Design of an integrated biorefinery for bio-ethylene production from forest industrial waste.

CARDOZO, R.E.; FELISSIA, F.E.; AREA, M.C.; CLAUSER, N.M.; VALLEJOS, M.E.

XXIV TECNICELPA 2021 | XI CIADICYP 2021

Conferencia; XXV TECNICELPA ? International Forest, Pulp and Paper Conference and XI CIADICYP ? Iberoamerican Congress on Pulp and Paper Research; 2021

TECNICELPA

The globalforest industry is focused on the development of technologies for waste reuseor valorization. The use of regional resources in biorefineries could be astrategy to improve the profitability and mitigate the environmental impact ofthe involved industrial sectors, adding a new value chain into the forestindustry. Pine sawdust is an important lignocellulosic waste from the primaryprocessing of wood industrialization in Argentina, which could be a promisingraw material to produce second-generation ethanol (2G ethanol) and its manyderivatives as bio-ethylene based products. Bio-ethylene production requiresthe sawdust fractionation into its main components, the application ofeffective purification processes, and its cost-effective conversion intomonomers and platform molecules, the base of bio-ethylene production. Theprocess design and technical and economic evaluation, including a rigorous sensitivityassessment, are required for developing and consolidating the biorefinery schemeson an industrial scale.This studydeveloped the mass and energy balance for bio-ethylene production. The proposedproduction process is composed by the following steps: i) soda-ethanolpretreatment to remove the lignin from the raw material; ii) simultaneoussaccharification and fermentation (SSF) to convert the cellulose to glucose andthen to ethanol; iii) ethanol recovery (at 95% of concentration); iv) ethanoldehydration to bio-ethylene and; v) bio-ethylene recovery through an ethylenetower and stripper. The operational conditions of steps i and ii were adoptedfrom previous experimental studies developed by our research group; moreover,steps iii to v were adopted from updated bibliography. In the proposed process,111 kg of bio-ethylene per ton of dry sawdust could be obtained (purity of 99, 95%).Besides, 177 kg of CO2 from SSF are produced and could be used for lignin recoveryfrom the pretreatment spent liquor. Energy consumption is about 1.3 MWh/t ofdry sawdust, and the highest consumption is in pretreatment and ethanolrecovery processes (>90% of total energy consumption). For the proposedprocess, it is necessary to develop integration alternatives (regarding rawmaterial, processes, others) and a technical economic assessment, with arigorous sensitivity analysis of economic and processes variables to determinethe feasibility of the developed scheme and potential improvements that couldbe developed