I’ve been trying to figure out a method to make a waste oil “gasifier” so to speak. I know it’s been talked about here before, but I have a few ideas I wouldn’t mind running by you guys to see what you think.
This guy seemed to have success. By success I mean the engine actually ran, admittedly poorly ran, but it ran nonetheless. I’m sure the first wood gasifier powered engine didn’t run great on the first try either, but if it will fire even a couple times then it’s safe to say it can be made better.
Obviously this guys setup is incredibly inefficient, and some improvements can be made. Here are some drawings of what I’m thinking of…
So my idea would be to have the exhaust, after passing through a catalytic converter, heat oil in a heat exchanger. The heat exchanger would most likely be a coiled up copper or stainless steel tube, although if a guy could get his hands on an old EGR that would most likely work just as well if not better.
The oil would be pumped through at a consistent rate, the pumping rate fiddled with and tuned for the best heat exchange rate. Once passing through the heat exchanger it would go up to the “carburetor”. In the carburetor there would be an inlet and return line, so that the “bowl” will not fill up 100%, instead leaving space above the oil level for the hot smoke (vapor) to separate out. A needle valve of sorts would be installed in order to tune the air/fuel ratio for the best results.
The hot oil can then return to the pump, not the tank, where it can be recirculated through to be heated (vaporized, gasifier) once again. An orifice plate can be installed on the outlet from the oil tank so that the system can replenish itself of whatever oil is being used up to fuel the engine. My thinking behind using the orifice is that you will achieve more “gasification” by reheating as much as the hot oil coming back from the carburetor as possible, rather than having to heat the colder oil from the tank every single time. It probably wouldn’t be a bad idea either to have a liquid to liquid heat exchanger installed to use engine coolant to preheat the oil before it passes through the exhaust heat exchanger. The engine coolant is waste heat anyway, so why not put it to good use first.
Obviously there are a few drawbacks to the system. From a cold start with no exhaust flow the system couldn’t build the heat needed to gasify the oil. I think there are a few possible solutions to this. Number one is have a “dual fuel” sytem, where you can start on gasoline and once everything is up to temperature switch over to oil. The other could be to TEE in a sort of oil burner near the heat exchanger which could be used to heat and gasify the oil that way until the engine is producing enough heat on its own and the oil burner system can be shut down.
I’m not sure if this idea has any merit or practical feasibility whatsoever, but I do like the idea of using waste heat from the engine to achieve the gasification. Catalytic converters get extremely hot, the “smoke point” of most oils, which is the temperature at which they will combust, is usually somewhere between 400f to 500f. This temperature is usually far exceeded at the outlet of a catalytic converter. My thinking is also that it should be almost self regulating as it were, meaning that at low engine load, your exhaust temp goes down, which in turn will gasify less oil, but hopefully still enough to maintain what is needed for the engine. At high engine load, the exhaust temperature goes up, which in turn will gasify more oil, again hopefully enough for what is needed by the engine.
We know from the video posted that it is in fact possibly to run an engine on oil smoke, maybe with some good tweaking and effort it can be made to be practical.
Anyway that’s my idea. Please let me know your thoughts, or maybe problems that I have failed to think about.