Use of green solvents as pre-treatment of dissolving pulp to decrease CS2 consumption from viscose production

Abstract

Choline chloride-based deep eutectic solvents are widely used in biomass processing. In this work, four different green solvent mixtures were used as pre-treatment of acid sulphite dissolving pulp with the hypothesis of increasing the possibilities to produce viscose fibres and decreasing the use of the harmful and toxic carbon disulphide in the process. The experiments were performed at two different pulp to solvent mass ratios. Pulp quality parameters were also measured to determine the suitability of the pre-treatment: α-cellulose, viscosity, lignin and pentosan content. In addition, X-ray diffraction analysis of pulps at the best solid to liquid ratio was performed to obtain the influence of the crystallinity index. Best results were obtained with the use of lactic acid, with reactivity values close to 94 %, giving a reduction of CS2 usage of 15.83 %. Furthermore, a linear relationship between the crystallinity index calculated by the XRD and reactivity with a regression factor of 0.87 was found.

Mechanical pretreatment of lignocellulosic biomass toward enzymatic/fermentative valorization

“…Cellulose is a homopolymer formed by units of glucose linked together by a β 1,4-glycosidic bond, and it is the most abundant natural polymer on earth ( Arce et al., 2020 ). Hemicellulose is a heteropolymer formed mainly by five-carbon sugars ( Joy and Krishnan, 2022 ).…”