Abstract: A method and apparatus for generating acetylene gas by reacting water and calcium carbide wherein a tank containing water is pressurized by a pump in a manner feeding the water to another vessel wherein it reacts with particulate calcium carbide to generate acetylene gas. A portion of the acetylene gas is returned through a pressure regulator to the water tank in a manner maintaining regulated system operating pressure on the water to sustain the reaction without overproduction of the gas. The apparatus can be located in a vehicle for on board generation of acetylene gas as fuel for the internal combustion engine thereof.