TECNO-ECONOMIC ASSESSMENT OF CNF AND CMF PRODUCTION FROM FORESTRY INDUSTRIAL WASTES FOR A MULTIPRODUCT BIOREFINERY

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

Lisboa

Congreso; XXIV TECNICELPA 2021 | XI CIADICYP 2021; 2021

Tecniclpa-Riadicyp

The manufacture of nanomaterials from sustainable and renewable resources extends the promising potentials of nanotechnology. Cellulose nanofibrillated (CNF) and cellulose microfibrillated (CMF) revolutionized the field of biobased nanomaterials because of their unique characteristics and properties. In the production processes, biomass is processed to remove hemicelluloses, lignin, extractives, and inorganics. These pretreatments, which involve fractionation and bleaching, are usually applied for the manufacturing of biofuels and high valueadded products. The solid material, containing mainly cellulose, is subjected to an intensive mechanical process in aqueous suspensions. Production of these materials is an interdisciplinary field. Intense investigations have been focusing on these materials to make them potential candidates for the profit of the industrial sector, mainly related to technical assessments of production pathways, evaluation of properties, strategies for nanocellulose surface modifications, and its applications. However, a technoeconomic assessment is necessary to determine and analyze variables that most affect theproduction processes. Initially, a block diagram and complete mass and energy balance must be developed and modeled. Then, the process is simulated, and the techno-economic analysis is carried out with a sensitivity assessment to obtain the most important variables, parameters, and potential opportunities for cost optimization. This study is the starting point of a techno-economic assessment for the production process of CNF and CMF from forest-industrial waste (see Graphical abstract). In the proposed study, several software tools could be used. For mass and energy balances, software like Aspen Plus, Aspen Hysys, and Microsoft Excel. For optimization, GAMS software. Techno-economic assessment will be developed in Microsoft Excel, and finally, a sensitivity analysis will be carried out by Oracle Crystal Ball software. An annual disponibility of about 100,000 tons of dry sawdust of eucalyptus as raw material was assumed. Global yields after pretreatment (hemicelluloses extraction and delignification) are about 30 % of initial dry material sawdust. From this process, it is possible to obtain hemicellulosic sugars and lignin that could be valorized and, from the bleached pulp, about 3 million tons of CNF and CMF (1% of consistency). Reported energy consumptions of the mechanical step for CNF and CMF production from wood pulp can range from 500 kWh/t to 70 MWh/t, depending on the pulp and the applied treatment. Production costs reported starts at USD 2/kg (without information on how the cost estimation was performed) and could reach USD 17/ kg (dry equivalent), taking into account depreciation. Energy consumption and production costs of the reported literature could reach very high values, so the next steps of this study are to determine and analyze energy consumption, supplies and capital investment followed by integration strategies, and sensitivity and environmental assessments, to determine and develop alternatives for process improvement.