Biodiesel refers to animal oil, vegetable oil and methanol and other short-chain alcohols esterified, transesterified fatty acid methyl ester obtained after purification, is a renewable clean energy.

The raw material of refined cotton is cotton linters, and the main chemical components are cellulose, lignin and hemicellulose. It is composed of carbon, hydrogen and oxygen and has good hydrophilicity and good adsorption.