Bio-diesel FAQ's
We have received the following questions from new and existing customers. We hope these questions will help you to understand bio-diesel filtration and will assist you in making an informed decision as to the necessity and benefits of filtration. In addition, we hope this will be a useful guide as to where filtration and water-removal can be best applied to your process.
The BD6000 Unit
The BD6000 is ideal for use in cleaning and removing water from processed biodiesel. It can also be used to filter waste vegetable oil (WVO) or freshly pressed Rape Seed Oil (RSO). This is known as the Pre-Process Filtration Stage and should be carried out as per the following General Guidelines for Use.
GENERAL GUIDELINES FOR USE
For the BD6000 to operate effectively and efficiently, you will need to pre-filter your WVO or RSO and filter your biodiesel using a 'staged filtration' method. You will need three IBC containers for this. 'Staged filtration' means slowly increasing the filtration efficiency of the strainers and bags to remove larger particulate first and smaller particulate later.
PRE-PRODUCTION FILTRATION OF WVO
You will need to remove the SDFC-W high performance elements and connect a stainless steel pre-filter to the BD6000 unit. This is sold as an optional extra and would be essential if you need to filter WVO.
- Begin by placing a course, 870 micron stainless steel mesh re-cleanable filter insert into the pre-filter housing.
- Put your WVO into the first IBC container.
- Ensure that the suction lance is not positioned in the "white, creamy paste which will settle on the bed of the IBC storage container.
- Run the unit and pump the WVO through the filter housing and into a secondary storage container. This will remove a large percentage of the FFA (free fatty acids). It may be necessary to empty out and jet-wash this course mesh element during this process.
- Repeat this filtration process at 560 micron.
- For best results repeat this process with 200, 100 and 50 micron bags. All micron size inserts are available on request.
- Transfer the clean WVO into the third IBC before production.
PRE-PRODUCTION FILTRATION OF RSO
You will need to remove the SDFC-W high performance elements and connect a stainless steel pre-filter to the BD6000 unit. This is sold as an optional extra and would be essential if you need to filter RSO.
- Begin by placing a course, 870 micron stainless steel mesh re-cleanable filter insert into the pre-filter housing.
- Put your RSO into the first IBC container.
- Run the unit and pump the RSO through the filter housing and into a secondary storage container. This initial pass will trap most of the rape seed shell and "cake" in the mesh filter. Remove and clean when necessary.
- Repeat this filtration process at 560 micron.
- For best results repeat this process with 200, 100 and 50 micron bags. All micron size inserts are available on request.
- Transfer the clean RSO into the third IBC before production.
You are now ready for production.
POST-PRODUCTION FILTRATION
Once you have produced your biodiesel, you can use the BD6000 to remove excess water and contaminant and clean it up.
(If you are unsure of why you should filter your bio-diesel, see our FAQs below).
You will need to replace the SDFC-W high performance elements for this stage of the filtration process.
The SDFC-W replacement cartridges rely on absorption to remove water from bio-diesel. By circulating the fuel several times, the elements will have time to "absorb" the water. The pump on the BD6000 is rated for continuous use and is ideal to be left running for extended periods. Although you will see an immediate improvement in the cleanliness and clarity of the fuel in a single pass, the elements need time to 'absorb' the water effectively and you will therefore need to run the filtration process several times. Particulate contamination will also be removed at the same time. To achieve maximum filtration efficiency, you should run the filtration process at least four times.
It is important to note that best results and longer element life are achieved when used in conjunction with adequate settling processes.
You should have an IBC storage container dedicated to the filtration process. This should be the penultimate stage before transferring the fuel into the final dispensing IBC for resale.
Up to 1000 litres per day can be effectively filtered by the DB6000 two pot unit (flow rate 600l/hr).
For larger production quantities, it may be advisable to opt for the larger BD6000 four pot unit (flow rate 1300 l/hr).
Biodiesel FAQ's
We have received the following questions from new and existing customers. We hope these questions will help you to understand biodiesel filtration and will assist you in making an informed decision as to the necessity and benefits of filtration. In addition, we hope this will be a useful guide as to where filtration and water removal can be best applied to your process.
Q : What will happen to my vehicle if I run it on un-filtered biodiesel?
A: Contaminated biodiesel may cause the following problems to engines:
• Corrosion of fuel injection equipment components.
• Elastomeric seal failures
• Low pressure fuel system blockage
• Fuel injector spray hole blockage
• Increased dilution and polymerisation of engine sump oil
• Pump seizures due to high fuel viscosity at low temperatures
• Increased injection pressure
• Water is the central promoter of rust
Q : I am considering re-selling the biodiesel I produce. Do I really need to filter it before I sell it on?
A: Yes, it would be advisable to do so to prevent any potential claims against you. In addition to the above list of problems that contaminated biodiesel may cause, a few more problems could occur, namely:
• Free methanol in biodiesel corrodes aluminium & zinc and results in a low flash point. High possibility of failure due to corrosion of fuel injection equipment.
• Biodiesel process chemicals such as potassium & sodium compounds and solid particulate will result in blocked nozzles.
• Dissolved water in biodiesel will lead to the reversion of biodiesel to fatty acid and will result in filter blockage.
• Free water in mixtures causes corrosion, sustains bacteria, increases the electrical conductivity of fuel which results in sludging and corrosion of fuel injection equipment.
• Free glycerine, mono- & di-glyceride may lead to corrosion of non-ferrous metals, will leave sediments on moving parts causing lacquering resulting in filter clogging.
• High viscosity at low temperatures may result in excessive heat locally in rotary distributor pumps and higher stressed components. This could lead to pump seizures and poor nozzle spray. Corrosive acids (formic & acetic) will corrode all metallic parts if not removed effectively and will result in the failure of fuel injector equipment.
Q: Do I really need to filter my biodiesel or can I run my car on the fuel produced?
A: All responsible reactor manufacturers will advise of the need for filtration to remove excess water and contaminants from the final product.
Q : I heard that I should not be concerned about "particulate contamination', as long as my biodiesel is "clear" everything should be okay?
A: Not true at all! Solid particulate will cause system damage and removal is essential!
Q: Can I filter Waste Vegetable Oil (WVO) with the BD6000 unit?
A: Yes, the unit can be used in this application. For best results, you will need to adhere to our guidelines for use (see above).
Q: Can I filter freshly pressed Rape Seed Oil (RSO) with the BD6000 unit?
A : Yes, freshly pressed rape seed oil is becoming increasingly popular as it is more consistent in quality. For best results, you will need to adhere to our guidelines for use (see above).
Q : Is the pump suitable to pump WVO and RSO?
A: Yes, the pump on the unit is highly dirt tolerant and will effectively pump WVO and RSO.
Q: What do I do if the quality of my WVO is poor? I have just taken delivery of poor quality WVO? Should I return it or use it?
A: It is best to use only those fryer oils which are liquid and clear at room temperature, not creamy and pasty. The titration result should be less than 3.5 mL of standard titrant (1 gram of lye in 1 litre distilled water). In some cases the oil may look suitable or even rather creamy, yet have a high titration value. Should this be the case, it is better to seek advice from the bio-diesel reactor manufacturer or agent.
Q : Once I have invested in your unit what is the pence per litre cost to produce clean biodiesel?
A: If the BD6000 is used properly, multi-pass filtration is performed and adequate settling processes are used in your production process, the cost adder per litre should be no more than 2 pence per litre. We offer very attractive price breaks for larger quantity purchases of SDFC-W elements.
Q : What do you mean by "Multi-pass filtration"?
A: The SDFC-W replacement cartridges rely on absorption to remove water from biodiesel. By circulating the fuel several times, the elements will have time to "absorb" the water and you will therefore need to run the filtration process several times. The pump on the BD6000 is rated for continuous use and is ideal to be left running for extended periods. It is best to have an IBC storage container dedicated to the filtration process. This should be the penultimate phase of the staged filtration process before transferring the fuel into the final dispensing IBC for resale.
Q: How long will the SDFC-W water removal elements last?
A: Each filter cartridge will hold 800 mL of water. The BD6000 (2 pot unit) will absorb 1.6 litres of water per element change-out. A 4 pot version is available for larger production quantities and will remove twice this amount per element changeout. The amount of water present in your biodiesel can be significantly reduced by allowing longer settling times and better settling methods. Additional settling processes such as "bubbling" are encouraged and would allow for longer element life.
We offer very attractive price breaks for larger quantity purchases of SDFC-W elements.
Q: How long should I run the unit for?
A: The BD6000 is designed for multi-pass filtration and continuous use. Although you will see an immediate improvement in the cleanliness and clarity of the fuel in a single pass, the elements need time to "absorb" the water effectively. Particulate contaminant will also be removed at the same time.
Q: How can I reduce the number of replacement SDFC-W elements used?
A: Settling is the key to initial water removal. The more water that is removed by adequate settling processes, the longer the replacement elements will last.
Q: How will I know when the filter elements need replacing?
A: This depends on the contaminants in your biodiesel. -Solid contamination: The BD6000 is fitted with a cut-off switch which will turn the unit off when the pressure exceeds 4 bar. -Water contamination: As the filter elements absorb water from the biodiesel, they will "soften up" as the water is retained. This means that the cut-off blockage pressure of 4 bar is not possible to reach. It is therefore best to replace elements on a 'time used" basis. This will vary from user to user depending on the quality of their production process as well as on the settling procedures used and settling time allowed.
Q: How many litres per day can I filter with your unit?
A: Smaller production quantities up to 1000 litres per day can be effectively handled by the DB6000 2 pot unit (flow rate 600 l/hr). For larger production quantities it may be advisable to opt for the larger BD6000 4 pot unit (flow rate 1300 l/hr).
Q: How long will I need to run your unit before my fuel is clean?
A: Multi-pass filtration is required to achieve the best results. Try to circulate your storage container at least 4 times. This will allow for maximum filtration efficiency.
Q: Where does your filtration unit fit into the overall production process?
A: The BD6000 can be used upstream and downstream of your production process. It can be used to filter WVO (Waste Vegetable Oil) and RSO (Rape Seed Oil) if the operational guidelines are followed properly (see above). It is most effective at removing excess water and contaminant from the finished product. Best results and longer element life are achieved when used in conjunction with adequate settling processes. (see diagram)
Q: What do I do if my biodiesel is very "wet and cloudy"?
A: Settling processes are essential in biodiesel production. The longer the fuel is allowed to settle, the better the overall quality of the fuel will be. Water will gather at the base of the storage container and should be drained off at regular intervals.
Q: What other water-removal processes are there?
A: There are several processes and each has advantages and disadvantages.
• Gravity Separation: Free, but can be time consuming
• Centrifuge Separation: Centrifuge systems will "spin' the water out but generally only remove free water. Very expensive.
• Vacuum Dehydration: High cost and generally not best suited for biodiesel.
• Heating: Can be used but generally impractical and expensive.
• Polymer Absorption: Will remove free and emulsified water. Low Cost.
Q: Why is a pre-filter fitted to the filtration unit?
A: A spun-bonded media pre-filter is fitted for two reasons: a) To extend the life of the SDFC-W elements. b) To catch any large contaminants and offer the pump the necessary protection.
Q: Why are there extension lances on the suction hose as well as on the return hose of the filtration unit?
A: The extension lances need to be positioned in your 'Filtration' IBC and positioned as far apart as possible in order to ensure maximum circulation. This multi-pass circulation will allow the elements sufficient time to absorb water and remove contaminants from the biodiesel. The longer the circulation time, the better the filtration efficiency of the elements and cleanliness of the fuel.
Q: We need to increase our production but don't have time for settling and filtration.
A: IBC storage units can be purchased very cheaply these days. The key to quality bio-diesel production is adequate settling stages and multi-pass filtration.
Q: Which vehicles are suitable to run on biodiesel?
A: Please contact your vehicle manufacturer for suitability.
Q: I own a taxi / haulage company and am considering using biodiesel for my fleet of new vehicles? How can I guarantee the best possible quality biodiesel for my fleet?
A: The quality of the finished product is largely dependent on the quality of the WVO used. Source quality WVO wherever possible. Follow the bio-reactor production guidelines to the letter. Allow for adequate storage and settling processes. Drain off water at regular intervals. Over-stretching the capability your reactor is not advised. Use a dedicated filtration IBC and rely on multi-pass filtration to polish your fuel.
Q: I have invested lots of money in my biodiesel production reactor. I really would like a filtration unit but cannot afford it now.
A: The initial investment costs can be very high, depending on your production quantities and reactor of choice. Import duties etc don't help either. It is however advisable to build "good practice" into your production methods from the very beginning to avoid any possible difficulties later on.
Q: Why do I need to wash my biodiesel at all? It is time consuming and I can't see the benefits.
A: Yes, washing is essential to remove excess production chemicals. Adequate settling and filtration processes also take a little longer, but the positives significantly outweigh the negatives. Should you be considering re-selling your biodiesel, you should be aware of any possible liability claims that could arise from producing poor quality fuel.
Q: I am producing biodiesel on a small scale for my own vehicle? Is filtration really necessary?
A: If it is your own vehicle then final responsibility lies with you. It may take several months before the effects of moisture and solid particulate contamination begin to cause problems. Older vehicles are generally more tolerant to contaminated fluids, but modern cars almost certainly will experience a host of problems in time.
Q: I noticed that you were offering a similar unit on ebay recently? Is this the same unit you are promoting now?
A: We do offer ex-demonstration units on ebay from time to time. These are filtration units which have been used in our in-house promotions. We must however point out that these units are offered in their basic format i.e. without suction and delivery lances, pre-stainer and pre-filter housing with spun-bonded element. ebay is becoming increasingly popular for shoppers and it is a useful re-sale channel for us. If you have recently purchased an ex-demonstration unit from ebay, please note that all the necessary attachments are available to purchase as add-ons to the unit. Please contact us to discuss your requirements.
Q: I am a farmer producing biodiesel on a small scale for my farming machinery? Do I still need to filter and remove water from my biodiesel?
A: Older agricultural machinery is generally less sensitive to moisture content in the fuel. However, on modern machinery it is advisable to filter prior to use.
Q: I notice you have a 'particle counter' to count the level of contaminants in biodiesel. Do I really need one of these to produce clean biodiesel?
A: No, you don't! The PC9000 particle counter will display cleanliness levels in real time and is a useful tool to trend the performance of the filter elements and overall cleanliness of the fuel. The filter elements will still remove water and particulate effectively. It is handy however when an independent verification of filtration performance is required e.g. to satisfy a potential customer as to the quality of your bio-diesel.
Q: My filtration unit is making a strange "droning" noise? What is wrong with it?
A: This is usually due to a blockage on the suction side. Check all strainers, pre-filters and filter elements that may need cleaning or replacing.
Q: My biodiesel is 'waxing' in cold weather, what should I do?
A: Biodiesel can wax at low temperatures and should be stored at temperatures above 0°C. It can be stored underground in most cold climates. Above ground fuel systems should be protected with insulation, agitation, heating systems or other measures if freezing weather is common. This precaution applies to tanks, pumping equipment and the vehicles themselves. The pre-filter attachment to the BD6000 will assist in the wax removal process.
Q: How long can I store my biodiesel before use/resale ?
A: Biodiesel can be stored for many years provided that it is kept free of condensation and bacteriological growths. Any water still present in biodiesel after the washing and settling processes can attract microbial growths (algae), which can contaminate fuel systems. By multi-pass filtration you will remove solid and water contaminants and eliminate this problem. Biodiesel is hydroscopic and has the tendency to absorb water and will draw moisture from the atmosphere. Ensure that your storage containers are properly sealed. Run your filtration unit to remove excess water.
Disclaimer
The BD6000 unit is to be used according to the guidelines shown above. Filtertechnik take no responsibility whatsoever for the quality of the end product.
