Plant-based chemical production Tamil revision mind map as a four-quadrant grid: ethanol from anaerobic yeast fermentation of glucose stopping at about fifteen percent concentration then concentrated by fractional distillation, vinegar from a second aerobic Acetobacter oxidation step of ethanol to about four to eight percent acetic acid, essential oils extracted from plant material by steam distillation exploiting their volatility and immiscibility with water, and bio-diesel made by transesterification of plant oil triglycerides with methanol and a sodium or potassium hydroxide catalyst giving methyl esters and glycerol by-product, noted as a carbon-neutral fuel.