Capacity Design of a Kraft Lignin Biorefinery for Production of Biophenol via a Proprietary Low-Temperature/Low-Pressure Lignin Depolymerization Process

In Canada, there is a kraft lignin (KL) surplus of ∼1.06 millions (M) t·year –1 (after ensuring pulp mills’ recovery boiler demand). This KL supply can create a US$1.5 billion lignin-based bioproducts industry. Lower molecular weight and higher reactivity depolymerized kraft lignin is a promising bioreplacement for petroleum-based chemicals such as phenols and polyols for the synthesis of biophenol formaldehyde or biopolyurethane resins. This work provides an economic analysis for biophenol production of a proprietary KL depolymerization process for eight scenarios with a KL treatment capacity ranging from 10,000 t·year –1 of KL to 120,000 t·year –1 and two recovery percentages (85% and 90%). The eight scenarios were examined on capital investment, manufacturing cost, net present value (NPV), and discounted payback period (PBP). A risk assessment through Monte Carlo analysis is presented to address uncertainties in capital investment, main raw materials cost, and biophenol selling price. From the analysis, the total variable manufacturing costs varies from ∼1081 up to 1101 US$·t –1, and the total fixed manufacturing costs from ∼63 to 154 US$·t –1 . All scenarios are feasible; however, in small KL capacities, such as 10,000 t·year –1, the investment is less attractive yielding a PBP longer than 5 years. Although, KL capacities above 40,000 t·year –1 lead to ∼3-year PBPs and high NPVs (above US$35M). The risk analysis demonstrated that lignin-based phenol production is susceptible to biophenol price and KL cost variations.