Using the high temp of the exhaust gases to preheat the primary air as Kristijan suggests is one of the easiest ways.
If you use EGR, try to feed the exhaust as hot as possible into the gasifier (insulated pipes).
Another use of the hot exhaust gasses was done by the DEUTZ-company. They built a tractor, were the spare wood was stored in big tight bucket in cages. The hot exhaust was led through this buckets and dried the wood. A picture of this tractor can be found in the PEGASUS-book (Library / Pegasus Gasifier | Drive On Wood!) on page 29. The long bucket lies on the rear fender. A smart idea in my point of view.
Using a turbine to drive an generator sounds nice. You could also run a thermoelectric element to create electric energy.
Creating HHO sounds nice first, but it is not without reason called “detonating gas” in German. Feeding it into the burning zone of the gasifier might not a good idea, better instead directly into the engine manifold.
But here we are more in the field of a thought experiment again, quite impractically for mobile applications in my point of view. What we discuss here might be of more interest for stationary applications, where space an weight is not a question and you run under more stable load.
My choice for mobile applications: Find a good balance between heat economy/recovery and compact build/weight for the gasifier to get rich gas with reasonable effort. And try as much inner streamlining of all the piping to avoid unnecessary pressure and thus power losses.
Keeping it simply simple (KISS) in the build, the way it operates, less moving parts, air and gas flow is okay as long as it is not restricted to much to keep a good vaccum flow not ranging to high. Control valves as few as possible. But still making a good rich gas production. Hearted air 600*f at the nozzles from waste heat from the exhaust is really good.
Removing excessive unneeded water and tars is another important thing.
Removing soot, ash from the rich gas is also needed.
Reheating gas for final filtering through paper if used.
Doing all these things with out any moving parts and delivering the rich gas up to the engine compartment is the goal for the KISS build.
Yes, and even mixing the air and gas before going into the engine.
Why, just look at who is driving the most miles day after day.
Bob
I think Roger Blomli has pointed out an effective use of process heat to raise system efficiency in the Weiss system, to pre-pyrolize incoming fuel without introducing all the oxygen and nitrogen needed to produce syngas from cold fuel.
do the exhaust gases contain water vapor? do they manage to dry the wood?
The injecting HHO into the gasifier (vs intake manifold) would allow a better synchronization of the flow of gas with the needs of the engine (in my opinion)
Yes, they do from the combustion of the hydrogen. Temperature is the key of drying the wood. If the temp of the exhaust is above 100°C, the steam fraction is kind of superheated and can dry the wood. If the temp is too low, you get condensation and thus the opposite effect of moisting the wood.
Tractors often run at high loads (ploughing etc.) at low speeds, so you get a high exhaust temp with low cooling effect of airflow. Because of this, this predying method might work good on tractors or stationary engines, but moderate on trucks.
Yes the first part is right. Hotter. But l am afraid just heat it self will do the job.
Say you inject air in at 1 bar and 500c, or atm pressure and 500c, you will get the same gas composition. But a smaller reaction zone in the gasifier!
Now, 500c and 800c air will make a hell of a difference!
But thats just chemical theory. For sure you will have to do a test
