Impact of co-product selection on techno-economic analyses of alternative jet fuel produced with forest harvest residuals

This article details techno-economic analyses for producing alternative jet fuel (AJF) at a greenfield integrated biorefinery (IBR) using softwood forest residues. The scenarios and their corresponding economic outcomes differ based on the co-product selections. The selected technology to produce AJF uses a mild bisulfite pretreatment process to prepare the feedstock for enzymatic hydrolysis and fermentation to isobutanol, which is then upgraded to hydrocarbon 'drop-in' fuels using an alcohol-to-jet process. The hydrocarbons are a combination of jet fuel and aviation gasoline (AvGas). The residuals are used to produce co-products. Four co-product scenarios are compared to quantify the impact of co-product selection on the primary products, jet fuel, and AvGas minimum selling prices (MSPs). For the baseline (BL) scenario, residuals are burned to create steam for conversion to electricity. The excess power generated is sold at a wholesale price to the grid. The total capital investment for an IBR with a forest residue feed rate of 721 k dry metric ton year(-1) is 1027 MM US$, and the AJF MSP is 2.07 US$ L-1. The BL scenario is compared with three co-product selections: 1) liquid calcium lignosulfonate and electricity; 2) activated carbon; and 3) a combination of liquid calcium lignosulfonate and activated carbon. As anticipated, the conversion of residuals into higher value co-products provides additional revenue to offset the production cost of hydrocarbons. The alternative co-product scenarios reduced the predicted MSPs; however, the most cost-competitive model, the scenario where both activated carbon and calcium lignosulfonates are produced, reduced the jet fuel MSP to 1.49 US$ L-1, a 28% reduction. (c) 2020 Society of Chemical Industry and John Wiley & Sons, Ltd