Search

With fatty acid as raw material, using the two-step method, first, we use concentrated H 2 SO 4 as a catalyst for esterification of fatty acid and methanol to reduce AV (acid value), and then we added methanol into the peristaltic pump to make its AV drop to below 1 mg KOH /g oil. The best condition of first stage: the temperature is 65±2°C, the catalyst dosage is 1%, the methanol to fatty acid ratio is 80%, and reaction time is 1h. The best condition of second stage: temperature is 100±5°C, the methanol flow rate 1mL/min, and the reaction time is 2h. The final biodiesel esterification ratio is 99.52%. This method has many advantages, such as it can reduce the reaction time, improve esterification ratio, reduce AV in a short time, and the technology is so simple that there is no by-products, so we can save the cost and reduce the investment.

Used Tween-80 as emulsifier, industrial lipase as catalyst to hydrolyze waste oil from restaurants and make mixed fatty acid. We discussed the enzyme concentration, substrate concentration, temperature and time on hydrolysis. Through the experiment, we found that when we used emulsifier which contains 2% oil in the system, we could get the optimal parameter for hydrolysis of waste oil from restaurants as follows: concentration of catalyst 5% (W/W), weight ratio of oil to water 1:4 (W/W) , temperature at 40, and hydrolysis time 24h. Under these conditions, the acid value of hydrolyzed waste oil of restaurants reached 171.8 mg KOH/g.