washing with heat

[Captaincademan Senior Member Find all posts View Profile Close Captaincademan]

Re: washing with heat

Thanks for the great info Wesley, But I wont be pulling a vacuum on it as the vessel is way to hard to seal.

I have an abundance of electrical power courtesy of my solar installation so I think I will just boil it off.

I started a little experiment yesterday but I got interrupted, so I will have to start again.

here is what I noticed in yesterday's incomplete test:

1Kg of Bio in a saucepan on BBQ

initially it was cloudy after coming out of pump (had to prime pump so it still had some air in it when I pushed it through - hence the cloudy nature), but clarified quite quickly over heat. To be expected.

Then at bang on 65 degrees the most minute bubbles I have ever seen started to appear. They obviously increased with increase in temp (as per what you said about being mixed with higher boiling point substances).

Interestingly once over 100 degrees, there was visible vapour coming off the bio, and teh bubbles started to coalesce and increase in size with a soap like reflective sheen to them. I can only put this down to the water that is created in the brew mixing with the present residual soap. now there certainly wasnt a lot, just a few here and there on the surface.

glycerine started to drop out really quickly. I didnt measure it in any way, but there was a considerable portion of teh bottom of teh saucepan covered in glycerine within about 20 mins of being on heat.

I let my glycerine settle out of the brew for a week in the mixer before i transfer my fuel to my storage tanks, and then after it comes out of my storage tanks it goes through a glycerine trap I made, then through my golden rod filter. I can honestly say that the glycerine that settled out was not already separated from the bio when I put it in the saucepan.

I probably wont find time this weekend to do it properly, but I will post results when I get them done.

[Tony From West Oz Vice Chairperson of WARFA Find all posts View Profile Close Tony From West Oz]

Re: washing with heat

Cade,
Keep up the good work.
Once you have this one completed, perhaps you could do a test on the already settled and filtered biodiesel, for comparison.
Tony

[smithy Senior Member Find all posts View Profile Close smithy]

Re: washing with heat

Cade, when you return the saucepan to the kitchen, don't tell the Mrs what you have been doing with it!

[WesleyB Donating Member Find all posts View Profile Close WesleyB]

Re: washing with heat

Methanol is miscible in biodiesel and glycerine. So demething allows the glycerine in the biodiesel that's dissolved in the methanol to separate. I expect soap also falls out, so the resulting soap level will be lower. Someone years ago on biodiesel Ireland demethed, let it settle, getting a lowered soap content as indicated by soap content tests. A dry wash after settling for a week a month or longer might be in order.

[Captaincademan Senior Member Find all posts View Profile Close Captaincademan]

Re: washing with heat

I just popped out to the shed in between tasks and weighed the brew left in the saucepan. Now a lot of things went wrong with this little attempt so its rather meaningless, but the bio mixture with all drop out poured back in together measured 30 grams lighter on 1000 grams initial measure. so that means that I removed 3% of the initial weight of the brew as water and methanol.

I would estimate that the amount of glycerine in the bottom was less than or around 1ml.

I will do again properly from start to finish with as many variables as I can controlled, and then repeat to confirm. it wont be for a week or to though. I am coming up to the end of my study so its head down and bum up at the moment!

[Dr Mark Senior Member Find all posts View Profile Close Dr Mark]

Re: washing with heat

Re: washing with heat

'Luckily for you I am a Chemist, unlike anyone else on this forum.'

I think you need to pull your head out of your arse.

Sorry, you've lost me. What is the purpose of this post?

[Dr Mark Senior Member Find all posts View Profile Close Dr Mark]

Re: washing with heat

Since we started to lock horns Tilly on various forums, all you have ever done is belittle any tests or experiments I have ever done. You may try to play the great god on this forum but you don't know everything.

Have a look at my rider on your warnqvist test thread and you will see what I mean.

Sorry to other forum members for throwing this thread off topic but I do get really cheesed off with this guy.

You are right. He's not a chemist and a substantial amount of what he says is wrong. I stopped reading his posts years ago.

[Captaincademan Senior Member Find all posts View Profile Close Captaincademan]

Re: washing with heat

Well I decided to revive my train of thought on this one. I thought I would push the boundaries a little with the temperature, and found something very interesting (to me anyway).

I put 100ml of unwashed freshly batched bio in a saucepan and put it on my bbq wok burner. heres what i noticed:

* at around 60 degrees or so, there was visible vapour starting. no surprises - I would assume its the methanol leaving the brew.
* approaching 100 degrees the edges of the fuel started to boil here and there - ever so tiny little bubbles. also no surprises there - just the water left over from the reaction leaving town.
* now it starts to get interesting. the fuel started showing ripples under the surface (you could see them as the light was refracting differently) and they sort of woft around. they remained present the whole time from then on.
* somewhere around 130 degrees (hard to tell as the temperature of the pan fluctuated big time depending on where in the pan I took my reading) it started to change colour slightly.
* somewhere between 150 and 180 degrees it went a nice treacle brown. heating stopped at this point.

now its even more interesting - there are a heap of floaties that are in suspension all through the fuel, and its that lovely treacle brown colour. I then took this heated fuel and put 20ml of water in it - applied with a hand pump sprayer on fine mist - and let to settle. I did a second one with non heated fuel to compare.

So I wanted to see this process again, so I repeated and got the same results. I ran this fuel while it was hot through a 2 micron filter and the clarity was exceptional. I left this to cool on its own.

I repeated a third time and viola, around 180 degrees it goes brown and floaties appear. I cooled this one in some ice water to get it back to room temp, and the floaties remained in suspension. I then filtered it, and once again the clarity was exceptional. I left all of this over night. note - I also filtered some un heated fresh bio to compare - and the clarity was also very good.

next day, the washed fuel samples are starting to clear, and as expected are not completely washed, so they are not very clear.

both of the heated samples - cold filtered and hot filtered are showning some drop out, which is not present in the un heated control.

the cold filtered fuel is crazy clear. when I put a LED torch under it and shine it up through it, you would expect to see a shaft of light, but you dont, as there is nothing in suspension to pick up the light. very impressed. The next little experiment will to be do a wash on it and see if it is any different to the first heated but unfiltered washed sample.

so if the heating does appear to perform the same function as washing, I am thinking of making the following rig:

build a turk burner outside my shed, and plumb a copper line from the bio brewer to it with a small 12v pump on the cold side with a bypass and valve so I can regulate the flow. Pass the fuel through the turk burner in a copper coil, and then send back to the tank. install a digital temp gauge to monitor the output temp. I should be able to regulate the temp by adjusting the flow. find someway of working out the flow rate and then try to make this predictable at each batch so i can then just run the pump for a period of time, allowing for say 3 changes of tank volume.

after this its just a case of running off any sediment and filtering the fuel. I reason that the sediment should drop out regardless of filtering, I just filter it on the way to the storage tank after it has settled for a few days.

My only concern is what have I actually done to the fuel by heating it to 180 degrees? is the brown colour caused by carbon or something such as? have I 'burnt' the fuel and reduced its calorific value?

I am looking forward to hearing some comments - good and bad on what I have done or what I could improve, or if the process has no value at all.

[Captaincademan Senior Member Find all posts View Profile Close Captaincademan]

Re: washing with heat

So I have been doing a little more reading and in particular it seems that the 'smash it to pieces' method of water washing seems very easy according to the journey to forever website. The only reason I am reluctant to water wash (I know a lot of you guys have been doing it forever) is it seems counter intuitive to me to be adding water to the fuel and then have to hope that you get it all out again after. What about any water that might drop out in your tank after the the fuel goes through a few heat cycles (trips through the fuel pump and return to the tank). Is the addition of metho / methanol etc an acceptable solution to 'soak' up any water that may present and allow it to be burnt? I am really interested in improving my fuel quality but am very time poor so I need a solution that is quick, easy and no fuss. misting and bubbling seems like it will take too long for me.

As much as I am interested in seeing if washing with heat is viable, I am also mindful of the obvious dangers in heating bio up past its flash temp, so I am all ears.

[Tony From West Oz Vice Chairperson of WARFA Find all posts View Profile Close Tony From West Oz]

Re: washing with heat

Cade,
Good to see you are back experimenting with your bio.
Even better to see that you have recognised some of the risks associated with this experiment.
What I would like to identify is the composition of the 'floaties' that you created by heating the biodiesel to 180°C
I would imagine that the brown colouring is due to the biodiesel getting 'burnt' at the bottom of the saucepan. The metal of the saucepan is at a much higher temperature than the biodiesel, so there is a risk of changing it's chemical properties by heating it to a much higher temperature while heating the oil to 180°C. If you can heat it with a heat source which is within a few degrees of the desired temperature of the biodiesel, you may be able to minimise / eliminate the browning of the biodiesel.
If you can get an insulated container and add insulation around the heating elements, monitor the element and biodiesel temperatures, and heat the biodiesel much slower, I would be interested in seeing if the biodiesel changes colour at temp <180°C

Keep up the good work.
Tony

[Bueff Biofuel Enthusiast Find all posts View Profile Close Bueff]

Re: washing with heat

Hi Cade,

looks like you're on to something here,

I usually wash once using about 60 ltr for a batch of 1000ltrs, but my brew is kept at 65 deg at all times. after I drain the soap/water the fuel is absolutely crystal clear, even once cold. I might try to heat that to 180 deg and see what happens.

I have a glass 2 ltr Erlenmeyer flask and give that shot. That would rule out contamination of a metal pans.

Does anyone think it would be a issue using the flask at that temperature?

Thanks guys

[Captaincademan Senior Member Find all posts View Profile Close Captaincademan]

Re: washing with heat

Hey Jens,

do you mist and bubble or do you just jam in the water and belt it up with your brewer? it is interesting that you keep it heated.

the things that really surprised me about the heating of the bio was that the 'floaties' suddenly appeared out of an otherwise pretty clear brew, and once left to cool and settle and the floaties were filtered out, that there is some drop out in the bottom of the flask. I cant help but wonder if 'floaties' plus 'dropout' = the goodies that washing removes. I will try to put some more time aside one night after work to see what happens if I wash a batch of heated fuel.

I was thinking Tony that I could put a pyro glass (old coffee plunger) in a pan on the bbq and heat the fuel up in that. I am not sure that the metal of the saucepan is the issue, but it would be nice to know if the floaties can be made to appear before the fuel goes brown. either way I am kind of steering away from it all now, just because of the inherent dangers of 200 litres of very hot fuel just waiting to accept a flame / spark. When I first started this train of thought I wasnt expecting such high temperatures to be needed. I was kind of hoping it would all happen somewhere around 70 degrees as the methanol was removed. and maybe it will if I keep it at 70 deg for longer?? hmm? but first things first, I need to know if what I have done by heating the fuel is a positive or a negative.

[Dr Mark Senior Member Find all posts View Profile Close Dr Mark]

Re: washing with heat

Well I decided to revive my train of thought on this one. I thought I would push the boundaries a little with the temperature, and found something very interesting (to me anyway).

I put 100ml of unwashed freshly batched bio in a saucepan and put it on my bbq wok burner. heres what i noticed:

* at around 60 degrees or so, there was visible vapour starting. no surprises - I would assume its the methanol leaving the brew.
* approaching 100 degrees the edges of the fuel started to boil here and there - ever so tiny little bubbles. also no surprises there - just the water left over from the reaction leaving town.
* now it starts to get interesting. the fuel started showing ripples under the surface (you could see them as the light was refracting differently) and they sort of woft around. they remained present the whole time from then on.
* somewhere around 130 degrees (hard to tell as the temperature of the pan fluctuated big time depending on where in the pan I took my reading) it started to change colour slightly.
* somewhere between 150 and 180 degrees it went a nice treacle brown. heating stopped at this point.

now its even more interesting - there are a heap of floaties that are in suspension all through the fuel, and its that lovely treacle brown colour. I then took this heated fuel and put 20ml of water in it - applied with a hand pump sprayer on fine mist - and let to settle. I did a second one with non heated fuel to compare.

So I wanted to see this process again, so I repeated and got the same results. I ran this fuel while it was hot through a 2 micron filter and the clarity was exceptional. I left this to cool on its own.

I repeated a third time and viola, around 180 degrees it goes brown and floaties appear. I cooled this one in some ice water to get it back to room temp, and the floaties remained in suspension. I then filtered it, and once again the clarity was exceptional. I left all of this over night. note - I also filtered some un heated fresh bio to compare - and the clarity was also very good.

next day, the washed fuel samples are starting to clear, and as expected are not completely washed, so they are not very clear.

both of the heated samples - cold filtered and hot filtered are showning some drop out, which is not present in the un heated control.

the cold filtered fuel is crazy clear. when I put a LED torch under it and shine it up through it, you would expect to see a shaft of light, but you dont, as there is nothing in suspension to pick up the light. very impressed. The next little experiment will to be do a wash on it and see if it is any different to the first heated but unfiltered washed sample.

so if the heating does appear to perform the same function as washing, I am thinking of making the following rig:

build a turk burner outside my shed, and plumb a copper line from the bio brewer to it with a small 12v pump on the cold side with a bypass and valve so I can regulate the flow. Pass the fuel through the turk burner in a copper coil, and then send back to the tank. install a digital temp gauge to monitor the output temp. I should be able to regulate the temp by adjusting the flow. find someway of working out the flow rate and then try to make this predictable at each batch so i can then just run the pump for a period of time, allowing for say 3 changes of tank volume.

after this its just a case of running off any sediment and filtering the fuel. I reason that the sediment should drop out regardless of filtering, I just filter it on the way to the storage tank after it has settled for a few days.

My only concern is what have I actually done to the fuel by heating it to 180 degrees? is the brown colour caused by carbon or something such as? have I 'burnt' the fuel and reduced its calorific value?

I am looking forward to hearing some comments - good and bad on what I have done or what I could improve, or if the process has no value at all.

The brown stuff is caused by the methyl ester polymerising. As it's unsaturated it's prone to this, and is promoted by heat (as it readily exceeds the otherwise substantial activation energy of the process). But in a broader sense (as I've attempted to explain before) the problem with this approach is azeotropes. In simplest terms, if you have a mixture of liquids, one doesn't necessarily start to boil off when you reach its boiling point. And methanol is prone to this more than most chemicals due to its small size and propensity to hydrogen-bond with other organic molecules. https://www.drchemical.com.au/uncategorised/biodiesel

[Captaincademan Senior Member Find all posts View Profile Close Captaincademan]

Re: washing with heat

Hi Mark,

The floaties do not appear to be brown. they appear to be a whispy whitish. they are the same density as the body of the fuel, i.e. they do not sink or swim. they stay suspended nicely. the total body of the liquid changes to a brown hue, completely evenly distributed. there is a slight amount of brown dropout that appears on the bottom after a few hours though, looks exactly like glycerine sitting in the bottom. intersetingly the sample that was hot filtered had more dropout than the sample that was cold filtered.

interesting point about the components not boiling off at their respective temperatures. dont forget Mark, a lot of us are not classically educated and our eyes glaze over with use of terms we are completely unfamiliar with - such as 'azeotropes'. we sometimes need a lay explanation to assist (as you have done so in the post above - thankyou).

given your access to good gear and a scientific approach, would you mind please heating up some unwashed bio (made with a single stage method) to around 180 degrees and putting some comments on as to what you observe? I know this is putting you out, and completely understand if you dont have the time or inclination, but I'm sure the broader community would benefit from the experiment being done properly rather than done on a greasy old bbq outside in the wind with more variables than you can imagine.

I will still persist as I am pretty keen to see where this goes, and whether or not there is a process that can be developed which is safe and efficient..

[Alga Senior Member Find all posts View Profile Close Alga]

Re: washing with heat

G'day Cade, this may not be relevant in this case, but may add some light to what's happening. Have only ever heated BD when drying on the sun, but have heated VO to almost boiling temp to see what happens to the oil. Have seen those white floaties when it goes over 200deg C and wondered what they were, when the temp goes over 210degC, they disappeared. Have also found when the VO is heated over 206degC, it turns a bit brown, almost like it is burnt. It really thins the oil and stays that way and there is a lot of fatty stuff in the bottom when it cools down. Some one told me it wasn't fats, but some other stuff which should be removed during the oil processing, it might have been silicate or something similar and is in the fibre of the seed.

I tried the heating method to see if it made it easier to work with and it did, but the centrifuge does the job with a huge reduction in labour and time, stopped doing that. It was a bit dangerous when the oil started to evaporate above 216degC. When I make BD again in a couple of months, will heat it up to see the results and let you know if you haven't work it out by then.

Agree with you about the technical jargon, loses me. I'm a think about it, work out the plan, safety levels, then experiment to see if it works and what happens.