Integrated Synthesis of Biodiesel, Bioethanol, Isobutene, and Glycerol Ethers from Algae

Abstract

In this paper, we design an integrated process for the production of diesel substitutes, biodiesel and glycerol ethers, from algae with internal production of the intermediates ethanol and isobutene. The starch from the algae is converted into glucose. Part of it is fermented to ethanol so that we produce the alcohol needed to transesterify the algae oil while the rest is fermented to isobutene, which is needed in the production of glycerol ethers to enhance biofuels production capacity. We use CHEMCAD coupled with MATLAB for the rigorous simulation of the integrated biorefinery and evaluate the algae composition for such integrated facility. This is followed by energy integration using SYNHEAT and a detailed economic analysis. The integrated facility has promising production cost for liquid fuels, 0.46 $/gal, and an investment costs of $205M, almost half the production cost and only and investment $40M above the plant that buys the isobutene from the market.