Energy and economic analysis for a desalination plant powered by municipal solid waste incineration and natural gas in Brazil

With the problems of water availability in Brazil and throughout the world, there is a need to search for water supply alternatives. Brazil, despite being a country rich in water resources, has non-uniform water distribution which presents an imbalance between supply and demand in different regions of the country. The northeast region is the most affected by the lack of water, mainly the semiarid northeast, followed by the southeast. The installation of desalination plants in Brazil is a favorable option for solving water supply problems in Brazil, since it is an efficient technique already used in many countries. However, its significant energy consumption makes it necessary to search for alternative energy technologies for its supply. One such option is incineration. Thus, the present study consists of an energetic and economic feasibility analysis of the installation of a desalination plant in Brazil, using incineration as an energy source. Through energy analysis, the results showed that incineration does not produce enough energy to power the desalination plant. For a population of 500,000, the incineration plant provides only 36% of the energy required by desalination. However, this frame can increase to 73% with the use of municipal consortia. The economic analysis was carried out using desalination cost (DC) as a parameter, and three sensitivity analyses were carried out in order to assess possible reductions in this cost: variation in the import rate, the tax rate, and the use of municipal consortia. The results showed that while the use of consortia and favorable public policies to guarantee national production of this technology are very important in reducing costs, government incentives to reduce the tax rate promote the greatest reduction in the DC, reaching 0.956 USD/m3 for a population of 500,000 inhabitants.