This is a concept vehicle that, to my knowledge, has not been tested but is based on a proved design.
The future producer gas fueled suburbia will need some form of transportation. One possible solution would be a compressed producer gas powered railed trolley. The compressed gas would be the motive fluid for the prime mover. After the motive fluid (pure producer gas) is exhausted from the prime mover it would be burned in the heat exchanger in order to heat the producer gas, expansion, before entering the prime mover. Just like the compressed air vehicles of the past except we exchange the air for producer gas and before exhausting the gas (after it has done work in the prime mover) we burn it in the heat exchanger. A compressed air machine would just exhaust the air after it was used in the prime mover.
In the above picture ,  you can see a compressed air trolley and in the below picture is the same powered lorry . These machines enjoyed some popularity during the golden years of producer gas plants but vanished after the war.
For the most part they worked on the following cycle: A stationary compressor and air accumulator provides the motive fluid thus filling the trolleys air accumulator (tank from now on). As the prime mover requires motive fluid, air passes from the tank to the heat exchanger thus providing more energetic motive fluid. From the heat exchanger the air enters the prime mover to do work. Also there could be heat exchangers in between the stages of the prime mover. Some of the prime movers were of the triple expansion design.
There were at least three types of heat exchangers: Hot water, combustion and atmospheric thermo extraction. Extracting heat from the atmosphere is the most interesting, by far. This is the reason for the fins that were casted on to the prime movers cylinders in addition to the atmospheric heat exchanger, these heat exchanger would be found between the stages of the prime mover. This would be a good point to ponder, picture in your mind the energy paths. Remember that our entropy diagrams start at absolute zero and we want to focus on the change in entropy.
Our energy pathways:
First we need to compress the producer gas (no soot please) at the gas plant. Don