The present invention addresses the processing of waste and low-value products that contain bone material to produce useful materials in reliable purities and compositions, at acceptable cost, and with high energy efficiency. In particular, the invention comprises a process that converts various feedstocks such as offal, animal manures, and municipal sewage sludge, to useful materials including gas, oil, specialty chemicals, and carbon solids. The process heats the feedstock in order to breakdown proteins and separate organic material from bone material, applies further heat and pressure to the resulting liquid mixture, separates out various components, then further applies heat and pressure to one or more of those components. The invention further comprises an apparatus for performing a process of converting waste products into useful materials, and an oil product that arises from the process.