Pyrolysis oil are affected by temperature, reaction time, algae species, algae concentration, reaction atmosphere, and catalysts, in subcritical water reaction conditions. Bio-oil typically requires significant additional treatment to render it suitable as a refinery feedstock to replace crude oil derived from petroleum, coal-oil, or coal-tar. Tar is a black mixture of hydrocarbons and free carbon obtained from a wide variety of organic materials through destructive distillation. Tar can be produced from coal, wood, petroleum, or peat. Wood-tar creosote is a colourless to yellowish greasy liquid with a smoky odor, produces a sooty flame when burned, and has a burned taste. It is
Coal gasification as Bill McKibben who view any continued use of fossil fuels as counterproductive. The by-products of coal gas manufacture included coke, coal tar, sulfur and ammonia; all useful products. Dyes, medicines, including sulfa drugs, saccharin and many organic compounds are therefore derived from coal gas. Coke is used as a smokeless fuel and for the manufacture of water gas and producer gas. Coal tar is subjected to fractional distillation to recover various products, including Sulfur is used in the manufacture of sulfuric acid and ammonia is used in the manufacture of fertilisers. According to the Gasification and Syngas Technologies Council,