Development of Torre-briquetting Process to Convert Mixed MSW into High Energy Density Solid Fuel.

A combination of wet torrefaction and binderless briquetting processes, namely torre-briquetting process, has been developed in Indonesia to treat the mixed municipal solid waste into a solid fuel. A mixture of organic and plastic waste was treated in a 2.5 L reactor using saturated steam in the temperature range of 175 to 225°C. Afterwards, the products were briquetted in varied pressure of 500 to 1000 bar. It was observed that the wet torrefaction process at the temperature of 225°C, residence time of 30 min and sample-to-water ratio of 1:2.5 was able to produce the solid product with heating value of up to 5923 kcal/kg, equivalent to that of bituminous coal. In the briquetting aspect, the briquetted product showed adequate drop test durability of 90% at 1000 bar briquetting pressure. The density of the briquette however, has not reached the standard of 1000 kg/m3, presumably due to the presence of large sized plastic in the briquette. The results suggest that by employing wet torrefaction, the organic fibers in the mixed waste are trapped into the plastic matrix, producing granules which are suitable for briquetting. Therefore, the torre-briquetting process can be a revolutionary solution to treat the MSW without any separation required to produce high caloric solid fuel. [ABSTRACT FROM AUTHOR]