TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Process: Glycerol and biofuel are separated, and methoxylated fatty acid is washed by mixing fatty acids with water, and removing water. The water contains phosphoric acid. Water is sprayed on the methoxylated fatty acids during washing. The methoxylated fatty acids are aerated during washing, using a limewood airstone. The fatty acids are washed at least two times, preferably three times with water. Potassium methylate or sodium methylate is further added to the reaction mixture to convert fatty acid acyl-glycerides to glycerol and biofuel. The fatty acid material is trap grease, which is starting material. The fatty acid material is fractionated in conical-bottomed tank to separate water and grease, during heating for reducing viscosity. The fatty acid material is passed through one or more, preferably two self-cleaning screening devices, in which one is disc filter or a liquid solid separator comprising a cylindrical screen. The disc filter is a vibratory disc filter. The fatty acid material is passed through a decanter centrifuge after passing through self-cleaning screening devices. The fatty acid material is sequentially passed through a vibratory disc filter, a liquid solid separator comprising a cylindrical screen and having a finer mesh than the disc filter, and a decanter centrifuge. The glycerol is separated from the biofuel, and fractionated by settling in conical bottom container into glycerol fraction and residual fraction comprising biofuel and/or fatty acid acyl-glycerides. The fractionation is performed in a centrifugal decanter. The washed biofuel is dewatered in a water-oil separating coalescing filter, and filtered with a filter, which excludes fatty acid acyl-glycerides. The filter is polytetrafluoroethylene-coated filter membrane, and has size of 2 micron. The washed biofuel is sequentially passed through a 30 microns filter, a 10 microns filter, a water-oil separating coalescing filter and a filter excluding fatty acid acyl-glycerides and passing biofuel. The glycerol is heated under pressure at 200degreesC and 200 psi to produce propylene glycol.Preferred Conditions: The trap grease is filtered at 25-65degreesC, preferably 52degreesC, using a screen filter. The screen is a belt, and is cylindrical. The fatty acid material is converted to glycerol and biofuel at 25-65degreesC, preferably 52degreesC.Preferred Apparatus: The screen filter further comprises a screw within the cylindrical screen for advancing material through the filter. The filtering, dewatering and conversion of material to glycerol and biofuel are performed using processing equipment configured within a commercial shipping container. The biofuel processing system further has a decanter centrifuge at downstream of self-cleaning screening devices and upstream of reaction vessels, and 3-5 filter units differing in pore size and connected in series provided between the pre-filter assembly and reaction vessels. The mesh size of filter units decreases along downstream direction. The filter units are bag filters. The system has reaction vessel (I) at downstream to pre-filter assembly, and reaction vessel (II) downstream to the reaction vessel (I). The methanol feed and acid feed are fluidly connected to vessel (I), and methylate feed is fluidly connected to vessel (II). The system further has a pH controller having a probe within the same reaction vessel, temperature controller having a probe in reaction vessels, fractionation container provided at downstream to reaction vessels to receive glycerol from vessels, centrifugal decanter provided at downstream to reaction vessels, dewatering device provided at downstream to wash tank for dewatering the washed biofuel, and a pump or solenoid fluidly connected to the acid feed upstream of the reaction vessel under control of the pH controller. The heater is an electric resistance heater. EXAMPLE - Grease (in gallon) (100) was pumped from a fractionation tank into a processing tank. The tank was heated at 95degreesF for 2 hours. Methanol (36) was transferred to the processing tank. The contents were mixed at 95degreesF for 3 hours. Sulfuric acid (407) was added, and the mixture was transferred to another processing tank. Pre-mixed potassium methylate (12) was added, and heated for 15 minutes. The mixture was uniformly stirred for 25 minutes, and glycerol was drained. The biofuel was transferred to the wash tank, aerated and washed, giving a biofuel.