(202a) Comparative Techno-Economic Analysis of Bio-Hydrocarbon Production from Pyrolysis-Derived Bio-Oil Via Hydroprocessing and Zeolite Cracking

This work examines the comparative techno-economic analysis of two pathways for the upgrading of fast pyrolysis-derived bio-oil into bio-hydrocarbons, viz. hydroprocessing and zeolite cracking. The hydroprocessing pathway entails a two-stage hydrodeoxygenation process, followed by a hydrocracking process, which is coupled with a steam reforming process of the aqueous phase of the bio-oil to supplement hydrogen requirements for hydroprocessing. The zeolite upgrading pathway features a single stage regenerator, assumed to be in a full combustion mode and fitted with a catalyst cooler to tackle excess heat due to the accompanying excess coke formation typically associated with this route. The two production pathways were modelled in Aspen Plus® process simulator based on a hypothetical 72 t/day fast pyrolysis plant. Aspen Process Economic Analyser® was used for equipment sizing and cost estimation. The respective minimum fuel selling prices (MFSPs) were estimated by the discounted cash flow method, assuming the plant operates for 20 years at a 10% annual discount rate. The models of the two upgrading pathways were compared in terms of energy efficiency and profitability with regards to their relative MFSPs. Furthermore, sensitivity analysis and uncertainty analysis via Monte-Carlo simulations were conducted for the two upgrading pathways to examine the effect of variations in economic parameters on profitability in a deterministic and probabilistic manner, respectively. The energy efficiencies of the hydroprocessing and the zeolite cracking upgrading routes were 68% and 52%, respectively with corresponding MFSPs of £6.25/GGE and £7.20/GGE. Sensitivity analysis revealed that the MFSPs of both upgrading pathways are mainly sensitive to variations in fuel yield, operating cost, and income tax. Furthermore, uncertainty analysis via Monte-Carlo simulations resulted in probability distributions for hydroprocessing and zeolite cracking with expected MFSPs of £6.42/GGE and £8.30/GGE and standard deviations of £1.05 and £1.39, respectively. The results provide evidence to support past research regarding the economic viability of the production of biofuels from hydroprocessing and zeolite cracking. The results obtained from this work suggest that the upgrading of pyrolysis derived bio-oil via hydroprocessing is more techno-economically viable than the zeolite upgrading route.