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> Safety
Making biodiesel should always be a safe and enjoyable way to reduce emissions and save money. However, the safety aspects of home biodiesel production should always be addressed when looking at purchasing a biodiesel processor. We have found that most equipment currently on sale or kits to assemble at home are fundamentally unsafe. This was highlighted recently where a producer of biodiesel in Northampton received 20% burns by trying to use a homemade kit to produce his fuel.
In the hundreds of home biodiesel kits Green Fuels have sold since 2004 we have had no incidents where our customers themselves have been harmed from the production of biodiesel, this consistently proves that with the correct equipment the production of biodiesel at home can be a safe and easy activity.
When we developed the Fuelpod 1, Fuelpod 2 and the Fuelpod 3 we made sure we addressed everything that was practically possible with regards to health and safety. During their development, we have been in regular consultation with The Health and Safety Executive (HSE) meaning we can be sure that we have done everything practically possible to provide a safe and user friendly system. For your information we have briefly listed below areas that we felt needed to be addressed when looking at home scale production:
Batch size:
For home scale production we deemed 100 litres to be the maximum 'safe' batch size. This volume was determined as you will only use 17 litres of methanol in the process. The majority of our customers opt to use the smaller 50 litre batch size system primarily due to the duty level of 2,500 litres pa or approx 50 litres per week and therefore only use 8.5 litres of methanol per batch.
Heating:
Although more expensive, we use external band heaters to preheat the oil for our home kits. These can be fitted to a separate drum of oil or to the sump as on the Fuelpod 2 and 3, keeping the heating part of the process away from the reaction - i.e. the oil is heated prior to the reaction taking place not during the reaction when you are adding chemicals. As the band heaters are thermostatically controlled it makes it very difficult to overheat the oil and removes any elements from contact with flammable liquids such as methanol.
Many systems we have seen use immersion heaters, even fitted to plastic tanks which we consider extremely unsafe. In such a situation the heating element could easily over heat the vessel or ignite the methanol. Float switches only solve this issue in normal operation, if a float switch fails it is extremely likely that the processor will melt or ignite.
Chemical addition:
All of our systems use venturi pipes to add the methanol and methylate from a separate vessel. By using the venturi the methanol is never 'neat' in the tank as you need to be pumping oil around to pull the liquid in. As the reaction is fairly swift when the mixture is added, it minimises the risk of having a flammable liquid in the reaction tank. This system also negates the need to ‘pour’ chemicals. This careful mixing procedure is one of the key issues in making a consistently good quality biodiesel which forms the basis of all our equipment design.
The addition of chemicals in a slow and controlled manner allows the reaction to build up to completion. Adding all of the chemicals in one go results in a high concentration of catalyst at the surface of the oil. This leads to the formation of soaps which reduces the amount of catalyst available to allow the formation of methyl esters and consequently leaving un-reacted oil.
‘Pouring’ chemicals into the reaction vessel poses a significant risk. Here the vapours are quickly released as the liquid hits the hot oil which vastly increases the risk of spillage. The flammability risks of methanol are similar to that of petrol and so one must ask ‘would I do this with petrol?’ - the answer is always a resounding 'no', which reinforces our efforts to eliminate any need for pouring, meaning our customers can remain safe and comfortable whilst processing their own fuel.
Chemicals:
Most of our customers use liquid methylates as opposed to dry caustic soda so that there is no exothermic reaction (heat producing reaction). The quality of the fuel is further improved as there is no chance of un-dissolved caustic interfering with the reaction. With the storage of chemicals we always recommend that methanol should be stored in 25 Litre containers where possible or should be bunded and kept away from any sources of ignition.
The volume of chemicals is also significant. Our standard pack size consists of 4 x 25 litre containers of methanol and 1 x 10 litre container of Sodium Methylate. To put this in perspective this would be the equivalent of two cars with tanks of petrol stored in the garage. It is our view that the storage of containers holding greater than 25 litres is potentially unsafe for storage in a domestic garage.
Materials:
When developing our range of systems we had to ensure that all of the materials were resistant to both acidic (oil) and alkaline (during the reaction) environments. We also had to certify that the materials used would catalyse the reaction, hence no copper is used and any brass components are zinc plated. Lastly, we had to ensure that all pipe work and tank materials were resistant to degradation at a reaction temperature of 65oC and resistant to higher temperatures.
Containment:
We have incorporated a sump for oil pre-heating which also acts as a bund during the reaction. The system is also closed meaning that the chemicals are added by sealed containers and the vent pipe goes back to the chemical container. We have also shown that even with larger batches adding the chemicals via a venturi pipe the reaction works so efficiently that minimal methanol vapours are formed. In addition to this we have employed consultants to test methanol vapours in and around our systems and found that the only significant vapours are contained within the reaction vessel and posed little risk.
However regardless of the above, we always recommend that during the reaction suitable ground level ventilation is available for your own safety as methanol vapour is heavier than air (i.e. open door or air vent bricks).
Controls:
On the Fuelpod 2 and 3 we use air controls and an ATEX (explosion proof) approved air pump for operating the system. By using air and dry stop connectors the potential to form sparks is completely eliminated and furthermore you cannot remove a pipe and spray the fuel over the garage. The compressor can then be sited safely more than 1m away from the plant.
On the basic Fuelpod 1 we use a non-sparking pump situated on the drum away from the reactor. The pump has a thermal and load cut-off so if the oil is over heated or if the valves are closed it stops working.
Training:
We provide a comprehensive manual and guide as well as the opportunity for our customers to attend a training day prior to purchase. A level of competence can be achieved by careful study of the manual and furthermore supplimented by attendance at one of our training days. The manual provides all of the MSDS details for the chemicals used in the process as well as guidance. We also provide personal protective equipment including gloves and safety glasses, with the equipment.
Green Fuels customers are provided with a dedicated support line to quickly answer any questions or queries raised.
Purification / Washing:
With the Fuelpod 2 and 3 we use ion exchange resin to purify the fuel. This is a contained system which uses very small quantities of consumables and is extremely simple to use to achieve a good quality fuel. It is this type of system that is used in most commercial scale plants in operation today.
With the basic Fuelpod 1 we use a water mist wash system which is reliable but takes longer and produces approximately 50 litres of waste soapy water per batch.
We try to discourage anyone who wishes to run unwashed or unpurified fuel in their car as the fuel will be fairly alkaline and any soaps present will build up in filters, pumps and on injectors.
Fuel Quality:
At Green Fuels we run everything from a diesel Smart car up to a 5.0 litre V10Tdi VW Touareg on 100% biodiesel. We are extremely confident that the fuel produced from our equipment can be consistently of the highest quality. Instructions and equipment are always provided to allow our customers to carry out basic tests on their fuel to ensure that it is always suitable for use. The aim is that they too will be able to share in our confidence that they are producing and using biodiesel of a high and reliable standard.
Overall you can be assured that we have done our utmost to provide the safest, most reliable, user friendly biodiesel processors on the market today.
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