reactants, agents and/or byproducts of the first and/or the second set of reaction conditions from the reactor to the pulp processor.

18. The reactor system of Claim 17, wherein the reactor and the pulp processor are in communication so as to facilitate transfer of the one or more reactants, agents and/or byproducts from the reactor to the pulp processor.

19. The reactor system of Claim 18, wherein the one or more reactants, agents and/or byproducts are transferred from the reactor to the concentrator of the pulp processor.

20. The reactor system of any one of Claims 1 to 19, further comprising a power supply for providing power and/or steam to the reactor and the pulp processor.

21. The reactor apparatus, reactor system or method of Claim 13, wherein the second treatment chamber is for treating the lignocellulosic material with an alkali, a sulphide, a sulphite and/or a carbonate to produce a third reaction product.

22. The reactor apparatus, reactor system or method of Claim 21, wherein said system or apparatus are adapted to transfer the third reaction product from the pulp processor to the reactor.

23. The reactor apparatus, reactor system or method of Claim 22, wherein the reactor and the pulp processor are in communication so as to facilitate transfer of the third reaction product from the pulp processor to the reactor.

24. The reactor apparatus, reactor system or method of any one of Claims 21 to

23, wherein the third reaction product is transferred from the second treatment chamber, the washing chamber, the screen, and/or the bleaching chamber of the pulp processor to the pretreatment chamber, the first treatment chamber and/or the refiner of the reactor, and wherein the reactor is operating in the second mode for treatment of the third reaction product by the second set of reaction conditions.

25. The reactor apparatus, reactor system or method of any one of Claims 21 to

24, wherein the third reaction product is transferred from the washing chamber and/or the screen of the pulp processor to the pretreatment chamber and/or the first treatment chamber of the reactor, and wherein the reactor is operating in the first mode for treatment of the third reaction product by the first set of reaction conditions.

26. The reactor apparatus, reactor system or method of Claim 24 or Claim 25, wherein the first and/or second set of reaction conditions are substantially performed without contacting the third reaction product with a further chemical agent in the reactor.