Lignin extraction from sawdust: optimization of experimental studies, computer-aided simulation and techno-economic analysis of scale-up process design with uncertainty quantification

Abstract

Lignin is an essential raw material that shows huge potential in novel value-added industrial applications. Most of previous researches on production of lignin from biological sources are confined to laboratory endeavors owing to the paucity of basic process engineering studies on lignin extraction from bio-material. Therefore, this investigation is aimed at optimizing lab based proof-of-concept, computer-aided batch simulation and techno-economic assessment of scale-up process design of lignin recovery from sawdust. Box–Behnken design was used to design and optimize lignin recovery from sawdust at varied temperature (60–100 °C), time (90–270 min) and concentration of NaOH (15–25%). Aspen Batch Process Developer was used for the simulation of the recovery and scale-up design of the recovery of lignin, techno-economic analysis models were developed for the evaluation of commercialization potential of the scale-up study while sensitivity and uncertainty analysis was carried out using Monte Carlo simulation to study the effect of key parameters on the techno-economic analysis developed models. The simulated results from Aspen Batch Process Developer and optimum experimental condition for the recovery of lignin are in agreement with a deviation of 0.0025, cycle time of 1445 min and flowrate of 0.00084 g/min at base case condition. The techno-economic analysis show that recovery of 50,000 kg/batch of lignin was possible and the optimum condition that are Fixed Capital Investment ($21.5 M), interest rate (10.25%) and Cost of Lignin ($1) lead to a profitability response of net present value ($34.97), internal rate of return (34.14%) and productivity index ($1.62) for a 15-year investment plan. The sensitivity and uncertainty analysis is favorable to the simulation study used for this prediction.