JP2009022180A - Method for producing sugar solution from cellulosic biomass - Google Patents
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本発明は、セルロース系バイオマスを原料として酸糖化処理を行うことによって酸糖化処理液を製造する方法と、該糖化処理液から効率よく糖液と酸を回収する方法に関する The present invention relates to a method for producing an acid saccharification treatment liquid by performing an acid saccharification treatment using cellulosic biomass as a raw material, and a method for efficiently recovering a sugar solution and an acid from the saccharification treatment solution.
地球温暖化対策で、二酸化炭素排出量の削減目標を定めた京都議定書が批准され、日本は二酸化炭素排出量を１９９０年比で６％削減しなければならない。二酸化炭素排出削減には、化石燃料エネルギーを使用するのではなく、バイオマスをエネルギーに転換することによって得られるバイオマスエネルギーを利用することが有効である。バイオマス転換の方法としては、多数の著書（非特許文献１〜４）に示されているように、バイオマスを熱分解、ガス化、嫌気性発酵などによって炭化水素化、糖化、アルコール生成する等、多くの技術開発がなされてきている。 As a measure against global warming, the Kyoto Protocol, which has set targets for reducing carbon dioxide emissions, has been ratified, and Japan must reduce carbon dioxide emissions by 6% compared to 1990 levels. In order to reduce carbon dioxide emissions, it is effective to use biomass energy obtained by converting biomass into energy instead of using fossil fuel energy. As a method of biomass conversion, as shown in many books (Non-Patent Documents 1 to 4), biomass is hydrolyzed, gasified, anaerobically fermented, etc. Many technological developments have been made.
その中でも、バイオマスに含まれる糖質を発酵することによりエタノールを得る方法が特に広く研究されている。エタノールは、液体燃料、特に輸送用燃料として利用することが可能であり、既にアメリカやブラジルではトウモロコシやサトウキビから得られるデンプンや砂糖を原料としてバイオエタノールを製造するプロセスが実用化されている。 Among them, a method for obtaining ethanol by fermenting carbohydrates contained in biomass has been particularly extensively studied. Ethanol can be used as a liquid fuel, particularly as a transportation fuel. In the United States and Brazil, a process for producing bioethanol from starch and sugar obtained from corn and sugarcane has already been put into practical use.
このような背景下に、日本でもバイオアルコールビジネスは動き出しており、２００６年から３％アルコールを添加したガソリンの販売が開始されるが、２０００年実績のガソリン使用量で換算した場合、全てのガソリンに添加すれば約１８０万キロリットルのアルコール需要が見込まれる。しかし、トウモロコシ、芋、ムギ、コメ、サトウキビなど穀物アルコールの生産コストに占める原料コストの割合は４０〜７０％を占め、かつ原料が食料として競合する問題が指摘されている。この為、これ以上の大量かつ安価なエタノール生産原料としては、食料として競合しないセルロース系バイオマスしかないと考えられている。 Against this backdrop, the bioalcohol business has begun to move in Japan, and sales of gasoline with 3% alcohol added will start in 2006. However, when converted to gasoline consumption in 2000, all gasoline Alcohol demand of about 1.8 million kiloliters is expected. However, the ratio of the raw material cost to the production cost of cereal alcohol such as corn, straw, wheat, rice and sugarcane accounts for 40 to 70%, and the problem that the raw material competes as food is pointed out. For this reason, it is thought that there is only cellulosic biomass which does not compete as food as a raw material for producing ethanol in large quantities and at a lower price.
セルロース系バイオマスとしては、サトウキビバガス、稲ワラ、トウモロコシ茎葉などの草本系バイオマスと、建築廃材、林地残材、間伐材などの木質系バイオマスに大別される。セルロース系バイオマス変換の共通点として、これらの材料を可溶化し、糖を抽出した後に、その糖を利用してアルコール発酵を行う必要がある。 Cellulosic biomass is broadly classified into herbaceous biomass such as sugar cane bagasse, rice straw, and corn stover, and woody biomass such as construction waste, forest land and thinned wood. As a common point of cellulosic biomass conversion, it is necessary to solubilize these materials and extract sugar, and then perform alcoholic fermentation using the sugar.
植物に由来するセルロース系バイオマスは、セルロース、ヘミセルロース及びリグニンの三種の主成分から成り立っている。セルロースはβ１−４結合をしたＤ−グルコースの重合体であり、結晶領域と非結晶領域で構成されている。その他の構成多糖がヘミセルロースで、キシロース、アラビノース、マンノース等の種々の単糖で構成されている。但し、リグニンはフェニルプロパンを基本単位とする芳香族性高分子で、セルロースやヘミセルロースなどの糖組成物とは構造が異なる。 Cellulosic biomass derived from plants consists of three main components: cellulose, hemicellulose, and lignin. Cellulose is a polymer of D-glucose having β1-4 bonds, and is composed of a crystalline region and an amorphous region. Another constituent polysaccharide is hemicellulose, which is composed of various monosaccharides such as xylose, arabinose and mannose. However, lignin is an aromatic polymer having phenylpropane as a basic unit and has a structure different from that of sugar compositions such as cellulose and hemicellulose.
セルロース系バイオマスから糖を抽出するためには、植物体内に高分子で存在しているセルロースとヘミセルロースを可溶化すると同時にグルコースなどの単糖類に分解する糖化工程が必要となってくる。糖化方法としては、セルラーゼやキシラナーゼなどの多糖分解酵素による酵素糖化と、硫酸や塩酸などによる酸加水分解による酸糖化が提案されている。 In order to extract sugar from cellulosic biomass, a saccharification step is required to solubilize cellulose and hemicellulose that are present in macromolecules in the plant body and at the same time decompose into monosaccharides such as glucose. As saccharification methods, enzymatic saccharification with polysaccharide degrading enzymes such as cellulase and xylanase and acid saccharification by acid hydrolysis with sulfuric acid or hydrochloric acid have been proposed.
このうち酵素糖化法では、酵素反応が円滑に行われるために基質であるセルロースやヘミセルロースを覆っているリグニンを取り除く必要がある。また、巨大な酵素分子が基質に接触するための空隙が必要であることから、微粉化処理、水熱処理、超音波処理など物理的、化学的な様々な前処理が必要であることが指摘されている。これらの前処理としては、現時点において、経済的、エネルギー収支的に有効な方法は提案されておらず、さらに、酵素生産の場合はコスト的な問題もあり、実用化の障壁となっている。 Among them, in the enzymatic saccharification method, it is necessary to remove lignin covering the cellulose and hemicellulose which are substrates in order to carry out the enzymatic reaction smoothly. In addition, it is pointed out that various physical and chemical pretreatments such as pulverization, hydrothermal treatment, and ultrasonic treatment are necessary because of the need for voids for large enzyme molecules to contact the substrate. ing. At present, no effective method for economical and energy balance has been proposed for these pretreatments. Furthermore, in the case of enzyme production, there is a problem of cost, which is a barrier to practical use.
一方、酸加水分解による酸糖化法としては、主成分であるセルロース、ヘミセルロースなどの多糖を硫酸や塩酸などの酸による加水分解によって単糖に低分子化することにより可溶化し、芳香族高分子物質であるリグニンと分離する方法が古くから取り組まれてきている。酸糖化法は、酵素糖化法と比べても薬品費が安価であり、反応速度も速いことが特徴であるといえる。 On the other hand, as the acid saccharification method by acid hydrolysis, polysaccharides such as cellulose and hemicellulose, which are main components, are solubilized by lowering them to monosaccharides by hydrolysis with acids such as sulfuric acid and hydrochloric acid, and aromatic polymers. The method of separating from the substance lignin has been addressed for a long time. It can be said that the acid saccharification method is characterized by a low chemical cost and a high reaction rate as compared with the enzymatic saccharification method.
これまでに提案されてきた酸糖化法は、触媒として用いる酸の濃度によって希酸法と濃酸法に大別される。希酸法は数％程度の硫酸を用いて高温高圧条件下で行なうことにより糖化を目指す方法で、濃酸法は７０％程度の硫酸もしくは４０％程度の塩酸を用いる方法である。希酸法では、糖の収率が低いことが課題であるが、濃硫酸を用いた加水分解では糖の収率が高いことも特徴であるといえる。 The acid saccharification methods proposed so far are roughly classified into a dilute acid method and a concentrated acid method depending on the concentration of the acid used as a catalyst. The dilute acid method is a method aiming at saccharification by using about several percent sulfuric acid under high temperature and high pressure conditions, and the concentrated acid method is a method using about 70% sulfuric acid or about 40% hydrochloric acid. In the dilute acid method, the problem is that the yield of sugar is low, but hydrolysis using concentrated sulfuric acid is also characterized by a high yield of sugar.
以上に挙げたバイオマスの酸加水分解による酸糖化法の実用化に向けて、様々な方法が検討されているが、それらに共通する問題として、可溶化した処理液中に含まれる糖と硫酸の分離・回収及び再利用が困難であることがコスト面及び環境面での課題であると考えられてきた。特に、得られた糖をアルコール発酵させて、燃料あるいは工業原料とする要請に対処するためには、処理液のｐＨを酵素が働けるｐＨにする必要があり、現在知られている優れた耐塩性酵母を用いるとしても、ｐＨを１．５以上にする必要がため、酸により糖化された酸・糖混合液を中和するか、酸を効率的に除去する必要がある。このような中和または除去の方法としては、これまでに以下のような技術が提案されている。 Various methods have been studied for practical application of the acid hydrolysis method by acid hydrolysis of biomass as mentioned above. However, as a common problem, sugar and sulfuric acid contained in the solubilized processing solution The difficulty in separation / recovery and reuse has been considered to be a problem in terms of cost and environment. In particular, in order to cope with the demand for using the obtained sugar as a fuel or an industrial raw material by alcoholic fermentation, it is necessary to set the pH of the treatment liquid to a pH at which the enzyme can work, and the excellent salt resistance currently known. Even if yeast is used, the pH needs to be 1.5 or higher, so it is necessary to neutralize the acid / sugar mixed solution saccharified with the acid or to efficiently remove the acid. As such a neutralization or removal method, the following techniques have been proposed so far.
（１）酸糖化液に対して消石灰（Ｃａ（ＯＨ）２）を添加して使用した硫酸を中和処理し、生成した石膏を固液分離することで糖化液から硫酸を除去する方法（特許文献１）。 (1) A method of removing sulfuric acid from a saccharified solution by neutralizing the sulfuric acid used by adding slaked lime (Ca (OH) 2 ) to the acid saccharified solution, and separating the produced gypsum into solid and liquid (patent) Reference 1).
（２）酸糖化液をイオン交換樹脂に流し、水を溶離水として糖と硫酸の溶出時間の差を用いて分離する方法。硫酸は回収・濃縮後に再利用される（特許文献２）。 (2) A method in which an acid saccharified solution is poured into an ion exchange resin, and water is used as an elution water to separate the saccharified solution using a difference in elution time between sugar and sulfuric acid. Sulfuric acid is reused after recovery and concentration (Patent Document 2).
（３）酸糖化液中の糖を強酸性カチオン交換樹脂上に吸着させ、硫酸溶出後に糖を回収することで、糖と硫酸を分離する方法。糖化液はさらに消石灰で中和処理され、硫酸は回収・濃縮後に再利用される（特許文献３）。 (3) A method of separating sugar and sulfuric acid by adsorbing sugar in an acid saccharified solution onto a strongly acidic cation exchange resin and recovering the sugar after elution with sulfuric acid. The saccharified solution is further neutralized with slaked lime, and sulfuric acid is reused after recovery and concentration (Patent Document 3).
（４）硫酸とグルコースの混合液を陰イオン交換膜により拡散透析する方法において、イオン交換膜の含水量を特定の範囲とすることにより酸回収率を向上せしめる方法（特許文献４）。 (4) A method of improving the acid recovery rate by setting the water content of the ion exchange membrane within a specific range in a method of diffusive dialysis of a mixed solution of sulfuric acid and glucose with an anion exchange membrane (Patent Document 4).
これらの方法中、（１）や（３）の方法では、大量の石膏が排出されるため、石膏の利用方法、もしくはその処理に多大なコストが必要であり、排水処理においても環境面に多大な負荷がかかることが課題となっている。また、（２）の方法では、回収された硫酸は大幅に希釈されており、再利用するには濃縮に大きなエネルギー及びコストが必要となる。さらに、（４）の方法は、硫酸の除去量が少なく、その後の酵素によるアルコール発酵のために多大な中和処理が必要となる。 Of these methods, the methods (1) and (3) require a large amount of gypsum to be discharged, which requires a large amount of cost for using or treating the gypsum. The problem is that a heavy load is applied. Further, in the method (2), the recovered sulfuric acid is greatly diluted, and in order to reuse it, large energy and cost are required for concentration. Furthermore, in the method (4), the removal amount of sulfuric acid is small, and a great amount of neutralization treatment is required for the subsequent alcoholic fermentation by the enzyme.
本発明は、固形バイオマスの酸加水分解による酸糖化法で、コスト面及び環境面で課題となっている酸回収において、イオン交換膜を用いて酸の回収及び再利用を可能とし、プロセス全体のエネルギーコスト及び環境負荷を低減することを目的としている。 The present invention is an acid saccharification method by acid hydrolysis of solid biomass, and enables acid recovery and reuse by using an ion exchange membrane in acid recovery, which is a problem in terms of cost and environment. The objective is to reduce energy costs and environmental impact.
上記目的を達成するための本発明は、次の各発明から選択される発明を包含する。 To achieve the above object, the present invention includes an invention selected from the following inventions.
（１）セルロース系バイオマスを酸糖化処理することによって酸・糖混合液を製造する酸糖化工程、該酸糖化工程から得られる酸・糖混合液を陰イオン交換膜を用いる拡散透析法により５０℃以下の温度で透析処理を行って酸と糖液を分離する透析処理工程を有することを特徴とする、セルロース系バイオマスから糖液を製造する方法。 (1) Acid saccharification step for producing an acid / sugar mixture by subjecting cellulosic biomass to an acid saccharification treatment, and the acid / sugar mixture obtained from the acid saccharification step at 50 ° C. by diffusion dialysis using an anion exchange membrane A method for producing a sugar solution from cellulosic biomass, comprising a dialysis treatment step of performing a dialysis treatment at the following temperature to separate an acid and a sugar solution.
（２）前記酸糖化工程に供給されるセルロース系バイオマスは、加熱水及び／又は有機溶剤によりリグニン物質を除去する処理が施されていることを特徴とする、（１）項記載のセルロース系バイオマスから糖液を製造する方法。 (2) Cellulosic biomass according to (1), wherein the cellulosic biomass supplied to the acid saccharification step is subjected to a treatment for removing a lignin substance with heated water and / or an organic solvent. Of producing sugar solution from
（３）前記酸糖化工程と前記透析処理工程の間に、酸糖化工程から得られる酸・糖混合液を露光処理及び／又は５０℃以上の温度による加熱処理をしてリグニン物質を固形化し、濾過して除去するリグニン物質除去工程を設けることを特徴とする、（１）項又は（２）項に記載のセルロース系バイオマスから糖液を製造する方法。 (3) Between the acid saccharification step and the dialysis treatment step, the acid / sugar mixture obtained from the acid saccharification step is subjected to exposure treatment and / or heat treatment at a temperature of 50 ° C. or more to solidify the lignin substance, A method for producing a sugar solution from the cellulosic biomass according to (1) or (2), wherein a lignin substance removing step of removing by filtration is provided.
（４）前記酸糖化工程における酸糖化処理は、温度１５〜３５℃でセルロース系バイオマスを酸加水分解して糖化する処理であることを特徴とする（１）項〜（３）項のいずれか１項に記載のセルロース系バイオマスから糖液を製造する方法。 (4) The acid saccharification treatment in the acid saccharification step is a treatment of acid hydrolysis and saccharification of cellulosic biomass at a temperature of 15 to 35 ° C., any one of (1) to (3) A method for producing a sugar solution from the cellulosic biomass described in Item 1.
（５）前記酸糖化処理工程における酸糖化処理は、濃度３０〜７０質量％の硫酸を使用してセルロース系バイオマスを酸加水分解して糖化する処理であることを特徴とする（１）項〜（４）項のいずれか１項に記載のセルロース系バイオマスから糖液を製造する方法。 (5) The acid saccharification treatment in the acid saccharification treatment step is a treatment of acid hydrolysis and saccharification of cellulosic biomass using sulfuric acid having a concentration of 30 to 70% by mass (1) to A method for producing a sugar solution from the cellulosic biomass according to any one of (4).
（６）前記透析処理工程は、陰イオン交換膜の一方の側に通液する酸・糖混合液と、他方の側に通液する回収用水の流速比を、「酸・糖混合液／回収用水＝０．５〜２」として透析処理して糖液を分離取得する工程であることを特徴とする、（１）項〜（５）項のいずれか１項に記載のセルロース系バイオマスから糖液を製造する方法。 (6) In the dialysis treatment step, the flow rate ratio of the acid / sugar mixed solution passing through one side of the anion exchange membrane and the recovery water flowing through the other side is expressed as “acid / sugar mixed solution / recovery”. It is a step of separating and obtaining a sugar solution by dialysis treatment as “water for use = 0.5 to 2”, and the sugar from the cellulosic biomass according to any one of items (1) to (5) A method for producing a liquid.
（７）前記イオン交換膜に通液する処理液及び回収用水の流速が、陰イオン交換膜を挟んで互いの流動方向が逆方向となるように、単位膜面積当たり毎分３〜８ｍｌであることを特徴とする、（６）項記載のセルロース系バイオマスから糖液を製造する方法。 (7) The flow rate of the treatment liquid and the recovery water flowing through the ion exchange membrane is 3 to 8 ml per unit membrane area so that the flow directions of the anion exchange membrane are opposite to each other. A method for producing a sugar solution from the cellulosic biomass according to item (6).
（８）前記透析処理工程における透析処理が遮光下で行われることを特徴とする（１）項〜（７）項のいずれか１項に記載のセルロース系バイオマスから糖液を製造する方法。 (8) The method for producing a sugar solution from the cellulosic biomass according to any one of (1) to (7), wherein the dialysis treatment in the dialysis treatment step is performed under light shielding.
（９）前記透析処理工程が、前記酸・糖混合液中の酸を９９質量％以上除去する工程であることを特徴とする、（１）項〜（８）項のいずれか１項に記載のセルロース系バイオマスから糖液を製造する方法。 (9) The dialysis treatment step is a step of removing 99% by mass or more of the acid in the acid / sugar mixed solution, according to any one of (1) to (8), Of producing sugar liquid from cellulose-based biomass.
（１０）前記透析処理工程で分離される酸含有回収用水を前記酸糖化工程における酸糖化処理に循環使用する循環系を有することを特徴とする、（１）項〜（９）項のいずれか１項に記載のセルロース系バイオマスから糖液を製造する方法。 (10) Any one of items (1) to (9), characterized by having a circulation system that circulates and uses the acid-containing recovery water separated in the dialysis treatment step for the acid saccharification treatment in the acid saccharification step. A method for producing a sugar solution from the cellulosic biomass described in Item 1.
本発明によれば、従来、環境負荷が高いことや、エネルギー効率が低いために実用化が難しかったバイオマスの酸糖化方法が実用的に可能となる。さらに、酸糖化法は草本系のバイオマスから木質系のバイオマス、デンプン系廃棄物まで広く原料として利用することが可能となるため、食料と競合しない大量かつ安価な液体燃料生産技術が提供される。 According to the present invention, a method for acid saccharification of biomass, which has been difficult to put into practical use because of its high environmental burden and low energy efficiency, can be practically used. Furthermore, since the acid saccharification method can be widely used as a raw material from herbaceous biomass to woody biomass and starch waste, a large-scale and inexpensive liquid fuel production technology that does not compete with food is provided.
以下、本発明を更に詳しく説明する。
本発明が処理対象となる固形バイオマスとしては、間伐材、建築廃材、木材チップ、おがくず、剪定材、林地残材、竹、古新聞、雑誌、段ボール、古紙、パルプ、パルプスラッジや、木質材含有物を含む産業・生活廃棄物などのセルロース系バイオマスが挙げられる。他に、籾殻、リンター、綿、木綿バガス、ワラ類、トウモロコシ穂軸などの草本系農産廃棄物などが含まれる。また、廃パン、残飯、廃デンプン、規格外小麦、廃棄米などデンプン系廃棄物なども酸糖化処理により速やかに単糖化、可溶化が可能であるため、セルロース系バイオマスに限らず広範囲な原料を利用可能である。
Hereinafter, the present invention will be described in more detail.
Solid biomass to be treated by the present invention includes thinned wood, construction waste, wood chips, sawdust, pruned wood, forest land residue, bamboo, old newspaper, magazine, cardboard, waste paper, pulp, pulp sludge, and woody material Cellulosic biomass such as industrial and domestic waste containing waste. Others include herbaceous agricultural waste such as rice husk, linter, cotton, cotton bagasse, straw, and corn cobs. In addition, starch-based wastes such as waste bread, leftover rice, waste starch, non-standard wheat, and waste rice can be quickly saccharified and solubilized by acid saccharification treatment, so a wide range of raw materials are not limited to cellulosic biomass. Is available.
本発明の方法においては、まず、酸糖化工程において、上記バイオマス原料を３０〜７０質量％濃度の酸で処理することにより、多糖類及び単糖類を溶出させる。酸としては、硫酸、硝酸、塩酸、リン酸、沸酸などの鉱酸やトリフルオロ酢酸のような有機酸もしくは、これらの酸混合液が使用可能であるが、中でも硫酸が望ましく、多糖類及び単糖類を溶出させる反応は、常圧で速やかに起こる。反応は、温度３５℃以下で速やかに進行するが、フルフラールなどの発酵阻害物質の生成を抑えるために２０℃以下が好ましい。但し、１５℃未満だと、溶出速度が遅くなるので、１５℃以上であることが好ましい。 In the method of the present invention, first, in the acid saccharification step, polysaccharides and monosaccharides are eluted by treating the biomass raw material with an acid having a concentration of 30 to 70% by mass. As the acid, a mineral acid such as sulfuric acid, nitric acid, hydrochloric acid, phosphoric acid, boiling acid, an organic acid such as trifluoroacetic acid, or a mixed solution thereof can be used. The reaction for eluting monosaccharides occurs rapidly at normal pressure. The reaction proceeds rapidly at a temperature of 35 ° C. or lower, but 20 ° C. or lower is preferable in order to suppress the production of fermentation inhibitors such as furfural. However, when the temperature is lower than 15 ° C, the elution rate becomes slow, and therefore, the temperature is preferably 15 ° C or higher.
次いで、得られた酸糖化処理液、即ち、酸・糖混合液は、透析処理工程において、ガラス繊維濾紙やポリフッ化エチレン系繊維製濾布などによって固液分離して清澄な溶液を得た後、透析処理工程に送ってイオン交換膜の片面に接触させ、他方の面に水（回収用水）を接触させることにより、処理液中の硫酸などの酸を選択的に他方の面側に透過させることができる。 Next, after the obtained acid saccharification treatment solution, that is, the acid / sugar mixture solution, is subjected to solid-liquid separation with a glass fiber filter paper or a polyfluorinated ethylene fiber filter cloth in the dialysis treatment step to obtain a clear solution. Then, the acid is sent to the dialysis treatment process and brought into contact with one side of the ion exchange membrane, and water (recovery water) is brought into contact with the other side to selectively permeate the acid such as sulfuric acid in the treatment liquid to the other side. be able to.
本発明の方法において、透析処理工程で使用する陰イオン交換膜は、高分子材料により形成される膜であり、高分子の分子中にカチオン基を有するものである。カチオン基としては、四級アンモニウム基、四級ピリジニウム基などである。陰イオン交換膜は、溶液中のカチオン物質、中性溶解物は透過せず、小さなアニオン及び水素イオンのみを透過させる。 In the method of the present invention, the anion exchange membrane used in the dialysis treatment step is a membrane formed of a polymer material, and has a cationic group in the polymer molecule. Examples of the cationic group include a quaternary ammonium group and a quaternary pyridinium group. The anion exchange membrane does not permeate cationic substances and neutral lysates in the solution, and allows only small anions and hydrogen ions to permeate.
高分子材料としては、一般に、ハロアルキルスチレン及び、これと共重合可能なモノマーとの共重合体を四級アミノ化するか、ビニルピリジン及びこれと共重合可能なモノマーとの共重合体を四級ピリジニウム化したものである。共重合可能なモノマーとしては、スチレン、ビニルトルエン、クロルスチレン、ビニルナフタレンなどのビニルモノマー、或いは、ジビニルベンゼンなどのジエンモノマー、アクリル酸、メタクリル酸、アクリル酸エステル、メタクリル酸エステルなどのアクリル系モノマーなどが挙げられる。ジエン系モノマーを共重合することにより、耐薬剤性を向上することが一般的である。また、エポキシ基を有する高分子物質を混合することも可能である。 As the polymer material, generally, a copolymer of a haloalkylstyrene and a monomer copolymerizable therewith is quaternized, or a copolymer of vinylpyridine and a monomer copolymerizable therewith is quaternized. Pyridiniumized. Examples of the copolymerizable monomer include vinyl monomers such as styrene, vinyl toluene, chlorostyrene, and vinyl naphthalene, diene monomers such as divinylbenzene, and acrylic monomers such as acrylic acid, methacrylic acid, acrylic ester, and methacrylic ester. Etc. It is common to improve chemical resistance by copolymerizing a diene monomer. It is also possible to mix a polymer substance having an epoxy group.
透析処理工程では、処理液中に含まれる糖類はイオン交換膜を通過することなく処理液中に残存し、酸の移動は濃度差を駆動力とするため、逆浸透膜などの運転とは異なり、圧力を負荷する必要はない。
透析処理工程では、イオン交換膜を挟んで対面している糖化処理液と回収用水の流動方向は逆方向に流すことが必要である。静置法あるいは順方向に流す方法では、酸の除去率を１００％に近づけることは困難である。
In the dialysis treatment process, the saccharides contained in the treatment liquid remain in the treatment liquid without passing through the ion exchange membrane, and the acid transfer is driven by the concentration difference, which is different from the operation of a reverse osmosis membrane or the like. There is no need to load pressure.
In the dialysis treatment step, it is necessary that the saccharification treatment liquid and the recovery water flow facing each other with the ion exchange membrane interposed therebetween to flow in opposite directions. With the stationary method or the method of flowing in the forward direction, it is difficult to bring the acid removal rate close to 100%.
酸糖化処理工程におけるセルロース系バイオマス原料として、木質系バイオマス、即ち、リグニンを含むバイオマス原料を用いた場合は、酸糖化処理液中には酸可溶性リグニンが溶解している。酸可溶性リグニンは、酸による溶解処理直後は可溶化していても、光酸化や温度により重合し、不溶化してしまい、その後の透析処理工程でイオン交換膜による酸の除去を阻害する。この為、イオン交換膜による硫酸回収時には遮光を行うことや、処理液及び回収用水の温度を５０℃以下、好ましくは４０℃以下、最も望ましくは、３０℃以下にすることによって、不溶物質の生成を抑制し分離効率を向上することが可能となる。 When woody biomass, that is, biomass raw material containing lignin is used as the cellulose-based biomass raw material in the acid saccharification treatment step, acid-soluble lignin is dissolved in the acid saccharification treatment liquid. Even if the acid-soluble lignin is solubilized immediately after the dissolution treatment with an acid, it is polymerized and insolubilized by photooxidation or temperature, and the removal of the acid by the ion exchange membrane is inhibited in the subsequent dialysis treatment step. For this reason, generation of insoluble substances can be achieved by shielding light during the recovery of sulfuric acid by an ion exchange membrane, or by setting the temperature of the treatment liquid and water for recovery to 50 ° C. or lower, preferably 40 ° C. or lower, and most desirably 30 ° C. or lower. It is possible to suppress separation and improve separation efficiency.
前記した溶解リグニンの重合による阻害を防ぐため、酸糖化工程における酸処理に先立って、リグニンを加熱水あるいは有機溶剤により除去することも好ましい態様である。また、処理液に光を当て、更には温度を５０℃以上にしてリグニンの重合・不溶化を促進した後、濾過あるいは比重分離してから、透析処理工程に送ってイオン交換膜による透析を開始することも好ましい態様である。 In order to prevent the inhibition by the polymerization of the above-mentioned dissolved lignin, it is also a preferred embodiment that lignin is removed with heated water or an organic solvent prior to the acid treatment in the acid saccharification step. In addition, after irradiating the treatment liquid with light and further promoting the polymerization / insolubilization of lignin by raising the temperature to 50 ° C. or higher, it is filtered or separated by specific gravity, and then sent to the dialysis treatment process to start dialysis with an ion exchange membrane This is also a preferred embodiment.
以下、本発明を実施例により詳細に説明するが、本発明は以下の実施例に限定されるものではない。以下に示す各実施例において、％は、特に断りがない限りは質量％を示す。 糖濃度の測定には、フェノール硫酸法を用いた。測定方法については、「還元糖の定量法」（福井作蔵著 学会出版センター）を参考にした。硫酸濃度の測定は、ダイオネクス社製イオンクロマト装置ＩＣＳ-３０００で硫酸イオン濃度を測定した。 EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to a following example. In each Example shown below,% shows the mass% unless there is particular notice. The phenol sulfuric acid method was used for measuring the sugar concentration. For the measurement method, we referred to “Quantitative method for reducing sugar” (Sakuzo Fukui Publishing Center). The sulfuric acid concentration was measured with an ion chromatograph ICS-3000 manufactured by Dionex.
＜実施例１＞
平均粒子径２０ｍｍサイズに調製されたスギ木片４００ｇをプラスチックビーカーに投入し、７０％硫酸５００ｍｌを加え、硫酸（処理液）の温度を１５℃に保ちながら１５０ｒｐｍの攪拌速度で攪拌機により８時間攪拌した。
上記処理液をアドバンテック社製ガラス繊維濾紙ＧＡ−１００で濾過を行い、処理液と残渣を分離した。本操作により、全糖４０．７ｇ／ｌの糖化処理液が得られた。この処理液を原液として、以下の透析工程における膜分離操作を行った。
<Example 1>
400 g of cedar wood pieces prepared with an average particle size of 20 mm were put into a plastic beaker, 500 ml of 70% sulfuric acid was added, and the mixture was stirred for 8 hours with a stirrer at a stirring speed of 150 rpm while maintaining the temperature of sulfuric acid (treatment liquid) at 15 ° C. .
The said process liquid was filtered with the glass fiber filter paper GA-100 made from Advantech, and the process liquid and the residue were isolate | separated. By this operation, a saccharification treatment solution having a total sugar of 40.7 g / l was obtained. Using this treatment solution as a stock solution, membrane separation operation in the following dialysis step was performed.
図１のように、０．３４２ｍ２の面積を持つ陰イオン交換膜（旭硝子社製セレミオンＤＳＶ）をセットし、膜面の片側（図の左側）に水を満たした。図示していないが、回収用水の出口（図の下部）にはバルブがあり、操業開始と同時に、上部からの給水速度と同一の速度で出口から流出するように制御する。
膜面の片側下部より処理液を通液し、操業を開始する。操作条件は処理液流量、回収用水流量をそれぞれ毎分１ｍｌとし、膜をセットした装置全体を冷却し、処理液及び回収水の温度を５０℃以下に保つようにし、約１０時間、前述の条件において運転することによって装置の平衡化を行った。平衡化が終了後、脱塩液及び回収酸をそれぞれ５ｍｌずつサンプル採取した。各サンプルの酸濃度及び硫酸濃度を測定し、以下の式によって、糖濃度比率、硫酸除去率、糖通過率、硫酸濃度比率を算出した。
As shown in FIG. 1, an anion exchange membrane (Celemion DSV manufactured by Asahi Glass Co., Ltd.) having an area of 0.342 m 2 was set, and water was filled on one side (left side in the figure) of the membrane surface. Although not shown in the drawing, a valve is provided at the outlet of the recovery water (lower part of the figure), and is controlled to flow out from the outlet at the same speed as the water supply speed from the upper part at the same time as the operation starts.
The treatment liquid is passed from the lower part on one side of the membrane surface, and the operation is started. The operating conditions were a treatment liquid flow rate and a recovery water flow rate of 1 ml each minute, the entire apparatus on which the membrane was set was cooled, and the temperature of the treatment liquid and the recovery water was kept at 50 ° C. or lower for about 10 hours. The device was equilibrated by operating at. After equilibration was completed, 5 ml each of the desalted solution and the recovered acid were sampled. The acid concentration and sulfuric acid concentration of each sample were measured, and the sugar concentration ratio, the sulfuric acid removal rate, the sugar passage rate, and the sulfuric acid concentration ratio were calculated according to the following equations.
糖濃度比率（％）＝（透析液中の糖濃度（％）／原液中の糖濃度（％））×１００
硫酸の除去率（％）＝（透析液中の硫酸濃度（％）／原液中の硫酸濃度（％））×１００
糖の通過率（％）＝（回収酸中の糖濃度（％）／原液中の糖濃度（％））×１００
硫酸濃度比率（％）＝（回収酸中の硫酸濃度（％）／原液中の硫酸濃度（％））×１００
Sugar concentration ratio (%) = (sugar concentration in dialysate (%) / sugar concentration in stock solution (%)) × 100
Removal rate of sulfuric acid (%) = (sulfuric acid concentration in dialysate (%) / sulfuric acid concentration in stock solution (%)) × 100
Sugar passage rate (%) = (sugar concentration in recovered acid (%) / sugar concentration in stock solution (%)) × 100
Sulfuric acid concentration ratio (%) = (sulfuric acid concentration in recovered acid (%) / sulfuric acid concentration in stock solution (%)) × 100
それぞれのサンプルについて糖濃度比率、硫酸除去率、糖通過率、硫酸濃度比率を算出した結果を表１に示す。バイオマスを硫酸処理した処理液をイオン交換膜で分離処理を行ったところ、原液中の酸は回収酸液中にほとんどが回収され、脱塩液は高い糖濃度を維持していることが判明した。また脱塩液中の硫酸は８６％除去されており、本実施例により、イオン交換膜を用いることによって、酸と糖の分離が可能であることが判明した。 Table 1 shows the results of calculating the sugar concentration ratio, the sulfuric acid removal rate, the sugar passage rate, and the sulfuric acid concentration ratio for each sample. When the treatment solution obtained by treating the biomass with sulfuric acid was separated using an ion exchange membrane, it was found that most of the acid in the stock solution was recovered in the recovered acid solution, and the desalted solution maintained a high sugar concentration. . In addition, 86% of the sulfuric acid in the desalted solution was removed, and it was found from this example that acid and sugar can be separated by using an ion exchange membrane.
＜実施例２＞
実施例１と同様に処理液を得て、同じ膜を用いて膜分離を行った。操作条件として、原液流量は毎分１ｍｌであるが、回収用水流量をそれぞれ毎分０．５ｍｌ、２ｍｌ、４ｍｌで行い、その他の条件は実施例１と同様に行った。これを実施例２−１〜３とした。実施例１と同様に平衡化を行った後にサンプル採取を行い、同様に糖濃度比率、硫酸除去率、糖通過率、硫酸濃度比率を算出した結果を表２に示し、比較のために実施例１のデータも転記した。硫酸の除去率は回収用水流量の増大に伴って上昇するが、糖通過率も上昇する結果、糖回収率は減少することが判明した。本実施例によって、原液と回収用水の流速比は０．５〜２付近が良好であることが判明した。
<Example 2>
A treatment liquid was obtained in the same manner as in Example 1, and membrane separation was performed using the same membrane. As operating conditions, the stock solution flow rate was 1 ml per minute, but the recovery water flow rate was 0.5 ml, 2 ml, and 4 ml per minute, respectively, and the other conditions were the same as in Example 1. This was designated as Examples 2-1 to 2-3. Samples were collected after equilibration in the same manner as in Example 1, and the results of calculating the sugar concentration ratio, sulfuric acid removal rate, sugar passage rate, and sulfuric acid concentration ratio in the same manner are shown in Table 2. The data of 1 was also posted. It was found that the removal rate of sulfuric acid increases with an increase in the recovery water flow rate, but the sugar recovery rate decreases as a result of the increase in the sugar passage rate. According to the present example, it was found that the flow rate ratio of the stock solution and the water for recovery was good around 0.5-2.
＜実施例３＞
実施例１と同様に処理液を得て、同じ膜を用いて膜分離を行った。操作条件として、原液流量、回収用水流量を共に毎分０．５、２ｍｌ、３ｍｌ、５ｍｌで行い、その他の条件は実施例１と同様に行った。これを実施例３−１〜４とした。実施例１と同様に平衡化を行った後にサンプル採取を行い、同様に糖濃度比率、硫酸除去率、糖通過率、硫酸濃度比率を算出した結果を表３に示し、比較のために実施例１のデータも転記した。硫酸除去率は流量の増大に伴って緩やかに減少するが、糖濃度比率は流量が毎分２ｍｌ付近で良好であることが判明した。本実施例によって、流速は単位膜面積あたり、毎分３〜８ｍｌ付近が良好であることが判明した。
<Example 3>
A treatment liquid was obtained in the same manner as in Example 1, and membrane separation was performed using the same membrane. As operating conditions, both the stock solution flow rate and the recovery water flow rate were 0.5, 2 ml, 3 ml, and 5 ml per minute. The other conditions were the same as in Example 1. This was designated as Examples 3-1 to 4. Samples were collected after equilibration in the same manner as in Example 1, and the results of calculating the sugar concentration ratio, sulfuric acid removal rate, sugar passage rate, and sulfuric acid concentration ratio in the same manner are shown in Table 3. The data of 1 was also posted. The sulfuric acid removal rate gradually decreased as the flow rate increased, but the sugar concentration ratio was found to be good when the flow rate was around 2 ml / min. According to this example, it was found that the flow rate was good at around 3 to 8 ml per minute per unit membrane area.
＜実施例４＞
実施例１と同様に処理液を得て、同じ膜を用いて膜分離を行った。操作条件として、原液流量、回収用水流量を共に毎分２ｍlで行った。以上は実施例３−２と同様の条件である。実施例３−２とは異なり、装置全体を遮光して膜分離処理を行い、これを実施例４とした。実施例３−２と同様に平衡化を行った後にサンプル採取を４時間おきに行い、同様に透析液の硫酸除去率の経時変化を示した結果を図２に示し、比較のために実施例３−２の条件についても同様にデータ採取した。経時的なサンプル採取を行うと、実施例３−２ではサンプル採取後４８時間で硫酸除去率が急激に減少しているが、遮光を行うことにより、硫酸除去率の減少が抑制している。本実施例によって、膜分離時に遮光することによって、分離効率が維持されることが判明した。
<Example 4>
A treatment liquid was obtained in the same manner as in Example 1, and membrane separation was performed using the same membrane. As operating conditions, the stock solution flow rate and the recovery water flow rate were both 2 ml / min. The above are the same conditions as Example 3-2. Unlike Example 3-2, the entire apparatus was shielded from light and subjected to membrane separation treatment, which was designated as Example 4. Samples were taken every 4 hours after equilibration in the same manner as in Example 3-2. Similarly, the results showing the change over time in the sulfuric acid removal rate of the dialysate are shown in FIG. Data were collected in the same manner for the condition 3-2. When sample collection is performed over time, in Example 3-2, the sulfuric acid removal rate rapidly decreases 48 hours after sample collection, but the reduction of the sulfuric acid removal rate is suppressed by performing light shielding. According to this example, it was found that the separation efficiency was maintained by shielding light during membrane separation.
＜実施例５＞
実施例１と同様に処理液を得て、同じ膜を用いて膜分離を行った。操作条件として、遮光下、原液流量、回収用水流量を共に毎分２ｍｌで行った以外は実施例４と同様の条件である。実施例４とは異なり、装置全体を３０℃、６０℃に維持し、これを実施例５−１〜２とした。実施例４と同様に平衡化を行った後にサンプル採取を４時間おきに行い、同様に透析液の硫酸除去率の経時変化を示した結果を図３に示し、比較のために実施例４の条件についても同様にデータ採取した。経時的なサンプル採取を行うと、実施例５−２ではサンプル採取後６０時間で硫酸の除去率が徐々に減少しているが、装置を処理液及び回収用水の液温度が３０℃に維持されるように制御することより、硫酸除去率の減少が抑制している。本実施例によって、膜分離時に装置温度を３０℃に維持することによって、分離効率が維持されることが判明した。
<Example 5>
A treatment liquid was obtained in the same manner as in Example 1, and membrane separation was performed using the same membrane. The operating conditions were the same as in Example 4 except that both the stock solution flow rate and the recovery water flow rate were performed at 2 ml / min. Unlike Example 4, the entire apparatus was maintained at 30 ° C. and 60 ° C., which were designated as Examples 5-1 and 5-2. Samples were taken every 4 hours after equilibration in the same manner as in Example 4, and the results showing the change over time in the sulfuric acid removal rate of the dialysate are shown in FIG. Data were collected in the same manner for the conditions. When samples were collected over time, in Example 5-2, the removal rate of sulfuric acid gradually decreased in 60 hours after sample collection, but the liquid temperature of the treatment liquid and recovery water was maintained at 30 ° C. By controlling in such a manner, a decrease in the sulfuric acid removal rate is suppressed. According to this example, it was found that the separation efficiency was maintained by maintaining the apparatus temperature at 30 ° C. during membrane separation.
以上の実施例から、拡散透析を５０℃以下で行う場合で、処理水と回収用水の流速を１ｍｌ／分とした場合は、９９％以上の酸除去率となり、流速を２ｍｌ／分とした場合でも、拡散透析の液の温度を３０℃に制御し、遮光下で行えば、ほぼ１００％近い酸除去率を達成できることが判明した。 From the above examples, when diffusion dialysis is performed at 50 ° C. or less and the flow rate of treated water and recovery water is 1 ml / min, the acid removal rate is 99% or more, and the flow rate is 2 ml / min. However, it was found that when the temperature of the diffusion dialysis solution was controlled at 30 ° C. and performed in the dark, an acid removal rate of nearly 100% could be achieved.
Claims (8)
The acid-containing recovery water separated in the dialysis treatment step has a circulation system that circulates and uses the acid-containing recovery water in the acid saccharification treatment in the acid saccharification step. A method for producing sugar liquid from cellulosic biomass.
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Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2012183031A (en) * | 2011-03-07 | 2012-09-27 | Kawasaki Heavy Ind Ltd | Method for electrodialysis and apparatus for electrodialysis |
| CN102816877A (en) * | 2012-08-29 | 2012-12-12 | 上海交通大学 | Hydrothermal saccharification method and device for cellulose biomass |
| WO2013090782A1 (en) * | 2011-12-14 | 2013-06-20 | The Trustees Of Dartmouth College | System and method for increasing carbohydrate and lignin concentration in hydrolysate of biomass pretreatment |
| WO2016047979A1 (en) * | 2014-09-24 | 2016-03-31 | 한국과학기술연구원 | Method for separating sugar from hydrolysate containing acid solution and using same for fermentation |
| KR20190061728A (en) * | 2017-11-28 | 2019-06-05 | 한국과학기술연구원 | Method for separation of acid and sugars to reduce energy consumption |
| CN115103819A (en) * | 2020-02-18 | 2022-09-23 | 株式会社F.C.C. | Ion exchange device |
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2007
- 2007-07-18 JP JP2007186809A patent/JP2009022180A/en active Pending
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2012183031A (en) * | 2011-03-07 | 2012-09-27 | Kawasaki Heavy Ind Ltd | Method for electrodialysis and apparatus for electrodialysis |
| WO2013090782A1 (en) * | 2011-12-14 | 2013-06-20 | The Trustees Of Dartmouth College | System and method for increasing carbohydrate and lignin concentration in hydrolysate of biomass pretreatment |
| CN102816877A (en) * | 2012-08-29 | 2012-12-12 | 上海交通大学 | Hydrothermal saccharification method and device for cellulose biomass |
| WO2016047979A1 (en) * | 2014-09-24 | 2016-03-31 | 한국과학기술연구원 | Method for separating sugar from hydrolysate containing acid solution and using same for fermentation |
| KR20190061728A (en) * | 2017-11-28 | 2019-06-05 | 한국과학기술연구원 | Method for separation of acid and sugars to reduce energy consumption |
| US10435426B2 (en) | 2017-11-28 | 2019-10-08 | Korea Institute Of Science And Technology | Method for separation of acids and sugars to reduce energy consumption |
| KR102003918B1 (en) * | 2017-11-28 | 2019-10-17 | 한국과학기술연구원 | Method for separation of acid and sugars to reduce energy consumption |
| CN115103819A (en) * | 2020-02-18 | 2022-09-23 | 株式会社F.C.C. | Ion exchange device |
| CN115103819B (en) * | 2020-02-18 | 2023-11-21 | 株式会社F.C.C. | Ion exchange device |
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