A method and apparatus for a steam biomass reactor converts organic waste placed inside a sealed steam injected reactor to biogas (methane CH4 and carbon dioxide CO2). The amount of liquid introduced into the reactor can be minimized, increased methane and CO2 can be produced, and the methane produced can have higher Btu values as compared to methane produced in other reactors. Some embodiments provide a method of injecting steam into a sealed vessel that is loaded with organic waste and collecting the methane produced by accelerated decomposition/biodegradation of the organic component of the waste within the vessel. The steam accelerates the decomposition of the organic refuse, thereby enhancing the production of methane gas and CO2.