Ok, if using this gas for an engine. Remember that it comes out with various impurties also. Tars and resins that are not good for an engine and depending on your setup maybe  even some ash.

The above is why you really want to cool and filter the gas well before running it. Cooling it will condense the steam, tars, creasote etc.. that will eat your engine.
 In the old vehicles it was cheap and easy to just pull a head do a vavle job and stick it back on. Not so with todays cars though! So where in the WWII days we find pics of the gasers mounted on the rear of a vehicle feeding an engine directly (it looks like) they could clean the valves themselfs for a buck in a couple hours on a saturday when needed :)

To cool the gas is easy, lots of ways to do that. To filter the gas I think charcaol would be about the best filter to use. I never got that far yet, but I was going to make a batch of charcoal then put it in another barrel as a filter for the gas. This charcoal would suck up the inpurities letting just clean gas by. When the charcoal barrel filter needs new charcoal I figure the dirty stuff can be burned as a heat source to bake the next batch of charcoal and gas.

It must be rememberd if using for a vehicle that the system must be well sealed for the engine to draw a vacume to keep the process running. Also when dealing with the gas from a gasifier you have alot of carbonmonoxide so a leak of escaping gas could be deadly, even worse so than a normall leaky autoexhaust would be.

I been busy with other stuff and gone awhile etc.. but I think this is something I may get back into myself also for One truck for now. You also of course have to have a way for the engine to get the feul in correct feul air mixture that various constantly for a vehicle whereas a gennie could just be setup to run a constant speed and forgotton nearly
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nothing to lose