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| − | <metadesc>Making biodiesel using Anhydrous Sodium Methylate ASM .</metadesc> | + | <metadesc>Making biodiesel using anhydrous sodium methylate ASM .</metadesc> |
| − | This page gives a guide to making Biodiesel from Anhydrous Sodium Methylate (ASM), a liquid [[catalyst]] which can be used in place of the more conventional [[Sodium Hydroxide]] or [[Potassium Hydroxide]] catalysts. | + | This page gives a guide to making Biodiesel from anhydrous sodium methylate (ASM), a liquid [[catalyst]] which can be used in place of the more conventional [[Catalyst|sodium hydroxide]] or [[Catalyst|potassium hydroxide]] catalysts. |
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| | + | Anhydrous sodium methylate (ASM) is a white powder in pure form but for practical use as a [[catalyst]] in diy biodiesel it is dissolved in pure [[methanol]] at 25% to 30% concentration. |
| | + | In this form it is a colourless, viscous fluid with a slightly sweet alcohol smell - very similar to [[methanol]] which, after all, makes up a large proportion of the fluid volume. |
| | + | ASM is both highly flammable, corrosive and toxic through inhalation, skin contact and ingestion. It evaporates readily to leave a white powdery residue and at low temperatures it tends to precipitate out as a colouless crystal. |
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| − | ==What is it and where do I get it from?==
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| − | ===What is Anhydrous Sodium Methylate===
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| − | It is a white powder in pure form but for practical use as a [[catalyst]] in diy biodiesel it is dissolved in pure [[methanol]] at 28% to 30% concentration.
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| − | In this form it is a colourless, viscous fluid with a slighlty sweet alcohol smell - very similar to [[methanol]] which, after all, makes up a large proportion of the fluid volume.
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| − | ASM is both highly flammable,corrosive and toxic through inhalation, skin contact and ingestion. It evaporates readily to leave a white powdery residue and at low temperatures it tends to precipitate out the white solid.
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| − | ===Availability===
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| − | Compared to [[Sodium Hydroxide]] and [[Potassium Hydroxide]] which are readily available from a number of chemical suppliers around the UK, ASM is somewhat harder to source.
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| − | One well known biodiesel chemical supplier does sell it in various pack sizes from 25litre HDE cans to 1000litre IBCs and new sources are starting to appear.
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| − | Current prices are in the £1.50 to £2.20 per litre range
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| | + | ==Availability== |
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| | + | Compared to [[Catalyst|sodium hydroxide]] and [[Catalyst|potassium hydroxide]] which are readily available from a number of chemical suppliers around the UK, ASM is somewhat harder to source. |
| | + | One well known biodiesel chemical supplier does sell it in various pack sizes from 25litre HDE cans to 1000litre IBCs and new sources are starting to appear. |
| | + | Current (Sept 2012) prices are in the £1.50 to £2.20 per litre range |
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| − | ==Making biodiesel with Anhydrous Sodium Methylate==
| + | As of 2019 Anydrous Sodium Methylate has become increasingly difficult to source due to regulations relating to storage. |
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| − | ===Calculating how much to use===
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| − | A lot of clever people have gone through a lot of complex calculations to work out the correct amount of ASM to use. However, a certain James Leach from the Vegetable Oil Diesel forum has simplified pages of complex organic chemistry down to a simple, single line equation
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| − | ::<big>'''ml of Methylate = ((Base Amount + titration value) X batch volume in litres) X 5'''</big>
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| − | This is based upon the use of a 0.1% Sodium Hydroxide titration solution (ie the normal 1g of Sodium Hydroxide in 1 litre of de-ionised water that most of us use and also known as Lye Water).
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| − | A good starting point for the base figure is 5.0 although clearly the base figure is adjustable and can be tweaked to get as low as possible whilst maintaining good results.
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| − | As an example : assuming a batch size of 150 litres, a titration of 2.0g/l (using 0.1% NaOH titration fluid) and using a base value of 5.0 g/l gives
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| − | ::<big>'''((5.0 + 2.0) X 150) X 5 = 5250ml of Methylate</big>
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| − | Whilst it is perfectly possible to use a single stage reaction for making biodiesel, many brewers are now taking advantage of the benefits of the two stage no titration process with it's reduced chemical usage, reduced soap production and better yields.
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| − | Methylate lends itself nicely to the [[two stage process with no titration]] and the base figure can often be reduced somewhat.
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| − | For the first stage of the process, the formula is
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| − | ::<big>'''ml of methylate = (base figure X batch volume) X 5</big>
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| − | A [[3/27 test|conversion test]], be that 3/27, 5/45 or 10/90 is then done to identify the remaining unconverted litres in the batch
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| − | The second stage formula is then
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| − | ::<big>'''ml of methylate = (base figure X unconverted litres) X 5</big>
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| − | Several brewers, including myself, have achieved very good results using a base figure of 4.0 for both stages.
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| − | As a worked example, using the same '''150 litre batch''' as the single stage example, a base figure of '''4.0''' and an assumed fallout of '''2.0ml in a 10/90 test''' gives
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| − | ::'''First stage : ml of Methylate = (150 X 4.0) X 5 = 3000ml'''
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| − | The 2.0ml of fallout in the 10/90 suggests that 20% of the 150 litre batch or 30 litres remain unconverted
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| − | ::'''Second stage : ml of Methylate = (30 X 4.0) X 5 = 600ml'''
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| − | This demonstrates the significant saving in chemicals of the two stage process, giving '''3600ml''' for the two stage instead of '''5250ml''' for the single stage, '''a 31% saving''' and is based on real world results I have seen in my own processor.
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| − | ===Mixing===
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| − | The ease of mixing is without doubt the best feature of mixing Sodium Methylate.
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| − | Using conventional solid catalysts is a labour intensive process. Whilst [[Potassium Hydroxide]] flakes dissolve relatively easily in methanol, [[Sodium Hydroxide]] micro pearl is more trouble and full sized [[Sodium Hydroxide]] pearl requires significant effort.
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| − | Mixing Sodium Methylate and [[Methanol]] is an instantaneous process, comparable to mixing fruit cordial with water since both are liquids.
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| − | ===Reducing the Methanol volume=== | + | ==Storage== |
| − | The second advantage of using Methylate is that around 70% of the fluid is actually methanol. This means that less methanol needs to be added to the batch.
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| − | Conventional wisdom has been around 20% methanol using solid catalysts whereas using Sodium Methylate this can be reduced signficantly.
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| − | In my own processor, using the two stage no titration process, I have seen perfect 10/90 tests using just 12% methanol in each stage.
| + | Shelf life of ASM is quoted as 12 months from delivery if kept dry and in original packaging. Storage temperature should not exceed 30°C, and at temperatures below 10°C the active ingredient may start to precipitate. Warming, combined with agitation will help re-dissolve the active ingredient. |
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| − | ===A real world example===
| + | Crystallisation temperatures of ASM solutions: |
| − | Let's assume a batch size of '''150 litres''', a [[two stage process with no titration]], a base figure of '''4.0''' and a dropout on the 10/90 [[3/27 test|conversion test]] at the end of the first stage of 2.0ml
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| − | For the first stage:
| + | *25% ... -2°C |
| − | <big>Methanol volume = 12% X 150litres = 18 litres,
| + | *28% ... 0°C |
| − | Methylate volume = (150 X 4.0) X 5 = 3000ml</big>
| + | *30% ... 5°C |
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| − | For the second stage, which has 30 uncoverted litres:
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| − | <big>Methanol volume = 12% X 30litres = 3.6 litres,
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| − | Methylate volume = (30 X 4.0) X 5 = 600ml</big>
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| − | Giving a total of '''21.6 litres of methanol and 3.6 litres of Methylate'''
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| − | ==The pros and cons of using Sodium Methylate== | + | ==The pros and cons of using anhydrous sodium methylate== |
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| | ===Pros=== | | ===Pros=== |
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| | [[Category:Biodiesel]] | | [[Category:Biodiesel]] |
| | [[Category:Chemicals]] | | [[Category:Chemicals]] |
| − | [[Category:Processing methods]]
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This page gives a guide to making Biodiesel from anhydrous sodium methylate (ASM), a liquid catalyst which can be used in place of the more conventional sodium hydroxide or potassium hydroxide catalysts.
Anhydrous sodium methylate (ASM) is a white powder in pure form but for practical use as a catalyst in diy biodiesel it is dissolved in pure methanol at 25% to 30% concentration.
In this form it is a colourless, viscous fluid with a slightly sweet alcohol smell - very similar to methanol which, after all, makes up a large proportion of the fluid volume.
ASM is both highly flammable, corrosive and toxic through inhalation, skin contact and ingestion. It evaporates readily to leave a white powdery residue and at low temperatures it tends to precipitate out as a colouless crystal.
Availability
Compared to sodium hydroxide and potassium hydroxide which are readily available from a number of chemical suppliers around the UK, ASM is somewhat harder to source.
One well known biodiesel chemical supplier does sell it in various pack sizes from 25litre HDE cans to 1000litre IBCs and new sources are starting to appear.
Current (Sept 2012) prices are in the £1.50 to £2.20 per litre range
As of 2019 Anydrous Sodium Methylate has become increasingly difficult to source due to regulations relating to storage.
Storage
Shelf life of ASM is quoted as 12 months from delivery if kept dry and in original packaging. Storage temperature should not exceed 30°C, and at temperatures below 10°C the active ingredient may start to precipitate. Warming, combined with agitation will help re-dissolve the active ingredient.
Crystallisation temperatures of ASM solutions:
- 25% ... -2°C
- 28% ... 0°C
- 30% ... 5°C
The pros and cons of using anhydrous sodium methylate
Pros
- Mixing it with methanol is as easy as making orange squash
- Being a liquid, there is no corrosive dust to worry about
- Being around 70% methanol, using methylate requires less methanol in the batch
Cons
- Methylate is considerably more expensive than solid catalysts although this can be offset against methanol savings
- Availability is still an issue although this is improving
Julesandtash 21:11, 15 September 2012 (BST)
