NOVELTY - A portable production system (200) for biodiesel production, comprises: reactor (4) including reaction vessel; at least one ultrasonic transducer disposed within reaction vessel configured to subject biodiesel precursor to ultrasonic radiation to promote transesterification reaction of vegetable oil and/or animal fat; heater; and mechanical stirrer.    USE - As portable production system for biodiesel production (claimed).    ADVANTAGE - The portable production system for biodiesel production uses ultrasonic transducers, where use of ultrasonic bath results in good results in terms of conversion into ester, as well as improved reaction time on industrial scale; avoids excessive inputs external to production route; and avoids use of catalyst in two stage reaction that can interfere with reaction kinetics, where reaction product is reprocessed as input. Further certain compounds that are not transformed into biodiesel when transesterification reaction occurs, as well as gums, can be kept in oil, even if they are not transformed, as they provide some advantageous characteristics to oil and fuel, such as stability to oxidation, as in case of tocopherols and sterols. The improvements in transesterification processes use ultrasound to increase degree of conversion, and to reduce reaction time and power consumption. The system is more compact than other processes, especially where continuous production processes are conducted, which favor construction of small-scale production at low cost. The reaction environment is advantageous over homogeneous catalysis process, allows for sustainable development of biodiesel production using novel heterogeneous catalysts, is easier to operate in continuous process, provides possibility to obtain cleaner glycerin, and does not require neutralization of catalyst and continuous addition of this material during process. The ultrasound irradiation provides foster greater interaction between phases and results in consequent increase in yield, and enables reduced reaction time and reagent consumption to save energy. The equipment enables study, knowledge and control of important process variables. The equipment has the form of facility, plant or production unit, and can be fixed or mobile, and can be used to produce relatively small amounts compared to known continuous process methods, enabling saving in use and consumption of reagents and supplies, as well as has characteristic of being portable i.e. easily transported and deployed in small spaces. The reactor enables synthesis of biodiesel through irradiation with ultrasound, and includes reservoirs in transparent borosilicate-type glass, which enable visual monitoring of all process steps. Additionally, system is scalable, so that it can be sized to produce smaller batches e.g. for teaching, much larger batches e.g. to provide fuel for large fleet of vehicles, or provides continuous process in low volumes. The reactor/system further uses dry purification process or drywash, by means of ion exchange polymer resin, without generating waste wash water, which can otherwise be problematic in conventional biodiesel production. The production system works with any type of oilseed oils, including those coming from processes of cooking foods.    DETAILED DESCRIPTION - A portable production system (200) for biodiesel production, comprises: reactor (4) including reaction vessel; at least one ultrasonic transducer disposed within reaction vessel configured to subject biodiesel precursor to ultrasonic radiation to promote transesterification reaction of vegetable oil and/or animal fat; heater; and mechanical stirrer. The system is supported by rolling chassis (20) having several casters, and fittings for lifting of chassis. The system further includes at least one pump (8) for changing air pressure; at least one pump (6) for liquid; tank for holding recovered reactant; tank for holding biodiesel produced; and dry wash purification column (11). The ultrasonic transducer(s) is/are piezoelectric transducers, are submerged within reaction vessel, and are contained within columnar housing fabricated of titanium for promoting propagation of ultrasonic energy into reaction vessel. The ultrasonic transducer(s) include several ultrasonic transducers arranged at angle with respect to each other, to disperse ultrasonic energy throughout reaction vessel. The ultrasonic transducer(s) operates at, at least one frequency selected from 19-40 kHz. The reaction vessel is transparent. The heater includes at least one heater element having heater cover shaped to change flow of reactants stirred by mechanical stirrer. The mechanical stirrer includes assembly having motor, output shaft connected to motor, and at least one propeller connected to output shaft. The several mechanical stirrers include several assemblies. The decantation and distillation, in addition to ultrasonic radiation and stirring, are carried out in reaction vessel.    DESCRIPTION OF DRAWING(S) - The figure shows rear perspective view of mobile/portable production plant/facility/system for biodiesel production, revealing interior components.    Ultrasonic reactor (4)    Ultrasonic generator (5)    Fuel/liquid pump (6)    Fuel filter (7)    Vacuum or compressor air pressure pumps (8)    Heat exchanger (10)    Purification column (11)    Stainless steel tube or cylinder of purification column (11A)    Upper supply of cylinder of purification column (11B)    Lower output of cylinder of purification column (11C)    Biodiesel tank (12)    Casters to facilitate movement or rolling of assembly (15)    Structural mobile chassis (20)    Portable production system for biodiesel production (200)