ABSTRACT
This chapter reviews the advances in the biodrying of sewage sludge. A first step will be to define the characteristics of sewage sludge as a possible solid fuel after a drying process, including a brief explanation of the difference between biodrying of sewage sludge and other moist wastes such as municipal solid wastes. Later, a deep review of the literature will be made and the advances in modelling the process will also be addressed. Biological drying, or simply “biodrying,” is an alternative pretreatment method aimed at combustion that has been developed. Biodrying, which is based on a process similar to composting, aims to remove water from biowastes with high water content using the heat generated during the aerobic degradation of organic substances, in addition to forced aeration. Drying has long been recognised as part of the composting process, and it is usually viewed as a secondary and unwanted effect of this process.
