Solvent Pulping at Atmospheric Pressure

Abstract

The kraft process has been the mainstay of the paper industry for than 100 years, but the process is unsatisfactory in regard to environmental protection and a pretreatment method for lignocellulosic biomass. Thus there is growing interest in unconventional solvent pulping methods that are based on the use of organic solvents in pulping liquors. A variety of solvent pulping methods free of sulfur compounds has been explored. This paper deals only with solvent pulping methods at atmospheric pressure among which there are phenol pulping with a small amount of HCl, tetrahydrofurfurylalcohol pulping with HCl, acetic acid pulping with HCl followed by bleaching with peroxyacetic acid, formic acid-peroxyformic acid pulping, and acetic acid pulping with sulfuric acid.