Techno-economic assessment (TEA) and sensitivity analysis for a biochar-based slurry fuel plant

Abstract

This work explores the economic viability of a pyrolysis plant processing biochar-based slurry fuel (CS) from rice straw (RS) at production rates of 10 and 40 tonnes/h. Minimum selling prices for 40 wt% biochar in water (CS-W100) and ethanol (CS-E100) slurries were A$ 0.07 and A$ 0.052 per MJ, respectively. The most cost-effective scenario involves processing 40 tonnes/h of feedstock, yielding CS-E100 at A$ 1434.30 per tonne (or A$ 0.052/MJ). A sensitivity analysis highlights the selling price as a pivotal factor, with increased CS-E100 prices to A$ 1476.04 and A$ 1566.63/tonne resulting in profitable scenarios with payback periods of 14 and 8 years and internal rates of return of 14 % and 22 %, respectively. Monte Carlo analysis indicates a 74.73 % and 98.79 % probability of positive net present value (A$ 44.44 million and A$ 140.90 million) at the mentioned selling prices. The study introduces a pioneering hybrid simulation, combining literature and experimental data, to transform waste-to-energy materials into affordable and clean energy solutions through novel slurry fuels.