Abstract: Solid organic substrates, such as sewage sludge, peat, and biomass, are dewatered in a three-stage process comprising mechanical dewatering of the substrate, followed by combination of the dewatered substrate with an organic solvent, followed by removal of the water-solvent mixture. The dried product is a granular, free-flowing substance suitable for incineration in relatively low-cost equipment. Conveniently, solvent will be recovered from the water-solvent mixture by conventional means, such as distillation, and recycled to the solvent mixing stage.