Abstract:
An improved process for manufacture of a purified gas containing hydrogen and carbon monoxide is described wherein a fuel is partially combusted in a reactor to produce a crude gas product containing soot, ash and contaminating gases such as HCN, H.sub.2 S and COS, the crude gas product is subsequently cooled in a waste heat boiler and the cooled gas is washed in a scrubber to remove the entrained soot particles. In this improved process, removal of soot, ash and gaseous contaminants from the cooled crude gas product is facilitated by washing the cooled gas in a scrubber with an aqueous salt solution containing at least 10% by weight of an alkaline water-soluble salt, which salt solution is subsequently regenerated by removal of absorbed gases and suspended solids (soot and ash) and recycled to the scrubber.
Abstract:
This is an improved continuous process for producing a clean methane-rich gas stream without the concomitant formation of particulate carbon which would ordinarily decrease the efficiency of the process and shorten the life of the catalyst. By-product superheated steam is simultaneously produced at a maximum temperature. The product stream may have a methane content up to 98 to 99 mole % or higher and a gross heating value up to 1000 BTU per SCF or more. Process steps include partial oxidation of a hydrocarbonaceous fuel under operating conditions that produce a synthesis gas containing 10 to 30 mole % methane (dry and CO2free basis) and a H2/CO mole ratio of 2.6 or higher, and reacting the methane-rich process gas stream in one to three catalytic methanation stages under critical operating conditions that increase the methane content in the process gas stream stepwise up to 98 mole % or higher without incipient soot formation for each corresponding CH4 content of the feed as one proceeds from one methanation step to another. Heat from the highly exothermic methanation reaction is used to make valuable by-product superheated steam. The product gas may be burned without polluting the atmosphere.
Abstract:
The soot content of a hydrogen and carbon monoxide-containing gas mixture obtained by the partial combustion of a hydrocarbonaceous fuel is substantially reduced by passing the partially-combusted gases through a soot-conversion zone maintained at an elevated temperature and pressure, and retarding the passage of soot particles through the zone for a sufficient period of time that the soot is substantially converted to carbon monoxide. An apparatus suitable for effecting soot-conversion is also disclosed.