pyrogas

from The Century Dictionary.

• noun A trade-name of a gaseous mixture obtained by Tobianski, in Belgium, by burning garbage, rags, sawdust, waste paper, etc., in a specially constructed furnace with limited access of air, and carrying the smoke through a tower containing coke or some other porous absorbent soaked with naphtha or alcohol. It is proposed to use the product as a source of heat, light, and mechanical or electrical energy.