With the rise of biodiesel production (Liu et al., 2022), glycerine pitch, a by-product, has become increasingly abundant and available. This is the residual material left after the purification of crude glycerol, a substance produced in large quantities as a waste by-product in biodiesel or oleochemical plant. Crude glycerol can be refined by vacuum distillation to produce pure glycerol. In the distillation process, the undistilled materials will accumulate at the bottom of the vacuum distillation column as residues, which are known as glycerine pitch