Process Of Biodiesel Production From Amygdalus Pedunculata Pall. Oil

Nowadays, the energy shortage and environmental pollution are serious problems in the world. Biodiesel, as a renewable biofuel, which is environmental friendly, has caused wide concern. The cost of biodiesel is the key problem of restricting biodiesel marketization. The catalyst, as a part of the cost of biodiesel, affecting the industrial development of biodiesel. It is significantly important to find a catalyst with high catalytic activity, stable, reusable and inexpensive. Therefore, Amygdalus pedunculata Pall. was chosen as raw material, and Na2SiO3 as catalyst to prepare biodiesel. Meanwhile, considering ultrasonic assisted transesterification is helpful to reduce the cost of biodiesel because of its advantages such as lower temperature, shorter reaction time and lower consumption of methanol, ultrasonic assisted transesterification catalyzed by KOH was studied as well. The results are as follows:1. The optimal process of extraction of Amygdalus pedunculata Pall. oil by solvent method was researched, on the basis of single factor experiments, the orthogonal test was used in synthetically analysising the influence of temperature, time and liquid to solid ration for extraction ratio. The optimum extraction process was obtained: Amygdalus pedunculata Pall. seed was extracted by petroleum ether at the ratio of 1(material):5(petroleum ether) and at 75℃for 0.5 hours, the extraction ratio was 89.27%.2. The physical and chemical properties of Amygdalus pedunculata Pall. oil were determined. The result shows that its saponification value is 190.625 mg KOH/g, acid value is 1.215 mg KOH/g, molecular weight is 888.55, the major compositions of fatty acid in Amygdalus pedunculata Pall. oil were tested by GC (Gas Chromatography), including oleic acid, linoleic acid and palmitic acid with content of 72.12%, 26.26% and 1.61%, respectively.3. The influence of catalyst preparation conditions on catalytic activity was studied, and the orthogonal test was used in optimization of technological parameters from single factor experiments, optimal conditions for catalyst preparation were as follows: the catalyst size of 60 meshes calcined at 250℃for 0.5 h. The catalyst prepared under this condition was used in transesterification, the conversation ratio was 93.44%.4. The conversion rate reached 99.28% under the following optimal conditions of orthogonal experiments: catalyst dosage was 1%, molar ratio of methanol to oil was 18:1, reacted at 75℃for 1 h. The conversion rate kept more than 95% even the catalyst was reused for 5 times.5. KOH was chosen from four kinds of catalysts including KOH, NaOH, CH3ONa and Na2SiO3 as catalyst to study ultrasonic assisted transesterification. The optimal transesterification process was: ultrasonic frequency was 40 kHz, KOH concentration was 1.5%, molar ratio of methanol to oil was 7:1, reacted at room temperature for 15min, the conversation ratio tested by GC was 99.08%.6. The composition of fatty acid methyl esters in biodiesel from Amygdalus pedunculata Pall. oil catalyzed by Na2SiO3 was consistent with which catalyzed by KOH, and their contents were a little different. The main fatty acid methyl esters tested by GC were palmitate methyl ester, oleic acid methyl ester and linoleic acid methyl ester.