Processor - with pre-heat / drying tank
 This section contains content relating to commercially available items or equipment.
|
While processors systems can have several tanks, a system employing just two tanks has been developed by Goat Industries in the UK to try and eliminate as many hazards as possible.
Contents
Basic design
The design ensures that all the electrics and heaters are located in one tank, while the reaction with Methanol takes place in a second, separate tank. The temperatures required for biodiesel production of around 60°C presents no flammability or toxic risks in respect of vegetable oil or finished Biodiesel, provided the heating element is always submerged in liquid, so the oil is heated using an electrical heating element which is interlocked with a level switch in a dedicated tank.
The Methanol and catalyst is mixed to make Methoxide in the sealed reactor tank by a manually powered paddle arrangement. The preheated oil is then manually pumped into the Methoxide thus making it an AAF reaction.
As the design concept precludes the use of electrical power after the initial heating of the oil, water washing is used for final Methanol and soap removal after draining the Glycerol. Although not a flexible design in terms of recovering Methanol, it’s probably one of the safest. Once any soap, excess Methanol and catalyst have been removed in the wash water, the Biodiesel is pumped back to the first tank for spray drying.
The Twyn Tub or 'TT' range of processors are an industrial type of design that produces biodiesel to the European standard, EN14214. The process starts off in the left hand tank, that has heating elements inserted and the main reaction takes place in the right hand tank, which is compltely free of any electrical items. The plant was designed to be as safe as reasonly possible without using extortionately expensive components and isolating the reaction stage of the process was found to be the most cost effective way of doing this.
- TT700A
In the photo above, it can be seen that an air operated main pump and mixing ram is used ,whilst smaller models can be hand operated. The left hand heating tank is open at the top and has a high quality level sensor built into it's side to ensure that the heater elements are not turned on accidentally. Most accidents in making biodiesel have been caused this way, especially if the plant design allows methanol vapour to be present at any time in the heating tank during the process. This design does not allow this to happen.
The plant has a large number of valves, inlets and outlets to enable the pumps to work in a large number of different permutations, making the plant as a whole extremely flexible. A separate, electric pump, is used on the left hand side to avoid contamination of the final product with fluids in the main air operated pump. The process uses water to purify the biodiesel, with spray nozzles for washing and drying. No ionic exchange resins are used as these turn the soaps back to acids which are corrosive to vehicle engine parts.
