Autothermal biodrying of municipal solid waste with high moisture content

To carry out autothermal drying processes during the composting of biomass, a horizontal tubular reactor was designed and tested. A biodrying tunnel of the total capacity of 240 dm³ was made of plastic material and insulated with polyurethane foam to prevent heat losses. Municipal solid waste and structural plant material were used as the input substrate. As a result of autothermal drying processes, moisture content decreased by 50 % of the initial moisture content of organic waste of about 800 g kg⁻¹. In the tested cycles, high temperatures of biodried waste mass were achieved (54–56°C). An appropriate quantity of air was supplied to maintain a satisfactory level of temperature and moisture removal in the biodried mass and high energy content in the final product. The heat of combustion of dried waste and its calorific value were determined in a calorimeter. Examinations of pyrolysis and gasification of dried waste confirmed their usefulness as biofuel of satisfactory energy content.