W-400 plant is designed for producing methyl esters from rape oil and vegetable oils (density close to rape oil density). Produced during the process of esterification, in the presence of alkaline catalyst, the methyl ester, together with oil-derivative diesel gas, are a component of ecological biofuel, designed to Diesel engine propelling, especially farm tractors. The technology is realized through portion method, according to the process recommended by Industrial Institute of Agricultural Machinery in Poznan, Poland. The received fuel component is environment friendly. It contains over 100 times less sulphur than the diesel oil, it perfectly mixes with it in any proportion, even in the engine tank.