A comparative study of graphene production based on biomass and graphite through the life cycle assessment approach

Abstract

Graphene is graphite composed of a single layer, consisting of sp2 carbon atoms hybridized in a hexagonal crystal lattice. Graphene can be synthesized using rich carbon materials, such as graphite and biomass. Graphene production is developed to be synthesized on an industrial scale. An important parameter within industrial process is the impact on environmental health and safety. In this study, a comparative study of environmental impacts was carried out through a life cycle assessment (LCA) approach for graphene synthesis from two different methods, namely chemical activation based on biomass (rice husk) and electrochemical exfoliation based on flake graphite as raw materials. The utilized software is open LCA with cradle to gate as system boundary. The functional unit as the basis for calculation is 27.0833 kg/hour of graphene production. Environmental impacts resulting from the production of graphene-based on biomass and flake graphite are acidification, eutrophication, global warming (GWP 100a), human toxicity, and photochemical oxidation. The highest impact contribution resulting from the graphene production process from flake graphite is eutrophication which value 17551.58 kg PO43- eq. that caused by the material transportations and flake graphite neutralizing unit process. The highest contribution to the impact on graphene production from rice husks is global warming potential (GWP 100a) of 24.2572 kg CO2 eq. originating from the transportation unit process. The suggested improvement recommendations for the two production process systems are substituting diesel fuel with biodiesel (B30) or substituting the transportation mode with electric vehicle (EV) and recycling acid in the graphite flake neutralizing unit process. Through these recommendations, both impact category that contributed the most and other impacts successfully decreased.