A larch based biorefinery: pre-extraction and extract fermentation to lactic acid

Abstract

In a forest based biorefinery, pulp and paper are the main products, while side-streams are utilized for value-added products. One biorefinery concept is to remove hemicelluloses from wood by extraction prior to pulping and converting them into biofuels or chemicals. This study presents a concept of a larch wood based biorefinery and focuses on the mass balance of pre-extraction. Sugar rich extracts were obtained by hot water extraction of Siberian larch (Larix sibirica Lebed.) wood chips at different temperatures and times. At 1608C and 60-90 min the extract contains 13-16% hemicelluloses (on wood). The composition of extracts and extracted wood has been determined to have a basis for mass balances. Fermentation of the hydrolyzed extract with Bacillus coagulans MXL-9 resulted in consumption of all C6 and C5 sugars and produced lactic acid in high yield. In an earlier work, it was demonstrated that water pre-extraction of larch chips followed by polysulfide-anthraquinone (PSAQ) pulping still produced a good papermaking pulp at a yield comparable to the corresponding non-extracted kraft pulp. Accordingly, the present results show that a larch wood based biorefinery has a potential for industrial application.

Chemical Pretreatments of Wood Chips Prior to Alkaline Pulping - A Review of Pretreatment Alternatives, Chemical Aspects of the Resulting Liquors, and Pulping Outcomes

“…LCM-derived hydrolysates can be fermented with different microorganisms, the aim being at the production of ethanol or other platform chemicals, such as small-size organic acids (Ragauskas et al 2006;Koutinas et al 2008;Sánchez and Cardona 2008;Hörhammer et al 2011;Boucher et al 2014). For fermentation purposes, biomass is converted into sugar solutions, and these substrates are then fermented by case-specific microorganisms to overproduce metabolic products.…”

Modification of acid hydrolysis lignin for value-added applications by micronization followed by hydrothermal alkaline treatment

“…Basically, this process consists of the catalytic conversion of wood polysaccharides (cellulose and hemicellulose) into monosaccharides. One way is the acidic (or enzymatic) treatment of biomass before pulping as prehydrolysis (Gütsch and Sixta 2011;Hörhammer et al 2011;Testova et al 2011;Rodríguez-López et al 2012). Another approach is an exhaustive acidic hydrolysis of biomass with diluted sulfuric acid, which was widely applied in approximately 50 plants in the 20 th century in the former Soviet Union (Chudakov 1972;Rabinovich 2014).…”

Polyoxometalate (POM)-aided modification of lignin from wheat straw biorefinery

“…A branch of the biorefinery efforts is dealing with the modification of established biomass conversion processes, for example, by the introduction of a prehydrolysis step before pulping, and the conversion of dissolved carbohydrates to value-added products ( G ü tsch and Sixta 2011 ;H ö rhammer et al 2011 ;Sch ü tt et al 2011 ;Testova et al 2011 ). The development of new processes based on organic solvents and acids (organosolv process) has also a long tradition (Jim é nez et al 1998(Jim é nez et al , 2004Saake et al 1998 ;Abad et al 2002 ;Lehnen et al 2002 ;Claus et al 2004 ;Yawalata and Paszner 2006 ;Iakovlev et al 2009 ).…”