Tecno-economic assessment of CNF and CMF production from forestry industrial wastes for a multiproduct biorefinery

CLAUSER, NICOLÁS M.; FELISSIA, FERNANDO E.; AREA, MARÍA C.; VALLEJOS, MARÍA E.

Congreso; CIADICYP; 2021

The manufacture of nanomaterials from sustainable and renewable resources extends the promisingpotentials of nanotechnology. Cellulose nanofibrillated (CNF) and cellulose microfibrillated (CMF) revolutionized the field of biobased nanomaterials because of their unique characteristics and properties. Inthe production processes, biomass is processed to remove hemicelluloses, lignin, extractives, andinorganics. These pretreatments, which involve fractionation and bleaching, are usually applied for themanufacturing 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 focusingon these materials to make them potential candidates for the profit of the industrial sector, mainlyrelated to technical assessments of production pathways, evaluation of properties, strategies fornanocellulose surface modifications, and its applications. However, a technoeconomic assessment isnecessary 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 sensitivityassessment to obtain the most important variables, parameters, and potential opportunities for costoptimization. This study is the starting point of a techno-economic assessment for the productionprocess 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, AspenHysys, and Microsoft Excel. For optimization, GAMS software. Techno-economic assessment will bedeveloped in Microsoft Excel, and finally, a sensitivity analysis will be carried out by Oracle Crystal Ballsoftware.An annual disponibility of about 100,000 tons of dry sawdust of eucalyptus as raw material wasassumed. 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 andlignin 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 pulpcan range from 500 kWh/t to 70 MWh/t, depending on the pulp and the applied treatment. Productioncosts 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, sothe next steps of this study are to determine and analyze energy consumption, supplies andcapitalinvestment followed by integration strategies, and sensitivity and environmental assessments, todetermine and develop alternatives for process improvement.