Towards greener furfural: evaluating the technical, economic and environmental feasibility of heterogeneous catalysis in biomass conversion

Abstract

Furfural is a key biomass-derived platform chemical with a large market volume, yet its production has largely been outsourced from Europe due to the high energy demand for reactor heating and the significant environmental impact of acidic waste generation. Current industrial processes, predominantly the Chinese Batch Process (CBP), rely on sulphuric acid as a catalyst and require extensive steam stripping, contributing significant environmental constraints. This study explores the feasibility of a more sustainable furfural production by evaluating an alternative process based on a heterogeneous acid catalyst. The proposed process integrates scale-up considerations to improve reactor performance, replacing steam stripping with nitrogen stripping and sulphuric acid with Amberlyst-70® as heterogeneous catalyst. A detailed process simulation, techno-economic analysis (TEA), and life cycle assessment (LCA) were conducted to compare the material and energy balances of both processes and to assess the viability of the heterogeneous catalytic process (HCP). Results indicate that the current selectivity of Amberlyst-70® is insufficient for technical feasibility, as a 5.5-fold improvement in furfural-to-tar selectivity is required to match the steam consumption of CBP. If this target is met, both processes exhibit similar minimum selling prices (>€3000 per t), although significantly above current market levels. However, the HCP presents a potential cost reduction pathway (<€1000 per t) through the valorisation of lignin and cellulose by-products, offering a competitive advantage. Environmental analysis highlights key benefits of the HCP, including a significant reduction in freshwater ecotoxicity by eliminating sulphuric acid and improved energy efficiency through enhanced process integration. Nonetheless, energy consumption and maize cob usage remain critical environmental hotspots. Overall, the study identifies catalyst selectivity as the key bottleneck preventing the implementation of the HCP. Further development of a more selective and stable heterogeneous catalyst, alongside integrated biorefinery strategies, could enable the competitive and sustainable production of furfural.