... taste, which is given priority to hydrogen, also contains carbon monoxide, acetylene, methane and other inert gases, and can be ... Test results Hydrogen(V/V)% 52.821 Carbon monoxide(V/V)% 42.818 Carbon dioxide(V/V)% 3.703 Methane(V/ ... of the fuel gas and generation limits of the carbon monoxide, reducing the degree of appearing yellow-smoking. Low ...