通过生物质废弃物热解途径制备生物炭的技术经济前景分析

Abstract Biochar derived from biogenic waste residue is regarded among the most sustainable resources in broad applications, including soil quality enhancement, energy storage, and hydrogen storage, but also as a promising green alternative fuel. This work completed a standardized techno-economic assessment study of slow pyrolysis , the most known process for biochar production, to address the uncertainties of this process’s cost-effectiveness and profitability for industrial deployment. Process schemes were implemented in Aspen Plus® v12, simulating the pyrolysis reactor using a kinetic RCSTR model (validated against existing experimental results) and integrating char and bio-oil collection. The produced syngas was combusted to fulfill heat requirements in feedstock drying and decomposition steps, in addition to electricity generation in an integrated steam power cycle. The study investigated the impact of key design parameters, such as residence time and temperature, on key performance indicators, such as the levelized cost of biochar (LCOB), biochar yield, composition, energy density, and overall plant energy efficiency. Those two design parameters affected both CAPEX (e.g., the size of the pyrolysis reactor, combustor, and steam power cycle) and OPEX (overall energy efficiency, generated electricity, and bio-oil for external sale) of the plant, favoring short residence time and low-temperature operating conditions. The lowest LCOB of 8.23 €/MWh was obtained for 300 °C and 10 min of pyrolysis, and the highest LCOB of 18.99 €/MWh was obtained for 500 °C and 60 min. The assessment outputs were compiled using the design of experiments, generating a predictive correlation of LCOB as a function of key process parameters and by-product market price.