Heat Generation by Catalytic Environmentally Friendly Combustion of Methane

Abstract

It is known that environmentally friendly flameless combustion of hydrocarbons without formation of nitrogen oxides is an important way to dispose of natural gas. In this regard, the development of energy-saving and environmentally friendly catalytic combustion technologies of light hydrocarbons for heating of greenhouses and use of formed CO2 for carbon dioxide additional fertilizing of plants is the aim of the present work. Polyoxide heat resistant (up to 1,473 K) highly efficient Mn-containing catalysts for deep oxidation of methane and propane-butane in vapor-air mixture have been developed. Prototype of catalytic heat generator was created for ecologically clean methane and propane-butane burning. Pilot testing of catalytic heat generator for heating of greenhouses were conducted and carbon dioxide fertilizing of plants by combustion products of propane-butane mixture was carried out. It was shown that the Mn catalyst contains crystalline CeO2 and nanoparticles of Mn2O3 (d = 30 - 40 Ǻ) using BET, XRD, TEM and ESDR methods. Its amount decreases by heating to 1,173 K through a partial interaction with rare earth elements with the formation of La(Ce)MnO3, CeAlO3, then hexaaluminate LaMnAl11O19 at 1,273 - 1,473 K, which are active in oxidation of CH4 to CO2. Such phase composition is main condition for optimum deep oxidation of CH4.