http://energy.cleartheair.org.hk/wp-content/uploads/2013/09/...
which I see as pessimistic. Although the plasma torch is using a fraction of the energy output, they are blasting oxygen or air into the reactor so pyrolysis is driven by combustion as well. The reactor is not breaking down dioxins so those need to be stripped. From an air pollution quality it looks acceptable but not great. Heterogenous feedstocks will confound the thing.
This gasification facility is in a class by itself,
https://www.netl.doe.gov/research/Coal/energy-systems/gasifi...
it was not able to pay for its capital costs but after a bail out it has been highly successfully at paying its operations costs. It is highly optimized and it is not just selling natural gas but also nitrogen fertilizer (uses the nitrogen from the liquid air factory that makes oxygen for the blast) and coal tar products and even waste CO2. It has a huge coal seam across the street so it is always consuming the same stuff so the preprocessing and cleanup are all standardized. It was “too big to fail” so people did stay the course and get it spinning like a top.