Hint: When carbon burns in presence of oxygen are known as the combustion process. Process for the production of combustible gases containing carbon monoxide from solid carbonaceous materials, which includes fixed-bed gasification of lump fuel or pulverulent fuels in suspension. Because of these combustible gases high calorific value is used as fuels.
Complete step by step solution:
Water-gas: a mixture of carbon dioxide and hydrogen produced by passing steam over red-hot cake. The process is an endothermic reaction. The water-gas has lower calorific values than coal gas. This gas is also known as blue gas.
$C(co*ke)+{{H}_{2}}O\to CO+{{H}_{2}}$
Net calorific value = gross calorific value-586 cal/g
Synthesis gas: this gas produced from industrially by steam reforming of natural gas involves catalytic decomposition of methane. The synthesis gas and water gas have the same composition but differ in the calorific values.
Producer gas: this gas mixture containing carbon monoxide CO, carbon dioxide $C{{O}_{2}}$ , hydrogen ${{H}_{2}}$ , and nitrogen ${{N}_{2}}$ , which is referred to as wood gas, town gas, or syngas. This gas is used to power gas turbines due to less calorific value.
Semi-water gas: the mixture of water gas and producer gas b passing through air and steam on heated co*ke.
So, $CO+{{H}_{2}}$ is known as water gas.
Note: A combustible mixture does not burn until it reaches the ignition point. The presence of carbon and gas will start burning at lower temperatures. This phenomenon is called catalytic combustion. Once a combustible gas is hom*ogeneously mixed with air, the mixture will stay hom*ogeneous with random motion.
