CFD Modeling of Plasma Gasification Reactor for Municipal Solid Waste

Plasma gasification of municipal solid waste (MSW) is one of the thermochemical technologies that convert waste into energy. The waste is exposed to high temperatures to transform the organic compounds into synthetic gas that could be used as power source, fuel substitute or reactive in the biofuel production. The inorganic compounds are melted completely and an inert environmentally friendly vitrified is obtained, that could be used as building material. Plasma gasifiers have some advantages against traditional gasifiers, for example, high temperature and heating rates lead to compact reactors, improving their performance and conversion rates. Moreover, all the inorganic residues are processed in a melting chamber, leaving a fully vitrified, strong, and resistant to chemical leaching material. On the other hand, this kind of technology has some disadvantages like high initial investment and high electric consumption of plasma torches. All these aspects, as well as others, are being studied at the Instituto Tecnológico de Costa Rica, through the development of computational fluid dynamics (CFD) models, defining a prototype reactor with a capacity of 1-2 metric tons of MSW per day and using DC nontransferred arc thermal plasma torch. Variations on composition within the MSW and process conditions will be studied in order to achieve high efficiency and economic feasibility. The CFD models include mechanical, thermal and chemical aspects of the turbulent reactive flows inside the gasification reactor, with 0-D, 2-D, as well 3-D considerations. The experimental phase of the project will be developed soon, taking into account the CFD models results, to implement the technology and eventually improve it.