PROCESS FOR MANUFACTURING GASES RICH IN METHANE

• US 3,870,738 A
• Filed: 01/23/1973
• Issued: 03/11/1975
• Est. Priority Date: 01/24/1972
• Status: Expired due to Term

• Current Assignee: Kenzo Yamamoto, Seiichi Matsuoka, Toshio Shioda
• Original Assignee: Kenzo Yamamoto, Seiichi Matsuoka, Toshio Shioda
• Inventors: Yamamoto, Kenzo, Matsuoka, Seiichi, Shioda, Toshio
• Primary Examiner(s): Mars, Howard T.
• Application Number:
  US05/326,007
• Time in Patent Office: 777 Days
• Field of Search: 260/449M,449S,449.6S
• US Class Current: 518/704
• CPC Class Codes: C01B 3/38 using catalysts
• CPC Class Codes: C07C 1/02 from oxides of a carbon preparation of liquid hydrocarbon mixtures of undefined composition C10G2/00; of synthetic natural gas C10L3/06
• CPC Class Codes: C07C 9/04 Methane production by treatment of sewage C02F11/04; natural gas, synthetic natural gas C10L3/06
• CPC Class Codes: Y02P 30/40 Ethylene production

Abstract

A process for manufacturing gases rich in methane, wherein a mixture of feed hydrocarbon containing at least two carbon atoms in the molecule and steam is subjected to adiabatic low temperature steam reforming reaction to form a reformed gas substantially comprising methane, hydrogen, carbon monoxide, carbon dioxide and steam. Then the reformed gas is divided into two streams and one of them is introduced in the first stage of plural methanization reaction zones arranged in series at a temperature of 200* - 550*C under a pressure of 0 - 150 Kg/cm2G, while the other is cooled, and after removing the condensed water is introduced in the second and, if present, subsequent methanization reaction zones, to subject the reformed gas to adiabatic methanization reaction.

Claims

1. In a process for producing a gas rich in methane wherein a gaseous mixture of feed hydrocarbon containing at least two carbon atoms and steam is subjected to steam reforming in contact with a reforming catalyst at a temperature within the range of 350* C and 550* C and a pressure within the range of 0 kg/cm2G and 100 kg/cm2G to produce an effluent stream of reformed gas mixture comprising as constituent gases methane, water, hydrogen, carbon monoxide and carbon dioxide, and subjecting the said effluent steam of reformed gas to exothermic methanization by passing it through a reaction zone under methanization reaction conditions of a temperature in the range of 2,000* C to 550* C and a pressure in the range of 0 kg/cm2G and 150 kg/cm2G and in contact with methanization catalyst to produce a methane-rich gas, the improvement which comprises:

dividing said effluent stream of reformed gas into two stream parts to constitute a first stream part and a second stream part;

flowing through a first methanization reaction zone containing methanization catalyst and under said methanization reaction conditions, only said first stream part containing all of said constituent gases to obtain a first methanized reaction product gas;

cooling said second stream part to condense the water therein and separating the condensed water from the remainder of said second stream part to obtain a dewatered gaseous second stream part;

flowing said dewatered gaseous second stream part conjointly with said first methanized reaction product gas through one or more additional methanization reaction zones containing methanization catalyst and under said methanization reaction conditions, said additional methanization reaction zone or zones being separate from said first methanization zone and connected in series with said first methanization zones and all of the methanization reactions being carried out adiabatically, and separating from the last of the methanization reaction zones an effluent gas enriched in methane.

2. A process for manufacturing gases rich in methane according to claim 1, characterized in that refinery off gas, LPG, light naphtha, heavy naphtha or kerosene is used as the feed hydrocarbon.

3. A process for manufacturing gases rich in methane according to claim 1, characterized in that two or three methanization reaction zones are employed as the plural methanization reaction zones arranged in series.

4. A process for manufacturing gases rich in methane according to claim 1, characterized in that said plural methanization reaction zones are provided in a single methanization reactor.

5. The method of claim 4, wherein said effluent gas rich in methane is subsequently subjected to a step of removal of carbon dioxide.