WO2023015325A1 - Système et procédé d'obtention de lignine et d'acide carboxylique à partir de sous-produits de procédés de réduction en pâte - Google Patents
Système et procédé d'obtention de lignine et d'acide carboxylique à partir de sous-produits de procédés de réduction en pâte Download PDFInfo
- Publication number
- WO2023015325A1 WO2023015325A1 PCT/ZA2022/050038 ZA2022050038W WO2023015325A1 WO 2023015325 A1 WO2023015325 A1 WO 2023015325A1 ZA 2022050038 W ZA2022050038 W ZA 2022050038W WO 2023015325 A1 WO2023015325 A1 WO 2023015325A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- lignin
- liquor
- carboxylic acid
- acid
- filtrate
- Prior art date
Links
- 229920005610 lignin Polymers 0.000 title claims abstract description 139
- 238000000034 method Methods 0.000 title claims abstract description 124
- 238000004537 pulping Methods 0.000 title claims abstract description 36
- 239000006227 byproduct Substances 0.000 title claims abstract description 17
- 150000001732 carboxylic acid derivatives Chemical class 0.000 title abstract 4
- 239000000706 filtrate Substances 0.000 claims abstract description 35
- 150000007524 organic acids Chemical class 0.000 claims abstract description 32
- 239000000725 suspension Substances 0.000 claims abstract description 28
- 239000012065 filter cake Substances 0.000 claims abstract description 27
- FEWJPZIEWOKRBE-UHFFFAOYSA-N Tartaric acid Natural products [H+].[H+].[O-]C(=O)C(O)C(O)C([O-])=O FEWJPZIEWOKRBE-UHFFFAOYSA-N 0.000 claims abstract description 13
- 235000002906 tartaric acid Nutrition 0.000 claims abstract description 13
- 239000011975 tartaric acid Substances 0.000 claims abstract description 13
- 239000002245 particle Substances 0.000 claims abstract description 8
- 150000001735 carboxylic acids Chemical class 0.000 claims description 78
- 238000005406 washing Methods 0.000 claims description 29
- 230000020477 pH reduction Effects 0.000 claims description 27
- 238000001914 filtration Methods 0.000 claims description 26
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 21
- 239000002253 acid Substances 0.000 claims description 20
- 238000002425 crystallisation Methods 0.000 claims description 14
- 230000008025 crystallization Effects 0.000 claims description 14
- 238000000605 extraction Methods 0.000 claims description 14
- 239000013078 crystal Substances 0.000 claims description 13
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 13
- 229910001868 water Inorganic materials 0.000 claims description 13
- 238000010438 heat treatment Methods 0.000 claims description 11
- 238000004090 dissolution Methods 0.000 claims description 8
- 238000001556 precipitation Methods 0.000 claims description 8
- 238000001953 recrystallisation Methods 0.000 claims description 7
- 230000015572 biosynthetic process Effects 0.000 claims description 6
- 239000006185 dispersion Substances 0.000 claims description 3
- 239000002655 kraft paper Substances 0.000 abstract description 9
- UIIMBOGNXHQVGW-UHFFFAOYSA-N sodium;hydron;carbonate Chemical compound [Na+].OC(O)=O UIIMBOGNXHQVGW-UHFFFAOYSA-N 0.000 abstract description 9
- 239000000243 solution Substances 0.000 description 28
- 239000000047 product Substances 0.000 description 11
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 9
- 238000000746 purification Methods 0.000 description 7
- 238000011084 recovery Methods 0.000 description 7
- 239000002023 wood Substances 0.000 description 7
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 6
- 239000000126 substance Substances 0.000 description 6
- 230000008901 benefit Effects 0.000 description 5
- 238000001035 drying Methods 0.000 description 5
- 238000004519 manufacturing process Methods 0.000 description 5
- 238000000926 separation method Methods 0.000 description 5
- 229920001131 Pulp (paper) Polymers 0.000 description 4
- 150000001875 compounds Chemical class 0.000 description 4
- 239000011369 resultant mixture Substances 0.000 description 4
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 description 3
- 229920002488 Hemicellulose Polymers 0.000 description 3
- MUBZPKHOEPUJKR-UHFFFAOYSA-N Oxalic acid Chemical compound OC(=O)C(O)=O MUBZPKHOEPUJKR-UHFFFAOYSA-N 0.000 description 3
- 238000007605 air drying Methods 0.000 description 3
- 239000007864 aqueous solution Substances 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 3
- KRKNYBCHXYNGOX-UHFFFAOYSA-N citric acid Chemical compound OC(=O)CC(O)(C(O)=O)CC(O)=O KRKNYBCHXYNGOX-UHFFFAOYSA-N 0.000 description 3
- 238000007796 conventional method Methods 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- WXUAQHNMJWJLTG-UHFFFAOYSA-N 2-methylbutanedioic acid Chemical compound OC(=O)C(C)CC(O)=O WXUAQHNMJWJLTG-UHFFFAOYSA-N 0.000 description 2
- 229920003043 Cellulose fiber Polymers 0.000 description 2
- 230000001112 coagulating effect Effects 0.000 description 2
- 238000010411 cooking Methods 0.000 description 2
- BDAGIHXWWSANSR-UHFFFAOYSA-N methanoic acid Natural products OC=O BDAGIHXWWSANSR-UHFFFAOYSA-N 0.000 description 2
- 235000005985 organic acids Nutrition 0.000 description 2
- 239000000123 paper Substances 0.000 description 2
- 230000001376 precipitating effect Effects 0.000 description 2
- BDERNNFJNOPAEC-UHFFFAOYSA-N propan-1-ol Chemical compound CCCO BDERNNFJNOPAEC-UHFFFAOYSA-N 0.000 description 2
- 239000000376 reactant Substances 0.000 description 2
- GRVFOGOEDUUMBP-UHFFFAOYSA-N sodium sulfide (anhydrous) Chemical compound [Na+].[Na+].[S-2] GRVFOGOEDUUMBP-UHFFFAOYSA-N 0.000 description 2
- 239000010902 straw Substances 0.000 description 2
- KDYFGRWQOYBRFD-UHFFFAOYSA-N succinic acid Chemical compound OC(=O)CCC(O)=O KDYFGRWQOYBRFD-UHFFFAOYSA-N 0.000 description 2
- OSWFIVFLDKOXQC-UHFFFAOYSA-N 4-(3-methoxyphenyl)aniline Chemical compound COC1=CC=CC(C=2C=CC(N)=CC=2)=C1 OSWFIVFLDKOXQC-UHFFFAOYSA-N 0.000 description 1
- 244000025254 Cannabis sativa Species 0.000 description 1
- 235000012766 Cannabis sativa ssp. sativa var. sativa Nutrition 0.000 description 1
- 235000012765 Cannabis sativa ssp. sativa var. spontanea Nutrition 0.000 description 1
- 240000000491 Corchorus aestuans Species 0.000 description 1
- 235000011777 Corchorus aestuans Nutrition 0.000 description 1
- 235000010862 Corchorus capsularis Nutrition 0.000 description 1
- 229920000742 Cotton Polymers 0.000 description 1
- 241000219146 Gossypium Species 0.000 description 1
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 1
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 1
- 239000005864 Sulphur Substances 0.000 description 1
- 235000011054 acetic acid Nutrition 0.000 description 1
- 150000007513 acids Chemical class 0.000 description 1
- PYKYMHQGRFAEBM-UHFFFAOYSA-N anthraquinone Natural products CCC(=O)c1c(O)c2C(=O)C3C(C=CC=C3O)C(=O)c2cc1CC(=O)OC PYKYMHQGRFAEBM-UHFFFAOYSA-N 0.000 description 1
- 150000004056 anthraquinones Chemical class 0.000 description 1
- 235000009120 camo Nutrition 0.000 description 1
- 229920002678 cellulose Polymers 0.000 description 1
- 239000001913 cellulose Substances 0.000 description 1
- 235000005607 chanvre indien Nutrition 0.000 description 1
- 238000001311 chemical methods and process Methods 0.000 description 1
- 235000015165 citric acid Nutrition 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 230000009977 dual effect Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000007717 exclusion Effects 0.000 description 1
- 235000013305 food Nutrition 0.000 description 1
- 235000019253 formic acid Nutrition 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 239000011121 hardwood Substances 0.000 description 1
- 239000011487 hemp Substances 0.000 description 1
- 229910052500 inorganic mineral Inorganic materials 0.000 description 1
- 239000012978 lignocellulosic material Substances 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 239000011707 mineral Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000011368 organic material Substances 0.000 description 1
- 235000006408 oxalic acid Nutrition 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 238000010979 pH adjustment Methods 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 239000002002 slurry Substances 0.000 description 1
- 239000000344 soap Substances 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- 229910052708 sodium Inorganic materials 0.000 description 1
- 229910052979 sodium sulfide Inorganic materials 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000001384 succinic acid Substances 0.000 description 1
- 150000004763 sulfides Chemical class 0.000 description 1
- 230000035899 viability Effects 0.000 description 1
Classifications
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
- D21C11/00—Regeneration of pulp liquors or effluent waste waters
- D21C11/0007—Recovery of by-products, i.e. compounds other than those necessary for pulping, for multiple uses or not otherwise provided for
Definitions
- This invention relates to the production of lignin and carboxylic acids from byproducts of pulping processes used to digest lignin sources such as, but not limited to, wood pulp.
- Pulping processes are used to produce paper pulp by digesting wood or other sources of lignin. Such processes remove lignin, hemicelluloses, and other compounds from the wood to free the cellulose fibres in the wood.
- the Kraft process and the soda pulping process are examples of pulping processes.
- the Kraft process is used to convert wood into wood pulp, which consists of almost pure cellulose fibres, the main component of paper.
- the kraft process entails treatment of wood chips with a hot mixture of water, sodium hydroxide, and sodium sulphide (Na2S), known as white liquor. This treatment breaks the bonds that link lignin, hemicellulose, and cellulose.
- the Kraft process is the dominant method of producing paper.
- Soda pulping is a chemical process for making wood pulp with sodium hydroxide as the cooking chemical.
- the soda process gives pulp with lower tear strength than other chemical pulping processes. It is typically used for easily pulped materials like straw and some hardwoods.
- Black liquor is produced by pulp mills as a byproduct of the Kraft and soda pulping processes. It is typically present in the form of a liquid or slurry.
- Black liquor that is derived from the Kraft process comprises an aqueous solution containing the inorganic chemicals used for cooking, as well as the degraded, dissolved wood substance. This has hundreds of components, including carboxylic acids, lignin residues, dissolved hemicelluloses, and methanol.
- the liquor typically contains around 15% w/w solids, of which 10% are inorganic and 5% are organic.
- the organic constituents in black liquor are 40%-45% soaps, 35%-45% lignin, and 10%— 15% miscellaneous other organic materials.
- Black liquor from the soda pulping process includes residual soda, lignin derivatives, low molecular weight organics, anthraquinone and sulphides.
- lignin extraction includes separation and washing steps.
- lignin is precipitated by acidifying the black liquor, preferably by using CO 2 .
- the resultant lignin suspension is filtered to produce a lignin filter cake, which is then suspended again to form a second lignin suspension.
- the pH of this suspension is reduced to below 8 and it is filtered to form a second lignin filter cake.
- the washing step is then carried out. It involves purifying the second lignin cake by displacement washing in a low pH solution. Acidified wash water, virgin acid, or clean water may be used for this step.
- the filter cake is then dried to a level specified for different uses of the lignin.
- the filtrate remaining after the formation of the second lignin filter cake can be recycled back to suspend the first lignin filter cake and optionally wash it.
- the pH of the filtrate can be adjusted before doing so, to allow control to be exercised over the sodium and sulphur balance in the pulp mill.
- the LignoForceTM process described in US8771464 is another way of separating lignin from black liquor. This process addresses problems of filtration resistance in conventional lignin recovery processes. Filterability is improved by oxidizing the black liquor under controlled conditions before the acidification step.
- the LignoForceTM process uses a filter press instead of a belt filter for lignin cake filtration and washing.
- a method for obtaining lignin and carboxylic acid from a byproduct of a pulping process for digesting a source of lignin comprising the steps of acidifying a spent liquor obtained from the pulping process by adding at least one organic acid to the liquor, thereby to precipitate a lignin component from the liquor yielding a first lignin suspension of precipitated lignin particles in the liquor; filtering the first lignin suspension to separate a first lignin-containing filtrand or filter cake from a first filtrate of the suspension; and extracting the carboxylic acid from the first filtrate.
- the spent liquor may comprise a black liquor from a pulping process.
- the extracted carboxylic acid may comprise tartaric acid; therefore, the method may include extracting tartaric acid from the first filtrate.
- the method may include extracting tartaric acid from the first filtrate.
- a plurality of other types of carboxylic acids may be extracted and recovered using the disclosed method.
- the method may include a step of pre-heating the liquor prior to the acidification step.
- the step of pre-heating the liquor may comprise heating it to a temperature in a range from 30-70 °C.
- the method may include holding or maintaining the liquor at a substantially isothermal temperature while the acidification and precipitation are carried out.
- the isothermal temperature may be > 40 °C.
- the step of extracting the carboxylic acid from the first filtrate may comprise a first crystallization step wherein the carboxylic acid in the first filtrate is subjected to crystal formation.
- the first crystallization step may include lowering the temperature of the first filtrate.
- the carboxylic acid yielded by the first crystallization step may be subjected to an acid purification or washing process involving at least one dissolution and re-crystallization step.
- the method may thus include dissolving the crystallized carboxylic acid in water and re-crystallizing it.
- the crystals may be washed multiple times by dissolution and recrystallization in water, thereby to increase further the purity of the carboxylic acid.
- the step of acidifying the liquor may comprise adjusting its pH level to a pH ⁇ 8.
- the organic acid that is added to the liquor may be provided as a solution having an acid concentration of at least 5% w/v.
- the organic acid may be provided as a solution having an acid concentration > 8% w/v.
- the solution may have an acid concentration of about 10% w/v.
- the organic acid solution may be added to the liquor in a ratio of liquor to solution ranging from about 1 :3 to about 1 :4.5 v/v, i.e. , 3 to 4.5 volume units of the organic acid solution for every one volume unit of the liquor.
- This ratio is variable, however, and can be adjusted depending upon the desired pH level of the resultant mixture of acid and liquor.
- the method may include recovering the first lignin-containing filter cake.
- the method may further include subjecting the first filter cake to a lignin purification or washing process.
- the lignin washing process may comprise one or more steps of dispersing or suspending the first filter cake in water and filtering the resultant dispersion to yield a washed lignin-containing filtrand or filter cake.
- the lignin washing process may include one or more additional washing steps in which the washed lignin-containing filter cake is further washed with alcohol.
- the alcohol used for the lignin washing step may be added by way of an alcohol solution.
- the alcohol solution may be a dilute aqueous solution. It may have an alcohol concentration of 10%-50% v/v inclusive.
- the alcohol may be selected from the group consisting of methanol, ethanol, propanol, and mixtures thereof.
- the lignin washing process may yield a final lignin cake.
- the final lignin cake may be dried in a drying step before the lignin is stored.
- the drying step may comprise air-drying the lignin.
- the pulping process from which the spent liquor is derived may be selected from the group consisting of a Kraft process, a soda pulping process, and a mild alkaline process.
- the source of the lignin may be selected from the group consisting of pulp wood, straw, jute, hemp, and cotton.
- a system for obtaining lignin and carboxylic acid from a byproduct of a pulping process for digesting a source of lignin comprising a source of spent liquor from the pulping process; an acidification component configured to acidify the liquor by adding at least one organic acid to the liquor, thereby to precipitate a lignin component from the liquor yielding a first lignin suspension of precipitated lignin particles in the liquor; a filtration component configured to filter the first lignin suspension to separate a first lignin-containing filtrand or filter cake from a first filtrate of the suspension; and a carboxylic acid extraction component configured to extract the carboxylic acid from the first filtrate of the liquor.
- the spent liquor may comprise a black liquor from a pulping process.
- the carboxylic acid may comprise tartaric acid.
- the system may further include a heating component configured to pre-heat the liquor and to maintain the liquor at a substantially isothermal temperature while the liquor undergoes acidification and precipitation.
- the heating component may be configured to pre-heat the liquor to a temperature in a range from 30-70 °C. It may be configured to maintain the liquor at an isothermal temperature > 40 °C during acidification thereof by the acidification component.
- the carboxylic acid extraction component may be configured to perform a first crystallization step wherein the carboxylic acid in the first filtrate is subjected to crystal formation, thereby to yield crystals of the carboxylic acid.
- the system may further include a carboxylic acid purification or washing component configured to purify or wash the resultant carboxylic acid crystals by dissolution and re-crystallization.
- the acidification component may be configured to perform a pH adjustment operation whereby the pH level of the liquor is adjusted to a pH ⁇ 8.
- the acidification component may be configured to add the organic acid to the liquor as a solution having an acid concentration of at least 5% w/v.
- the acidification component may be configured to add the organic acid to the liquor as a solution having an acid concentration > 8% w/v, for example, about 10% w/v.
- the acidification component may be configured to add the organic acid solution to the liquor in a ratio of liquor to solution ranging from about 1 :3 to about 1 :4.5 v/v, i.e. , 3 to 4.5 volume units of the organic acid solution for every one volume unit of the liquor. This ratio is variable, however, and can be adjusted depending upon the desired pH level of the resultant mixture of acid and liquor.
- the system may include additional components configured to perform ancillary steps of the method of the invention as detailed above.
- the system may include recovery means for recovering the final carboxylic acid and lignin products of the system for downstream use or processing, or for chemical reactions.
- the pulping process and the source of the lignin may be as described above.
- the present invention extends to carboxylic acid obtained by the disclosed method, including but not limited to tartaric acid.
- the invention also extends to the use of a carboxylic acid obtained by the disclosed method as a reactant in a downstream chemical reaction.
- the present invention extends, further, to lignin or an intermediate lignin product obtained by the disclosed method.
- the invention extends further to the use of lignin or an intermediate lignin product obtained by the disclosed method to produce heat or as a reactant in a downstream chemical reaction.
- Figure 1 is a schematic process flow diagram illustrating an exemplary mode of performing the disclosed method for obtaining lignin and carboxylic acid from a black liquor byproduct of a pulping process.
- the byproduct may be a spent liquor such as black liquor.
- the pulping process may be selected from the group consisting of a Kraft process, a soda pulping process, and a mild alkaline process.
- the disclosed method may facilitate dual separation and extraction of the lignin and carboxylic acid using a bifurcated processing stream. Recovery of the two products by separation and extraction may accordingly be carried out simultaneously and concurrently, as opposed to consecutively as in conventional methods of obtaining carboxylic acid from lignin sources. Additionally, the carboxylic acid may be extracted at a lower temperature than is typically used in conventional processes to obtain carboxylic acid from lignin sources.
- the method addresses a need, previously unmet, for methods which are less complex, and which have lower energy demands than other methods of producing lignin and carboxylic acid from byproducts of pulp processing.
- carboxylic acids in black liquor the inventor has identified tartaric acid as a viable compound for extraction.
- succinic acid and methylsuccinic acid have been identified in black liquor.
- Tartaric acid has not, however, been identified or targeted for recovery by extraction.
- reference numeral 100 indicates, generally, an exemplary process for carrying out the disclosed method for recovering lignin and carboxylic acid from a spent liquor such as black liquor.
- the method (100) may include preheating (101) the black liquor.
- the liquor may be preheated to a temperature in a range from 30-70 °C.
- the lignin may be precipitated (103) while the liquor is maintained at a substantially isothermal temperature. This temperature may be > 40 °C. The period for which the liquor is maintained at the substantially isothermal temperature may range from 40-80 minutes.
- the precipitation step may involve acidifying the liquor by adding at least one organic acid to it. This step may be carried out while the liquor is maintained at the substantially isothermal temperature referred to above.
- the acidification step may comprise adjusting the pH level of the liquor to a pH ⁇ 8.
- the organic acid used for the acidification step may be selected from the group consisting of citric acid, oxalic acid, formic acid, acetic acid, and combinations thereof. Instead, or in addition, it may comprise any other type of organic acid capable of precipitating at least one type of lignin.
- the organic acid may be provided as a solution having an acid concentration of at least 5% w/v, and in some cases > 8% w/v. For example, the solution may have an acid concentration of 10% w/v.
- the organic acid solution may be added to the black liquor in a ratio of liquor to solution ranging from about 1 :3 to about 1 :4.5 v/v, i.e. , 3 to 4.5 volume units of the organic acid solution for every one volume unit of the liquor.
- This ratio is variable, however, and can be adjusted depending upon the desired pH level of the resultant mixture of acid and liquor.
- the addition of the organic acid to the liquor may be performed in a gradual, continuous, or stepwise manner.
- the acidification step causes a lignin component to be precipitated from the liquor, yielding a first lignin suspension of precipitated lignin particles in the liquor.
- This suspension may also be referred to as a lignin precipitation solution.
- the step of precipitating the lignin component may include coagulating the precipitated lignin particles to promote their subsequent filtration.
- the coagulating step may include a secondary heating step wherein the first lignin suspension is heated to a temperature ⁇ 100 °C.
- the first lignin suspension may then be filtered in a first filtration step (105 / Filtration 1), producing a first lignin-containing filtrand and a first filtrate which may contain the carboxylic acid.
- the step of filtering the lignin suspension may be performed using a high pressure filter press.
- the filtrand may be obtained as a lignin filter cake.
- the process (100) then bifurcates into two separate and concurrent sub-processes (107; 109). These two sub-processes relate, respectively, to the extraction, filtration and washing of the carboxylic acid on the one hand; and to the separation, purification, and recovery of the lignin on the other hand.
- carboxylic acids may be extracted from the first filtrate of the black liquor. It will be appreciated that a plurality of different types of carboxylic acids may be recovered using the disclosed method. As mentioned, the disclosed method may be used for extracting tartaric acid, provided the liquor that is being processed contains that acid. Exemplary modes of performing the disclosed method may yield 25-35 g of tartaric acid for every 10 g of organic acid used for precipitation of the lignin.
- the step of extracting the carboxylic acid from the first filtrate may comprise a first carboxylic acid crystallization step (111) wherein the carboxylic acid in the first filtrate is subjected to crystal formation by dissolution and crystallization, typically carried out following the addition of water to the filtrate.
- the first crystallization step may involve lowering the temperature of the first filtrate.
- Raw carboxylic acid crystals produced by the first crystallization step may be filtered in a first carboxylic acid filtration step (113 / Filtration 4) to yield a carboxylic acid filtrand.
- the carboxylic acid filtrand yielded by the first crystallization step may be subjected to at least one purification or washing process (115) involving further dissolution and re-crystallization.
- the method may thus include dissolving the filtrand of the raw crystallized carboxylic acid in water and recrystallizing it.
- the resultant crystals may be washed multiple further times by dissolution and recrystallization in water, thereby progressively increasing the purity of the carboxylic acid product.
- the washed crystals from the washing step (115) may be filtered out (117 / Filtration 5) and recovered.
- the filtrates from the carboxylic acid filtration steps (113; 117) may serve as a feedstock for further processing downstream (119), to yield other products that are not discussed herein.
- the raw lignin filtered out of the black liquor may be washed or purified.
- a first lignin-washing step (121) the first lignin-containing filtrand or filter cake obtained from the first filtration (105) may be re-dispersed or re-suspended in water. Subsequent washing may be carried out in alcohol, as discussed further below.
- the suspension of lignin in water may be filtered (123 / Filtration 2) to yield a water-washed lignin filtrand. This may then be subjected to a further washing step (125), this time using alcohol.
- the alcohol used for this washing step may be provided as a dilute aqueous solution of alcohol.
- the alcohol solution may have a concentration in a range from 10%-50% v/v.
- the alcohol used for the washing may be selected from the group consisting of methanol, ethanol, propanol, and mixtures thereof.
- a further filtration step (127 / Filtration 3) may be used to separate out the alcohol-washed lignin, producing a final lignin filter cake (129) and a final filtrate.
- the final filtrate may be joined with the filtrate from the first filtration step (105) and the filtrate from the downstream lignin filtration step (123) and may be added to the first carboxylic acid crystallization step (111 ).
- purification of the lignin may include further alcohol washing processes (not shown), each using a fresh volume of aqueous alcohol solution.
- the method may include a drying step (not shown) for drying the lignin of the final lignin cake (129) before recovering it and storing it as a dried lignin product.
- the drying step may comprise air-drying the lignin.
- the air-drying may be performed at ambient atmospheric conditions.
- a system for separating lignin and extracting carboxylic acid from a byproduct of a pulping processes is also disclosed.
- the byproduct may comprise spent liquor from the pulping process concerned.
- the spent liquor may be a black liquor derived from one of the types of pulping processes listed previously.
- the system may include a heating component configured to pre-heat the liquor and to maintain the liquor at a substantially isothermal temperature.
- the heating component may be configured to pre-heat the liquor to a temperature in a range from 30-70 °C. It may be configured to maintain the liquor at an isothermal temperature > 40 °C.
- the system may include an acidification component configured to acidify the liquor by adding at least one organic acid thereto. It may be configured to do so while the liquor is held at the substantially isothermal temperature by the heating component.
- the acidification component may be configured to adjust the pH level of the liquor to a pH ⁇ 8.
- the acidification component may be configured to add the organic acid to the liquor as a solution having an acid concentration of at least 5% w/v.
- the acidification component may be configured to add the organic acid to the liquor as a solution having an acid concentration > 8% w/v, for example, about 10% w/v.
- the acidification component may be configured to add the organic acid solution to the black liquor in a ratio of liquor to solution ranging from about 1 :3 to about 1 :4.5 v/v, i.e., 3 to 4.5 volume units of the organic acid solution for every one volume unit of the liquor. This ratio is variable, however, and can be adjusted depending upon the desired pH level of the resultant mixture of acid and liquor.
- the organic acid may be selected from the group of organic acids described above,
- acidification carried out by the acidification component may precipitate a lignin component from the liquor yielding a first lignin suspension of precipitated lignin particles in the liquor.
- This suspension may also be referred to as a lignin precipitation solution.
- the system may further include a filtration component for filtering the first lignin suspension to separate a first lignin-containing filtrand or filter cake from a first filtrate of the suspension.
- the system may further include a carboxylic acid extraction component configured to extract the carboxylic acid from the first filtrate of the liquor.
- the carboxylic acid extraction component may be configured to perform a first crystallization step wherein the carboxylic acid in the first filtrate is subjected to crystal formation, thereby to yield crystals of the carboxylic acid.
- the system may further include a carboxylic acid purification or washing component configured to purify or wash the resultant carboxylic acid crystals by dissolution and re-crystallization.
- the system may further include a lignin washing component.
- This component may be configured to perform the steps of sub-process (109) set out above.
- Feed means may be provided for feeding the black liquor to the system for processing.
- the system may include additional components configured to perform ancillary steps of the method of the invention as detailed above.
- the carboxylic acid extracted by the process may comprise tartaric acid.
- the system may include recovery means for recovering the final carboxylic acid and lignin products of the system for downstream use.
- the disclosed method and system may have several benefits. They may permit lignin and carboxylic acid to be separated or extracted simultaneously from black liquor. Lignin and carboxylic acid may be obtained without the need to depolymerize the lignin to produce the carboxylic acids, which has been the process used in previous technologies used for production of carboxylic acids from lignin sources. This is an important advantage of the presently disclosed method since it facilitates extraction of the lignin in an ongoing single process, which has benefits for scaling the method up to industrial levels of production.
- the disclosed method may also permit carboxylic acid recovery to be carried out at relatively low temperatures, which in turn provides advantages of energy savings and relative simplicity.
- the disclosed method involves the use of organic acids as opposed to potentially harmful and corrosive mineral acids.
- the disclosed method also addresses a need for practical methods of extracting high-value products such as tartaric acid from lignocellulosic material on an industrial scale. Biorefinery viability is promoted since the extraction of carboxylic acids as by-products provides a valueadding proposition to increase production profitability.
- the disclosed method gives at least two valuable products from a single concurrent process, whereas in the past, as mentioned, lignin has been required as an intermediate towards producing carboxylic acids.
- the method and system are adapted to produce lignin having good levels of purity because of the step of washing the lignin with dilute alcohol.
- the extracted lignin may be used in the production of fuels, materials, and chemicals, and the extracted carboxylic acid may be used in the food and chemical industries, amongst others.
Landscapes
- Paper (AREA)
Abstract
L'invention concerne un système et un procédé d'obtention de lignine et d'acide carboxylique à partir d'un sous-produit d'un procédé de réduction en pâte pour digérer une source de lignine, telle que le procédé Kraft ou le procédé de réduction en pâte à la soude. Une liqueur résiduaire obtenue à partir du procédé de réduction en pâte est acidifiée par ajout d'au moins un acide organique à la liqueur, ce qui permet de précipiter un composant de lignine à partir de la liqueur et d'obtenir une suspension de particules de lignine précipitée dans la liqueur. Cette suspension est filtrée pour séparer un gâteau de filtration contenant de la lignine d'un premier filtrat de la suspension, et l'acide carboxylique est extrait du premier filtrat. L'acide carboxylique peut, par exemple, comprendre de l'acide tartrique.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
ZA202105810 | 2021-08-06 | ||
ZA2021/05810 | 2021-08-06 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2023015325A1 true WO2023015325A1 (fr) | 2023-02-09 |
Family
ID=82898945
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/ZA2022/050038 WO2023015325A1 (fr) | 2021-08-06 | 2022-08-05 | Système et procédé d'obtention de lignine et d'acide carboxylique à partir de sous-produits de procédés de réduction en pâte |
Country Status (1)
Country | Link |
---|---|
WO (1) | WO2023015325A1 (fr) |
Citations (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2006031175A1 (fr) | 2004-09-14 | 2006-03-23 | Lignoboost Ab | Methode pour separer de la lignine de liqueur residuaire |
US20100325947A1 (en) | 2008-02-21 | 2010-12-30 | Lignoboost Ab | Method for separating lignin from black liquor, a lignin product, and use of a lignin product for the production of fuels or materials |
US20110297340A1 (en) * | 2010-06-03 | 2011-12-08 | Fpinnovations | Method for separating lignin from black liquor |
WO2012161865A1 (fr) * | 2011-05-24 | 2012-11-29 | Liquid Lignin Company, Llc | Procédé de traitement de lignine |
US20150233057A1 (en) * | 2014-02-18 | 2015-08-20 | Api Intellectual Property Holdings, Llc | Lignin-coated cellulose fibers from lignocellulosic biomass |
US20160177040A1 (en) * | 2014-12-22 | 2016-06-23 | Innventia Ab | Method of producing lignin with reduced amount of odorous substances |
WO2017181280A1 (fr) * | 2016-04-20 | 2017-10-26 | Fpinnovations | Récupération de lignine et production de furfural à partir de flux de préhydrolysat de biomasse |
WO2017222455A1 (fr) * | 2016-06-22 | 2017-12-28 | Valmet Ab | Procédé de production de lignine à substances odorantes en quantité réduite |
WO2018115592A1 (fr) * | 2016-12-21 | 2018-06-28 | Teknologian Tutkimuskeskus Vtt Oy | Procédé de production de lignine réactive |
WO2020243805A1 (fr) * | 2019-06-03 | 2020-12-10 | Suzano S.A. | Procédés d'extraction de lignine de liqueur noire |
-
2022
- 2022-08-05 WO PCT/ZA2022/050038 patent/WO2023015325A1/fr unknown
Patent Citations (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2006031175A1 (fr) | 2004-09-14 | 2006-03-23 | Lignoboost Ab | Methode pour separer de la lignine de liqueur residuaire |
US20100325947A1 (en) | 2008-02-21 | 2010-12-30 | Lignoboost Ab | Method for separating lignin from black liquor, a lignin product, and use of a lignin product for the production of fuels or materials |
US20110297340A1 (en) * | 2010-06-03 | 2011-12-08 | Fpinnovations | Method for separating lignin from black liquor |
US8771464B2 (en) | 2010-06-03 | 2014-07-08 | Fpinnovations | Method for separating lignin from black liquor |
WO2012161865A1 (fr) * | 2011-05-24 | 2012-11-29 | Liquid Lignin Company, Llc | Procédé de traitement de lignine |
US20150233057A1 (en) * | 2014-02-18 | 2015-08-20 | Api Intellectual Property Holdings, Llc | Lignin-coated cellulose fibers from lignocellulosic biomass |
US20160177040A1 (en) * | 2014-12-22 | 2016-06-23 | Innventia Ab | Method of producing lignin with reduced amount of odorous substances |
WO2017181280A1 (fr) * | 2016-04-20 | 2017-10-26 | Fpinnovations | Récupération de lignine et production de furfural à partir de flux de préhydrolysat de biomasse |
WO2017222455A1 (fr) * | 2016-06-22 | 2017-12-28 | Valmet Ab | Procédé de production de lignine à substances odorantes en quantité réduite |
WO2018115592A1 (fr) * | 2016-12-21 | 2018-06-28 | Teknologian Tutkimuskeskus Vtt Oy | Procédé de production de lignine réactive |
WO2020243805A1 (fr) * | 2019-06-03 | 2020-12-10 | Suzano S.A. | Procédés d'extraction de lignine de liqueur noire |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
RU2642787C2 (ru) | Способ и система для обработки лигнина | |
EP2254913B1 (fr) | Procédé pour le prétraitement de lignocellulose à l'aide d'un solvant pour super-cellulose et de solvants très volatils | |
US20160130752A1 (en) | Method for the treatment of spent pulping liquor for the removal and production of a lignin containing product | |
CA2804186A1 (fr) | Procede de production de lignine precipitee a partir de liqueur noire et lignine precipitee ainsi produite | |
WO2009104995A1 (fr) | Procédé pour séparer la lignine de la liqueur noire, produit de lignine, et utilisation d'un produit de lignine pour la production de combustibles ou de matériaux | |
WO2017102814A1 (fr) | Procédé de décomposition et de carbonisation hydrothermale de boues de curage | |
CN109810232B (zh) | 一种生物质造纸及综合利用的方法 | |
EP3445754B1 (fr) | Récupération de lignine et production de furfural à partir de flux de préhydrolysat de biomasse | |
KR20220138012A (ko) | 개질된 황산 및 그 용도 | |
CN103608514A (zh) | 回收化学品的方法 | |
EP2928856B1 (fr) | Procédé pour la production d'acide lévulinique et d'acide formique à partir de biomasse | |
CA2997566C (fr) | Procede pour l'extraction de la silice | |
JP2002504489A (ja) | トール油ピッチからフィトステロールを調製するための方法 | |
WO2023015325A1 (fr) | Système et procédé d'obtention de lignine et d'acide carboxylique à partir de sous-produits de procédés de réduction en pâte | |
CN114364841B (zh) | 从黑液提取木质素的工艺 | |
CN109970543B (zh) | 阿昔洛韦缩合副产物与溶剂回收利用的方法 | |
CN108474174B (zh) | 生产生物产品的方法 | |
EP3510195B1 (fr) | Procédé et système de traitement d'effluent de papeterie usagé | |
EP3333310B1 (fr) | Procédé et système de traitement de biomasse | |
EP3126569B1 (fr) | Procédé de traitemetn d'une solution de lavage usée d'un processus de récupération de lignine | |
CA3063821A1 (fr) | Conversion catalytique de lignine | |
Jahan et al. | Dissolving pulp from white press cuttings | |
CN103266518B (zh) | 一种降低黑液中硅含量的方法 | |
CN112939764A (zh) | 一种2-羟基-3-萘甲酸的生产工艺 | |
US1358129A (en) | Treatment of wood and recovery of organic products therefrom |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 22754754 Country of ref document: EP Kind code of ref document: A1 |
|
NENP | Non-entry into the national phase |
Ref country code: DE |