For those just starting out with biomass gasification for engine power; Start here. Charcoal systems are very low cost, easy to build, easy to operate and tar will not be an issue. This is just opposite of what you will experience building a raw fuel biomass gasifier. Most that build a charcoal system and learn methods to mass produce charcoal most likely will not even bother with raw fuel technology. Charcoal is much easier to produce as your labor to process fuels is less and it does not require large energy intensive equipment for the process. You have less limitations of what you can use as you not limited to only fuels that will fit a chipper or chunking machine. You process in much larger pieces for a kiln and there is no limit to how many kilns you can operate. They are low tech, and low cost. The heat energy to produce the charcoal is not much more than the energy required to power an energy hungry chipping machine. You then get energy back with the water drip systems. In the end your net energy output is only just shy of raw fuels gasification. The trade off, is no tar, stable operation, less time involved to process fuels and fast fuel production. Drying fuels for raw fuel gasification takes way more time and if you put wet fuel in a gasifier you will make tar. Other advantages are you can combine heat and hot water applications into the charcoaling process making it way more efficient than direct raw fuel gasification.
So here are Gary Gilmores Simple Fire plans. Download them, create a thread "Joes Simple Fire Build" For example and start building. I will personally help you if needed and others will start to participate as soon as builders and TOG users become more active here on the forum. I will also support the simple fire with a DIY bag filter and blower system here on the forum this spring.