Joe Street's Vacuum Biodiesel Processor Plans
By Rick Da Tech
Joe Street designed his water heater based processors and posted his plans for them on his web site Non-profit Fuel Cooperative using the creative commons copyleft. The pdf processor plans and the edited text in this article are from his web site.
His design concept was to produce a small scale farm type biodiesel reactor which by nature of its design and construction affords the ability to get consistently reliable quality results when used in conjunction with proper procedures and good quality chemicals to convert bio-oil feed stocks of reasonable quality into methyl ester fuel suitable for use in diesel internal combustion engines and oil burner type heating equipment.
As a general overview, this is a vacuum type reactor. He chose the vacuum approach because it has several significant advantages over other types of reactors. He doesn't like the idea of pressurizing a plastic container which contains methoxide to force it into the reactor.
He uses vacuum to draw the methoxide into the reactor which has less potential for an accident. Similarly it can be used to draw the oil into the reactor. Vacuum also allows rapid drying of the oil prior to the reaction which is essential, and saves much time, and also allows rapid drying of the fuel at the end which also saves days per batch in process time. Vacuum also lends itself to methanol recovery which he doesn't consider to be optional, from the perspective of sustainability and environmental responsibility. He chose to use forced exhaust at the methoxide mixer, liquid trap and vacuum pump to increase safety in the use of the system. Safety is always the primary concern and then after that every effort is made to optimize the effectiveness of the system for obtaining a quality result. He tries to use parts that are commonly available and wherever possible work to reduce overall cost by careful selection of components so long as it doesn't compromise safety and quality. The reactor is designed with long term reliability in mind.
30 Liter Reactor - pdf
Basic vacuum processing - pdf