Comparative techno-economic assessment of multi-feedstock to multi-product integrated lignocellulosic biorefinery

Abstract

A techno‑economic assessment was performed for a multi‑feedstock lignocellulosic biorefinery that converts Norwegian tomato and cucumber crop residues, spent coffee grounds, and brewers’ spent grain into value‑added chemicals. Scenario 1 integrates dilute oxalic‑acid hydrolysis (DAH) with oxalic‑acid‑assisted ethanol‑organosolv delignification (ORG) and co‑produces ethanol, lactic acid, ethanol‑organosolv lignin, furfural, 5‑hydroxymethylfurfural, and electricity. Scenario 2 omits the lactic‑acid train, whereas Scenario 3 employs DAH, only without the ORG or lactic acid sections. Mass and energy balance simulations informed discounted cash flow models for feedstock capacities of 25 and 250 kt/yr. At 25 kt/yr, all scenarios were unprofitable. Scaling to 250 kt/yr improved outcomes for Scenarios 1 and 3, yielding 11.5–12.6 % internal rate of return (IRR), US$ 183.7–185MM net present value (NPV). ORG inclusion reduced overall returns due to elevated capital and operating costs. Integrated operation produced negative net unit production costs, indicating internal cost cross-subsidization among co-products. Sensitivity analysis identified revenue and operating expenditures as primary determinants of NPV and IRR. Monte Carlo analysis estimated a 93.7 % probability of profitability in all simulated outcomes. The findings underscore the importance of scaling up and diversifying product portfolio in future biorefinery deployments.