Bio-oil is a broad concept. At present, it usually refers to bio-fuel oil, most of which is based on alcohols.

used in restaurants, canteens and industrial fuels.

The composition and physical and chemical properties of bio-oil are influenced by many factors, such as raw material types, water content, reactor types, reaction parameters, product collection methods, etc. However, bio-oil prepared by different methods still has some similar properties, such as high water content, particulate impurities, high viscosity, poor stability, corrosiveness, etc., which is very different from traditional fossil fuels (diesel oil and gasoline) and also gives bio-oil.