Maximizing the utilization of lignocellulosic biomass: Process development and analysis

Herein, an innovative strategy is proposed for the manufacture of biochemicals (dissolving pulp, furfural, high-purity lignin, and acetic acid) from lignocellulosic biomass. Utilizing sulfuric acid as the catalyst and a mixture of water and γ-valerolactone (GVL) as the solvent, the biomass was successfully fractionated into four major components: 1) cellulose, which was converted into dissolving pulp for fiber production; 2) hemicellulose, which was decomposed into furfural, a valuable platform chemical; 3) lignin, which was purified intensively for the production of carbon foams or battery anodes; and 4) acetate, which was converted into acetic acid, a chemical that is potentially useful as a H₂ carrier and in H₂ production. Separation subsystems were developed to recover the water and GVL mixture effectively for reuse in biomass fractionation and to separate cellulose, hemicellulose, lignin, and acetate for further treatment. To reduce the energy requirements, a heat pump was introduced and heat integration was conducted. The integrated process achieved a positive NPV ($19.9 million), making our process economically viable against initial uncertainties and high risks related to the project. Furthermore, dissolving pulp production was found to be the major environmental contributor accounting for 47.1% of fossil depletion and 36.4% of climate change.