WO2012137204A1

WO2012137204A1 - Lignin products and methods for their production

Info

Publication number: WO2012137204A1
Application number: PCT/IL2012/050122
Authority: WO
Inventors: Aharon Eyal
Original assignee: Hcl Cleantech Ltd.
Priority date: 2011-04-07
Filing date: 2012-04-04
Publication date: 2012-10-11

Abstract

A broad aspect of the invention relates to lignosulfonates and their production. One aspect of some embodiments of the invention relates to methods to produce lignosulfonates. In some exemplary embodiments of the invention, lignin remaining after hydrolysis of a lignocelluosic substrate (e.g. wood) is contacted with a sulfonating reagent. In some exemplary embodiments of the invention, the lignin remaining after hydrolysis has a higher average molecular weight and/or a higher degree of cross-linking than lignin in the lignocelluosic substrate and/or than lignosulfonate produced by conventional sulfite pulping in the paper industry. A relative degree of cross-linking can be ascertained by comparing O:C ratio and/or melting point and/or molecular weight and/or solubility between samples. In some embodiments, an increase in a degree of cross-linking contributes to a decrease in O:C ratio.

Description

LIGNIN PRODUCTS AND METHODS FOR THEIR PRODUCTION

RELATED APPLICATIONS

In accord with the provisions of 35 U.S.C. § 119(e) and §363, this application claims the benefit of :

US 61/473134 filed on April 7, 2011 by Aharon EYAL et al. and entitled "Lignocellulose Conversion Processes and Products";

US 61/483663 filed on May 7, 2011 by Aharon EYAL et al. and entitled "Lignocellulose Conversion Processes and Products";

US 61/483,777 filed on May 9, 2011 by Aharon EYAL et al. and entitled "Hydrolysis Systems and Methods";

US 61/487,319 filed May 18, 2011 by Aharon EYAL et al. and entitled "Hydrolysis Systems and Methods";

US 61/491243 filed on May 30, 2011 by Robert JANSEN et al. and entitled "Lignin Compositions, Systems and Methods for Processing Lignin and/or HCl"; each of which is fully incorporated herein by reference;

US 61/552402 filed on October 27, 2011 by Aharon EYAL et al. and entitled "Lignin Compositions, Methods of Producing the Compositions, Methods of Using Lignin, and Products Produced Thereby" ;

US 61/559529 filed on November 14, 2011 by Aharon EYAL et al. and entitled "Lignin Compositions, Methods of Producing the Compositions, Methods of Using Lignin, and Products Produced Thereby";

US 61/561181 filed on November 17, 2011 by Aharon EYAL et al. and entitled "Lignin Products and Methods for Their Production";

US 61/626,307 filed on September 22, 2011 by Aharon EYAL et al. and entitled "Lignin and Lignin Particles";

US 61/602,514 filed on February 23, 2012 by Aharon EYAL et al. and entitled "Lignin Compositions, Methods of Producing The Compositions, Methods of Using Lignin Compositions, and Products Produced Thereby";

US 61/619,434 filed on April 3, 2012 by Aharon EYAL et al. and entitled "Lignin Products and Methods for Their Production"; each of which is fully incorporated herein by reference.

In addition, in accord with the provisions of 35 U.S.C. § 119(a) and/or §365(b), this application claims the benefit of:

PCT/IL 2011/000424 filed on June 1, 2011 by Robert JANSEN et al. and entitled "Lignin Compositions, Systems and Methods for Processing Lignin and/or HCl"; PCT/US2011/057552 filed on October 24, 2011 by Aharon EYAL et al. and entitled "Hydrolysis Systems and Methods"; each of which is fully incorporated herein by reference. FIELD OF THE INVENTION

This invention relates to lignin products and methods to produce them.

BACKGROUND OF THE INVENTION

Mechanical pulping of wood to make pulp for paper began in Germany in the 1840s. The increased demand for paper led to development of chemical processes such as use of sulfurous acid to treat wood and use of calcium bisulfite, Ca(HS03)2, to pulp wood. By the late 19th century the first commercial sulfite process pulp mill was built.

It used magnesium as the counter ion. In the 1950s calcium replaced magnesium as the standard counter ion in sulfite process pulp production.

Sulfite pulping surpassed mechanical pulping as an industrial process by the beginning of the 20th century.

However, a competing chemical pulping process, the sulfate or Kraft process was developed in 1879 and the first Kraft mill opened in 1890. The invention of the recovery boiler in the early 1930s allowed Kraft mills to recycle almost all of their pulping chemicals. This recycling capability, together with the ability of the Kraft process to process a wider variety of wood types and produce stronger fibers made the Kraft process the major industrial pulping process by the 1940s.

Sulfite pulps now account for less than 10% of the total chemical pulp production and the number of sulfite mills continues to decrease.

Sulfite pulps contain lignosulfonates as well as non-cellulose components of the wood from which the pulp is produced.

SUMMARY OF THE INVENTION

A broad aspect of the invention relates to lignosulfonates and their production.

One aspect of some embodiments of the invention relates to methods to produce lignosulfonates. In some exemplary embodiments of the invention, lignin remaining after hydrolysis of a lignocelluosic substrate (e.g. wood) is contacted with a sulfonating reagent. In some exemplary embodiments of the invention, the lignin remaining after hydrolysis has a higher average molecular weight and/or a higher degree of cross-linking than lignin in the lignocelluosic substrate and/or than lignosulfonate produced by conventional sulfite pulping in the paper industry.

A relative degree of cross-linking can be ascertained by comparing 0:C ratio and/or melting point and/or molecular weight and/or solubility between samples. In some embodiments, an increase in a degree of cross-linking contributes to a decrease in 0:C ratio. Alternatively or additionally, in some embodiments an increase in a degree of cross-linking contributes to an increase in melting point. Alternatively or additionally, in some embodiments an increase in a degree of cross-linking contributes to an increase in molecular weight. Alternatively or additionally, in some embodiments an increase in a degree of cross-linking contributes to a decrease in solubility.

Another aspect of some embodiments of the invention relates to lignosulfonates with a higher average molecular weight (MW) and/or degree of cross-linking than lignosulfonates produced from a same lignocellulosic substrate according to a conventional sulfite pulping process.

Another aspect of some embodiments of the invention relates to lignosulfonates including at least 100 PPB, optionally at least 500 PPB, optionally at least 1PPM , optionally at least 10PPM, optionally at least 50PPM, optionally at least 100PPM of an SI solvent.

Another aspect of some embodiments of the invention relates to lignosulfonates with a covalently bound chloride (CI) content of at least 10 PPB, optionally at least 100 PPB, optionally at least 500 PPB, optionally at least 1 PPM, optionally at least 10 PPM, optionally at least 100 PPM.

Another aspect of some embodiments of the invention relates to lignosulfonates with at least 10 PPB, optionally at least 100 PPB, optionally at least 500 PPB, optionally at least 1 PPM, optionally at least 10 PPM, optionally at least 100 PPM on a dry matter basis of a lignin polymer bound to an alcohol of at least 6 carbon atoms by an ether bond

It will be appreciated that the various aspects described above relate to solution of technical problems associated with production of high molecular weight lignosulfonate.

Alternatively or additionally, it will be appreciated that the various aspects described above relate to solution of technical problems related to rendering lignin suitable for downstream industrial processes. In some exemplary embodiments of the invention, rendering lignin suitable for downstream industrial processes includes production of lignosulfonate with a degree of purity higher than typically found in lignosuulfonates produced by conventional sulfite pulping in the paper industry.

In some exemplary embodiments of the invention, there is provided a method including: providing a stream comprising at least 40%, at least 50%, at least 60%, at least 70%, at least 80% or even 90 % or more solid lignin (i.e. actual solids as opposed to dissolved solids) on a dry matter basis; and contacting the stream with an SO₂ donating reagent (e.g. a sulfite salt) to form lignosulfonate from at least a portion of the lignin. In some embodiments, the solid lignin comprises at least 30%, at least 35%, at least 40%, or even at least 50% of the stream on an as is basis. Alternatively or additionally, in some embodiments the stream comprises water and HC1 at a concentration of at least 30% HC1/[HC1 +water] by weight. Alternatively or additionally, in some embodiments the stream comprises water and HCl at an HCl: water ratio > 0.4. Alternatively or additionally, in some embodiments the stream comprises at least one item selected from the group consisting of water and an SI solvent. Alternatively or additionally, in some embodiments the stream comprises an SI solvent at a concentration of 100 PPB, 200 PPB, 500PPB, or 1000 PPB or intermediate or greater concentrations on a dry matter basis. Alternatively or additionally, in some embodiments the stream comprises solid lignin, less than 10%, 9%, 8%, or 7% water and less than 5%, 4%, 3%, 2% or 1% acid. Alternatively or additionally, in some embodiments the stream comprises at least 2%, at least 3%, at least 4%, at least 5% or even 6% or more cellulose by weight on a dry matter basis. Alternatively or additionally, in some embodiments the stream comprises less than 25%, 20%, 15%, or 10% cellulose by weight on a dry matter basis. Alternatively or additionally, in some embodiments the stream comprises at least 4%, 5%, 6%, 7%, 8%, 9%, 10% cellulose by weight on a dry matter basis relative to the amount of lignin. Alternatively or additionally, in some embodiments the stream comprises cellulose at a cellulose:lignin weight ratio of less than 0.1. Alternatively or additionally, in some embodiments the contacting occurs at a temperature of at least 130 °C, at least 140 °C or even at least 150 °C. Alternatively or additionally, in some embodiments the contacting occurs at a temperature not exceeding 170 °C or 160 °C. Alternatively or additionally, in some embodiments the contacting continues for at least 0.5 or at least 1 hour. Alternatively or additionally, in some embodiments the contacting continues not more than 4, 3 or 2 hours. Alternatively or additionally, in some embodiments the method includes separating the lignosulfonate from an acid (e.g., HCl or H2SO4). In some embodiments, the lignosulfonate is in a dissolved form at the time of separation. Alternatively or additionally, in some embodiments transformation of solid lignin to dissolved lignosulfonate contributes to ease of separation from acid. In some embodiments the separating includes extraction with an extractant comprising an SI solvent. In some embodiments, this SI extraction involves liquid-liquid (aqueous-solvent) contact.

As used in this specification and the accompanying claims the term "SI solvent" refers to an organic solvent which is less than 15% soluble in water and has a polarity related component of Hoy's cohesion parameter (delta-P) between 5 and 10 MPa 1/2 and/or a hydrogen-bond related component of Hoy's cohesion parameter (delta-H) between 5 and 20 MPa 1/2. Optionally, SI includes an alcohol, ketone or aldehyde with 5, optionally 6, or 8 or more carbon atoms. Optionally, SI includes a hexanol, a heptanol or an ocatnol such as 2-ethyl-hexanol and combinations thereof. Delta-P is the polarity related component of Hoy's cohesion parameter and delta-H is the hydrogen bonding related component of Hoy's cohesion parameter.

The cohesion parameter, as referred to above or, solubility parameter, was defined by Hildebrand as th ot of the cohesive energy density:

where AEvap and V are the energy or heat of vaporization and molar volume of the liquid, respectively. Hansen extended the original Hildebrand parameter to a three-dimensional cohesion parameter. According to this concept, the total solubility parameter, delta, is composed of three different components, or, partial solubility parameters relating to the specific intermolecular interactions:

^■7 "7 ^

* = 4- + &Γ

in which delta-D, delta-P and delta-H are the dispersion, polarity, and Hydrogen bonding components, respectively. Hoy proposed a system to estimate total and partial solubility parameters. The unit used for those parameters is MPa 1/2. A detailed explanation of that parameter and its components can be found in "CRC Handbook of Solubility Parameters and Other Cohesion Parameters", second edition, pages 122-138. That and other references provide tables with the parameters for many compounds. In addition, methods for calculating those parameters are provided.

Alternatively or additionally, in some embodiments the separating includes distillation. Alternatively or additionally, in some embodiments the separating includes chromatographic separation. Alternatively or additionally, in some embodiments the separating includes ion- exchange. Alternatively or additionally, in some embodiments the separating includes membrane separation (e.g. ultrafiltration). Alternatively or additionally, in some embodiments the stream comprises less than 1%, less than 0.5%, or less than 0.1% monomeric sugars on a dry matter basis. Alternatively or additionally, in some embodiments the stream comprises less than 0.3%, less than 0.2%, less than 0.1%, or less than 0.05% multivalent ions on a dry matter basis. Alternatively or additionally, in some embodiments stream includes less than 1%, less than 0.5% or less than 0.1% chloride (CI) on a dry matter basis. Alternatively or additionally, in some embodiments the stream includes less than 0.5% ash content 0.5% on a dry matter basis. Alternatively or additionally, in some embodiments the stream has a sulfur content of less than 70 PPM on a dry matter basis. Alternatively or additionally, in some embodiments the stream includes less than 5% soluble carbohydrates on a dry matter basis. Alternatively or additionally, in some embodiments the stream has a tall oils content of less than 0.5%, 0.4%, 0.3%, or 0.2% on a dry matter basis. Alternatively or additionally, in some embodiments the stream comprises less than 100 PPM, less than 50 PPM, less than 10 PPM, or less than 1 PPM phosphorus (P) on a dry matter basis.

According to various exemplary embodiments of the invention at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80% of the lignosulfonate has a molecular weight of at least 40 or at least 50 kDa (kiloDalton) as measured by gel-permeation chromatography. As used in this specification and the accompanying claims the term "gel- permeation chromatography" or "GPC" indicates high precision liquid chromatography (HPLC) with reference to standards of known MW. Measurement of molecular weight of solid lignin compositions optionally includes solubilization of the lignin. Alternatively or additionally, according to various exemplary embodiments of the invention at least 30%, at least 40%, at least 50%, at least 60%, at least 70% or at least 80% of the solid lignin in the stream has a molecular weight of at least 40 or at least 50 kDa as measured by gel-permeation chromatography. Alternatively or additionally, in some embodiments the lignosulfonates comprise at least one sulfonate group per four lignin units. Alternatively or additionally, in some embodiments the lignosulfonates comprise at least 4% sulfur by weight. Alternatively or additionally, in some embodiments, the providing includes increasing an average MW of the lignin in a lignocellulosic feed material. Alternatively or additionally, in some embodiments the increasing the average MW employs an acid (e.g. HC1). In some embodiments, the acid functions as a catalyst. In some embodiments, the method includes increasing an average degree of cross-linking of the lignin in a lignocellulosic feed material. In some embodiments the increasing employs an acid (e.g. HC1). In some embodiments, the acid functions as a catalyst.

In some exemplary embodiments of the invention, there is provided a composition including lignosulfonate, wherein at least 30% of the lignosulfonate has a molecular weight of at least 40 kDa, or at least 50 kDa as measured by gel-permeation chromatography. In some exemplary embodiments of the invention, there is provided a composition comprising: lignosulfonate characterized by an average molecular weight at least 10% greater than lignosulfonate prepared from a same lignocellulosic substrate according to previously known sulfite pulping methods. Alternatively or additionally, in some exemplary embodiments of the invention there is provided a composition comprising: lignosulfonate characterized by an average degree of cross-linking at least 10% greater than lignosulfonate prepared from a same lignocellulosic substrate. Alternatively or additionally, in some exemplary embodiments of the invention there is provided a composition comprising: lignosulfonate; and an SI solvent at a concentration of at least 100 PPB on a dry matter basis. Alternatively or additionally, in some exemplary embodiments of the invention there is provided a composition comprising: lignosulfonate comprising a covalently bound chloride (CI) content of at least 10 PPB on a dry matter basis. Alternatively or additionally, in some exemplary embodiments of the invention there is provided a composition comprising: lignosulfonate comprising at least 10 PPB on a dry matter basis of a lignin polymer bound to an alcohol of at least 6 carbon atoms by an ether bond.

In some exemplary embodiments of the invention, there is provided a composition comprising lignin wherein the lignin has an average molecular weight of at least 40kDa, or at least 50 kDa as measured by gel-permeation chromatography. In some embodiments, the lignin has a covalently bound chloride content of least 10 PPB on a dry matter basis and/or at least 10 PPB of a lignin polymer bound to an alcohol of at least 6 carbon atoms by an ether bond and/or an SI solvent at a concentration of at least 100 PPB on a dry matter basis.

In some exemplary embodiments of the invention, there is provided a cement product comprising lignosulfonate with an average molecular weight of at least 40 kDa or at least 50 kDa. According to various exemplary embodiments of the invention the lignosulfonate in the cement product has at least 10 PPB on a dry matter basis of covalently bound chloride and/or at least 10 PPB on a dry matter basis of a lignin polymer bound to an alcohol of at least 6 carbon atoms by an ether bond and/or an SI solvent at a concentration of at least 100 PPB on a dry matter basis.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although suitable methods and materials are described below, methods and materials similar or equivalent to those described herein can be used in the practice of the present invention. In case of conflict, the patent specification, including definitions, will control. All materials, methods, and examples are illustrative only and are not intended to be limiting.

As used herein, the terms "comprising" and "including" or grammatical variants thereof are to be taken as specifying inclusion of the stated features, integers, actions or components without precluding the addition of one or more additional features, integers, actions, components or groups thereof. This term is broader than, and includes the terms "consisting of" and "consisting essentially of" as defined by the Manual of Patent Examination Procedure of the United States Patent and Trademark Office.

The phrase "consisting essentially of" or grammatical variants thereof when used herein are to be taken as specifying the stated features, integers, steps or components but do not preclude the addition of one or more additional features, integers, steps, components or groups thereof but only if the additional features, integers, steps, components or groups thereof do not materially alter the basic and novel characteristics of the claimed composition, device or method. The phrase "adapted to" as used in this specification and the accompanying claims imposes additional structural limitations on a previously recited component.

The term "method" refers to manners, means, techniques and procedures for accomplishing a given task including, but not limited to, those manners, means, techniques and procedures either known to, or readily developed from known manners, means, techniques and procedures by practitioners of architecture and/or computer science.

Percentages (%) of chemicals are WAV (weight per weight) unless otherwise indicated. Weights and/or percentages are on a dry matter basis unless otherwise indicated.

Indicated molecular weights are measured by gel-permeation chromatography unless other methods are mentioned. Molecular weights may vary according to actual measurement conditions.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to understand the invention and to see how it may be carried out in practice, embodiments will now be described, by way of non-limiting example only, with reference to the accompanying figures. In the figures, identical and similar structures, elements or parts thereof that appear in more than one figure are generally labeled with the same or similar references in the figures in which they appear. Dimensions of components and features shown in the figures are chosen primarily for convenience and clarity of presentation and are not necessarily to scale. The attached figures are:

Fig. 1 is a schematic overview of an exemplary industrial context of some embodiments of the invention;

Fig. 2 is a schematic representation of one stage in lignin processing and/or HC1 recovery according to some exemplary embodiments of the invention;

Fig. 3 is simplified flow diagram of a method to produce lignosulfonate according to some embodiments of the invention; and

Fig. 4 is a simplified flow diagram of various embodiments of separation as depicted in

Fig. 3.

DETAILED DESCRIPTION OF EMBODIMENTS

Embodiments of the invention relate to methods to prepare lignosulfonate and to the resultant lignosulfonate compositions.

Specifically, some embodiments of the invention can be used to prepare liquid lignosulfonate and/or lignosulfonate with a desired degree of cross-linking and/or a desired molecular weight. The principles and operation of a methods and/or compositions according to exemplary embodiments of the invention may be better understood with reference to the drawings and accompanying descriptions.

Before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details set forth in the following description or exemplified by the Examples. The invention is capable of other embodiments or of being practiced or carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein is for the purpose of description and should not be regarded as limiting.

System Overview

Fig. 1 is a schematic overview of an exemplary industrial context of some embodiments of the invention depicting relevant portions of an acid hydrolysis system for processing of lignocellulosic material indicated generally as 100. Depicted system 100 includes a hydrolysis vessel 110 which takes in lignocellulosic substrate 112 and produces two exit streams.

In some exemplary embodiments of the invention, hydrolysis in vessel 110 increases an average MW and/or an average degree of cross-linking of the lignin in a lignocellulosic feed material (i.e. substrate 112).

The first exit stream is an acidic hydrolyzate 130 containing an aqueous solution of acid (e.g., HC1 or sulfuric acid) with dissolved sugars. The second exit stream 120 is a lignin stream. Various exemplary embodiments of the invention relate to processing of lignin stream 120 to remove the acid and water and/or recycling of the removed acid and/or ways to accomplish this recycling without diluting the acid (e.g., HC1).

In v exemplary embodiments of the invention, hydrolysis vessel 110 is of the type described in co-pending US Provisional application 61/483,777 filed May 9, 2011 entitled "Hydrolysis Systems and Methods" which is fully incorporated herein by reference.

In other exemplary embodiments of the invention, hydrolysis vessel 110 is of the type described in co-pending US Provisional application 61/487,319 filed May 18, 2011 entitled "Hydrolysis Systems and Methods" which is fully incorporated herein by reference.

Alternatively or additionally, the hydrolysis vessel may include hydrolysis reactors of one or more other types.

In depicted exemplary system 100, processing of lignin stream 120 occurs in lignin processing module 200 and produces lignin 220 which is substantially free of residual acid (e.g., HC1) and/or water and/or soluble carbohydrates. As will be explained below, lignin processing module 200 optionally includes two or more sub-modules. For purposes of the overview of system 100, it is sufficient to note that module 200 produces a re-cycled stream 140 of concentrated acid (e.g., HC1) which is routed to hydrolysis vessel 110. In some exemplary embodiments of the invention, HC1 gas 192 is added to stream 140 by means of an absorber 190. In some exemplary embodiments of the invention, the HC1 gas is also produced by module 200.

Exemplary Lignin Washing Equipment

Fig. 2 is a schematic representation of one sub-module in lignin processing module 200 according to some exemplary embodiments of the invention generally depicted as lignin washing module 201.

In the depicted embodiment, washing module 201 includes a series of four physically similar processing towers depicted schematically as 210, 222, 224 and 226. In other exemplary embodiments of the invention, a smaller or larger number of towers is employed. Each of these towers is designed to receive stream 120 at its lower end and move it upwards to be passed out from its upper end to the lower end of the next tower in line. Upward transport of stream 120 within the towers can be achieved, for example, using a rotating auger. Exit streams of these four towers are indicated as 120a, 120b, 120c and 120d respectively.

Tower 210 is configured as a drainage tower. As stream 120 is conducted upwards, concentrated acid (e.g., HC1; dashed line) is allowed to drain out of the stream and is recycled to reactor vessel 110. This drainage is a mechanical treatments which decreases the total flow in pounds per hour of lignin stream 120a relative to 120 and increases the amount of lignin relative to liquid, but does not alter the ratio of HQ: water.

Towers 222, 224 and 226 are configured as a countercurrent wash system for the rightwards moving lignin stream. Although three such towers are depicted, various exemplary embodiments of the invention may employ a single tower or 4, 5 or more towers. In the depicted exemplary embodiment countercurrent washing is with a recovered or recycled solution of about 30% HC1 (dashed line; 227) which is introduced into the top of tower 226 where it flows to the bottom. This wash stream is then transferred to the top of tower 224 where it flows to the bottom and is transferred again to the top of tower 222 where it flows to the bottom and is removed.

This washing serves to lower the HC1 concentration in 120d to about 30%. Alternatively or additionally, this washing serves to lower the soluble carbohydrate concentration in 120d to less than 3%, optionally less than about 1% ,optionally less than about 0.5%, optionally less than about 0.03%. In some exemplary embodiments of the invention, these carbohydrates washed from the lignin stream are routed back to hydrolysis reactor 110.

In the depicted exemplary embodiment, as the lignin stream moves through the series of four towers 210-226, the lignin concentration increases from 5 to 10%, optionally from about 7% (120) to about 12% (120d). Aqueous HCl leaving the bottom of tower 222 has a concentration between 30 and 42% and is returned to reactor vessel 110. In the depicted embodiment, this return is via absorber 190 where HCl gas is added to increase the HCl concentration.

Conversely, as the wash stream moves to the left, it increases in size as it absorbs liquid and sugars from the lignin stream.

Stream 120d is routed to a mechanical separation apparatus 250. Apparatus 250 may be, for example, a centrifuge or press. Optionally, apparatus 250 works on a continuous flow basis. Apparatus 250 extracts a stream of acidic liquid acid (e.g., HCl) (dashed line) which is returned to hydrolysis vessel 110. Optionally, this return is via tower 222 and/or absorber 190.

In some exemplary embodiments of the invention, the relatively low concentration of acid (e.g., HCl) in 120d contributes to an amenability of the stream to a desired industrial process. For example, a 30% HCl concentration can be processed in a flow through centrifuge (optionally 250) while a 42% HCl stream is much more difficult to process in this manner. Increased vapor pressure of HCl at higher concentrations contributes to the degree of processing difficulty.

Following removal of the bulk of the liquid, the lignin exits apparatus 250 as lignin stream 220e. Although the acid (e.g., HCl) concentration has not changed relative to 120d, the total amount of liquid to be processed is significantly reduced. Sugar concentration is still about 0.5%.

In some exemplary embodiments of the invention, lignin stream 120 is provided at a temperature of 12 to 17, optionally about 15 degrees centigrade. In some exemplary embodiments of the invention, the wash solution applied to column 226 from 320 is delivered at a temperature of 30 to 70, optionally about 50 degrees centigrade. These exemplary conditions result in a heat exchange so that stream 120d is below 30 degrees centigrade, optionally below 28 degrees centigrade, optionally 26 to 27 degrees, optionally about 25 degrees centigrade. In some exemplary embodiments of the invention, increasing temperature of the lignin stream contributes to an increase in washing efficiency. Optionally, this increase in efficiency is related to a decrease in viscosity. In some exemplary embodiments of the invention, a decrease in viscosity of a liquid portion of stream 120 contributes to an increase in draining efficiency. The context of Fig. 2 is described in co-pending application PCT/IL2011/000424 entitled "Lignin Compositions, Systems and Methods for Processing Lignin and/or HCl"; which is fully incorporated herein by reference.

According to various exemplary embodiments of the invention, washing module 201 contributes to a reduction in the sugar concentration in stream 120 by decreasing HCl concentration and/or by decreasing viscosity and/or by increasing temperature.

Exemplary input lignin stream Referring still to Fig. 2, stream 220e serves as an input lignin stream in some exemplary embodiments of the invention. In some exemplary embodiments of the invention, stream 220e is about 36-37% HC1/[HC1 +water]. Alternatively or additionally, in some embodiments of the invention, stream 220e is about 40% lignin on a total weight basis. Alternatively or additionally, stream 220e is about 42% water on a total weight basis. Alternatively or additionally, stream 220e includes at least 50% solid lignin on a dry matter basis and/or comprises includes at least 35% solid lignin on an as is basis and/or includes water and HC1 at an HChwater weight ratio > 0.4 and/or includes an SI solvent at a concentration of at least 100 PPB and/or includes less than 10% water and less than 3% HC1 on an as is basis.

Exemplary method to produce lignosulfonate

Fig. 3 is a simplified flow diagram of a method to produce lignosulfonate according to some exemplary embodiments of the invention indicated generally as method 300.

Depicted exemplary method 300 includes providing 310 a stream comprising at least 50%, 60%, 70% or 80% solid lignin on a dry matter basis and contacting 320 the stream with an SO₂ donating reagent to form lignosulfonate 330 from at least a portion of the lignin provided 310 in the stream. According to various exemplary embodiments of the invention the stream provided at 310 includes at least, 30%, at least 35%, at least 40%, at least 50% or even 60 % or more solid lignin as a percentage of total weight. Alternatively or additionally, in some embodiments, solid lignin accounts for at least 60% of solids in the stream. In some embodiments, solid lignin comprises at least 35%, 40%, 50%, 60%, 70% or 80% of said stream on an as is basis

In some embodiments, the stream provided at 310 includes water and HC1 at a concentration of at least 30% HC1/[HC1 +water] by weight. Alternatively or additionally, in some embodiments the stream includes water and/or an SI solvent. Alternatively or additionally, in some embodiments the stream includes water and HC1 at an HChwater weight ratio > 0.4. Optionally, the stream includes SI solvent at a concentration of at least 100 PPB, optionally at least 500 PPB, optionally at least 1 PPM, optionally at least 10 PPM.

In some exemplary embodiments of the invention, the stream provided at 310 includes solid lignin, less than 10% water and less than 3% HC1. Alternatively or additionally, in various embodiments, the stream includes less than 20%, optionally less than 10%, optionally less than 5%, optionally less than 1% cellulose by weight on a dry matter basis. Alternatively or additionally, in various embodiments, the stream includes cellulose at a cellulose :lignin weight ratio of less than 0.1, optionally less than 0.05, optionally less than 0.025.

In some exemplary embodiments of the invention, providing 310 includes increasing an average MW and/or a degree of cross linking of the lignin in a lignocellulosic feed material (112; Fig. 1), optionally the increasing employs HQ. In some exemplary embodiments of the invention, contacting 320 occurs at a temperature of at least 130 °C, optionally at least 135 °C, optionally at least 140 °C, optionally at least 150 °C. Alternatively or additionally, in some embodiments, contacting 320 occurs at a temperature not exceeding 170 °C, optionally not exceeding 165 °C, optionally not exceeding 160 °C, optionally not exceeding 155 °C. According to various exemplary embodiments of the invention contacting 320 continues for at least 1 ; 1.5 or 2 hours and/or contacting 320 continues not more than 3; 2.5 or 2 hours.

In the depicted exemplary embodiment, method 300 includes separating 340 lignosulfonate 340 from HC1. In some embodiments, the lignosulfonate is in a dissolved form. Optionally, the dissolved form contributes to ease of separation from HC1.

In some embodiments, the stream comprises less than 1%, optionally less than 0.5%, optionally less than 0.1% monomeric sugars.

In some embodiments, method 300 includes increasing 350 the average MW of the lignin prior to contacting 320 with an S02 donating reagent (e.g. a sulfite salt). Optionally, increasing 350 employs 348 HC1 (e.g. as a catalyst). Alternatively or additionally, in some embodiments method 300 includes increasing 360 an average degree of cross-linking among molecules of the solid lignin prior to contacting 320 with S02. Optionally, increasing 360 employs 348 HC1.

Exemplary lignin characteristics

According to various exemplary embodiments of the invention at least 30%, at least 40%, at least 50%, at least 60%, at least 70% or even 80% or more of the solid lignin in the stream has a molecular weight of at least 40 kDa as measured by gel-permeation chromatography. According to various exemplary embodiments of the invention at least 30%, at least 40%, at least 50%, at least 60%, at least 70% or even 80% or more of the solid lignin in the stream has a molecular weight of at least 50 kDa as measured by gel-permeation chromatography.

In some exemplary embodiments of the invention, the stream at 310 stream includes < 1% chloride (CI), optionally less than < 0.5%, optionally less than < 0.1% on a dry matter basis. Alternatively or additionally, in some exemplary embodiments of the invention the stream at 310 is characterized by includes < 0.5%, optionally < 0.25%, optionally < 0.1% ash on a dry matter basis. Alternatively or additionally, in some exemplary embodiments of the stream at 310 is has a sulfur content of less than 70 PPM, optionally less than 50 PPM, optionally less than 25 PPM. Alternatively or additionally, in some exemplary embodiments of the invention the stream at 310 has a soluble carbohydrate content of less than 5%, optionally less than 1.0%., optionally less than 0.5% on a dry matter basis. Alternatively or additionally, in some exemplary embodiments of the stream at 310 has a tall oil content of less than 0.5%, optionally less than 0.5%, optionally less than 0.1 % on a dry matter basis. Alternatively or additionally, according to various exemplary embodiments of the invention at least 30%, at least 40%, at least 50%, at least 60%, at least 70% or even 80% or more of the solid lignin in the stream has a molecular weight of at least 50 kDa as measured by gel-permeation chromatography.

In some exemplary embodiments of the invention, lignin in the stream at 310 comprises less than 0.3%, less than 0.2%, less than 0.1% or even less than 0.05% multivalent ions.

Alternatively or additionally, in some exemplary embodiments of the invention the stream at 310 comprises less than 100 PPM, less than 50 PPM, less than 10 PPM, or even less than 1 PPM Phosphorus (P) on a dry matter basis.

Exemplary lignosulfonate characteristics

According to various exemplary embodiments of the invention at least 30%, at least 40%, at least 50%, at least 60%, at least 70% or even 80% or more of lignosulfonate 330 has a molecular weight of at least 40 kDa as measured by gel-permeation chromatography. Alternatively or additionally, according to various exemplary embodiments of the invention at least 30%, at least 40%, at least 50%, at least 60%, at least 70% or even 80% or more of lignosulfonate 330 has a molecular weight of at least 50 kDa as measured by gel-permeation chromatography.

Alternatively or additionally, in some embodiments lignosulfonate 330 includes at least one sulfonate group per four lignin units. Alternatively or additionally, in some embodiments lignosulfonate 330 includes at least 4% sulfur by weight on a dry matter basis.

Exemplary compositions

Some exemplary embodiments of the invention relate to compositions including lignosulfonate. According to various exemplary embodiments of the invention the lignosulfonate has an average molecular weight at least 10% greater than lignosulfonate prepared from a same lignocellulosic substrate according to previously known sulfite pulping methods and/or an average degree of cross-linking at least 10% greater than lignosulfonate prepared from a same lignocellulosic substrate and/or an SI solvent concentration of at least 100 PPB and/or a covalently bound chloride (CI) content of at least 10 PPB on a dry matter basis and/or at least 10 PPB of a lignin polymer bound to an alcohol of at least 6 carbon atoms by an ether bond. Alternatively or additionally, at least 30% of the lignosulfonate in the composition has a molecular weight of at least 40 kDa as measured by gel-permeation chromatography.

Exemplary lignin compositions

Some exemplary embodiments of the invention relate to a lignin composition including lignin with an average molecular weight of at least 40kDa, or at least 50 kDa as measured by gel- permeation chromatography. According to various exemplary embodiments of the invention lignin in the composition has a covalently bound chloride content of at least 10 PPB on a dry matter basis and/or at least 10 PPB of a lignin polymer bound to an alcohol of at least 6 carbon atoms by an ether bond and/or an SI solvent at a concentration of at least 100 PPB.

Exemplary cement product

Some embodiments of the invention relate to cement products comprising lignosulfonate. In some embodiments, the lignosulfonate in the cement product has an average molecular weight of at least 40 kDa or at least 50 kDa. Alternatively or additionally, in some embodiment the lignosulfonate in the cement product has at least 10 PPB on a dry matter basis of covalently bound chloride and/or at least 10 PPB on a dry matter basis of a lignin polymer bound to an alcohol of at least 6 carbon atoms by an ether bond and/or an SI solvent at a concentration of at least 100 PPB on a dry matter basis.

Exemplary separation methods

Fig. 4 is a simplified flow diagram of a method to separate lignosulfonate from acid according to some exemplary embodiments of the invention indicated generally as 340. The depicted exemplary method illustrates (according to some embodiments) how separation 340 of method 300 may be accomplished.

As depicted in the figure, in some embodiments, separating 340 includes extraction 410 with an extractant comprising an SI solvent. According to various exemplary embodiments of the invention extraction 410 involves liquid-liquid (aqueous-solvent) contact. Alternatively or additionally, in some embodiments separating 340 includes distillation 450. Alternatively or additionally, in some embodiments separating 340 includes chromatographic separation 460. Alternatively or additionally, in some embodiments separating 340 includes ion-exchange 470. In the depicted exemplary embodiment, the result of separation 340 is de-acidified lignosulfonate 430 and/or acid 440 (e.g. HC1).

Alternatively or additionally, in some embodiments separating 340 includes membrane separation 480 (e.g. ultrafiltration).

Exemplary uses of Lignosulfonates

Lignosulfonates produced by methods described herein, or lignosulfonates decribed are useful (for example) in manufacture of products such as cement, asphalt, bitumen, plasticizers, and plasterboards. Oxidation of lignosulfonates can be used to produce vanillin. These products produced from lignosulfonate according to an exemplary embodiment of the invention can optionally be identified by presence of covalently bound chloride on a dry matter basis, and/or lignin polymer bound to an alcohol of at least 6 carbon atoms by an ether bond and/or presence of an SI solvent. The concentration of the marker molecule in the product will decrease as the percentage of lignosulfonate in the final product decreases. Exemplary advantages

Lignosulfonates are currently the largest lignin product not use primarily for combustion. For this reason lignosulfonate has a higher economic value than lignin per se. However, lignosulfonate resulting from connventional sulfite pulping in the paper industry is contaminated with relatively high concentrations of impurities derived from wood . These impurities include, but are not limited to, tall oils, resin acids, sulfur containing compounds and minerals. Purification of conventionally produced lignosulfonate is expensive.

Alternatively or additionally, since production parameters for conventional sulfite pulp are determined primarily by the requirements for cellulose pulp with a desired degree of purity, there is little room for parameter adjustment to improve lignosulfonate features.

In sharp contrast, various exemplary embodiments of the invention produce lignosulfonate with relatively low levels of impurities and/or relatively high molecular weight and/or a relatively high degree of cross-linking.

It is expected that during the life of this patent many chromatography and/or ion exchange resin will be developed and the scope of the invention is intended to include all such new technologies a priori.

As used herein the term "about" refers to ± 10 %.

Although the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims.

Specifically, a variety of numerical indicators have been utilized. It should be understood that these numerical indicators could vary even further based upon a variety of engineering principles, materials, intended use and designs incorporated into the various embodiments of the invention. Additionally, components and/or actions ascribed to exemplary embodiments of the invention and depicted as a single unit may be divided into subunits. Conversely, components and/or actions ascribed to exemplary embodiments of the invention and depicted as sub- units/individual actions may be combined into a single unit/action with the described/depicted function.

Alternatively, or additionally, features used to describe a method can be used to characterize an apparatus and features used to describe an apparatus can be used to characterize a method.

It should be further understood that the individual features described hereinabove can be combined in all possible combinations and sub-combinations to produce additional embodiments of the invention. The examples given above are exemplary in nature and are not intended to limit the scope of the invention which is defined solely by the following claims.

Each recitation of an embodiment of the invention that includes a specific feature, part, component, module or process is an explicit statement that additional embodiments not including the recited feature, part, component, module or process exist.

Specifically, the invention has been described in the context of acid hydrolysis of a substrate but might also be used in the context of other hydrolysis protocols.

All publications, references, patents and patent applications mentioned in this specification are herein incorporated in their entirety by reference into the specification, to the same extent as if each individual publication, patent or patent application was specifically and individually indicated to be incorporated herein by reference. In addition, citation or identification of any reference in this application shall not be construed as an admission that such reference is available as prior art to the present invention.

The terms "include", and "have" and their conjugates as used herein mean "including but not necessarily limited to".

Claims

CLAIMS:

1. A method comprising:

(a) providing a stream comprising at least 50% solid lignin on a dry matter basis; and

(b) contacting the stream with an SO₂ donating reagent to form lignosulfonate from at least a portion of the lignin.

2. A method according to claim 1, wherein said solid lignin comprises at least 35% of said stream on an as is basis.

3. A method according to claim 1, wherein the stream comprises water and HC1 at an HQ: water weight ratio > 0.4.

4. A method according to any of claims 1 to 3, wherein the stream comprises an SI solvent at a concentration of at least 100 PPB on a dry matter basis.

5. A method according to claim 1, wherein the stream comprises less than 10% water and less than 3% HC1 on an as is basis.

6. A method according to any of the preceding claims, wherein the stream comprises less than 20% cellulose by weight on a dry matter basis.

7. A method according to claim 1, wherein the stream comprises cellulose at a cellulose:lignin weight ratio of less than 0.1.

8. A method according to any of the preceding claims, wherein the contacting occurs at a temperature of at least 130 °C.

9. A method according to any of the preceding claims, wherein the contacting occurs at a temperature not exceeding 170 °C.

10. A method according to any of the preceding claims, wherein the contacting continues for at least 1 hour.

11. A method according to any of the preceding claims, wherein the contacting continues not more than 3 hours.

12. A method according to claim 3 or claim 5, wherein the method comprises separating the lignosulfonate from the HC1.

13. A method according to claim 12, wherein the separating comprises extraction with an extractant comprising an SI solvent.

14. A method according to claim 12 or 13, wherein the separating comprises distillation.

15. A method according to any of claims 12 to 14, wherein the separating comprises chromatographic separation.

16. A method according to any of claims 12 to 15, wherein the separating comprises ion- exchange.

17. A method according to any of claims 12 to 16, wherein the separating comprises membrane separation.

18. A method according to any of the preceding claims, wherein the stream comprises less than 1% monomeric sugars on a dry matter basis.

19. A method according to any of the preceding claims, wherein the stream comprises less than 0.3% multivalent ions on a dry matter basis.

20. A method according to any of the preceding claims, wherein the stream comprises < 1 % chloride (CI) on a dry matter basis.

21. A method according to any of the preceding claims, wherein the stream comprises < 0.5% ash on a dry matter basis.

22. A method according to any of the preceding claims, wherein said stream has a sulfur content of less than 70 PPM on a dry matter basis.

23. A method according to any of the preceding claims, wherein said stream comprises less than 5% soluble carbohydrates on a dry matter basis.

24. A method according to any of the preceding claims, wherein said stream comprises less than 0.5% tall oils on a dry matter basis

25. A method according to any of the preceding claims, wherein the stream comprises less than 100 PPM phosphorus on a dry matter basis.

26. A method according to any of the preceding claims, wherein at least 30% of the lignosulfonate has a molecular weight of at least 40 kDa as measured by gel-permeation chromatography.

27. A method according claim 26, wherein at least 30%, of the lignosulfonate has a molecular weight of at least 50 kDa as measured by gel-permeation chromatography.

28. A method according to any of the preceding claims, wherein at least 30% of the solid lignin in the stream has a molecular weight of at least 40 kDa as measured by gel-permeation chromatography.

29. A method according to any of the preceding claims, wherein at least 30% of the solid lignin in the stream has a molecular weight of at least 50 kDa as measured by gel-permeation chromatography.

30. A method according to any of the preceding claims, wherein the lignosulfonates comprise at least one sulfonate group per four lignin units.

31. A method according to any of the preceding claims, wherein the lignosulfonates comprise at least 4% sulfur by weight on a dry matter basis.

32. A method according to any of the preceding claims, wherein providing comprises increasing an average molecular weight of the lignin in a lignocellulosic feed material.

33. A method according to claim 32, wherein the increasing the average MW employs an acid.

34. A method according to any of the preceding claims, wherein providing comprises increasing an average degree of cross-linking of the lignin in a lignocellulosic feed material.

35. A method according to claim 34, wherein the increasing the average degree of cross- linking employs an acid.

36. A composition comprising lignosulfonate, wherein at least 30% of the lignosulfonate has a molecular weight of at least 40 kDa as measured by gel-permeation chromatography.

37. A composition according to claim 36, wherein at least 30%, of the lignosulfonate has a molecular weight of at least 50 kDa as measured by gel-permeation chromatography.

38. A composition comprising: lignosulfonate; and an SI solvent at a concentration of at least 100 PPB on a dry matter basis.

39. A composition comprising: lignosulfonate comprising a covalently bound chloride content of at least 10 PPB on a dry matter basis.

40. A composition comprising: lignosulfonate comprising at least 10 PPB on a dry matter basis of a lignin polymer bound to an alcohol of at least 6 carbon atoms by an ether bond.

41. A composition comprising lignin wherein the lignin has an average molecular weight of at least 40kDa as measured by gel-permeation chromatography.

42. The composition of claim 41 wherein the lignin has an average molecular weight of at least 50 kDA.

43. A composition according to claim 41 or 42 wherein the lignin has at least one of: (i) a covalently bound chloride, wherein the chloride is present in at least 10 PPB on a dry matter basis;

(ii) at least 10 PPB on a dry matter basis of a lignin polymer bound to an alcohol of at least 6 carbon atoms by an ether bond; and

(iii) an SI solvent at a concentration of at least 100 PPB on a dry matter basis.

44. A cement product comprising: lignosulfonate with an average molecular weight of at least 40 kDa.

45. A cement product according to claim 44, wherein the lignosulfonate has an average molecular weight of at least 50 kDa.

46. A cement product according to claim 44 or claim 45, wherein the lignosulfonate has at least one feature selected from the group consisting of:

(i) at least 10 PPB on a dry matter basis of covalently bound chloride;

(ii) at least 10 PPB on a dry matter basis of a lignin polymer bound to an alcohol of at least 6 carbon atoms by an ether bond; and (iii) an SI solvent at a concentration of at least 100 PPB on a dry matter basis.

47. A composition comprising: lignosulfonate characterized by an average molecular weight at least 10% greater than lignosulfonate prepared from a same lignocellulosic substrate according to previously known sulfite pulping methods.

48. A composition comprising: lignosulfonate characterized by an average degree of cross- linking at least 10% greater than lignosulfonate prepared from a same lignocellulosic substrate.