• 신재생에너지
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• 제6권4호
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• pp.6-14
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• 2010

Pretreatment of cellulosic biomass is necessary before enzymatic saccharification and fermentation. Extrusion is a well established process in food industries and it can be used as a physicochemical treatment method for cellulosic biomass. Aqueous ammonia soaking treatment at mild temperatures ranging from 60 to $80^{\circ}C$ for longer reaction times has been used to preserve most of the cellulose and hemicellulose in the biomass. The objective of this study was to evaluate the effect of extrusion treatment on aqueous ammonia soaking method. Extrusion was performed with miscanthus sample conditioned to 2mm of particle size and 20% of moisture content at $200^{\circ}C$ of barrel temperature and 175rpm of screw speed. And then aqueous ammonia soaking was performed with 15%(w/w) ammonia solution at $60^{\circ}C$ for 1, 2, 4, 8, 12 hours on the extruded and raw miscanthus samples respectively. In the combined extrusion-soaking treatment, most compositions removal occurred within 1~2 hours and on a basis of 1 hour soaking treatment values, cellulose was recovered about 85% and other compositions, including hemicellulose, are removed about 50% from extruded miscanthus sample. The combined extrusion-soaking treated and soaking only treated samples were subjected to enzymatic hydrolysis using cellulase and ${\beta}$-glucosidase. The enzymatic digestibility value of combined extrusion-2 hours soaking treated sample was comparable to 12 hours soaking only treated sample. It means that extrusion treatment can shorten the conventional long reaction time of aqueous ammonia soaking. The findings suggest that the combination of extrusion and soaking is a promising pretreatment method to solve both problems for no lignin removal of extrusion and long reaction time of aqueous ammonia soaking.

• 펄프종이기술
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• 제41권5호
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• pp.15-19
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• 2009

Ammonia soaking treatment was introduced for hemp woody core pretreatment to increase enzymatic saccharification of polysaccharides. Portions of the xylan, cellulose, and lignin were removed by aqueous ammonia soaking, which improved the enzymatic saccharification of cellulose and xylan. Following ammonia soaking, 37% ($50^{\circ}C$-6 day treatment) to 61% ($90^{\circ}C$-16 h treatment) of the cellulose was converted to glucose and 33% ($50^{\circ}C$-6 day treatment) to 48% ($90^{\circ}C$-16 h treatment) of the xylan to xylose. Cellulose responded better to enzymatic saccharification than did xylan after the ammonia soaking treatment. Aqueous ammonia soaking pretreatment was more effective than electron beam irradiation for increasing enzymatic saccharification of xylan and cellulose in hemp woody core.

• Korean Chemical Engineering Research
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• 제49권3호
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• pp.292-296
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• 2011

섬유소계 바이오매스의 전처리를 위한 암모니아수에 의한 침지공정(SAA; Soaking in Aqueous Ammonia)은 낮은 온도와 낮은 압력의 조건에서 수행하는 전처리 공정으로 고온고압이 필요로 하는 다른 전처리방법에 비해 그에 대한 비용을 절감할 수 있다는 장점이 있다. 본 연구에서는 다양한 바이오매스를 SAA공정에 적용시켜 그 특성을 보고자 한다. 실험을 행한 전처리 공정의 온도, 반응시간 그리고 암모니아수의 농도는 각각 $50{^{\circ}C}$, 72시간 그리고 15 wt%이다. 전처리 공정에 의해 초본계열은 탈리그닌이 초기 성분에 대해 60%로 되었고 전처리 전의 10-20%에 불과하던 당전환율이 전처리 후에 60-90%의 당전환율로 약 80%가 향상된 것으로 나타났지만 목본계열의 리그닌 성분은 10%정도만 제거되었고 당전환율은 전처리하지 않는 것과 별다른 차이를 보이지 않았다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 춘계학술대회 논문집
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• pp.418-421
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• 2009

Effects of aqueous ammonia soaking to three annual plants (hemp woody core, tobacco stalk and corn stover) awere investigated to focus on the enzymatic saccharification characteristics change by this treatment. At two different levels of treatment ($90^{\circ}C$-16 h and $45^{\circ}C$-6 days), higher temperature treatment led to more enzymatic saccharification of cellulose to glucose by commercial cellulase mixtures (Celluclast 1.5L and Novozym 342 from Novozyme Korea). Difference among annual plants were significant. corn stover was the best response to enzymatic saccharification of cellulose and xylan by comercial enzymes all treatment conditions but tobacco stalk was the worst response to all of them. chemical composition or physical structure difference may brought this difference.

• 펄프종이기술
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• 제41권1호
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• pp.61-66
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• 2009

Effects of aqueous ammonia soaking treatments to yellow poplar (Liriodendron tulipifera L.) were investigated to focus on chemical compositional changes and enzymatic hydrolysis characteristics changes by this treatment. Treatment temperature and time were main variables. At 3 different levels of aqueous ammonia soaking temperature and time ($145^{\circ}C$ -1 h, $90^{\circ}C$ -16 h and $45^{\circ}C$ - 6 days), lower temperature and longer soaking time led to more xylan removal based on carbohydrate compositional analysis. However, at higher temperature treatment led to more enzymatic saccharification of cellulose to glucose by commercial cellulose mixtures (Celluclast 1.5L and Novozym 342 from Novozyme, Denmark). Cellulose hydrolysis was gradually increased with increasing enzymatic hydrolysis time but xylan hydrolysis was leveled out at early stage (less than 10 h) of enzymatic hydrolysis.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 추계학술대회 초록집
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• pp.114.1-114.1
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• 2011

Bioenergy production from lignocellulosic biomass and agriculture wastes have been attracted because of its sustainable and non-edible source. Especially, canola is considered as one of the best feedstock for renewable fuel production. Oil extracted canola and its agriculture residues are reuseable for bioethanol production. However, a pretreatment step is required before enzymatic hydrolysis to disrupt recalcitrant lignocellulosic matrix. To increase the sugar conversion, more efficient pretreatment process was necessary for removal of saccharification barriers such as lignin. Alkaline pretreatment makes the lignocellulose swollen through solvation and induces more porous structure for enzyme access. In our previous work, aqueous ammonia (1~20%) was utilized for alkaline reagent to increase the crystallinity of canola residues pretreatment. In this study, significant factors for efficient soaking in aqueous ammonia pretreatment on canola residues was optimized by using the response surface method (RSM). Based on the fundamental experiments, the real values of factors at the center (0) were determined as follows; $70^{\circ}C$ of temperature, 17.5% of ammonia concentration and 18 h of reaction time in the experiment design using central composition design (CCD). A statistical model predicted that the highest removal yield of lignin was 54% at the following optimized reaction conditions: $72.68^{\circ}C$ of temperature, 18.30% of ammonia concentration and 18.30 h of reaction time. Finally, maximum theoretical yields of soaking in aqueous ammonia pretreatment were 42.23% of glucose and 22.68% of xylose.

• Journal of the Korean Wood Science and Technology
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• 제37권4호
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• pp.381-387
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• 2009

본 연구는 암모니아수 침지 처리가 옥수수대의 화학 조성과 효소당화 특성에 미치는 영향에 대하여 연구한 것이다. 암모니아수 침지에서 처리 온도와 시간이 본 연구에서 주요 변수였다. 무 처리 분말과 침지 처리 분말의 전체 조성 분석과 탄수화물 조성 분석 결과, 3가지 다른 수준의 암모니아수 침지 조건($140^{\circ}C$ - 1 h, $90^{\circ}C$ - 16h 및 $50^{\circ}C$ - 6일)에서 고온 단기간 처리가 더 많은 양의 자이란과 리그닌을 용출시켰다. 암모니아 침지에 의한 자일란과 리그닌 용출 제거 효과가 고온 침지 처리 된 옥수수 줄기 분말에서 상업용 셀룰라아제를 사용하는 셀룰로오스와 자이란의 효소 당화를 촉진시켰다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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• pp.253-253
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• 2010

Rice straw was pretreated with aqueous ammonia in order to enhance enzyme digestibility. Soaking in ammonia aqueous (SAA) was conducted with 15% ammonia, at $60^{\circ}C$. for 24 h. Optimization of both saccharification conditions and enzyme loading of SAA rice straw was carried out. Especially enzyme loading test was performed using statistical method. Moreover proton beam irradiation (PBI) was also performed to overcome the problem which inhibit the enzyme digestibility at 1-25 kGy doses with 45 MeV of beam energy. Optimal condition for enzymatic saccharification was follows; pH 4.8, $50^{\circ}C$, 60 FPU of enzyme activity, 1:4 ratio of celluase and ${\beta}$-glucosidase. Also, optimal doses of PBI on rice straw and SAA-treated rice straw for efficient sugar recovery were found to be 3 kGy, respectively. When saccharification was performed with optimal condition, glucose conversion yield was 89% of theocratical maximum in 48 h, and 3 kGy of PBI was applied to SAA-treated rice straw, approximately 90% of the theoretical glucose yield was obtained in 12 h. The results of X-ray diffractometry (XRD) support the effect of both SAA and PBI on sugar recovery, and scanning electron microscopy (SEM) images unveiled the physical change of the rice straw surface since rugged rice straw surface was observed.

• Korean Chemical Engineering Research
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• 제51권3호
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• pp.303-307
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• 2013

이 연구는 목질계 바이오매스에 대한 알칼리 용액의 침지와 침출 전처리의 효능을 비교한다. 볏짚과 보리짚과 같은 다양한 바이오매스는 수산화나트륨 용액, 수산화칼륨 용액, 암모니아수 그리고 탄산나트륨 용액에 의해 침지 공정으로 수행되었다. 암모니아수에 의해 전처리된 볏짚과 보리짚의 효소 소화율은 80% 이상으로 나타났다. 전처리된 유칼립투스 부산물, 낙엽송 그리고 리기다 소나무의 효소 소화율은 상대적으로 낮은 범위로 나왔다. 하지만 전처리된 유칼립투스 부산물은 초기 바이오매스에 비해 효소 소화율이 약 5배 증가되었다. 또한 침출 공정으로 전처리된 유칼립투스 부산물의 효소 소화율은 약 12배가 증가되는 것을 확인하였다.

• Korean Chemical Engineering Research
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• 제53권6호
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• pp.682-689
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• 2015

A two-step process was investigated for pretreatment and fractionation of rice straw. The two-step fractionation process involves first, soaking rice straw in aqueous ammonia (SAA) in a batch reactor to recover lignin-rich hydrolysate. This is followed by a second-step treatment in a fixed-bed flow-through column reactor to recover xylo-oligomer-rich hydrolysate. The remaining glucan-rich solid cake is then subjected to an enzymatic process. In the first variant, SAA treatment in the first step dissolves lignin at moderate temperature (60 and $80^{\circ}C$), while in the second step, hot-water treatment is used for xylan removal at higher temperatures ($150{\sim}210^{\circ}C$). Under optimal conditions ($190^{\circ}C$ reaction temperature, 30 min reaction time, 5.0 ml/min flow rate, and 2.3 MPa reaction pressure), the SAA-hot-water fractionation removed 79.2% of the lignin and 63.4% of the xylan. In the second variant, SAA was followed by treatment with dilute sulfuric acid. With this process, optimal treatment conditions for effective fractionation of xylo-oligomer were found to be $80^{\circ}C$, 12 h reaction time, solid-to-liquid ratio of 1:12 in the first step; and 5.0 ml $H_2SO_4/min$, $170^{\circ}C$, and 2.3 MPa in the second step. After this two-step fractionation process, 85.4% lignin removal and 78.9% xylan removal (26.8% xylan recovery) were achieved. Use of the optimized second variant of the two-step fractionation process (SAA and $H_2SO_4$) resulted in enhanced enzymatic digestibility of the treated solid (99% glucan digestibility) with 15 FPU (filter paper unit) of CTec2 (cellulase)/g-glucan of enzyme loading, which was higher than 92% in the two-step fractionation process (SAA and hot-water).