Electric Heating of WVO

[res0wc18]

So as most of you by now know that my vehicle fleet runs on waste vegetable oil and I have some fun engineering that’s actually useful I thought you would get a kick out of.

As I close in on completing my next daily driver the Grease Beast (1985 CUCV M1009 K5 military blazer) I have been considering going to electrical heating of the oil to aid in switch over times and all around better usage. Currently my systems on my other rigs consist of passive coolant based heating(think giant heat exchanger), and although this works good the engine has to be up to 100% temp for a while before you can even use it. Couple this with my relatively short commute(lake stevens) and it makes it a breaking point for the argument of using strictly biodiesel. In the 7 years I have been running alternative fuels I have seen the cost of chemicals needed to make biodiesel more than 5 fold in price. This makes it almost impossible at points to make it worthwhile.

Anyhow this all relates to a factor of sustainable living. I’ve been working more and more to say goodbye to petroleum products and the crooks that own them. This brings us to the current subject. So when most people hear “alternative fuels” they run in horror because it strikes fear in their mind of some backyard scientist with a half ton chevy nearly blowing himself(and the neighborhood) up. That’s not how I roll. I do something once to the best of my ability and don’t touch it again(and I don’t have to tell you that there isn’t any questionable dangerous offshore products involved). So over a conversation lately with one of my long time life mentors and friend who’s old enough to be my grandfather he had some words of wisdom to offer me, and that was to satisfy my mind and see what “could be”. So in short here it is.


I have not dealt with heat loss and btu requirements since I worked at the shipyard over 6 years ago(sometimes I miss that place…a lot more respect for people who could actually do something than here) so these are pretty decent calculations more than good enough for gubment work.

My feedstock is mostly a mix of soybean and canola mixed with some algae and peanut oil. Using facts from one of my favorite engineering sites http://www.ramacorporation.com/engineer/Engineerweb.pdf http://www.tempco.com/Catalog/Section 16-pdf/Section16.pdf i came up with some of these standards for the oil.

When vegetable oil is in the 160 degree F range it is considered to be safe to run in a diesel as it is within +/- 15% of the viscosity of number 2 diesel by the time it reaches the injectors. Considering our average temp around western wa is about 50 degrees and my fuel system flows about 1.5 gallons minute through a system that holds about one gallon we can assume some standards here from the charts above. All this is to figure what it would take to nearly instantly(1 minute or under) heat the oil.

(Flow rate in gal/min)*(specific weight density in lb/gal)* (desired heat rise in deg F)= required BTU’s/min

(1.5 gal/min) * (7.774lb / gal) * 150 deg. F = 576 BTU/min.

(note that .33 BTU = energy to raise 1 lb of veg oil 1 deg F)

576 BTU/min is... in watts (1W = 3.413 BTU/h): 168.76W


(576 BTU/min) * (60min/h) * (1W / 3.413 BTU/h) = 10.125 kW/h aka a lot of juice!

Now this is only part of the equation. I assumed a 150 degree heat rise to account for the 18% dissipation loss from the stainless housing that is about 40 cubic inches to ensure when it reaches the injectors it is 160 degrees or more.

Here is the real kicker though. ASME standards suggest no more than 60 watts/sq inch. Using this we can figure that we could only absorb(safely) 2.4kw of juice in my current housing or about 24% of what we need, not gonna work! So using this relationship I can figure that my housing needs to be 4 times the size or about 8” in diameter by 12” long. Not undoable but defiantly large for most small cars.

So now we move to electrical load requirements. The grease beast has two 100amp 28vdc alternators with two huge batteries that have a combined power of 2.52kw/h rating. These are large batteries but with the consumption of the heating elements they would last less than 15 minutes in the most ideal conditions without powering going to them. As a general rule you can’t take lead acids below 55% or they go kapoot, and even if you could get the oil to temp before starting the current system could only support that rate for about 38 minutes. So in relation we can derive I would need to have a 400 amp alternator system to keep up. When is the last time you saw a 400amp power unit? Welders ring a bell? http://www.zena.net/ this company makes realllllyyyyy nice stuff. Using these units one could produce enough juice to run a house(no joke) which is never a bad situation in a power outage/ rescue situation.



Saving you more boring technical details it is in theory very possible to subsist off of electrical heat but at about 5k in product. A lot more practical would be to have Adam build some custom units(which he said is doable) http://www.nationsautoelectric.com/ but again 2k in product.


In short you can buy one heck of a lot of fuel to get up to temp before switch over for 2k and electrical heating is to me at this point is only an option for the rich.

 

[cranetruck]

Consider an electrically heated whole house water heater for your WVO/VO tank (placed in truck bed). Use house current over night to heat before trip to work. Use diesel for trip back home if temperature of WVO/VO in the water heater isn't warm enough, although it may still be hot, these tanks are very well insulated.

 

[Beyond Biodiesel]

Currently my systems on my other rigs consist of passive coolant based heating(think giant heat exchanger), and although this works good the engine has to be up to 100% temp for a while before you can even use it. Couple this with my relatively short commute(lake stevens) and it makes it a breaking point for the argument of using strictly biodiesel. In the 7 years I have been running alternative fuels I have seen the cost of chemicals needed to make biodiesel more than 5 fold in price. This makes it almost impossible at points to make it worthwhile.

You might consider blending gasoline with your WVO. I have been doing it for 6.5 years on a 83 chevy van with a 6.2L DD engine. I went to blending for the much the same reasons that you are trying to electrically heat your WVO; because biodiesel chemicals are expensive, and toxic to use; and an SVO system takes so long to come up to temperature that it really is a long haul solution only, and not a around town solution.

However, blending gasoline at 20% with WVO at 80%, then settling it, then filtering it (like you have to do with SVO and biodiesel anyway), then I have a fuel that I can start up on and drive indefinitely on. The other option is, if you are in love with your SVO system, then your start-up fuel could be an 80/20 blend, that way you use less petroleum product.

 

[res0wc18]

Bjorn,

Yes I have my tank insulated with rhino lining material to make it more resistant to heat loss and it does help a lot. I have a 1kw Kats pad heat on the side of the tank that comes on when my block heater does and this too does drastically reduce the switch over times. There is times though when I am at a location when electricity is not available.

I have considered the diesel fired heater system that Armada installed. But I’m not exactly certain on how long that takes to get the coolant up to 100% temp/how much fuel that would consume. From his write-up that looked pretty tedious to install as well and some of the space needed for the system I need for my wvo system would be consumed.


Jeff,

I have been following your posts all over the net since you first appeared. Don’t worry I’m not one of these nuts that judge and tell you you’re wrong, some of those people were downright mean to you and I am sorry. This place is a lot more professional in the way we treat each other. So hope your tenure here is well suited.

I have often wondered what physical properties actually change when you do the gas blending/settling routine. I think you did some viscosity testing afterwards haven’t you, I thought I had watched a video of it somewhere.

 

[ducer]

What about using an exhaust type heat exchanger system? Take a section of the exhaust and double wall it for say a foot or so with fittings in each end for in and out. This way your not burning extra fuel to make the electricity, your just using waste heat from the combustion chambers. The reduction in exhaust flow and subsequent power loss would be negligable and certianly less than trying to generate enough electricity to heat the oil.

Denny

 

[joshs1ofakindxj]

I'm also very interested in the gas/WVO blending. Minimum octane right? I've recently gone from having access to a large amount of WMO to having access to large amounts of WVO so I need to change my operation.

 

[Beyond Biodiesel]

Jeff,

I have been following your posts all over the net since you first appeared. Don’t worry I’m not one of these nuts that judge and tell you you’re wrong, some of those people were downright mean to you and I am sorry. This place is a lot more professional in the way we treat each other. So hope your tenure here is well suited.

Thanks, I think it is just human nature to want to kill people you disagree with, instead of giving everyone a fair shake.

I have often wondered what physical properties actually change when you do the gas blending/settling routine. I think you did some viscosity testing afterwards haven’t you, I thought I had watched a video of it somewhere.

Yes, I did a lot of viscosity and specific gravity testing, and I videoed some of it, and it is up on my YouTube Chanel. Basically, gasoline blended at 50% with either canola oil or 10-40 motor oil produces a fuel blend that has the same viscosity and specific gravity as D2 diesel fuel; however, performance wise, 20% gasoline works just fine year round in most diesel engines. There is a problem for some IPs in taking the gasoline content above 30% due to the presence of alcohol in most US gasolines.

I'm also very interested in the gas/WVO blending. Minimum octane right? I've recently gone from having access to a large amount of WMO to having access to large amounts of WVO so I need to change my operation.

I have burned mostly vegetable oil-gasoline blends for the last 6.5 years with little problem. Yes, low octane, regular unleaded is what I use. However, if you are going to switch from WMO blends to WVO blends, then you will want to flush out your fuel system by running a few tanks of diesel fuel in between. Because some WMOs react very negatively with WVO.

 

[joshs1ofakindxj]

I have burned mostly vegetable oil-gasoline blends for the last 6.5 years with little problem. Yes, low octane, regular unleaded is what I use. However, if you are going to switch from WMO blends to WVO blends, then you will want to flush out your fuel system by running a few tanks of diesel fuel in between. Because some WMOs react very negatively with WVO.

What kind of negative reaction? Precipitation of sludge or something?

I've been mixing WMO, WVO, and diesel with little regard for about a year now and I am excited to switch to gas if it improves viscosity and cold starting.

I also saw your tip in another thread to mix the gas outside the fuel tank before filtering which is something else I need to start doing.

 

[turboseize]

I just found this thread and like to chime in. Disclaimer: Note that my vegetable oil experiences date back from 2003 to 2008. I did not follow the VO forums since I sold my last diesel in 2008.

In the good old days before Mutti killed biodiesel and vegetable oil, there were some (albeit rare) bad experiences to be read about in german forums. In some very rare instances, the engine oil polymerized, leading to costly engine failures. This was believed to be caused by unburned fuel entering the oil during cold-starts. It was also only observed on direct injection engines. (The other problem with DI engines reported was burned pistons, which was obviously caused by fuel trops directly hitting the piston.) That's why the forums stronly advised against the use of vegetable oil in direct-injection engines, unless equipped with a two-tank system.
Pre-chamber and vortex chamber engines such as old Mercedes or VW diesel were considered safe in this regard, with the only possible problem being distributor pumps not coping with the viscosity of VO and thus pre-heating the VO being mandatory. (Two-tank systems were encouraged, but not deemed absolutely necessary. However, it was strongly emphasized not to rev the engine before the fuel was heated up).
Pre-chamber diesel engines with an inline pump, such as old Mercedes engines were easiest. I ran my OM 615 (w123 200d) nearly 95.000km and my OM 617 for 80.000km on all possible blends between 100% dino and 100% vegetable oil without any modification. Cold starting below freezing sucked and once my filter froze (note: soya and sunflower are summer fuels only), but other than that, no real problems. Of course you have to change fuel filters more often, and valve clearances changed faster - interestingly in both directions. Seemed like they grew (indicating carbon build up) when driving with low loads and low revs and decreased when driving harder. So I reduced the checking and adjusting interval from 20.000km to "10.000 or earlier, if deamed necessary" - with a little bit experience, you could actually feel the difference. But on old Mercedes diesels, both filter changes and valve clearance adjustments are a matter of minutes, so that was not too much of a nuisance.


Should I ever find a reasonably priced M1008 in Germany (and obtain wife's permission to buy it) I'd therefore
- only blend up to 30% VO to the fuel on an unmodified car,
- with a single tank system with fuel heating, be extremely easy on the engine after cold starts and avoid high revs,
- prefer a two-tank system (if economically feasible), as I have read the GM 6.2 two start reluctantly even with diesel - and cold-starting a car on VO is much harder.

Note I do, unfotunately, have no exerience with the GM 6.2 and these thoughts are theoretical considerations based on previous personal VO experience with other engines and based on stuff I read.

 

[Beyond Biodiesel]

What kind of negative reaction? Precipitation of sludge or something?

I've been mixing WMO, WVO, and diesel with little regard for about a year now and I am excited to switch to gas if it improves viscosity and cold starting.

I also saw your tip in another thread to mix the gas outside the fuel tank before filtering which is something else I need to start doing.

Sorry, joshs1ofakindxj, I must have missed your question on this thread. The negative reaction when some WMOs meet some WVOs is a thick, black sludge that melts at about 160F. It will coat the bottom of your fuel tank, and fuel lines all of the way through your injector pump and coke your injectors.

I just found this thread and like to chime in. Disclaimer: Note that my vegetable oil experiences date back from 2003 to 2008. I did not follow the VO forums since I sold my last diesel in 2008.

In the good old days before Mutti killed biodiesel and vegetable oil, there were some (albeit rare) bad experiences to be read about in german forums. In some very rare instances, the engine oil polymerized, leading to costly engine failures. This was believed to be caused by unburned fuel entering the oil during cold-starts. It was also only observed on direct injection engines. (The other problem with DI engines reported was burned pistons, which was obviously caused by fuel trops directly hitting the piston.) That's why the forums stronly advised against the use of vegetable oil in direct-injection engines, unless equipped with a two-tank system.

Welcome to the alternative fuels section. Thanks for posting your Interesting comments. So, this is where the DI engine got maligned. The problem is in deed caused blow-by, but it is not polymerization of motor oil. It is a precipitate as described above, which collects on the cold parts of the engine, such as the oil pan and valve cover. The solution is quite simple. Change the motor oil ever 3,000 miles, and no sludge forms. The reason why the sludge forms is due to old burned motor oil reacts with vegetable oils. Biodiesel dies not seem to cause the problem, but SVO and blending does.

Pre-chamber and vortex chamber engines such as old Mercedes or VW diesel were considered safe in this regard, with the only possible problem being distributor pumps not coping with the viscosity of VO and thus pre-heating the VO being mandatory. (Two-tank systems were encouraged, but not deemed absolutely necessary. However, it was strongly emphasized not to rev the engine before the fuel was heated up).
Pre-chamber diesel engines with an inline pump, such as old Mercedes engines were easiest. I ran my OM 615 (w123 200d) nearly 95.000km and my OM 617 for 80.000km on all possible blends between 100% dino and 100% vegetable oil without any modification. Cold starting below freezing sucked and once my filter froze (note: soya and sunflower are summer fuels only), but other than that, no real problems. Of course you have to change fuel filters more often, and valve clearances changed faster - interestingly in both directions. Seemed like they grew (indicating carbon build up) when driving with low loads and low revs and decreased when driving harder. So I reduced the checking and adjusting interval from 20.000km to "10.000 or earlier, if deamed necessary" - with a little bit experience, you could actually feel the difference. But on old Mercedes diesels, both filter changes and valve clearance adjustments are a matter of minutes, so that was not too much of a nuisance.


Should I ever find a reasonably priced M1008 in Germany (and obtain wife's permission to buy it) I'd therefore
- only blend up to 30% VO to the fuel on an unmodified car,
- with a single tank system with fuel heating, be extremely easy on the engine after cold starts and avoid high revs,
- prefer a two-tank system (if economically feasible), as I have read the GM 6.2 two start reluctantly even with diesel - and cold-starting a car on VO is much harder.

Note I do, unfotunately, have no exerience with the GM 6.2 and these thoughts are theoretical considerations based on previous personal VO experience with other engines and based on stuff I read.

The multi-fuel engine is a DI engine, which is part of what makes it multi-fuel. My 6.2L is very similar to the old Mercedes design. Recent findings also indicated that the presence of a turbo-charger aides any diesel engine in burning waste oils as fuel.

 

[turboseize]

The old Mercedes Diesels had oil change intervals of 10.000km, but the manual said "under severe operating conditions, intervals have to be reduced". And as Autobahn speed means pedal to the floor on these rather asthmatic engines, I considered my driving "severe driving conditions" and thus changed oil every 5000km.
The VW TDI which reported problems had factory specified 15.000 to 20.000km service intervals...

So this does indeed fit very well with your explanation.




Do I get this right: The 6.2 is indirect injection (as old Merc), but has a rotary/distributor pump(similar to VW)?

 

[Beyond Biodiesel]

Do I get this right: The 6.2 is indirect injection (as old Merc), but has a rotary/distributor pump(similar to VW)?

Yes.