To accelerate direct transesterification or reduce reacting methanol volumes, n-hexane, n-pentane and diethyl ether all were used as co-solvent to improve lipid to methyl esters. The using of microwaves (MW) for enhancing direct transesterification of algal lipids from dry algal biomass also has been studied. In the study of Martinez-Guerra et al., the yields of the direct transesterification with microwave irradiation could contribute to higher algal lipid and FAEE yields.