Techno-economic performance analysis of biofuel production and miniature electric power generation from biomass fast pyrolysis and bio-oil upgrading

摘要

The techno-economic performance analysis of biofuel production and electric power generation from biomass fast pyrolysis and bio-oil hydroprocessing is explored through process simulation. In this work, a process model of 72 MT/day pine wood fast pyrolysis and bio-oil hydroprocessing plant was developed with rate based chemical reactions using Aspen Plus~® process simulator. It was observed from simulation results that 1 kg s~(-1) pine wood_(db) generate 0.64 kg s~(-1) bio-oil, 0.22 kg s~(-1) gas and 0.14 kg s~(-1) char. Simulation results also show that the energy required for drying and fast pyrolysis operations can be provided from the combustion of pyrolysis by-products, mainly, char and non-condensable gas with sufficient residual energy for miniature electric power generation. The intermediate bio-oil product from the fast pyrolysis process is upgraded into gasoline and diesel via a two-stage hydrotreating process, which was implemented by a pseudo-first order reaction of lumped bio-oil species followed by the hydrocrack-ing process in this work. Simulation results indicate that about 0.24 kg s~(-1) of gasoline and diesel range products and 96 W of electric power can be produced from 1 kg s~(-1) pine wood_(db). The effect of initial biomass moisture content on the amount of electric power generated and the effect of biomass feed composition on product yields were also reported in this study. Aspen Process Economic Analyser~® was used for equipment sizing and cost estimation for an nth plant and the product value was estimated from discounted cash flow analysis assuming the plant operates for 20 years at a 10% annual discount rate. Economic analysis indicates that the plant will require £16.6 million of capital investment and product value is estimated at £6.25/GGE. Furthermore, the effect of key process and economic parameters on product value and the impact of electric power generation equipment on capital cost and energy efficiency were also discussed in this study.