The by-product of biodiesel production is glycerol. It is produced in large quantities with a degree of purity amounting to about 80%. This is due to a transesterification of mainly vegetable oils using methanol. One fat molecule (triacylglyceride) reacts with three methanol molecules to produce glycerol and three fatty acid methyl esters (FAME). There are various uses for glycerol.
Further processing of crude glycerol helps produce pharmaceutical-grade glycerol with a degree of purity amounting to about 99 %. There are many different applications for pharmaceutical-grade glycerol in the food and pharmaceutical industry.