Resumo:
The environmentally appropriate disposal of municipal solid waste (MSW) is a critical issue for Brazilian cities, aggravated by the increase in waste generation above population growth and the global need for urgent reduction of the greenhouse effect. Biofuels appear as an apparently viable option for solving these problems, allied to reducing the dependence on fossil fuels. Today Brazil depends on the importation of fossil methanol for the production of biodiesel and for several industrial sectors. This work uses the LCA technique to evaluate the environmental impact of methanol production from MSW, comparing it with the impacts of waste disposal to landfill and incineration, having the generation of electricity as the final product at the system boundary. The results of the LCIA indicate that methanol production from MSW has a better environmental performance than the other alternatives in most of the impact categories analyzed, presenting, for example, a global warming potential (GWP) impact 77% lower than landfill and 81% lower than incineration. The generation of electricity from methanol is also more advantageous, being 140% higher than landfill generation and 40% higher than the energy obtained from incineration. The technology for methanol production from MSW is still incipient, as well as its use for electricity generation. Therefore, technological advances in these processes and incentive policies can make this solution even more attractive and technically and economically feasible and can bring benefits to cities in Brazil and other countries where the landfill is still the most viable solution for the disposal of MSW.
