Fossil fuels have a high energy density, meaning they contain a significant amount of energy per unit of volume, making them efficient for energy production and transport. Biodiesel is especially becoming a fossil fuel alternative and a key part of renewable energy. Several types of waste from homes, markets, street vendors, and other industrial places were collected and transesterified with Ni-doped ZnO nanoparticles for this study. These included castor oil, coffee grounds, eggshells, vegetable oil, fruit peels, and soybean oil. The Ni-doped ZnO’s were then calcined at 800 °C. The maximum conversion rate found in converting fruit peel waste into biodiesel is about 87.6%, and it was 89.6% when the oil-to-methanal ratio was about 1:2 and the reaction time was 140 min. This is the maximum biodiesel production compared to other wastes. Moreover, using vegetable oil with nanocatalyst, the maximum biodiesel production rate of about 90.58% was recorded with 15% catalyst loading, which is the maximum biodiesel production compared with the other wastes with nanocatalyst. Furthermore, at 75 °C and a concentration of catalyst of about 15% the maximum biodiesel production obtained by using castor oil is about 92.8%. It has the highest biodiesel yield compared with the yield recorded from other waste. The catalyst also demonstrated great stability and reusability for the synthesis of biodiesel. Using waste fruit peels with Ni-doped ZnO helps to progress low-cost and ecologically friendly catalyst for sustainable biodiesel production.

This research investigated the preparation of activated carbon derived from Krabok (Irvingia malayana) seed shells to improve the quality of crude glycerol obtained during biodiesel production. The activated carbon was prepared using a dry chemical activation method with NaOH, utilizing an innovative biomass incinerator. The results revealed that the resulting KC/AC-two-step exhibited favorable physicochemical adsorption properties, with a high surface area of 758.72 m2/g and an iodine number of 611.10 mg/g. These values meet the criteria of the industrial product standard for activated carbon No. TIS 900-2004, as specified by the Ministry of Industry in Thailand. Additionally, the adsorption efficiency for methylene blue reached an impressive 99.35 %. This developed activated carbon was then used to improve the quality of crude glycerol obtained from biodiesel production. The experimental results showed that the KC/AC-two-step increased the purity of crude glycerol to 73.61 %. In comparison, commercially available activated carbon (C/AC) resulted in a higher crude glycerol purity of 81.19 %, as analyzed by the GC technique. Additionally, the metal content (Zn, Cu, Fe, Pb, Cd, and Na) in purified glycerol using KC/AC-two-step was below the standards for heavy metals permitted in food and cosmeceuticals by the Food and Drug Administration of Thailand and the European Committee for Food Contact Materials and Articles. As a result, it can be inferred that Krabok seed shells have favorable properties for producing activated carbon suitable as an adsorbent to enhance crude glycerol purity. Furthermore, the improved crude glycerol from this research has potential for various industrial applications.

This study presents the synthesis, characterization, and utilization of marine macroalgae-derived bio-carbon catalysts (BC and KOH-AC) for the efficient conversion of waste cooking oil (WCO) into biodiesel. The biochar (BC) was produced through slow pyrolysis of macroalgal biomass, which was subsequently activated with potassium hydroxide (KOH) to produce a KOH-modified activated carbon (KOH-AC) catalyst. Advanced characterization techniques, including SEM, EDX, XRD, FTIR, and TGA, were used to examine the physicochemical characteristics of the catalysts. The synthesized catalysts were utilized to produce biodiesel from WCO, and the results revealed that the highest biodiesel yields, 98.96%, and 47.54%, were obtained using KOH-AC and BC catalysts, respectively, under optimal reaction conditions of 66 °C temperature, 12.3 M/O molar ratio, 130 min time, and 3.08 wt.% catalyst loading via RSM optimization. The kinetic and thermodynamic parameters, such as k, Ea, ΔH, ΔS, and ΔG, were determined to be 0.0346 min− 1, 43.31 kJ mol− 1, 38.98 kJ mol− 1, − 158.38 J K− 1 mol− 1, and 92.58 kJ mol− 1, respectively. The KOH-AC catalyst was recycled up to five times, with a significant biodiesel yield of 80.37%. The fuel properties of the biodiesel met ASTM (D6751) specifications, ensuring that it has excellent fuel characteristics and can be used as an alternative fuel.

This research aims to study the simultaneous extraction and transesterification of Chlorella vulgaris (C. vulgaris) using microwave irradiation with methanol as solvent and potassium hydroxide (KOH) as catalyst. The microwave-assisted insitu transesterification of C. vulgaris is assessed at various ratios of biomass-to-methanol, reaction times, and catalyst concentrations during the centrifugation and evaporation process. Gas chromatography-mass spectrometry (GC-MS) analysis is performed to confirm fatty acid methyl ester (FAME) composition. Biodiesel preparation is carried out by simultaneous extraction and transesterification of microalgae from C. vulgaris. The product is then characterized using Fourier transform infrared spectroscopy (FTIR) and proton nuclear magnetic resonance (1H-NMR); microalgae are observed using scanning electron microscopy (SEM). The highest amount of FAME is obtained at a biomass-to-methanol ratio of 1:12, reaction time of 40 min, and catalyst concentration of 2 wt%. Biodiesel shows conversion to about 77.64% of methyl ester (methyl myristate, methyl palmitoleate, methyl linoleate, methyl oleate, methyl arachidonate, and methyl 5,8,11,14,17-eicosapentanoate).

바이오디젤은 신재생연료이면서 환경 친화적인 수송용 액상 바이오연료이다. 곤충은 새로운 바이오디젤 원료로 여겨지고 있다. 특히, 동애등에는 높은 지질을 함유하고 있어 재생가능한 바이오디젤 원료이다. 동애등에 유래 바이오디젤은 포화지방산 함량이 높고 다불포화지방산 함량이 낮아 품질이 좋은 바 이오디젤을 만들 수 있다. 동애등에 유래 바이오디젤은 EN 14214의 대부분 품질기준을 만족한다. 동애등에는 기존의 식물성 원료, 미세조류에 비해 지질 수율이 높아 바이오디젤 생산성이 높다. 본 논문에서는 곤충 유래 바이오디젤의 전반적인 생산 방법과 품질 특성에 대해 서술하였다.

양송이 수확후 배지로부터 lipase 생산균을 분리하여 16S rDNA 유전자 분석을 통해 동정한 결과, Burkholderia cepacia ATCC와 99.8% 상동성을 나타냈다. 분리균 B. cepacia 배양여액 중에 함유된 효소단백질을 70% 황산암모늄으로 침전시켜 crude lipase를 회수하였다. 고정화 효소를 제조하기 위하여 crude lipase(CL)과 Novozyme lipase(NL)을 cross-linking 법에 의해 Silane화된 Silicagel에 고정화 시킨 결과, immobilized CL(ICL)은 61%, immobilized NL(INL)은 72%의 잔존활성을 유지하였다. 중성지방 Canola oil을 알칼리(NaOH) 촉매와 효소(CL 및 ICL) 촉매를 이용하여 지방산(fatty acid)으로 분해한 후, methanolysis에 의한 에스터전이반응(trans-esterification)을 통해 지방산으로부터 전환된 바이오디젤(fatty acid methyl ester, FAME)의 종류와 수율을 비교 하였다. 생성된 총 FAME 함량은 NaOH 781mg L-1, free lipase 681mg L-1, 고정화 lipase 598mg L-1순으로 높았으며, 지방산 조성별 FAME 함량은 linoleic acid(C18:1)가 약 50%로 가장 높았으며, stearic acid(C18:0)가 22%정도의 높은 수준이었다. 또한 반응시간이 증가함에 따라 CL과 ICL 모두 불포화지방산 FAME의 조성비는 감소하고, 상대적으로 포화지방산 FAME의 조성비는 증가하는 경향을 보여 lipase 효소가 transesterification 활성과 interesterification 활성을 동시에 가지는 것으로 여겨진다. 고정화효소의 잔여활성은 반복회수가 증가함에 따라 서서히 감소하여 4회 반복 후, 초기 활성도에 비해 ICL은 34% 와 INL은 21%까지 감소하였다.

에너지 소비의 증가와 화석 연료의 감소로 인해 바이오디젤과 같은 재생 가능한 대체 에너지 자원이 관심을 받고 있다. 미세조류를 이용한 바이오디젤은 기존의 농작물과 경쟁하지 않는 것과 더불어 많은 장점을 갖고 있다. 본 연구에서는 미세조류 배양의 생산 비용 절감과 축산 폐수 처리라는 두 가지 목표를 충족시키지 위해 돈분 액체 비료를 사용하였다. 옥외 배양 시스템(Small Scale Raceway Pond; SSRP)과 희석된 돈분 액체 비료를 이용하여 단일 미세조류 Chlorella sp. JK2, Scenedesmus sp. JK10 과 혼합 토착 미세조류 CSS를 20일 동안 각각 배양하였다. 미세조류 혼합균주인 CSS의 바이오매스 생산과 지질 생산성은 각각 1.19±0.09 g L-1, 12.44±0.38mg L-1 day-1로 단일 종에 비해 2배 이상 높았다. 돈분 액체 비료의 TN, TP의 제거율 역시 혼합 토착 미세조류 CSS에서 93.6%, 98.5%로 단일 종의 이용에 비해 30% 이상 높은 제거 효율을 보여주었다. 이를 통해 돈분 액체 비료는 미세조류 배양에 필요한 N과 P를 제공하며, 미세조류를 이용한 SSRP를 통하여 영양염류를 제거할 수 있는 가능성을 확인하였다. 또한 미세조류 배양을 위한 생산 비용의 감소로 경제성 있는 바이오디젤의 생산 가능성을 확인하였다.

하수 슬러지로부터 추출된 유지를 이용하여 바이오디젤 생산에 대해 고찰하였다. 바이오디젤 생산의 밝은 전망에도 불구하고, 이를 상용화하기 위한 노력은 매우 제한되어 있다. 주요 장애물 중 하나는 전체 생산비용의 약 70~75%를 구성하는 정제 유지의 공급 원료와 연관된 높은 가격이다. 따라서 이를 극복하기 위하여 폐유나 낮은 품질 유지 등의 저가 원료를 사용하여 바이오디젤의 생산 비용을 낮추는 기술이 제안되어 왔다. 이런 측면에서 하수 슬러지로부터 추출된 유지는 비교적 저렴하여 유망한 원료로 평가받고 있다. 본 연구에서는 하수 슬러지로부터 추출된 유지를 이용한 바이오디젤의 생산기술을 검토하였다. 하수 슬러지로부터 유지 추출공정 및 에스테르화 전환공정 및 무촉매 열화학 전환공정을 살펴보았다.

The demand of energy is increasing around the world due to the high dependency of our society on energy. So the worldwide recognition of the limited supply of fuels has led to a large scale effort in search of alternative energy sources. Biodiesel has been considered as an alternative fuel to the petroleum diesel in compression ignition engines and is receiving more and more attention. Biodiesel can be obtained by the transesterification of methanol with triglycerides, with glycerin as by- product. This paper introduces the transesterification reaction of lard oil with methanol in the presence of hexane as solvent and potassium hydroxides as catalyst. Different from other researches, a new method to analyze the reaction process in this research was developed by starting with the by-product, crude glycerin. This new method was verified and the effects of various parameters such as solvent, molar ratio of methanol to oil (3:1-12:1), catalyst concentration (0.5-4 wt%) on the traneseterification process were investigated. Molar ratio of methanol to oil was optimized and identified to be 8:1, catalyst concentration of 2 wt% with hexane as solvent and at a temperature of 57℃ were found to be optimum for the reactions. Under this condition for 4 hours, the production yield can be 96.95%.

카놀라유, 대두유, 자트로파유와 메탄올을 연속적으로 분리막 반응기에 순환시켜 바이오디젤을 제조하였다. 분리막은 반응기 역할과 반응 생성물로부터 미반응된 유지를 분리하여 고순도의 fatty acid methyl ester (FAME)를 생산하는 역할을 한다. 공칭 세공크기 0.2, 0.5 μm인 정밀여과형 세라믹 관형 분리막을 사용하였다. 운전압력 0.5 bar에서 0.2 μm 정밀여과막에 대한 투과유속은 공급유량 400 mL/min일 경우 15 L/m2·hr이었다. 또한 투과액중 FAME 함량은 0.5 bar에서 가장 높았으며 운전압력이 증가할수록 감소하였다.

Transesterification of fat of Tra catfish with methanol in the presence of the KOH catalyst yields fatty acid methyl esters (FAME) and glycerol (GL). The effects of the reaction temperature and reaction time on rate constants and kinetic order were investigated. Three regions were observed. In the initial stage, the immiscibility of the Tra fat and methanol limited the reaction rate, hence this region was controlled by the mass transfer. Subsequent to this region, produced FAME like a co-solvent made the reaction mixture homogeneous, therefore the conversion rate increased rapidly so it was controlled by the kinetic parameters of the reaction until the equilibrium was approached in the final slow region. A second-order kinetic mechanism was proposed involving second regions for the forward reaction. The rate determining step for the overall KOH catalyzed-methanolysis of Tra fat was the conversion of triglycerides (TG) to diglycerides (DG). This rate constant was increased from 0.003 to 0.019min-1 when the reaction temperature was increased from 35 to 60℃. Its calculated activation energy was 14.379 (kcal.mol-1).

The fat of Tra and Basa catfish (Mekong Delta, Viet Nam) was evaluated for the first time as the potential feedstock for biodiesel production, due to its abundance, availability and cheap cost. The unsaturated fatty acid contents of Tra and Basa fat were 57.97% and 64.17%, respectively. Biodiesel was prepared from Tra and Basa fat by methanolysis reaction using alkali catalysts like sodium hydroxide and potassium hydroxide. Effects of various process parameters on biodiesel production, such as molar ratio of methanol to fat, catalyst concentration, temperature and time were investigated. As those results, the transesterification can be performed under moderate conditions, and the biodiesel yields were shown more than 90%. KOH catalyst was the best catalyst for biodiesel production from both Basa and Tra fat. As the feedstock aspect, Basa fat was indicated more efficiency than that of Tra fat. The maximum yield could be achieved by the transesterification from Basa fat with 5:1 molar ratio of methanol to fat, 0.8% KOH catalyst, 50℃, and 50 min. For Tra fat, the optimal condition were at 6:1 molar ratio of methanol to fat, 0.8% KOH catalyst, 50℃, and 45 min. Nowadays, due to cheaper cost and abundance, Tra fat is a promised resource for cheap biodiesel production in Viet Nam.

Flesh wasters from tannery create major environmental problems. Despite their considerable fat content, these waster do not find important usage. Their disposal is also troublesome and costly. We have investigated the possible use of this fat as the production of biodiesel(fatty acid methyl esters) by transesterification using with fossil fuels. The fat released the waste by boiling water under the optimal condition (i.e., temperature, 120℃; decompression, 200mbar) and used to dry without refining for the production of fatty acid methyl esters. Under the optimal condition, the experimental value of biodiesel yield was about 96%. The result of the chemical and GC analysis showed fatty acid composition and characteristics of biodiesel. Evaluation of the product indicated that it was suitable for use as a biodiesel fuel. In result of this experiment oil extract from fleshing process can be transformed into an environmentally affination fuel, to provide economical and ecological profits.

Metal oxide promoted ceria-zirconia (Ce/Zr = 6/4) catalysts was applied to deoxygenation (DO) of oleic acid in batch mode at 300℃ under 1 bar of 20% H2/N2 condition. Metal oxide promoted ceria-zirconia catalysts were prepared by a co-precipitation method. As a result, Ni-Ce0.6Zr0.4O2 catalyst exhibited much higher oleic acid conversion, selectivity to C9 ~ C17 compounds (diesel fuel range), and oxygen removal efficiency than the others. This is due to the presence of free NiO species, synergy effect of nickel and Ce0.6Zr0.4O2, highest BET surface area, and the strong metal to support interaction (SMSI).

Recently biodiesel has drawn much attraction as renewable enegy due to its environmental benefits and the fact that it is made from renewable resources. However, the production cost of biodiesel is one of the main hurdle to commercialize it. One of the way to reduce the biodiesel production cost is to use the waste cooking oil as feedstock. In the conventional transesterification process of waste cooking oils for biodiesel production, the presence of free fatty acids and water causes severe problems such as formation of soap and decreasing of catalyst yield. Much effort has been devoted to solve the above problems and one of the promising way is the supercritical methanol treatment which is performed at the methanol supercritical environment (>239.45℃, >8.10 Mpa)one of the serious problems of the application of SCM process for the biodiesel production is the tough operation condition(high pressure, high temperature. In this study, we have studied about the supercritical methanol treatment for the biodiesel production with the soybean waste cooking oil as a feedstock in the present of various heterogeneous solid catalysts such as mesoporous silica and acid-doped mesorpous silica. Biodiesel conversion was increased at more mild opreation condition to the previous studies by using the catalysts. The conversion was more enhanced by modifying the catalysts.