Techno-economic analysis of municipal solid waste gasification for electricity generation in Brazil

The key objective of this paper is to analyze the techno-economic feasibility of this alternative for the Brazilian municipalities, classified according to population subgroups, using this parameter as a basis for the calculation of the municipal solid waste generated, the project costs and revenues. Different expenses were taken into consideration, like equipments and installation costs, operation and maintenance costs and the interest rate of the investment. In relation to revenues, they come from of the sale of electricity, the incomes of the recyclable materials, the fees paid by the Brazilian municipalities for the disposal of municipal solid waste in sanitary landfills and incomes by the carbon credits. An analysis of each population subgroup, combining three different economical scenarios was done, with an annual rate of interests of 10.58% for Scenario 1, 7.5% for Scenario 2 and 15% for Scenario 3. The economic feasibility was evaluated using as economic indicators the net present value and the internal rate of return. The net present value was positive for the municipalities with more than 60,714 inhabitants for the Scenario 1, 34,203 for Scenario 2 and 259,845 for Scenario 3. A hypothetic gasification plant is capable to generate 905 kW/ton municipal solid waste for a population of 60,714 inhabitants (Scenario 1), 794 kW/ton municipal solid waste for a population of 34,203 inhabitants (Scenario 2) and 1065 kW/ton municipal solid waste for a population of 259,845 inhabitants (Scenario 3). It is concluded that the economic feasibility increases with the installation of bigger units, showing a positive scale up gains, therefore as higher the capacity of the installation lower the specific costs and higher are the benefits.