Technical-environmental optimisation of the activated carbon production of an agroindustrial waste by means response surface and life cycle assessment

Abstract

In this study, a simultaneous optimisation of technical and environmental parameters for activated carbon production from soybean shells is presented. A 2 factorial design was developed to explore the performance of the technical responses yield and iodine number, and the single score of ReCiPe endpoint method, which was evaluated by means the life cycle assessment. The independent factors included in the design of experiments were the impregnation ratio, temperature, and time activation. Three quadratic equations were obtained and simultaneously optimised by maximisation of the overall desirability function. The principal results of the individual responses indicate that the iodine number is practically independent of the activation temperature in a range of 450 ºC-650 ºC; the yield is inversely proportional to activation time and exhibits minimum values between 500 ºC-600 ºC; and the environmental response single score presents the lowest value at a temperature and time activation of 450 ºC and 30 min, respectively. The most polluting stage of activated carbon production from soybean shells production is the impregnation stage, mainly for the use of ZnCl as activating agent and the energy consumption. The simultaneous optimisation of the three responses indicates that the optimal activated carbon should be produced at 180 min, 650 ºC, and an impregnation ratio of 1 g soybean shell g ZnCl.

Feasibility Assessment of a Bioethanol Plant in the Northern Netherlands

“…Additionally, first-generation resources require large amounts of fertile land, and most agricultural land is already occupied. Therefore, a better fitting source for the production of biofuels is organic residues since they have no negative impact on food production or land use, resulting in a more sustainable feedstock utilization for the production of bioethanol [25][26][27][28].…”

Carbonización hidrotermal del nejayote de maíz

“…Por el contrario, Dominguez Mendoza [16] reporta un rendimiento del 32 % al carbonizar bagazo de agave, pero obtiene un hydrochar con área superficial de 306 m?/g, similar incluso a algunos carbones activados producidos a partir de biomasas. Si bien el presente trabajo tuvo como principal objetivo verificar la viabilidad de la producción de hydrochar a partir de nejayote, es recomendable tomar en cuenta como variable de respuesta no solamente el rendimiento, sino también alguna otra variable indicativa de la calidad del producto o incluso de la sustentabilidad de este, tal y como lo han hecho otros autores [6,8,[17][18][19].…”

Generating Energy and Greenhouse Gas Inventory Data of Activated Carbon Production Using Machine Learning and Kinetic Based Process Simulation

“…Previous studies indicate that energy consumptions and greenhouse gas (GHG) emissions are mainly driven by the AC production stage that usually has large variations due to differences in the types and composition of biomass, process operational conditions, and sources of energy. , A few studies have tried to explore such variations by investigating AC production scenarios by varying process parameters. For example, Sepúlveda-Cervantes et al conducted a gate-to-gate LCA of soybean shell-based AC production using zinc chloride activation . By varying the operational conditions (i.e., activation temperature, time, and impregnation ratio), the electricity consumption of AC production changed from 17 to 50 MJ/kg AC, and the GHG emissions varied between 5.86 to 47.2 kg CO 2 -eq/kg AC .…”

“…For example, Sepúlveda-Cervantes et al conducted a gate-to-gate LCA of soybean shell-based AC production using zinc chloride activation . By varying the operational conditions (i.e., activation temperature, time, and impregnation ratio), the electricity consumption of AC production changed from 17 to 50 MJ/kg AC, and the GHG emissions varied between 5.86 to 47.2 kg CO 2 -eq/kg AC . Arena et al analyzed the impacts of different energy sources on the environmental footprints of coconut shell AC, which showed a significant reduction of most environmental impact categories (60–80%) by using electricity from renewable sources .…”