• Drying does not affect the nutrient content and calorific value of faecal sludge. • Drying leads to a modification of the chemical form of nitrogen in faecal sludge. • Moisture removal during drying decreases the thermal conductivity and heat capacity. • Dried sludge is heated at a faster rate compared to when it is wet. • Dried faecal sludge has the potential to be reused as organic fertilizer or biofuel.