The transesterification of vegetable oils into Biodiesel at 60℃ was performed on the rotary viscometer. The overall yield(%) of fatty acid methyl ester from canola oil at optimum conditions was 95%. The viscosities of fatty acid methyl esters were predicted by Orrick and Erbarr's model. The overall yield increased as the viscosities of fatty acid methyl esters decreased. The limiting molar ratio of methanol to oil appeared to be 1:5. The content of sodium hydroxide as the optimum catalyst appeared to be 0.5wt%.

Bio-diesel as fatty acid methyl ester was derived from such oils as soybean, peanut and canola oil by lipase catalyzed continuous trans-esterification. So the activation of lipase(Novozym - 435) was kept to be up to 4:1, the limiting molar ratio of methanol to oil under one-step addition of methanol due to the miscibility of oil and methanol through the static mixer for 4hrs and the elimination of glycerol on the surface of lipase by 7wt% silica gel. Therefore the overall yield of fatty acid methyl ester from soybean oil appeared to be 98% at 50·C of reaction temperature under two-steps addition of methanol with 2×2:1 of methanol to oil molar ratio at an interval of 5.5hrs, 7wt% of lipase, 24 number of mixer elements, 0.2ml/min of flow rate and 7wt% of silica gel.

Biodiesel as methyl esters derived from vegetable oils has considerable advantages in terms of environmental protetion. In the present work, methyl esters were produced from soybean oil by lipase-catalyzed transesterification. To reduce inactivation of commercial immobilized lipases emulsified two-step process was developed using the stepwise addition of methanol with 4:1 molar ratio at 4h intervals. Also with immobilized lipase from Candida antarctica(Novozym 435) high conversion of 98.5 percent was possible at 45℃ of reaction temperature with 4:1 of methanol-to-oil molar ratio and 1%(v/v) methyl glucoside oleic polyester as an emulsifier in the presence of cosolvent.

산업혁명 이후 화석연료를 통한 에너지의 소비는 이산화탄소의 형태로 전례 없는 대기 중 탄소의 유입을 증가시켰다. 인류에 의해 발생된 이산화탄소 형태의 탄소 유입은 지구온난화와 같은 전 지구적 환경 문제를 유발하였다. 따라서 다양한 분야에서 탄소유입을 줄이기 위한 노력은 진행되어 왔다. 대표적으로 화석 연료의 대체가 가능한 바이오 연료는 비교적 쉬운 생산 공정과 기반시설에 대한 뛰어난 적응력으로 인해 상업화 되었다. 그러나 상업화 된 바이오 연료는 식용작물의 사용으로 인해 원료의 가격상승과 윤리 도덕적 문제를 초래하였다. 이를 극복하기 위해 폐유와 미세조류와 같은 비식용 작물의 바이오 연료 전환이 연구 되었다. 값싼 원료의 이점에도 불구하고, 원료의 불순물(유리 지방산, 수분 등)의 제거를 위한 전처리 공정의 추가와 다양한 공정 설비 및 운영비용은 새로운 바이오 연료의 생산기술 향상에 대한 요구로 나타났다. 특히, 전이에스테르화 반응을 통해 비교적으로 기술적인 연구가 활발히 진행된 바이오 디젤의 경우 초임계 조건, 효소, 초음파를 활용한 반응이 활발히 연구되어져왔다. 또한 다공성 물질을 활용한 촉매 모사 전이에스테르화 반응은 유리 지방산, 수분같은 불순물 하에서도 높은 전환율을 유지하는 것으로 확인 되었다. 촉매모사 전이에스테르화 반응은 수많은 공극이 존재하는 다공성 물질을 이용하여, 반응물의 충돌 빈도를 상승시킴으로써 촉매 사용으로 발생하는 단점을 최소화하였다. 이전까지 촉매모사반응의 다공성 물질로써 상업화된 실리카겔을 사용하였으나 바이오매스를 활용한 바이오 차의 다공성 물질로써 활용이 연구됨에 따라, 바이오매스 유래 바이오 차의 촉매모사 전이에스테르화 반응에 대한 적용 연구를 제시하고자 한다. 다양한 바이오차 중에 다양한 물리적 화학적 성질을 가지고 있는 계분은 촉망받는 다공성 물질로 여겨진다. 또한 폐식용유는 촉매모사 반응의 높은 유리 지방산 저항력을 증명하기 위해 원료로써 선택되었다.

Biochemical methane potential (BMP) of residual wastes from transesterification was tested to safely recycle carcass via rendering process. The carcass was obtained from a buried site for avian influenza (AI) infected poultry. Rendered lipid generated by a pilot-scale high-pressure rendering process was the main source of transesterification for biodiesel recovery. To test the feasibility of waste-to-energy approach for AI infected carcass, we compared the BMPs of various fractions of rendered materials from the carcass. BMP and specific methanogenic activity results indicate that transesterification waste shows better digestibility than that of rendered lipid, and the digestion performance was comparable to that of liquid residue. Biogas yields of glycerol, rendered lipids, and liquid residue were estimated as 0.11 L/g chemical oxygen demand (COD), 0.06 L/g COD, and 0.17 L/g COD, respectively. Regression analysis support that biogas production rate of glycerol (21 mL/g COD/d) was much faster than that of lipid (7 mL/g COD/d) while that of liquid residue was similar (24 mL/g COD/d). In summary using transesterification waste as a bioresource for bioenergy conversion can be a viable and sustainable option for the complete termination of burial site.

Characteristics of the transesterification reaction between triglycerides in soy bean oil and methanol were investigated in the presence of acid catalysts. such as sulfuric acid and PTS (p-toluene sulfonic acid). Concentrations of diglyceride and monoglyceride which were intermediates in the reaction mixtures, were far below 10% of triglyceride under any reaction conditions. Thus, conversion of the reaction could be determined from the concentration of triglyceride. Dried PTS had more superior catalytic power than sulfuric acid for transesterification reaction between soy bean oil and methanol. When transesterification reaction of soy bean oil was catalyzed by 1 wt% of PTS at methanol stoichiometric mole ratio of 2 and 65℃, final conversion reached 95% within 48 hours. If FAME (fatty acid methyl ester) was added into reaction mixture of soy bean oil, methanol and PTS catalyst, it converted reaction mixture into homogeneous phase, and substantially increased reaction rate. When reaction mixture was freely boiling which had equal volumetric amount of FAME to soy bean oil, methanol stoichiometric mole ratio of 2 and 1 wt% of PTS, final conversion achieved value of 94% and temperature approached to 110℃ within 2 hours.