Hi Timothy,
Welcome.
Here we mostly want to run various kinds of engines. Emissions from burning woodgas or charcoalgas in an engine are very low because the flame temperature is relatively low. It makes almost zero NOx, so if you’re not running rich you will have almost zero emissions.
I think the easiest way to get started is with a charcoal gasifier. So you have to learn to make charcoal. Here is a link to some of my experiences.