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Making Bio Diesel

Making Bio-Diesel!

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IMPORTANT: Without going into legal speak, the information disclosed below is provided in good faith and to the best of our knowledge is accurate, however it is entirely your own decision as to whether you use any part of it, and entirely at your own risk if you choose to do so. We do not accept any liability whatsoever should this information be used or misused in ANY context. Copyright Refsol 2009, not to be reproduced without prior permission

We are not able to elaborate on the information provided below. Inevitably it will become a popular source and we do not have time to explain on an individual basis how to produce Bio Diesel, you will have to research it further by using online or published resources yourself

So you get a feel for how far you can go with Domestic Bio Fuel production, We will occasionally go into more technical aspects and conceptual ideas which, whilst they are practised by Home Brewers, are not necesarily safe for us to promote in our range of equipment or recommend that you attempt to copy them

Making Bio Diesel

The process of producing Bio Diesel in a domestic environment can be as simple or as involved as you want it to be

In a nutshell the process involves;

1. Source WVO

The key to quality Bio Diesel, is quality ingredients, or 'Feedstock'

The best quality feedstock is 'SVO' (Straight/New Vegetable Oil) but with the cost of SVO being so high this makes it a completely unviable option, therefore 'WVO' (Waste Vegetable Oil) is the obvious second choice

WVO must be from a source that does not use "Hydrogenated Vegetable Oils" or any other kind of solid, lard-like substance in their fryers. WVO must be a transparent liquid at room temperature, ideally resembling honey, however it can be of any colour. Some WVO is very dark and some is very light, the colour can be dependent upon the cooking temperature or colour of the food cooked in it

WVO is often supplied by restaurants in the 15 Litre Containers it is supplied to them in, these are most commonly Yellow Snap Lid Buckets, Steel Drums, or LDPE screw cap containers, it can help to identify the type of oil you have been given by the information on the buckets

Rapeseed, or Soya Bean Oil is the most commonly available oil (though not necessarily the cheapest) and best oil to use due to its low 'Cloud Point' (Solidification Point). This desirable property will be transferred to the finished Bio Diesel

The S.G of Bio Diesel will depend upon the type of WVO feedstock. Unless you know exactly what your feedstock is, then you will not be able to estimate the final S.G of your Bio Diesel. When measuring S.G with a hygrometer, make sure you are measuring it at the same temperature as your information guide suggests, or compare it with the S.G of Diesel at the same temperature, you want to achieve a similar S.G to that of Petroleum Diesel, though most Bio Diesel will have a slightly higher S.G than Diesel

2. Purify WVO

Purifying WVO can be a very messy business, we recommend you always use old clothes / overalls, protective goggles / face mask and a pair of latex (or alternative) gloves. WVO can smell extremely rancid, sometimes like vomit, this is caused by fermenting (rotting) meat particles in the oil and will dissipate as the oil is cleaned. Make sure you do not get any WVO in your mouth as it can cause food poisoning, we know of a number of customers who have experienced this, though they do still make Bio Diesel regardless!

Most impurities in WVO will settle very quickly if the fuel is warmed, then left to cool and settle in a room at around 20 Celcius. To settle impurities in the most efficient manner you will need a Conical Bottomed Tank. A Conical Bottomed Tank allows all major impurities to settle to the narrow bottom of a cone, where they can then be drained out easily via a Valve in the bottom of the cone

You can aid the settling process by removing very large particle contamination such as chips and batter before the oil is poured into the Conical Tank, this can be done very efficiently by Heating the oil in a Metal Drum to 50 Celcius, and then passing through graded Washable Nylon Monofilament Bags, from 800 to 200 micron, or, if your fuel is fairly clean a 200 Micron Washable Bag on itself should be adequate

After the oil has settled you will see a thick layer of creamy debris at the bottom of the tank, this will be food particles and animal fats, carefully drian this off via the bottom valve and discard completely, or pour into another vessel for longer term standing

A final athough possibly unnecessary stage of filtration could be either simple "Depth Filtration" using a housing with disposable elements, such as our 10" Housings or 20" Housings, or if you still want to eliminate waste filtration media, then a Centrifuge could be utilised, we do two types of Centrifuge, these being the OB Series Centrifuge, and the OBX Series Centrifuge

Your oil will now be of a standard acceptable for processing in a Bio Diesel Processor

3. Titration Test of WVO

Titration is the process used to find out how much catalyst is required to make biodiesel out of waste vegetable oil. The most common catalysts used are Potassium Hydroxide (KOH), or Sodium Hydroxide (NaOH - AKA Lye) You should titrate using the same catalyst that you are using to make your biodiesel

The chemistry of what's going on during a titration is to see how much of a base it's going to take to neutralize the free fatty acids (FFA's) in a sample of the same oil you're using to make biodiesel

Materials Required:

3x Bowls, minimum 50 ml capacity
3x Syringes, metered in 1 ml increments up to 10 ml
1x Pint of 91% Isopropyl Alcohol
1x Gallon of Distilled Water
1x Gram of Catalyst - Potassium Hydroxide (KOH) or Sodium Hydroxide (NaOH) (whichever you are using for your biodiesel)
PH Indicator solution - Phenol Red or Phenolphthalien
Sealable container, minimum 1 litre capacity
Scale with a resolution down to .05 of a gram (jewellery scales)

Create a batch testing "Titration Solution" that can be used for each titration:

NOTE: About every 90 days, remake this solution as it does "expire"

Label Bowls:

Prepare The Bowls:

Titration Process:

Titration Calculation:

The result will be how many grams of catalyst you'll use per liter of oil

Example:

100 liters of oil to be converted to biodiesel
If titrated to 4

If KOH, add 7 + 4 = 11 grams/liter X 100 liters = 1100 Grams
If NaOH, add 5.5 + 4 = 9.5 grams/liter X 100 liters = 950 grams
Add 1100 grams of KOH or 950 grams of NaOH to the methanol to make biodiesel using this oil

Accounting For Catalyst Purity:

In many cases it will be difficult to find 100% pure KOH or NaOH. To account for this, divide the "BASE" by the purity;

If KOH is used and it's 90% pure, then divide 7 by .90 (7/.90 = 7.8)
If NaOH is used and it's 95% pure, then divide 5.5 by .95 (5.5/.95 = 5.8)
Now, instead of using 7 or 5.5, use the "corrected" numbers to calculate how much catalyst is needed

Comments:

It is recommended to perform a titration 3 times and record the results. If the results are close (+/- 1), then you can proceed. If they are not close, you should repeat the tests ensuring that you follow the steps exactly until your results are close

Only use one syringe / bowl for one purpose, so as not to cause cross contamination

4. Prepare Catalyst

Following a Titration Test you will have worked out how much of each ingredient you need to mix into your catalyst. The most common catalyst 'Methoxide' is made from mixing Methanol (approximately 22% by volume of the WVO) and Sodium Hydroxide, this should be mixed together in a suitable container which is resistant to those chemicals, suitable materials would be LDPE, HDPE, and Stainless Steel. Most users mix by manual agitation, though Electric Mixers, and Hand Mixers are available, there are also some pre-mixed catalysts available such as Sodium Methylate which are more easy to use, some information on Sodium Methylate can be found HERE

5. Heat WVO

The main event in producing bio diesel is the chemical reaction between the WVO and Catalyst, this is called Transesterification. A Conical Tank is required for the transesterification process, to enable settling of Glycerol and other waste impurities once the reaction is complete. To being with, the WVO needs to be heated, this can be done either inside or outside of the Conical Tank, some people find it safer to heat in a Metal Drum with a Heater Underneath to avoid the risk of melting a plastic tank, whilst others put a Stainless Steel Immersion Heater and Stem Thrmostat through the side of the Conical Tank. The fuel needs to be heated to approximately 50 Celcius, though many people heat to slightly above 50 Celcius to allow for cooling when the Methoxide is added

6. Add Catalyst to WVO

REMEMBER - CATALYST IS HIGHLY FLAMMABLE

The Catalyst should be added in a way which excludes risk of ignition, this could be by gravity, Venturi Injection, or by using a non-sparking electric pump, such as the commonly used Clarke TAM105, DAB Circulator, or FMT 23-034-Viton. To ensure safety you should really use ATEX Approved (Explosion Proof) Pumps, however the cost of these pumps is very high and largely prohibitive for domestic production, therefore careful selection of a standard Bio-Diesel Compatible Pump is the most common practise, taking care to ensure that the motor vent is well away from any flammable fumes to avoid creating an ignition hazard

7. Mix Catalyst With WVO

Once the catalyst has been added to the WVO, it needs to be mixed, almost every means of mixing has been tried, including Electric Mixers, Hand Operated Mixers, and Pumped Circulation, however, the MOST EFFICTIVE means of mixing is by using a 16-Element Oilybits Static Mixer, this will mix all liquids that are passed through it 100%, so with an adequate pump over a period of time, will mix the entire contents of the tank many times over

8. Cool Mixture

The Bio Diesel should now be allowed to cool to room temperature, during this time a large amount of Glycerol (about the same volume as was added in Methanol) will sink to the bottom of the Conical Tank. Glycerol is a very dark colour, almost black, and is easily distinguishable from the main body of Bio Diesel

9. Settle Glycerol

After the Bio Diesel has cooled, much of the Glycerol will have settled out naturally, however, some trace Glycerol will remain. In a normal installation this would be ignored, then removed at a later stage through Ion Exchange Resin, however, to prolong the life of your Resin thereby reducing consumable waste, there is another, albeit very unexplored means of separating glycerol, this is "Electrostatic Separation Using High Voltage"

Electrostatic Sepation relies on the principle of putting a continuous high voltage electric charge through the Bio Diesel, how this works is that conducting particles including Glycerol, possibly Water, and other impurities, are attracted to the bottom of the vessel, away from the main body of (non conducting) Bio Diesel, what is amazing about this process is the speed at which it takes place, over about 20 minutes almost ALL electrically conductive particles are separated from the Bio Diesel and form a thick layer at the bottom of the Conical Tank. The only problem with this principle is that even 1000 Volts will only conduct through a small beaker of Bio Diesel, and to separate the contents of an entire 120 Litre Conical Tank would require tens of thousands of Volts, which presents obvious electrocution hazards

10. Drain off Glycrol

One you have settled out an acceptable level of Glycerol, this needs to be drained off via the tap in the bottom of the Conical Tank. Spent Glycerol has a small value in that it contains Glycerine, which is an expensive commodity, however you are unlikely to find anyone willing to pay for it, so usually it is disposed of, or turned into Hand Soap. To produce Hand Soap a small amount of sodium hydroxide is added to the Glycerol along with scent, the mixture is then left in the sun to evaporate off, and is then cut into bars

11. Wash Bio Diesel

What you are left with now is 'Raw', or 'Crude' Bio Diesel. Crude Bio Diesel is almost clean, but contains traces of Methanol, Methoxide, Soap, Glycerol and Water, and needs to go through a process called 'Washing'

Washing is practised in many forms, from Water Mist Washing using a 'Fogger', through to 'Dry Washing' in Ion Exchange Resin Towers and Centrifuges

The most simple and efficient way of separating trace contamination is with Ion Exchange Resin, deployed in a Pressure Vessel, or 'Resin Tower'. The best Ion Exchange Resin to use (in our opinion) is Purolite PD206, this is more appropriate for domestic use as it can be used without heating the Bio Diesel prior to purifying. Purolite PD206 should be deployed in a tower of 5:1 Height:Diameter ratio, with a recommended minimum bed depth of 610mm, allowing 50% for vertical expansion, this would point toward any tower with a height of 48 inches, though we find most customers use 0735 or 0844 towers due to the high cost of the resin for the bigger 0948 tower. The tower can be fed at a rate of 2 litres-per-hour, per 1 Litre of resin it contains, so for example, the 0948 tower, holding 22 litres of Purolite PD206 can be fed at 44 litres-per-hour. The only way of attaining EN standard on home brew Bio Diesel is by using Ion Exchange Resin. To feed the tower we recommend using a quiet running centrifugal pump with approximately 3.5 Bar of outlet pressure, such as our TAM105

Mist Washing of bio diesel is also very popular as it is very low cost. Mist Washing involves Pumping water at high pressure through an Atomiser, creating tiny water droplets which sink through the Crude Bio Diesel collecting impurities on the way. Mist washing will remove Saturated Methanol and Soap, and this is drained away until the misting water becomes clear, indicating that there is no soap or other water soluable contaminants left. The downside of this is that Bio Diesel is slightly Hydroscopic, and therefore absorbs some of the Water, which then needs to be removed either by Boiling, Bubble Drying, or through a Resin Tower, however, using Mist Washing in conjunction with a Resin Tower could prolong the life of the Resin even further. Mist washing can be made easier by using an Emulsion Breaker additive in the water, this helps to break the emulsion of the water and oil, speeding the settling process from about 9 hours down to 2/3 hours. The Emulsion Breaker needs to be added to water pre-heated to 40 C, then Sprayed onto the Biodiesel at 40 C for it to be most effective

Centrifuges are another waste-free method of purification, though they can be frustrating if you do not understand the principle of their operation and expect too much from them. Centrifuges work by means of spinning the oil at a high RPM, thereby increasing the Gravitational Force (G-Force) exerted on the Oil, this makes all impurities that are heavier than the oil itself separate to the outer wall of the Centrifuge Rotor where they mass into a solid layer. Oilybits are specialists in Centrifuges and supply the Oilybits OB Series, or Oilybits OBX Series Centrifuges

12. Mix in Performance Additives

This is entirely optional, as some users will prefer to use Biodiesel in its raw form to minimise impact on the environment, but there are a number of additives which all work to increase the usability, performance, and lifespan of Biodiesel, and we would certainly recommend you try them, certainly when using Biodiesel with newer vehicles with sensitive ignition systems which might dislike fuel of low cetane ratings for example;

Coldflow 402 or Coldflow 350 - Can reduces cloud (Solidification) point down to -15C. 402 is for Palm/Tallow/Lard Biodiesel, and 350 is for WVO/SVO/UCO Biodiesel

Bioboost 1000 - Increases cetane (flammability) rating from 2 to 6 points depending upon concentration used

Allklear 400 - Antioxidant which increases lifespan of fresh Biodiesel to up to 2 years

Biocontrol 41 - Biocide additive which, whilst designed for microbially contaminated, stored fuel, can also be added to new fuel to prevent microbial growth

13. Filter Bio Diesel

Finally after washing & adding any performance enhancing additives, you are left with useable Bio Diesel which can be stored in a Drum or IBC ready for use. The only step you may wish to take prior to using it is to put through a Goldenrod Water-Block Filter in the line from the tank to the vehicle. A Goldenrod Water-Block Filter will remove any condensation that may have formed in your storage tank, and also any particles or dust that may have settled in it or passed through a Resin Tower. You could also submerge a Mesh Sack of Oilybits Water Absorbing Polymer in the tank to absorb any free water which forms via condensation, thus prolonging the life of your Goldenrod Filter Element

Dispensing Into Vehicles

Dispensing into vehicles can be done simply straight from a Jerry Can, or you could install a suitable Pump, such as the FMT 23-034-Viton, with a Bio Diesel Compatible Hose, such as our Armorvin HNA Suction Hose, and Polipo Polyeurethane Lined Delivery Hose. Finally a Suitable Dispensing Nozzle will be required, and we can recommend our Self 3000 Manual Nozzle, or Husky 1+10 Automatic Nozzle, both of these nozzles have Viton seals that are completely resistant to Bio Diesel. Pipework Fittings should either be Polypropylene or 316 Stainless Steel, it is worth pointing out that Polypropylene fittings only have paralell threads which are more difficult to seal than the tapered threads featured on 316 Stainless Steel fittings

We hope you find this information useful, if you have any additional information which you think would benefit our readers then we would love to hear what youve got to say ... Just please dont email asking questions about making Bio Diesel as all we know is printed here, and such emails will not be responded to

Frequently Asked Questions

Is it legal to produce and use Bio-Fuels?
YES! Due to a change in regulations on the 30th June 2007, small-scale domestic producers who produce 2500 Litres of useable fuel or less per annum do not need to register, OR pay duty on this quantity of fuel, which can be used for business, private, or a combination of both uses, they must simply keep a record of the quantities of fuel they have produced, the records must be kept for 6 years. If you are producing more than 2500 Litres per annum, you will need to register yourself with H.M Customs & Excise. It is very simple to pay tax on your fuel, you can contact Customs and Excise on 0845 0109000 to become your own licensed fuel supplier, request form EX103 (this can also be downloaded on their website), complete and return it, then you will be issued your registration number. Following this they will send you a monthly form HO930, you just fill in how many litre’s you have used and send a cheque multiplied by the current duty rate per litre for each litre indicated. You can find details on the recent amendment to regulations HERE

What materials are compatible with vegetable oil?
All Ferrous Metals, Aluminium, Stainless Steel, Viton, Delrin, Acetyl, PTFE, Polycarbonate, Polyethylene, Polypropylene, Polyurethane, Nylon, and Nickel Plated Brass to name but a few of the most common materials. Generally speaking NBR / Nitrile / Rubber should be avoided. If you are using mixtures of Vegetable Oil with Diesel then you need to use Polipo PU (Polyeurethane) Lined Hose avoiding pure PVC so that it copes with the petrochemical element. For further reference a very comprehensive chemical compatibility chart is available HERE

What materials can be used to produce a Bio Diesel reactor?
Due to the presence of various caustic, and corrosive liquids, we recommend using only; PTFE, Polyethylene, Polypropylene, Polyurethane, Acetyl, Delrin, Stainless Steel, and Nickel Plated Brass. Pure PVC Clear Hoses may be used for visual aid, but these will weep and harden over time and need changing, so we recommend using Polyurethane Hose wherever transparency is not required. If you are using a budget pump on your system that has components other than these, ensure that it is drained and dried prior to any period of inactivity to prevent corrosion and subsequent contamination of your next batch of fuel

Do you sell Bio Diesel?
No. We only provide the equipment and knowledge to enable others to make their own biodiesel. We have no plans to produce Bio Diesel in the future as there are plenty of quality producers already in the marketplace

You sell hundreds of pumps, which one should i use on a Bio-Diesel Reactor?
There are 4 pumps that are most commonly used on home built Bio Diesel Reactors, the DAB 230v 45w 60lpm Centrifugal pump, the TAM105 230v 300w 40lpm Centrifugal pump, the FMT 23-034 230v 300w 60lpm Sliding Vane pump. In our experience the FMT 23-034 is the best Sliding Vane pump as it runs continuously. The DAB pump has very low power consumption and 3 speed settings, which is excellent, but it provides only 0.5 Bar of pressure, so if youre also running a spraying / misting head then you should use the TAM105 which will provide 3.5 Bar of pressure. Both the TAM105 and DAB pumps will run continuously

With your budget immersion elements, will a longer element heat the liquid any quicker?
No. All of our Elements are 3kW, this means they all heat liquid just as efficiently, although the watts-density will vary between the different lengths of element

Why do most reactors use 3/4"ID pipework, would 1"ID pipework not give greater flow?
No. Most Reactors use 3/4"ID pipework as a lower ID increases the Flow-Velocity, which aids mixing of the ingredients. With negligible head or downstream restrictions, a bigger pipe will transfer the same amount of liquid but liquid wont come out of the end with such force, its like putting your finger over the end of a hosepipe, the smaller the outlet becomes the further the water sprays

There are so many types of Ion Exchange Resin available, in your opinion, which one should I use?
For domestic production - Purolite PD206. Purolite PD206 is a high quality, 'dry' resin, and can be used with the media at room temperature, it will remove all problematic contaminants from Bio Diesel. We also used to sell Lewatitt GF202, this is designed for commercial production, where the Bio Diesel needs to be around 40 celcius. Lewatit GF202 is supplied "saturated" which means, whilst it is dry to the touch, it contains a large amount of water, which is why it is somewhat cheaper than Purolite PD206. There is another type of dry-wash-media available which is simply 'Sawdust' (Hardwood) this product does have cost and environmental benefits over IOX resin, but it will not remove saturated methanol, so Water Washing or Boiling Off (of the methanol @70c) of the crude Bio Diesel is therefore required prior to using this media, it is also difficult to use at it requires 'compaction' whereas IOX resin will sit at the bottom of a Resin Tower by gravity, and will also provide less flow restriction than compacted sawdust

What size of resin tower do you recommend?
For low scale domestic production, a Resin Tower of 35 inches in height is best as it gives a good bed-depth for the Bio Diesel to travel through, these are available from 7 to 10 inches in diameter. The bigger the tower capacity, the faster you will be able to pump your Bio Diesel through it. We also supply Resin Towers Complete With Purolite PD206 as a package

What is ATEX?
ATEX is a European Directive which is short for the French 'ATmospheres EXplosible'. 'ATEX' or 'Ex' Approval is available at various levels to suit differing explosion risk areas, and is a guarantee that a given product can provide no source of ignition in the environment to which its is rated. Basically, if your equipment is to be used in what the HSE deem to be an ATEX area, then all equipment inside that area will need to hold sufficient ATEX approval. you can find more details on ATEX by clicking 'ATEX' in the top navigation bar, or from the DTI, or BSI. These links may also prove useful
http://ec.europa.eu/enterprise/atex/guide/index.htm
http://www.hse.gov.uk/electricity/atex/definitions.htm
http://www.opsi.gov.uk/si/si2002/20022776.htm
http://www.hse.gov.uk/pubns/indg227.pdf