I tried this last night and it just wasn't working, too many distractions, too much noise in the house, other things on my mind, I don't know but every time I started typing my words flowed about as smoothly as a hunk of poo trying to get past the stick crammed up a politician's bunghole. Awful visual I know, but it is funny, isn't it?
Anyway, for years now, I forget how many, I've been absolutely fascinated by the concept of biofuels. I'm not a raging tree hugger as you all know, the environmental benefits of these fuels, for me anyway, are nothing more than an extremely welcome bonus. The reasons for my fascination are the renewability of these fuels, the reduction in dependence on foreign oil that they could potentially bring about, and the simple fact that a good 'ol boy like me with a little ingenuity can convert his old moonshine still to make free or cheap go juice. In the case of biodiesel all of the research that I've seen says that it's actually better for your engine as well, it has a higher lubricity than petro diesel, and it burns cleaner. Cheap, environmentally friendly, and it makes your engine last longer, what's not to love? A few things actually, but I'll get into that in a minute.
What started my whole fascination with this stuff was a story that I read in school back somewhere in the early 80's. It was about two women that set up a portable biodiesel refinery in the back of a Chevy diesel van, (I had one identical to it a few years ago and I sold it, I'm really kicking myself now), and drove it from L.A. to New York . . . . . . absolutely free. They stopped at restaurants, asked for their old fryer oil which they were gladly given I'm sure since restaurants have to pay rendering services to haul the stuff off, they refined it in their van, dumped it in the tank and drove to the next burger joint on down the line garnering funny looks all along the way since their exhaust smelled like french fries.
Ever since then the concept has been hanging in the back of my mind, never quite important enough to warrant any serious research, but just hanging around waiting for the opportunity to pick up a little more residual information and grow a bit. It grew a lot this past weekend, between the fellow I interviewed and the research that I couldn't wait to do when I got home, I at least have a basic knowledge of the concept to start from now.
Anybody got a diesel for sale dirt cheap/free? I need a guinea pig.
Now my experience as a diesel mechanic tells me that a diesel engine will run on just about anything, it won't necessarily run well, it won't necessarily run for very long, but it will run. Some people have successfully run diesel engines on unconverted waste fryer oil, it requires starting the engine on petro diesel, switching to a heated source of oil (it won't flow right if it's under about 150 degrees, it's too thick), then switching back to petro diesel long enough to flush the fuel system before shutting down the engine so that it will start the next time and avoid carboning up the injectors when the fryer oil continues to sizzle and burn inside the hot fuel system. While this may work, it's just not practical for most people. Rigging up nifty fuel tank heaters and plumbing in auxiliary fuel systems is far beyond the scope of most, besides the fact that waste oil contains too many undesirable ingredients to be a fuel that would be in any way beneficial to the engine.
Just not really feasible, we need an alternative fuel that can just be dumped straight into the tank if it's ever going to take off, no modifications or special considerations involved, biodiesel is approaching that point, it still has a few drawbacks, but it's getting really close to being a direct replacement for petro diesel. The worst of these drawbacks, in this part of the country at least, is it's intolerance to cold. Pure bio will begin to gel (solidify) at about 40 degrees F, but the guy that I talked to this past weekend (he didn't want his name mentioned) says he's been running a 50/50 mix of bio and petro in his Dodge Cummins pickup and hasn't had any problems as long as he parks his truck in the garage at night, he says it's been staying about 35 or 40 inside. Once the truck is started the fuel flowing through the head and back to the tank via the return line will be heated enough to keep the fuel in the tank warm. He's currently working on an auxiliary fuel tank with a coil inside that will circulate engine coolant to warm the fuel, then the truck can be run on straight bio in any weather as long as it's started on petro. Once again, rather complicated for most people but there are several electric fuel heaters on the market that could easily be installed on most vehicles and simply plugged in at night along with the normal engine heater. Power Service, (they've been making antigel additives for petro diesel for years), as well as a few other companies, are making an antigel additive especially formulated for bio, since additives for petro diesel don't work very well. These additives don't make bio handle cold like winterized petro diesel quite yet, but they do help and the research is ongoing.
I've been playing with the sample that he gave me and I've found that it will indeed gel quickly if left outside in the snow, but it melts almost instantly as soon as I bring it inside, it's really nifty to watch at any rate, kind of like fast melting candle wax. It smells nothing like petro diesel, no nose stinging sulfur smell, just a barely detectable aroma not unlike the aforementioned candle wax, the unscented kind, with a tiny hint of, you guessed it, french fries. I even went so far as to stick my face in front of the exhaust pipe of his running truck and take a big whiff. Keep in mind that this truck wasn't running on straight bio, it was on a 50/50 mix, but the exhaust smell wasn't nearly as volatile as the normal diesel exhaust, it smelled like the restaurant kitchens that I worked in back in high school, kind of made me hungry actually. That could be a hidden benefit for restaurants willing to give their fryer oil to biodiesel homebrewers, advertising. Give all of 'em enough grease to run their outfits on straight bio, and anyone caught behind them in traffic will be heading for the nearest McDonald's in no time.
The truck idled smoothly, and he tells me that besides the lubrication and reduced soot and carbon benefits of bio, that he hasn't noticed any particular difference in the way it runs as far as power or mileage is concerned. The research says that bio actually makes more power, as well as drastically reducing all categories of emissions with the exception of Nitrogen Oxides. The jury is still out on the NOx issue since there's some conflicting research, but the general consensus is that even if the NOx emissions are increased slightly, that the reductions in other emissions more than offset it, slightly retarding the engine timing can alleviate the increase anyway.
I've seen no research that indicates that bio hurts the engine, quite the contrary actually. Anytime a fuel burns cleaner engine wear is reduced, I've seen this in action as it pertains to gasoline engines converted to propane. Many that make the switch to bio report that the first thing they notice is a drastic reduction, almost total elimination in fact, of the big cloud of black smoke emitted during rapid acceleration. That black soot is what fouls the oil and contributes to much of the wear on many diesel engine components. Couple the reduction in carbon emissions to the much better lubrication and corrosion prevention qualities of biodiesel and I don't have any trouble at all seeing how it could be beneficial.
So what's the difference between biodiesel and plain old chicken fat you ask? Here's a simplified version of the process, there's a fair bit of chemistry involved but I'll just lay out the basic concept here, if you really want to dive into this stuff the place to find it is journeytoforever.org.
Petroleum oil and animal/vegetable fat are basically the same molecular structure. In the biological variety, however, there are a few undesirable elements floating around like triglycerides and free fatty acids. Triglycerides are, to make things simple, glycerin, which is nothing more than a thick goopy form of alcohol. Alcohol is hygroscopic, glycerin is really hygroscopic, meaning it soaks up water like a sponge, meaning it's bad stuff to have in a motor fuel. Free fatty acids are fat molecules that have broken free from the molecular chain as a result of the oil being heated in the fryer, they're bad for you, they're bad for your engine, and another of the interesting little side effects of making biodiesel is that one can find out which restaurants overheat their fryer oil, and avoid eating there, unless you want to die young. Both of these little nasties as well as a few others need to be removed before the stuff can go from hardening the arteries of the masses to making your mondo SUV or truck more environmentally friendly than the Geo Metro sitting next to you in traffic with some clueless treehugger in it flipping you the bird, if he only knew eh?
The way this is done is with a scientific process called transesterification. Big word I know but if you do any research beyond what I'm writing here it will make perfect sense, I encourage you to do so by the way if you have any interest in this stuff since I'm no expert, two days ago I couldn't have told you squat about how to make biodiesel, I've been really cramming for the final here and I've not yet even begun to dive into this stuff, if it works out like things typically do for me I'll do a lot more studying before I'm done. I'm a hopeless know-it-all.
The process of transesterification, in a very tiny nutshell, takes the bad alcohol glycerin, and replaces it with a more stable, less hygroscopic, and easier flowing alcohol, ethanol or more commonly methanol. Hence the term transesterification, the "ester" or alcohol in other words, is replaced with a different ester, glycerin for methanol in this case. It also removes the free fatty acids down to a point where they're insignificant. Other impurities are removed as well such as the soaps that are created during the chemical reaction that removes the glycerin.
First the oil is heated to about 130 degrees F. This removes the residual water left in the oil from cooking foods and sets it up for the transesterification process. A solution of methanol and sodium hydroxide (common household lye) is then added and the mixture is blended well by various different means and if all is done correctly the components will begin to separate. The glycerin will settle to the bottom, a thin layer of soap created by the lye reacting with the fat will form on top of that, and the biodiesel will float to the top. What's happened here is a chemical reaction that knocks the glycerin off it's rocker, and replaces it with the methanol. I just love chemistry when it makes engines run.
The biodiesel is then skimmed off the top, or the glycerin drained off the bottom, then the goodies have to go through a wash process in order to remove the excess methanol since free roaming alcohol can be extremely detrimental to the fuel system of an engine unless it's especially built for it, as in an alcohol fueled race engine. The biodiesel is commonly transferred to a separate wash tank, heated again, and water is added. The whole shebang is mixed well and if the first stage was done correctly the water will separate out rather quickly taking the water soluble impurities such as the excess methanol and soaps with it, it's then drained off the bottom of the tank. If the first stage wasn't done correctly you'll wind up with a nasty emulsion with the water suspended instead of settling out, if that happens you have to start all over since the glycerin wasn't adequately removed. (As I said, there's a lot more to it than what I'm outlining here, don't try this at home unless you do some more research first in other words.) This process is repeated three or four times until the water comes out clean, the honey colored yellow liquid left in the tank is biodiesel, high quality, extremely pure if made correctly, cheap, and very environmentally friendly.
There's then tests that you can do yourself to verify the quality of the finished product if you're worried about harming your engine, as well as labs that will analyze a sample for you, definitely a good idea since there's many places along the way to go wrong. Failing a proper test, you could always just taste it, I wouldn't advise it since it has methanol in it which can be poisonous to humans in relatively small quantities, but I'm told that the stuff tastes awful so I doubt anyone could drink enough of it to get sufficient methanol to hurt them. Since methanol isn't poisonous to most animals besides humans and monkeys you could pour this stuff out on the ground and it would be no more harmful than dumping your kitchen waste in your garden for compost, don't try that with petro diesel.
The waste products left over from the production of biodiesel aren't particularly harmful either. With a little ingenuity most of the methanol can be reclaimed and used over and over since most of it isn't absorbed, it's merely a carrier necessary for the reaction to keep going long enough to free the glycerin. That's where the moonshine still comes in handy. The glycerin has uses as well and can be recycled if you can find an outlet for it, if not it really doesn't matter since glycerin is a naturally occurring form of alcohol and will biodegrade almost instantly in it's pure form, dumping it in the trash is less harmful than trashing an empty paint can. The left over soaps are exactly that, soap, I'm sure there's people that have figured out uses for that, and once again, it's extremely biodegradable, nothing you couldn't or wouldn't dump down your drain on a daily basis. The left over wash water is the last waste product, it's just dirty water, no dissolved petroleum byproducts involved, a little soap and alcohol as well as some cooking oil residue, nothing that you couldn't dump down any drain in town or use to water your plants for that matter.
Add all this to the fact that making biodiesel helps get rid of a bothersome waste product, used fryer oil, and burns with far less emissions than petroleum, and you've got a product that even a treehugger could love. If you're far more "green" than I, you might even consider another environmental benefit that's seldom mentioned. Biodiesel is "carbon neutral", meaning that it adds no carbon to the environment. All of the carbon in biodiesel was once part of plants or animals not so very long ago, not pulled up from deep beneath the ground as in the case of petroleum. (dinosaur carbon must be bad, I guess?) I'm not sure what the exact benefit of that is, but it can't be bad, can it?