Process design and evaluation of value-added chemical production from crude glycerol obtained from biodiesel industry

Abstract

Excessive glycerol, a major by-product of biodiesel industry, has been increasingly utilized as a platform chemical feedstock for production of value-added chemicals. Accordingly, this study aims to simulate the productions of propionic acid (PA), succinic acid (SA), and dihydroxyacetone (DHA) from glycerol via fermentation. For PA production, diluents and extractants as well as techniques in the back-extraction are investigated, whereas the techniques of reactive extraction and direct crystallization, as well as the use of dimethyl sulfoxide (DMSO) as an electron acceptor for SA production are investigated. Meanwhile, the effects of carbon source types and glycerol types on the DHA productivity are investigated. All scenarios are evaluated based on glycerol utilization, economic performance, energy utilization, and environmental impacts. According to the simulated results, using 2-octanol as diluent can lead to the efficient production of PA. This results in cost savings of about 5.45 million USD/y and a significant reduction of CO2 emissions by 34% compared to petroleum-based production. Furthermore, the obtained results indicate that the addition of DMSO in the fermentation is key for the bio-based SA production – the best profit of 190 million USD of DPV, 33.3% of DCFROR, and 4.48 years of DPP are estimated. In addition, this study reveals that the addition of sorbitol as the secondary carbon source for DHA production was the most cost-effective and environmentally friendly. The heat integration is also investigated to improve the bio-based DHA production, which increases the total energy savings by 52−58%.