NOVELTY - Conversion of feedstock into useful material involves: (a) preparing a slurry from the feedstock; (b) reacting the slurry in a first reaction to produce a reacted feed comprising reacted solid product, reacted liquid product and water; (c) separating the solid product, water and liquid product from the reacted feed; and (d) converting the reacted liquid product into useful material in a second reaction.    USE - For converting a feedstock containing (e.g. rubber materials, tires, municipal sewage sludge, food processing waste comprising turkey offal, mixed plastics, PVC, animal manure or byproducts of food manufacture and distribution selected from turkey offal, fryer oils, corn stalks, rice hulls, waste scraps or last-press edible oils (e.g. canola, soybean, palm, coconut, rape seed, cotton seed, corn or olive oil)) selected from (e.g. by-products of paper manufacturing containing cellulose or lignin containing materials and other wood industry manufacturing, paper-pulp effluent, black liquor, leaves, grass clippings, bagasse, seaweed, cotton waste, animal waste, plastic bottles, old computers, municipal solid waste, oil-refinery residues, shale oil, drilling mud, harbor-dredged sediments, industrial sludges, milling waste, coal refinery wastes, tar sands, anthrax spores, infectious medical waste and biological pathogens) into pathogen-free material (e.g. carbon solids, mixture of hydrocarbons comprising fuel gas and oil and carbonaceous material (e.g. depleted of mercury-containing contaminants and depleted of sulfur-containing contaminants)) (all claimed). Also for converting agricultural and other waste or low-value materials containing carbon-based compounds to commercially useful products such as fertilizer and specialty organic chemicals.    ADVANTAGE - The method reduces the environmental pollution potential arising from inorganic waste stream; and processing waste and low-value product to produces useful materials in reliable purities and compositions at acceptable capital and operational coast, without producing malodorous emissions, and with high energy efficiency.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following:    (1) a fuel oil comprising (wt.%): paraffins (22), olefins (14), naphthenes (3), aromatics (6) and at least 14C (55), having cloud point of 10 degrees C, pour point of -20 degrees C, cetane index of 40 and heat content of 18800 BTU/lb;    (2) converting tires into oil involving:    (a) dissolving the tires in a solvent;    (b) preparing a slurry from the tires;    (c) reacting the slurry with water in a first reaction at 250 - 400 degrees C to produce a reacted feed, followed by separating the reacted solid product, water and reacted liquid product; and    (d) converting the reacted liquid product into oil in a second reaction at 300 - 225 degrees C;    (3) an apparatus comprising:    (a) a pre-treatment unit for producing a heated slurry from the feedstock;    (b) a first stage reactor communicating with the vessel to receive the heated slurry;    (c) at least one second stage separation unit communicating with the first stage reactor to receive the solid product, liquid product and water; and    (d) a third stage reactor communicating with the separation unit to receive the reacted liquid product; where    (e) the first stage reactor configured to subject the heated slurry to a first increased temperature and a first increased pressure to produce the reacted feed, the unit configured to separate out the reacted solid product, water and reacted liquid product, the third stage reactor configured to subject the reacted liquid product to a second increased pressure and temperature, thus converting the reacted liquid product to useful material.