Study on Conditioning of SO₂–Ethanol–Water Spent Liquor from Spruce Chips/Softwood Biomass for ABE Fermentation

The focus of this study is to develop a process for conditioning spent liquor produced by SO₂–ethanol–water (SEW) fractionation of spruce chips/softwood biomass for fermentation to butanol, ethanol, and acetone/2-propanol (so-called ABE process) by Clostridia bacteria. This study is an integral part of a project which aims at creating an economic process that can utilize cheap forestry residues such as twigs, cones, treetops, branches, and bark to produce renewable chemicals and liquid fuels. The results of this study suggest that the proposed scheme for conditioning of SEW spent liquor from spruce/softwood biomass can be successfully applied to produce chemicals and biofuels by ABE fermentation. Butanol, acetone, and ethanol are produced at a total yield of around 0.25 g/g sugars

Ferrofluid Synthesis Using Nitrosated Lignosulfonates

Modified lignosulfonates are shown to be an effective peptising agent in the synthesis of nanosized colloids of magnetite in aqueous media. The effects of lignin modification by nitrosation reaction, as well as the effects of molecular weight and lignosulfonate type, are explored. The results show that relative magnetic permeability (RMP) as high as 35 g/g Fe is achieved when using high molecular weight nitrosated lignosulfonates from the acid sulfite pulping process

Separation of Hemicellulose and Cellulose from Wood Pulp by Means of Ionic Liquid/Cosolvent Systems

Pulp of high cellulose content, also known as dissolving pulp, is needed for many purposes, including the production of cellulosic fibers and films. Paper-grade pulp, which is rich in hemicellulose, could be a cheap source but must be refined. Hitherto, hemicellulose extraction procedures suffered from a loss of cellulose and the non-recoverability of unaltered hemicelluloses. Herein, an environmentally benign fractionation concept is presented, using mixtures of a cosolvent (water, ethanol, or acetone) and the cellulose dissolving ionic liquid 1-ethyl-3-methylimidazolium acetate (EMIM OAc). This cosolvent addition was monitored using Kamlet–Taft parameters, and appropriate stirring conditions (3 h at 60 °C) were maintained. This allowed the fractionation of a paper-grade kraft pulp into a separated cellulose and a regenerated hemicellulose fraction. Both of these exhibited high levels of purity, without any yield losses or depolymerization. Thus, this process represents an ecologically and economically efficient alternative in producing dissolving pulp of highest purity