Integrated biodiesel production with glycerol-to-methanol conversion: A techno-economic and energy assessment

Biodiesel is a renewable energy source derived from biomass, such as palm oil, that reacts with methanol. However, commercial methanol generally comes from fossil fuels whose availability is decreasing. Therefore, an integrated process design for crude glycerol-to-methanol conversion in biodiesel production is needed. This study examines the development of integrated biodiesel production process with crude glycerol-to-methanol conversion, including energy analysis and economic evaluation. This study compares five process schemes, with a capacity of 66,000 tons of biodiesel/year: conventional biodiesel production (B1M0G0H0), integrated biodiesel production with crude glycerol-to-methanol conversion and make-up methanol (B1M1G0H0), integrated biodiesel production with crude glycerol-to-methanol conversion and make-up methanol with heat integration (B1M1G0H1), integrated biodiesel production with crude glycerol-to-methanol conversion and make-up glycerol (B1M0G1H0) and integrated biodiesel production with crude glycerol-to-methanol conversion and make-up glycerol with heat integration (B1M0G1H1). The result shows that integrated biodiesel production with crude glycerol-to-methanol conversion are able to reduce requirement for methanol purchases up to 100%. Process-B1M0G1H1 eliminates the need for methanol by adding 85% more energy from the conventional biodiesel process. Specific production cost for biodiesel of process-B1M0G0H0 is 920 USD/ton; process-B1M1G0H0 is 970 USD/ton; process-B1M1G0H1 is 960 USD/ton; process-B1M0G1H0 is 1000 USD/ton, and process-B1M0G1H1 is 980 USD/ton. The price of methanol has big impact on the economics of recycling glycerol into methanol in biodiesel production. If the price of methanol reaches 1400 USD/ton, then NPV of integrated biodiesel production process scheme with crude glycerol-to-methanol conversion is better than that of conventional biodiesel process.