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

Abstract

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.

Evolution of Lignocellulosic Macrocomponents in the Wastewater Streams of a Sulfite Pulp Mill: A Preliminary Biorefining Approach

“…Among the chemical processes, kraft is the most commonly used. However, other processes such as soda-anthraquinone (soda-AQ); ethanol-water pulping (organosolv); acid sulfite and bisulfite pulping; sulfite pretreatment to overcome recalcitrance of lignocellulose (SPORL); or SO 2ethanol-water process (SEW) can also be used [3][4][5][6][7][8][9][10]. Sulfite pulping is becoming popular because of the growing demand of high purity dissolving pulp for textile fiber production.…”

“…Nowadays, there are many efforts from the pulp and paper industries focused on sugar-rich resource valorization into energy and a wide variety of products. Several approaches tracing pathways and guidelines towards the conversion of pulping factories into lignocellulosic biorefineries (LCBR) can be found in the literature for kraft pulping [11][12][13][14], soda-AQ [15,16], organosolv [17][18][19], or SEW process [9,10]. Nevertheless, only a few contributions have been studied in the case of sulfite pulping [20,21].…”

“…In this sense, the first step was a deep control of the main resources throughout a total mass balance of the LCB. The mass balance provides a complete description based on lignin and carbohydrate content (hemicellulose and cellulose) of the materials [9,22]. The use of total mass balances in a whole process can point out the main resources for valorization options.…”

Effect of Residual Extractable Lignin on Acetone-Butanol-Ethanol Production in SHF and SSF Processes

“…Lignocellulosic biomass has great potential to replace petroleum-based liquid fuels and chemicals, thereby addressing our national needs for energy independence and domestic jobs, as well as environmental issues [1][2][3]. Butanol is one of the promising alternative biofuels, which can be produced from biomass [4]. Butanol production along with acetone and ethanol from sugars by Clostridium is known as "acetone-butanol-ethanol (ABE) fermentation" [5].…”

Effect of Residual Extractable Lignin on Acetone-Butanol-Ethanol Production in SHF and SSF Processes

“…Lignocellulosic biomass has great potential to replace petroleum-based liquid fuels and chemicals, thereby addressing our national needs for energy independence and domestic jobs, as well as environmental issues [1][2][3]. Butanol is one of the promising alternative biofuels, which can be produced from biomass [4]. Butanol production along with acetone and ethanol from sugars by Clostridium is known as "acetone-butanol-ethanol (ABE) fermentation" [5].…”