Title:
Hemicellulose Extraction from Softwood Chips for Bioethanol Production in a Cellulosic Fibre Production Mill
Author(s):
Chirat, C., Lachenal, D., Boiron, L., Pipon, G., Lloyd, J.A., Suckling, I.
Document(s):
Paper
Abstract:
Wood (composed of cellulose, lignin and hemicelluloses) is the main raw material used to produce paper cellulosic fibers used for the production of paper and board. Worldwide, the production of cellulosic fibers is about 150 million tons, using about 310 millions tons of wood. The main process used to produce cellulosic fibers is an alkaline process called the Kraft process. These mills look very much like biorefineries : the cellulose is isolated almost pure in the kraft process, and then valorised principally as paper, the hemicelluloses and the lignin are degraded and solubilised during the process, and form a very complex mixture, called “black liquor” that would be difficult to be valorised chemically. They are thus burnt in a recovery boiler, which covers very largely the energetic needs of the mill (in many cases, these mills are net electricity producers). The aim of this work is to define an extraction process of the hemicelluloses from softwood, prior to its transformation into cellulosic paper pulp by the process described above. The hemicellulose fraction (mainly composed of sugar in C6 for softwood species) that are extracted are relatively pure (contrary to the case where they are solubilised in the black liquor), and the cellulose fraction continues to be obtained as fibers. The lignin is thus left alone in the effluent of the kraft process and continues to be valorised thermically for the energetic needs of the mill. The hemicelluloses extracted and hydrolysed in hexoses are then fermented into bio-ethanol and could replace first generation bioethanol produced today from food raw material. Wood contains an average of 25 to 30% of hemicelluloses, which represents a huge potential. In this study, softwood chips were submitted to various hydrolysis treatments. Temperature, time and pH were varied so as to optimise the sugars extraction. The pre-hydrolysis liquors of the softwood chips were analysed for their sugar content, and submitted to fermentation tests for bio-ethanol production. The process developed in this study would represent an elegant way of producing second generation bioethanol in parallel to cellulosic fibers in an existing pulp mill.
Keywords:
biorefinery, hemicellulose, wood, second generation bioethanol, cellulose fiber
Topic:
Fuels from biomass
Subtopic:
Second generation biofuel production via thermochemical processing
Event:
18th European Biomass Conference and Exhibition
Session:
OD8.5
Pages:
1650 - 1654
ISBN-13:
978-88-89407-56-1
ISBN-10:
88-89407-56-5
Paper DOI:
10.5071/18thEUBCE2010-OD8.5
Price:
FREE
