Estimativa da produção de biogás no aterro sanitário em Campina Grande - PB.

Abstract

Landfill gas (LFG) is a set of gases commonly produced in sanitary landfills filled with municipal solid waste (MSW). Since LFG is a methane-rich by product that has a high calorific value, LFG energy recovery can be an alternative energy source. However, in order to make LFG energy projects feasible, it is necessary to estimate the amount of LFG generated in the landfill. For this, there are models used to theoretically quantify LFG generation in order to evaluate its productive and energetic potential for preliminary purposes. In this context, the present work aims to estimate the LFG production in the Campina Grande Sanitary Landfill (CGSL) through a comparison between existing theoretical models for this purpose, and with that, to evaluate the potential of LFG energy recovery. The methodology is composed by the following steps: basic variables determination (estimated population and MSW generation rate) for the models, application of the models, choice of the model to be best applied for the case under study and determination of the available electric energy, which was calculated based on three adopted scenarios that took into account the efficiency (Ef) of LFG collection and treatment . The results of the methane flow rates estimated by each model presented divergences. However, the values estimated by the first-order decay model proposed by IPCC, which are based on the characteristics of the MSW of the case under study, were chosen to represent the methane generation in the CGSL, which can reach 12.6 x106 m3.year-1, according to the refereed model. With the recovery of methane, the available energies for the optimistic (Ef=80%), moderate (Ef=60%) and pessimistic (Ef=40%) scenarios reach the values of 33x103, 24.7x103 and 16.4x103 MWh.year-1, respectively. It was concluded that there is a theoretical potential favorable to the energetic recovery of methane in the CGSL.