UC Riverside

The global concern of the depletion of fossil fuels and the threat of global climate change has spawned efforts in the development of sustainable fuels. The production of aviation fuels need to have a low overall CO₂ life cycle emission profile (a 20% reduction from the petroleum-based fuel baseline), and, most importantly, meet the demanding fuel specifications required for aviation fuels. Synthetic fuels have been produced commercially via the Fischer-Tropsch process for several years using fossil based feedstock (e.g., coal, lignite). The products, as either blended drop-in or totally synthetic fuel, have been tested and shown to have properties meeting oil specifications when used as an aviation fuel for both civil and military aircraft. The goal for this research was to assess the technical viability of producing drop-in aviation biofuels from co-mingled fossil and carbonaceous feedstock using the CE-CERT process. The CE-CERT process has been shown to have higher efficiency than conventional gasification technologies when used with non-sustainable feedstock. A model of the whole production process has been built using the Aspen Plus process modeling software. Life cycle analyses (LCA) using a modified GREET model were then conducted based on the results of the process modeling.

It is found that using biosolid as the sustainable portion of the feedstock, with additional carbon capture and storage (CCS), the CE-CERT process combined with synthetic aviation fuel production processes results in high fuel conversion efficiencies and very low GHG emissions. Biosolid mass percentage in feedstock should be higher than 17% to meet the GHG reduction goal. To have zero emission in the well-to-tank (WTT) process, biosolid mass percentage should be no higher than 23%. High biosolid mass percentage is not suggested for the process. A feedstock mass ratio of 75%coal/25%biosolid is quite ideal for the process.