KR101155307B1 - Method for producing bio-ethanol from a conifer using organosolv pretreatment - Google Patents

Method for producing bio-ethanol from a conifer using organosolv pretreatment Download PDF

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KR101155307B1
KR101155307B1 KR1020100053769A KR20100053769A KR101155307B1 KR 101155307 B1 KR101155307 B1 KR 101155307B1 KR 1020100053769 A KR1020100053769 A KR 1020100053769A KR 20100053769 A KR20100053769 A KR 20100053769A KR 101155307 B1 KR101155307 B1 KR 101155307B1
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pretreatment
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ethanol
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최인규
박나현
김혜연
여환명
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서울대학교산학협력단
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    • C12PFERMENTATION OR ENZYME-USING PROCESSES TO SYNTHESISE A DESIRED CHEMICAL COMPOUND OR COMPOSITION OR TO SEPARATE OPTICAL ISOMERS FROM A RACEMIC MIXTURE
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    • Y02P30/00Technologies relating to oil refining and petrochemical industry
    • Y02P30/20Technologies relating to oil refining and petrochemical industry using bio-feedstock

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Abstract

본 발명은 침엽수종 유래 원료를 당화 및 발효처리하여 바이오에탄올을 제조하는 방법에 있어서, 당화 단계 전에 유기용매 전처리 단계를 포함하며, 유기용매 전처리 단계는 침엽수종 유래 원료를 소정 시간 및 온도에서 중성촉매가 첨가된 유기용매에 담지하는 것을 특징으로 하는 바이오에탄올 제조방법에 관한 것으로, 바람직하게는 유기용매는 에탄올이 선택되며, 중성촉매는 염화마그네슘이 적용되어, 본 발명에 의한 유기용매 전처리에 의한 침엽수종 바이오에탄올 제조방법에 따라 종래 리그린 성분의 고비율로 인하여 바이오에탄올 제조가 용이하지 아니하였던 침엽수종이 바이오에탄올 원료로 재고될 수 있으며, 부식성 및 독성이 적으며 유해성이 낮은 바이오에탄올 제조가 가능하다. The present invention provides a method for producing bioethanol by saccharifying and fermenting a conifer species-derived raw material, the organic solvent pretreatment step before the saccharification step, the organic solvent pretreatment step is a neutral catalyst at a predetermined time and temperature The present invention relates to a method for producing bioethanol, characterized in that it is supported on an added organic solvent. Preferably, the organic solvent is selected from ethanol, and the neutral catalyst is applied with magnesium chloride, and coniferous water by organic solvent pretreatment according to the present invention. Depending on the species bioethanol production method, coniferous species, which were not easy to manufacture bioethanol due to the high ratio of lignin components, can be reconsidered as a bioethanol raw material, and can produce bioethanol with low corrosiveness and toxicity and low harmfulness. .

Description

유기용매 전처리를 적용한 침엽수종 바이오에탄올 제조방법{Method for producing bio-ethanol from a conifer using organosolv pretreatment}Method for producing bioethanol from softwood by applying organic solvent pretreatment {Method for producing bio-ethanol from a conifer using organosolv pretreatment}

본 발명은 유기용매 전처리에 의한 침엽수종 바이오에탄올 제조방법에 관한 것이며, 더욱 상세하게는 바이오매스인 침엽수종 유래 바이오에탄올 제조에 있어 유기용매 전처리 공정에서 중성촉매를 적용하여 효소가수분해 효율을 개선하기 위한 유기용매 전처리에 의한 침엽수종 바이오에탄올 제조방법에 관한 것이다.The present invention relates to a method for producing coniferous species bioethanol by organic solvent pretreatment, and more particularly, to improve enzymatic hydrolysis efficiency by applying a neutral catalyst in an organic solvent pretreatment process in the production of biomass conifer species derived from biomass. It relates to a method for producing softwood bioethanol by organic solvent pretreatment for.

바이오 연료의 하나인 바이오에탄올 제조 원료는 리그노셀룰로스(ligncellulose)를 이용하는 방향으로 진행되고 있다. 공지되는 바와 같이 셀룰로스(cellulose), 헤미셀룰로스(hemicellulose) 및 리그닌으로 이루어진 복합체인 리그노셀룰로스로 구성된 목질계 원료 성분은, 탄수화물부분인 셀룰로스 및 헤미셀룰로스가 리그닌과 강하게 결합되어 셀룰라제(cellulase)와 같은 섬유소 분해효소로 처리하더라도 당으로의 분해 수율이 이론적 수율의 20% 정도밖에 분해되지 않는 문제점이 있다. 이러한 당 분해 수율을 개선하기 위해 다양한 전처리 방법들이 도입되고 있다. 예를들면 황산은 높은 반응성 및 효율로 인하여 전처리 공정에 가장 많이 사용되지만, 높은 독성, 부식성 및 효소당화(소화) 공정에 대한 저해 물질 부산으로 인하여 활용이 점차 제한되고 있다. 또한 수산화나트륨을 이용한 염기성 전처리 (alkaline pretreatment) 역시 고려되고 있으나 고비용의 문제가 있었다. 한편, 바이오매스로서의 침엽수종은 자원량이 풍부하고, 바이오에탄올 제조에 가장 적합한 원료이기도 하지만 고-리그닌계 바이오매스라는 특성으로 적극적으로 활용되지 못하고 있다. Bioethanol production raw material, which is one of biofuels, is being progressed in the direction of using lignocellulose. As is known, the wood-based raw material component composed of lignocellulosic, a complex composed of cellulose, hemicellulose and lignin, is a carbohydrate moiety of cellulose and hemicellulose strongly bound to lignin, Even when treated with the same fibrinolytic enzyme, there is a problem that the yield of decomposition to sugar is only about 20% of the theoretical yield. Various pretreatment methods have been introduced to improve the yield of sugar decomposition. For example, sulfuric acid is most often used in pretreatment processes due to its high reactivity and efficiency, but its use is increasingly limited due to the inhibition of high toxicity, corrosiveness, and the inhibition of enzymatic saccharification (digestion) processes. Alkaline pretreatment with sodium hydroxide has also been considered, but there is a problem of high cost. On the other hand, coniferous species as a biomass is rich in resources, and is also the most suitable raw material for the production of bioethanol, but has not been actively utilized due to the characteristics of high-lignin-based biomass.

본 발명의 목적은 바이오에탄올 제조에 있어서 고-리그린 특성으로 인하여 원료로써 적합하지 않았던 침엽수종을 대상으로 유효한 전처리 방법을 제안하는 것이다. It is an object of the present invention to propose an effective pretreatment method for coniferous species which was not suitable as a raw material due to the high-ligin nature in the production of bioethanol.

본 발명의 다른 목적은 바이오에탄올 수율이 개선된 바이오매스 전처리 방법을 개시하는 것이다. 본 발명의 또 다른 목적은 부식성 및 독성이 적으며 유해성이 낮은 바이오에탄올 제조방법에 제안하는 것이다.Another object of the present invention is to disclose a biomass pretreatment method with improved bioethanol yield. Another object of the present invention is to propose a method for producing bioethanol having low corrosiveness and low toxicity and low toxicity.

본 발명의 목적은 침엽수종 유래 원료를 당화 및 발효하여 바이오에탄올을 제조하는 방법에 있어서, 상기 당화 단계 전에 유기용매 전처리 단계를 포함하며, 상기 유기용매 전처리 단계는 침엽수종 유래 원료를 소정 시간 및 온도에서 중성촉매가 첨가된 유기용매에 담지하는 것을 특징으로 하는 바이오에탄올 제조방법에 의해 달성된다. 비제한적으로, 상기 유기용매는 에탄올이 선택되며, 중성촉매는 염화마그네슘이 적용된다. 상기 특성 시간 및 온도는 바람직하게는 200~210℃, 10~20분의 반응조건을 가진다. 바람직한 침엽수종 유래 원료는 리기다소나무 목분일 수 있다.An object of the present invention is a method for producing bioethanol by saccharifying and fermenting a conifer species-derived raw material, comprising an organic solvent pretreatment step before the saccharification step, wherein the organic solvent pretreatment step is a predetermined time and temperature It is achieved by the bioethanol production method characterized in that the neutral catalyst is supported on the added organic solvent. Non-limiting example, ethanol is selected as the organic solvent, and magnesium chloride is applied as the neutral catalyst. The characteristic time and temperature preferably has a reaction condition of 200 ~ 210 ℃, 10 ~ 20 minutes. Preferred conifer species-derived raw material may be Rigida pine wood flour.

본 발명에 의한 유기용매 전처리에 의한 침엽수종 바이오에탄올 제조방법에 따라 종래 리그린 성분의 고비율로 인하여 바이오에탄올 제조가 용이하지 아니하였던 침엽수종이 원료로 재고될 수 있으며, 부식성 및 독성이 적으며 유해성이 낮은 바이오에탄올 제조가 가능하다. According to the method for producing coniferous tree bioethanol by organic solvent pretreatment according to the present invention, coniferous tree species, which were not easy to manufacture bioethanol due to the high ratio of ligline components, can be reconsidered as raw materials, have low corrosiveness and toxicity, and are harmful. This low bioethanol production is possible.

도 1은 산성촉매 전처리의 시간 및 온도 변화에 따른 효소당화 소화율을 도시한 것이다.
도 2는 중성촉매 전처리의 시간 및 온도 변화에 따른 효소당화 소화율을 도시한 것이다.
도 3은 고농도 염기성촉매 전처리의 시간 및 온도 변화에 따른 효소당화 소화율을 도시한 것이다.
도 4는 고농도 염기성촉매 전처리 후 전처리 수율을 도시한 것이다.
도 5 및 6은 각각 촉매별 최적조건에서의 글루코오스 전환율 및 동시당화발효를 통한 에탄올 생산율을 도시한 것이고, Raw material은 미-처리재료, SAE은 산성촉매 유기용매 전처리, MCE은 중성촉매 유기용매 전처리 및 2SHE은 고농도 염기촉매 유기용매 전처리 조건을 나타낸다.
도 7 및 8은 각각 촉매별 전처리 수율 및 화학 조성비율을 도시한 것이다.
Figure 1 shows the enzyme glycation digestibility with time and temperature changes of acidic catalyst pretreatment.
Figure 2 shows the enzyme glycation digestibility with time and temperature change of the neutral catalyst pretreatment.
Figure 3 shows the enzyme glycation digestibility with time and temperature changes of high concentration basic catalyst pretreatment.
Figure 4 shows the pretreatment yield after the high concentration basic catalyst pretreatment.
5 and 6 show the ethanol production rate through the glucose conversion rate and co-glycosylation fermentation at the optimum conditions for each catalyst, raw material is untreated material, SAE is acidic catalyst organic solvent pretreatment, and MCE is neutral catalyst organic solvent pretreatment. And 2SHE indicates high concentration of precatalyst organic solvent pretreatment conditions.
7 and 8 show the pretreatment yield and the chemical composition ratio of each catalyst.

이하 본 발명을 상세하게 설명하고자 하나 이는 단지 예시를 위한 것이고, 본 발명의 범위를 제한하는 것은 아니다. DETAILED DESCRIPTION Hereinafter, the present invention will be described in detail, but for the purpose of illustration only, it is not intended to limit the scope of the present invention.

본 발명은 침엽수종 유래 원료를 당화 및 발효하여 바이오에탄올을 제조하는 방법에 있어서, 상기 당화 단계 전에 제공되는 유기용매 전처리 단계에 특징이 있다. 본 발명의 유기용매 전처리 단계는 침엽수종 유래 원료를 소정 시간 및 온도에서 중성촉매가 첨가된 유기용매에 담지하는 것을 특징으로 하므로, 상기 반응조건에 이르게 된 과정 및 산성, 염기성 촉매 대비 중성 촉매가 적합한 성분이라는 결론에 이르게 된 실험 전략을 기술하고자 한다. 전체적인 실험을 요약하면, 중성촉매 뿐 아니라 대조군인 산, 염기 촉매를 이용하여 유기용매 전처리하고, 효소가수분해 공정에 의한 소화율을 비교하여 촉매에 대한 최적 조건을 모색하고, 이후 최적조건에서의 동시당화발효에 의한 에탄올 생산 효율 비교로 촉매를 평가하는 것이다.The present invention is a method for producing bioethanol by saccharifying and fermenting a conifer species-derived raw material, characterized in that the organic solvent pretreatment step provided before the saccharification step. The organic solvent pretreatment step of the present invention is characterized in that the conifer species-derived raw material is supported on the organic solvent to which the neutral catalyst is added at a predetermined time and temperature, and thus the neutral catalyst is suitable for the process leading to the reaction conditions and the acidic and basic catalysts. We describe the experimental strategy that led to the conclusion that it is a component. Summarizing the experiments, organic solvent pretreatment using acid and base catalysts as well as neutral catalyst, and digestion rate by enzyme hydrolysis process were compared to find optimum conditions for catalysts, and then co-glycosylation at optimum conditions. The catalyst is evaluated by comparison of ethanol production efficiency by fermentation.

실시예Example

본 발명에서 선택된 침엽수종 유래 원료는 전라남도 장흥군에서 채취한 리기다소나무이고, 실험용 분쇄기를 이용하여 40 mesh 크기의 목분으로 제조하여 공시재료로 사용하였다.The conifer species-derived material selected from the present invention is a Rigida pine tree collected from Jangheung-gun, Jeollanam-do, and was used as a test material by preparing wood powder having a size of 40 mesh using an experimental grinder.

1. 유기용매 전처리 단계1. Organic Solvent Pretreatment Step

내부온도 측정이 가능한 소형 고압반응기 (minibomb, 볼트 밀폐식, Hanul Autoclave, Co. Ltd)에 목분 (20g) 및 촉매 (200ml)가 첨가된 유기용매를 투입하였다. 산성 촉매로는 1% H2SO4 (w/v), 중성 촉매로는 1% MgCl2 (w/v), 염기 촉매로는 1-2% NaOH (w/v)를 사용하였으며, 유기용매로는 50% (v/v)의 에탄올을 사용하였다. 전처리는 목표온도까지 50분 동안 예열한 후, 목표온도에 도달한 시점부터 각각의 반응시간에 따라 반응시켰다. 반응온도는 150-210℃의 범위에서 10-20℃ 간격으로 반응시켰으며, 반응온도는 외부 전력에 의하여 조절하였다. 0-20분의 범위의 반응시간에서 실시하였고, 반응 종료와 동시에 얼음조(ice-chamber)에서 상온 이하로 냉각하였다. 반응에 투입된 에너지양을 평가하기 위하여, 시간과 온도를 하나의 지표로 나타낸 H-지표r (Gullichsen et al., 2000) 및 가혹지표 (severity factor) (Galbe and Zacchi, 2007)를 계산하였다. 전자의 경우 예열 시간을 고려하였고, 후자의 경우 예열 시간을 고려하지 않았다. 전처리 후, 바이오매스에서 화학 물질과 저해제를 제거하기 위하여 충분한 양의 증류수를 사용하여 세척하였고, 잔사는 이후 효소가수분해 공정에 투입하였다. 전처리 후 획득된 잔사 수율을 전처리 수율이라 하였다.Into a small high-pressure reactor (minibomb, bolt-sealed, Hanul Autoclave, Co. Ltd) capable of measuring the internal temperature was added an organic solvent added with wood powder (20g) and catalyst (200ml). 1% H 2 SO 4 (w / v) as acidic catalyst, 1% MgCl 2 (w / v) as neutral catalyst, 1-2% NaOH (w / v) as base catalyst, organic solvent 50% (v / v) of ethanol was used as the furnace. The pretreatment was preheated to the target temperature for 50 minutes, and then reacted according to the respective reaction time from the time when the target temperature was reached. The reaction temperature was reacted at intervals of 10-20 ° C. in the range of 150-210 ° C., and the reaction temperature was controlled by external power. The reaction time was carried out in the range of 0-20 minutes, and at the same time as the reaction was completed, the mixture was cooled to room temperature or lower in an ice-chamber. In order to evaluate the amount of energy input to the reaction, the H-index r (Gullichsen et al., 2000) and the severity factor (Galbe and Zacchi, 2007), which show time and temperature as one indicator, were calculated. In the former case, the preheating time was taken into account, while in the latter case the preheating time was not taken into account. After pretreatment, a sufficient amount of distilled water was used to remove chemicals and inhibitors from the biomass, and the residue was then added to the enzymatic hydrolysis process. The residue yield obtained after pretreatment was called pretreatment yield.

2. 효소가수분해 및 발효 단계2. Enzymatic Hydrolysis and Fermentation Step

2.1. 효소가수분해 단계2.1. Enzymatic Hydrolysis Stage

효소는 Celluclast 1.5L (Novo Co.) 및 β-glucosidase 강화 효소인 NS-50010 (Novo Co.)을 사용하였다. 상술하면, 삼각플라스크(250ml)에 전 단계에서 수득된 각각의 잔사 및 효소, 및 아세트산나트륨 완충액 (pH 5.0, 100ml)를 투입하여 50℃, 150 rpm으로 조절된 진탕 배양기에서 효소가수분해반응이 수행되었다. 가수분해 중 일정시간 간격으로 시료(1ml)를 채취하여 단당류 수율 분석에 사용하였다. 가수분해는 72시간 동안 배양되었으며, 종료 후 바이오매스가 가수분해에 의한 중량 감소율에 의하여 소화율을 측정하였다.Enzyme was used as Celluclast 1.5L (Novo Co.) and β-glucosidase enhancing enzyme NS-50010 (Novo Co.). Specifically, the enzyme hydrolysis reaction was performed in a shake incubator at 50 ° C. and 150 rpm by adding each residue and enzyme obtained in the previous step, and sodium acetate buffer (pH 5.0, 100 ml) to a Erlenmeyer flask (250 ml). It became. Samples (1 ml) were taken at regular time intervals during hydrolysis and used for monosaccharide yield analysis. Hydrolysis was incubated for 72 hours, and the digestibility was measured by the rate of weight loss due to hydrolysis of the biomass after termination.

2.2. 동시당화발효 단계2.2. Simultaneous Glycation Fermentation Stage

동시당화발효에서는 효모로 Saccharomyces cerevisiae ATTC® 20062 (NREL-5DA)가 채용되었다. 동시당화발효에 앞서 S. cerevisiae를 YP 배지에 투입하고, 30℃의 진탕배양기에서 24시간 동안 선배양하였다. 선배양 후, S. cerevisiae는 5000 rpm에서 10분 동안 원심 분리하였고, 증류수에 의하여 세척하였다. Celluclast 1.5L (Novo Co.) 및 NS-50010 (Novo Co.)이 효소가수분해(당화) 공정을 위하여 플라스크(250ml)에 투입되었고, 선배양된 S. cerevisiae (2g/l)를 발효공정을 위하여 연속하여 투입하였다. 이후 전처리한 바이오매스 (전건중량 5g) 및 아세트산나트륨 버퍼액(50ml)을 플라스크에 투입하여, 30℃, 150 rpm의 진탕배양기에서 96시간 동안 배양하였다. 배양 도중 시료(1ml)를 채취하여 에탄올 분석에 사용하였다. Saccharomyces as Yeast in Co-Saccharification Fermentation cerevisiae ATTC® 20062 (NREL-5DA) was employed. Prior to co-glycosylation fermentation, S. cerevisiae was added to YP medium and preincubated for 24 hours in a shaker at 30 ° C. After preculture , S. cerevisiae was centrifuged at 5000 rpm for 10 minutes and washed with distilled water. Celluclast 1.5L (Novo Co.) and NS-50010 (Novo Co.) were charged to a flask (250 ml) for enzymatic hydrolysis (glycosylation) process and pre-cultured S. cerevisiae (2 g / l) was added continuously for the fermentation process. Thereafter, the pretreated biomass (dry weight 5 g) and sodium acetate buffer solution (50 ml) were added to the flask and incubated for 96 hours in a shaker at 30 ° C. and 150 rpm. Samples (1 ml) were taken during the incubation and used for ethanol analysis.

분석예Analysis example

1. 단당류 및 에탄올 수율 분석1. Monosaccharide and Ethanol Yield Analysis

HPLC (HP 1100, Hewlett Packard, USA)를 이용하여 40℃에서 단당류 및 에탄올 수율을 분석하였다 (용리액-황산, 주입용량 5ul). 단당류 수율 분석으로는 SugarPakTM1 칼럼 (Waters, 6.5 × 300 mm, 5 um)을 사용하였고, 에탄올 수율 분석으로는 BioRad (Hercules, CA) Aminex HPX-87H 칼럼 (300 mm × 7.8 mm, 5 um)을 사용하였다. 물질의 정량은 굴절률 검출기 (HP 1100, Hewlett Packard, USA)로 분석하였다. 에탄올 수율은 NREL Chemical Analysis and Testing Standard Procedure LAP-008에 의하여 계산하였다 (LAP et al.)Monosaccharide and ethanol yields were analyzed at 40 ° C. using HPLC (HP 1100, Hewlett Packard, USA) (eluent-sulfuric acid, injection volume 5ul). SugarPakTM1 column (Waters, 6.5 × 300 mm, 5 um) was used for monosaccharide yield analysis and BioRad (Hercules, CA) Aminex HPX-87H column (300 mm × 7.8 mm, 5 um) for ethanol yield analysis It was. Quantification of the material was analyzed with a refractive index detector (HP 1100, Hewlett Packard, USA). Ethanol yield was calculated by NREL Chemical Analysis and Testing Standard Procedure LAP-008 (LAP et al.)

2. 화학 조성 분석2. Chemical Composition Analysis

산 가용성 리그닌 및 산 불용성 리그닌, 구성 당은 NREL Chemical Analysis and Testing Standard (NREL, 2005)에 따라 분석하였다 (NREL, 2005).Acid soluble lignin and acid insoluble lignin, constituent sugars were analyzed according to the NREL Chemical Analysis and Testing Standard (NREL, 2005) (NREL, 2005).

산성촉매(1% 황산)를 사용한 리기다소나무의 소화율은 반응온도 및 반응시간이 증가함에 따라 증가하였다 (도 1). 최대 소화율은 약 53-57%로 160℃에서 20분 동안 (반응온도-반응시간), 170℃에서 10분 동안, 170℃에서 20분 동안, 180℃에서 0분 동안, 180℃에서 10분 동안 및 190℃에서 0분 동안 전처리된 것이다. 중성촉매 (1% MgCl2)가 적용된 유기용매 전처리의 경우, 반응온도 및 반응시간이 증가함에 따라 소화율이 증가하였다 (도 2). 최대 소화율은 약 57-61%로 200℃에서 20분 동안 (반응온도-반응시간), 210℃에서 10분 동안, 210℃에서 20분 동안에서 전처리된 것이다. 산성촉매에 비하여 높은 온도 조건이 요구되었으나, 높은 소화율을 얻을 수 있었다. 한편, 염기성 촉매(1% NaOH)를 이용한 유기용매 전처리의 경우, 반응온도 및 반응시간이 증가함에도 불구하고 소화율이 향상되지 않았다. 210℃에서 20분 동안 (반응온도-반응시간)에서 처리한 바이오매스의 소화율이 불과 20%에 지나지 않았고, 미처리재의 소화율이 약 10%인 것을 감안하면 전처리의 효과가 거의 없었다.The digestibility of Rigidas pine with acid catalyst (1% sulfuric acid) increased with increasing reaction temperature and reaction time (FIG. 1). The maximum digestibility was about 53-57% for 20 minutes at 160 ° C. (reaction temperature-reaction time), 10 minutes at 170 ° C., 20 minutes at 170 ° C., 0 minutes at 180 ° C., 10 minutes at 180 ° C. And pretreated at 190 ° C. for 0 minutes. In the case of organic solvent pretreatment to which a neutral catalyst (1% MgCl 2) was applied, the digestibility increased with increasing reaction temperature and reaction time (FIG. 2). The maximum digestibility was about 57-61% pretreated for 20 minutes at 200 ° C. (reaction temperature-reaction time), for 10 minutes at 210 ° C. and for 20 minutes at 210 ° C. Higher temperature conditions were required than acidic catalysts, but high digestibility was obtained. On the other hand, in the case of organic solvent pretreatment using a basic catalyst (1% NaOH), the digestibility was not improved even though the reaction temperature and reaction time were increased. The digestibility of the biomass treated at 210 ° C. for 20 minutes (reaction temperature-reaction time) was only 20%, and considering that the digestibility of untreated material was about 10%, there was little effect of pretreatment.

전처리 후, 효소가수분해에 의한 소화율에 근거하여 SAS 프로그램 (SAS, version 9.1)을 이용한 통계적 유의성 분석을 실시하여 최적조건을 탐색하였다. 그 결과, 산성촉매 전처리 조건으로는 160℃-20분 (반응온도-반응시간), 170℃-10분, 170℃-20분, 180℃-0분, 180℃-10분, 190℃-0분을 얻을 수 있었으며, 중성촉매의 전처리의 조건으로는 200℃-20분과 210℃-10분을 얻을 수 있었다. 상기 조건에서 좀 더 세부적인 탐색을 위하여 전처리 후 바이오매스 수율 (이하 전처리수율), 효소당화에 의한 소화율 및 글루코오스 수율, 전처리 소요시간 및 온도를 수치화시킨 H-지표 및 가혹지표(severity factor)를 분석되었고 하기 표 1에 정리한다.After pretreatment, statistical significance analysis was performed using SAS program (SAS, version 9.1) based on digestibility by enzymatic hydrolysis. As a result, the acid catalyst pretreatment conditions were 160 ° C.-20 min (reaction temperature-reaction time), 170 ° C.-10 min, 170 ° C.-20 min, 180 ° C.-0 min, 180 ° C.-10 min, 190 ° C.-0 Minutes were obtained, and 200 ° C.-20 min and 210 ° C.-10 min were obtained as conditions for pretreatment of the neutral catalyst. Analyze the biomass yield after pretreatment (hereinafter pretreatment yield), digestibility and glucose yield by enzymatic saccharification, pretreatment time and temperature, and severity factor. And summarized in Table 1 below.

Figure 112010036643759-pat00001
Figure 112010036643759-pat00001

표 1은 산성 및 중성촉매를 이용한 유기용매 전처리 최적조건을 탐색 분석 결과를 보인다. 즉, 산성촉매-유기용매 전처리의 경우, 전처리 수율이 61.5%, 소화율이 57.0%, 글루코오스 수율이 75.5%로 최고 수치를, H-지표가 154.4, 가혹지표가 1.4로 최저 수치를 보이는 조건인 180℃-0분을 전처리 조건으로 선정하였다. 또한, 중성촉매가 적용된 유기용매 전처리의 경우, 210℃에서 10분 동안 전처리 바이오매스가 69.5%의 전처리 수율, 61.2%의 소화율과 75.9%의 글루코오스 수율로 좋은 효율을 보였다. H-지표의 경우 3650.2로 200℃에서 20분 동안의 전처리 바이오매스에 비하여 H-지표가 높았지만, 가혹지표가 4.2로 동일한 값을 나타내었으므로 전처리 조건으로 선정하였다. 한편, 염기성 촉매-유기용매 전처리의 경우, 상기된 바와 같이 1%의 NaOH를 촉매로 사용하였을 때 소화율이 210℃-20분의 가혹한 전처리 조건에서도 20% 정도로 거의 향상되지 않았다. 따라서 촉매의 농도를 2%로 높여 실시한 결과, 전처리 조건이 가혹해질수록 소화율이 계속 상승하였다 (도 3). 210℃에서 20분 동안의 전처리 바이오매스의 경우 소화율이 약 85.4% 정도로 매우 높았지만, 동시에 전처리 수율이 감소하여, 상대적으로 높은 58.8%의 전처리 수율과 58.0%의 높은 소화율을 모두 얻을 수 있는 190℃-20분을 최적 조건으로 선정하였다 (도 4). Table 1 shows the results of the search and analysis of the optimum conditions for organic solvent pretreatment using acidic and neutral catalysts. In the acidic catalyst-organic solvent pretreatment, the pretreatment yield was 61.5%, the digestibility was 57.0%, the glucose yield was 75.5%, and the H-index was 154.4, and the harshness index was 1.4. C-0 min was selected as pretreatment condition. In the case of the organic solvent pretreatment to which the neutral catalyst was applied, the pretreatment biomass showed good efficiency at 210 ° C. for 10 minutes with a pretreatment yield of 69.5%, a digestibility of 61.2%, and a glucose yield of 75.9%. In the case of the H-indicator, the H-indicator was higher than the pretreatment biomass at 200 ° C. for 20 minutes at 3650.2. However, since the harsh index had the same value as 4.2, it was selected as the pretreatment condition. On the other hand, in the case of basic catalyst-organic solvent pretreatment, as described above, when 1% NaOH was used as the catalyst, the digestibility was hardly improved to about 20% even under severe pretreatment conditions of 210 ° C-20 minutes. Therefore, as a result of increasing the catalyst concentration to 2%, as the pretreatment conditions were severe, the digestibility continued to increase (FIG. 3). The digestion rate of the pretreatment biomass for 20 minutes at 210 ° C. was very high at about 85.4%, but at the same time the pretreatment yield was reduced, resulting in a relatively high pretreatment yield of 58.8% and high digestibility of 58.0%. -20 min was chosen as the optimal condition (Figure 4).

상기와 같이 탐색된 최적 조건에서 글루코오스 전환율을 비교하기 위하여 전처리 후, Celluclast 1.5L 및 NS-50010을 이용하여 50℃에서 72시간 동안 효소 가수분해를 실시하여 글루코오스 전환율을 비교하였다 (도 5). 14.5% 가량의 전환율을 보이는 미-처리재료에 비하여, 상기 촉매가 적용된 경우 모두 글루코오스 전환율을 월등히 향상시킬 수 있었다. 특히 산성촉매의 경우 24시간 안에 93.7% 이상의 전환율을 보여 높은 효율을 나타냈고, 중성촉매 역시 83.6% 이상으로 우수한 전환율을 보였다. 염기촉매의 경우, 48시간 후 73.2% 이상의 글루코오스가 생산되었지만, 산성 및 중성촉매에 비하여 효율성이 상당히 떨어졌다.After the pretreatment in order to compare the glucose conversion rate at the optimum conditions as searched above, the glucose conversion rate was compared by performing enzymatic hydrolysis at 50 ° C. for 72 hours using Celluclast 1.5L and NS-50010 (FIG. 5). Compared to the untreated material showing a conversion rate of about 14.5%, all of the above catalysts were able to significantly improve the glucose conversion rate. In particular, the acidic catalyst showed a high conversion rate of 93.7% or more within 24 hours, and the neutral catalyst also showed an excellent conversion rate of 83.6% or more. In the case of the base catalyst, more than 73.2% of glucose was produced after 48 hours, but the efficiency was significantly lower than that of the acidic and neutral catalysts.

또한, 상기와 같이 탐색된 최적 조건에서 효소 및 Saccharomyces cerevisiae를 이용하여 30℃에서 96시간 동안 동시당화발효공정을 통한 에탄올 생산량을 비교하였다 (도 6). 이를 살펴보면, 산성촉매-유기용매로 전처리 바이오매스의 경우 24시간 안에 71.0%로 가장 높은 에탄올 수율을 획득하였으며, 중성촉매-유기용매 전처리 바이오매스는 약 59.8%로 높은 수율을 획득했다. 반면 염기성촉매-유기용매 전처리 바이오매스의 경우 45.4%로 가장 낮은 에탄올 수율을 나타냈다.In addition, enzymes and Saccharomyces under the optimal conditions as searched above The cerevisiae was used to compare the ethanol production through the simultaneous saccharification fermentation process at 30 ° C. for 96 hours (FIG. 6). In this regard, the pretreatment biomass with acidic catalyst-organic solvent obtained the highest ethanol yield of 71.0% within 24 hours and the neutral catalyst-organic solvent pretreatment biomass with high yield of about 59.8%. On the other hand, the basic catalyst-organic solvent pretreatment biomass showed the lowest ethanol yield of 45.4%.

상기 탐색 최적 조건에서 각각의 촉매를 이용하여 유기용매 전처리 한 후, 얻을 수 있는 바이오매스 양을 비교하기 위하여 전처리 수율을 비교하였다 (도 7). 1% 산 촉매-유기용매 전처리는 180℃에서 0분 동안 (반응온도-반응시간)에서, 1% 중성 촉매-유기용매 전처리는 210℃에서 10분 동안, 2% 염기 촉매-유기용매 전처리는 190℃에서 20분 동안 실시되었고, 결과는 도 7에 도시된다. 전처리 후 획득된 잔사 수율인 전처리 수율은 중성촉매를 이용한 유기용매 전처리에서 69.5%로 가장 높은 수율을 얻을 수 있었으며, 산성 및 염기성촉매를 이용한 유기용매 전처리의 경우 각각 61.5%와 58.8%로 상대적으로 낮은 수율을 얻을 수 있었다. 전처리 수율은 높을수록 전처리에 의하여 손실되는 바이오매스의 양이 적다는 것을 의미한다. 따라서 중성촉매를 이용한 유기용매 전처리에서 사용 가능한 바이오매스의 양이 가장 많다는 것을 의미한다. 이하, 촉매별 최적 조건에서 화학 조성을 분석하였다. 도 8에 정리된 바와 같이, 미-처리재료 화학 조성은 26.2%의 리그닌, 44.1%의 글루코오스, 16.6%의 아라비노오스, 13.6%의 갈락토오스로 구성되었다. 전처리에 의하여 헤미셀룰로오스가 가장 쉽게 분해되는 것을 확인할 수 있다. 리그닌의 함량은 산성촉매 및 중성촉매를 이용한 전처리 후에는 감소하지 않았으나, 염기촉매를 이용한 전처리 후에는 11.7%로 측정되어 리그닌의 상당량이 감소한 것을 확인할 수 있다. 또한, 글루코오스의 함량은 중성 촉매-유기용매 전처리 바이오매스에서 가장 높게 나타났다. 중성 촉매-유기용매 전처리 중 글루코오스의 손실이 거의 없었으나, 산 및 염기 촉매를 이용한 전처리의 경우 글루코오스의 손실이 상당량 발생하였다.Pretreatment yields were compared to compare the amount of biomass obtained after organic solvent pretreatment with each catalyst at the search optimum conditions (FIG. 7). 1% acid catalyst-organic solvent pretreatment at 180 ° C. for 0 min (reaction temperature-reaction time), 1% neutral catalyst-organic solvent pretreatment at 210 ° C. for 10 min, 2% base catalyst-organic solvent pretreatment 190 20 min at < RTI ID = 0.0 > C < / RTI > and the results are shown in FIG. The pretreatment yield, the residue yield obtained after pretreatment, was the highest at 69.5% in organic solvent pretreatment using neutral catalyst, and relatively low at 61.5% and 58.8% for organic solvent pretreatment using acidic and basic catalysts, respectively. Yield could be obtained. The higher the pretreatment yield, the less biomass lost by the pretreatment. Therefore, it means that the amount of biomass that can be used in the organic solvent pretreatment using a neutral catalyst is the largest. Hereinafter, the chemical composition was analyzed under the optimum conditions for each catalyst. As summarized in FIG. 8, the untreated material chemical composition consisted of 26.2% lignin, 44.1% glucose, 16.6% arabinose, and 13.6% galactose. It can be seen that hemicellulose is most easily decomposed by pretreatment. The content of lignin did not decrease after pretreatment with acidic catalyst and neutral catalyst, but after pretreatment with base catalyst, it was measured at 11.7%. In addition, the content of glucose was highest in neutral catalyst-organic solvent pretreatment biomass. There was little loss of glucose during neutral catalyst-organic solvent pretreatment, but significant loss of glucose occurred in pretreatment with acid and base catalysts.

요약하면, 산성촉매인 황산은 상대적으로 낮은 온도에서도 에탄올 효율이 우수하지만 전처리 수율이 낮고 전처리 중 글루코오스 손실이 발생하였다. 중성촉매인 MgCl2의 경우 효소가수분해 및 동시당화발효 공정의 효율 향상 측면에서 효과적이었으나, 우수한 효율을 얻으려면 고온 전처리가 필요하다. 그러나 높은 전처리 수율을 얻을 수 있었으며, 글루코오스 손실이 거의 발생하지 않는다. 한편 염기성촉매인 NaOH의 경우 리그닌의 효과적인 제거로 인한 소화율의 향상을 기대할 수 있으나 낮은 전처리 수율 및 높은 글루코오스 손실로 인한 문제가 발생한다. 공정 측면과 함께 고려될 때, 황산의 경우 부식성 및 독성, 발효 공정에 대한 저해제 생성 등으로 인한 여러 문제점으로 인하여 현재 사용이 지양되고 있고, 수산화나트륨은 고가이면서 동시에 침엽수에 대한 낮은 효율성으로 인하여 전처리 공정에 대한 경쟁력이 떨어진다. 따라서 본 발명에서 적용되는 중성촉매의 사용은 산성 및 염기성촉매에 비하여 상대적으로 부식성 및 독성이 적으며 유해성이 낮을 뿐 아니라 높은 전처리 수율로 인하여 실질적 글루코오스 및 에탄올 수율이 우수하여 산성촉매 대비 더욱 효율이 우수하다. 더불어, 중성촉매라는 점을 고려하면 공정의 규모를 늘렸을 때, 전처리 후 세척과정이 생략 가능하여 산성 및 염기 촉매에 비하여 공정의 간편성 및 좋은 효율을 보일 것이다.
In summary, sulfuric acid, an acid catalyst, has excellent ethanol efficiency at relatively low temperatures, but has low pretreatment yield and glucose loss during pretreatment. The neutral catalyst, MgCl 2 , was effective in improving the efficiency of enzymatic hydrolysis and co-glycosylation fermentation process, but high temperature pretreatment is required to obtain excellent efficiency. However, high pretreatment yields were obtained, with little loss of glucose. On the other hand, NaOH, which is a basic catalyst, can be expected to improve digestibility due to effective removal of lignin, but problems arise due to low pretreatment yield and high glucose loss. Considered in conjunction with the process aspects, sulfuric acid is currently being deprecated due to various problems due to corrosiveness and toxicity, generation of inhibitors to the fermentation process, and sodium hydroxide is expensive and at the same time pretreatment process due to low efficiency for conifers. To be less competitive. Therefore, the use of the neutral catalyst applied in the present invention is relatively less corrosive, less toxic and less harmful than acidic and basic catalysts, and is superior in efficiency to acidic catalysts due to its excellent yield of glucose and ethanol due to high pretreatment yield. Do. In addition, considering that it is a neutral catalyst, when the scale of the process is increased, the washing process after the pretreatment can be omitted, and thus the process efficiency and good efficiency will be shown as compared to the acidic and base catalysts.

Claims (4)

리기다소나무 목분을 당화 및 발효처리하여 바이오에탄올을 제조하는 방법에 있어서, 상기 당화 처리 단계 전에 에탄올 전처리 단계를 포함하며, 에탄올 전처리 단계는 활엽수종과 비교하여 고-리그닌 특성의 침엽수종 유래 원료를 10~20분 동안 200~210℃에서 염화마그네슘이 첨가된 에탄올에 담지하는 것을 특징으로 하는, 바이오에탄올 제조방법.
In the method of producing bioethanol by saccharifying and fermenting Rigida pine wood powder, the step of ethanol pretreatment includes the step of ethanol pretreatment before the step of saccharification, wherein Bioethanol production method, characterized in that supported on ethanol to which magnesium chloride is added at 200 ~ 210 ℃ for ~ 20 minutes.
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KR20190024433A (en) 2017-08-31 2019-03-08 한국화학연구원 Total usage of lignocellulosic biomass through organic solvent pretreatment process
KR20190125718A (en) * 2018-04-30 2019-11-07 (주)웰크론한텍 A Process for Continuous Hydrolysis of Lignocellulosic Biomass
WO2019212067A1 (en) * 2018-04-30 2019-11-07 (주)웰크론한텍 Method for continuous hydrolysis of herbaceous biomass

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20090111037A (en) * 2008-04-21 2009-10-26 지에스칼텍스 주식회사 Method for pretreating lignocellulosic biomass and method for manufacturing bio-fuel using the same
KR101055623B1 (en) 2008-02-29 2011-08-10 고려대학교 산학협력단 Biological pretreatment and saccharification method of lignocellulosic biomass and preparation method of bioethanol comprising same

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR101055623B1 (en) 2008-02-29 2011-08-10 고려대학교 산학협력단 Biological pretreatment and saccharification method of lignocellulosic biomass and preparation method of bioethanol comprising same
KR20090111037A (en) * 2008-04-21 2009-10-26 지에스칼텍스 주식회사 Method for pretreating lignocellulosic biomass and method for manufacturing bio-fuel using the same

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20190024433A (en) 2017-08-31 2019-03-08 한국화학연구원 Total usage of lignocellulosic biomass through organic solvent pretreatment process
KR20190125718A (en) * 2018-04-30 2019-11-07 (주)웰크론한텍 A Process for Continuous Hydrolysis of Lignocellulosic Biomass
WO2019212067A1 (en) * 2018-04-30 2019-11-07 (주)웰크론한텍 Method for continuous hydrolysis of herbaceous biomass
KR102100887B1 (en) 2018-04-30 2020-04-14 (주)웰크론한텍 A Process for Continuous Hydrolysis of Lignocellulosic Biomass

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