Techno-economic analysis of fast pyrolysis and upgrading facilities employing two depolymerization pathways
We evaluate the economic feasibility of fast pyrolysis and upgrading facilities 11 employing either of two depolymerization pathways: two-stage hydrotreating 12 followed by a FCC (fluid catalytic cracking) stage or single-stage hydrotreating 13 followed by a hydrocracking stage. In the hydrotreating/FCC pathway, two options 14 are available as the hydrogen source for hydrotreating: merchant hydrogen or 15 hydrogen from natural gas reforming. The primary products of the hydrotreating/FCC 16 pathway are commodity chemicals whereas the primary products for the 17 hydrotreating/hydrocracking pathway are transportation fuels and hydrogen. The two 18 pathways are modeled using Aspen Plus® for a 2000 metric tons/day facility. 19 Equipment sizing and cost calculations are based on Aspen Economic Evaluation® 20 software. 21 The fast pyrolysis bio-oil yield is assumed to be 65% of biomass. We calculate the 22 internal rate of return (IRR) for each pathway as a function of feedstock cost, fixed 23 capital investment (FCI), hydrogen and catalyst costs, and facility revenues. The 24 results show that a facility employing the hydrotreating/FCC pathway with hydrogen 25 production via natural gas reforming option generates the highest IRR of 13.3%. 26 Sensitivity analysis demonstrates that product yield, FCI, and biomass cost have the 27 greatest impacts on facility IRR. Monte-Carlo analysis shows that two-stage hydrotreating and FCC of the aqueous phase bio-oil with hydrogen produced via 1 natural gas reforming has a relatively low risk for project investment.