Low temperature process for the production of hydrogen

Details Low temperature process for the production of hydrogen Low temperature process for the production of hydrogen

2000-08-31

2003-01-21

Langel, Wayne A. (Department: 1754)

Chemistry of inorganic compounds

Hydrogen or compound thereof

Elemental hydrogen

C423S653000, C423S654000

Reexamination Certificate

active

06509000

ABSTRACT:

FIELD OF THE INVENTION
The present invention relates to a low temperature process for the production of hydrogen from methane or methane rich hydrocarbons and steam. More particularly the present invention relates to a low temperature process for the production of hydrogen from methane or methane rich hydrocarbons and steam using a group VIII metal oxide(s) containing solid catalysts in two parallel reactors. The present invention also particularly relates to a process for the continuous production of hydrogen from methane or methane rich hydrocarbons and steam at low temperature below 650° C. using a group VIII metal oxide(s) containing solid catalyst in two parallel reactors operated in a cyclic mariner for the decomposition of methane or methane rich hydrocarbons to hydrogen and carbon, which is deposited on the catalyst, and for the gasification of the carbon deposited on the catalyst by steam in the presence or absence of oxygen.
BACKGROUND OF THE INVENTION
The demand for hydrogen is increasing day by day for hydrotreating processes in petroleum industries and also for hydrogen fuel cells, both stationary and non-stationiary fuel cells. Since hydrogen is a non-polluting fuel, its use as a fuel particularly for fuel cells used in the automobile transport has been increasing very fast. However, hydrogen fuel cells require carbon monoxide free hydrogen as a fuel to avoid deactivation of the noble metal catalyst in the fuel cells.
The main natural sources of hydrogen are hydrocarbons and water. Amongst hydrocarbons, methane has the highest hydrogen to carbon ratio and is hence the most preferred choice amongst hydrocarbons for hydrogen conversion.
Conventional processes for the production of hydrogen are based on steam reforming of hydrocarbons, such as naphtha and methane or natural gas and autothermal reforming of hydrocarbons, particularly heavier hydrocarbons. Hydrogen production processes have been recently reviewed by Fierro and co-workers [Pena, M. A., Gomez, J. P., and Fierro, J. L. G., Applied Catalysis A. General, volume 144, page 7-57, 1996].
The prior art processes of hydrocarbon steam reforming and autothermal reforming are operated at high temperatures of over about 900° C. and the product stream of these processes contains appreciable amounts of carbon monoxide along with hydrogen. The prior art processes also suffer from the disadvantage that removal of carbon monoxide at low concentrations from hydrogen is very expensive. The high cost factor involved in the separation of carbon monoxide from hydrogen and limitations of high temperature required for operation renders both prior art processes uneconomical for the production of carbon monoxide free hydrogen.
The prior art also discloses processes for the production of carbon monoxide free hydrogen from methane at low temperatures of below 600° C. Recently, Kikuchi has described a process based on steam reforming of methane in a membrane reactor to produce hydrogen free of carbon monoxide (Kikuchi, E.,
Hydrogen permselective membrane reactors
, CATTECH, March 1997, pages 67-74, Balzer Science Publishers). Kikuchi discloses the use of a Pd/ceramic composite membrane for steam reforming of methane over a commercial supported nickel catalyst at temperatures as low as 500° C., to obtain methane conversion to carbon monoxide free hydrogen of upto 100%. The hydrogen produced in this process by the steam reforming of methane is continuously removed form the reaction system by the selective permeation of hydrogen through the Pd-membrane. However, this process suffers from the following limitations or drawbacks: 1) Because of the use of a number of Pd-membrane tubes, the capital costs are very high; 2) potential for the deactivation of the Pd-membrane due to the deposition of carbonaceous matter exists, 3) membrane stability is a problem; 4) there is a possibility of membrane failure due to the formation of pin holes in the membrane.
Japanese patent JP 09234372 A2 of Sep. 2, 1997 discloses a process for the manufacture of hydrogen by thermal decomposition of hydrocarbons at 200° C.-1000° C. using a catalyst containing nickel, alkali or alkaline earth compounds.
Russian patent RU 2071932 C1 of Jan. 20, 1997 discloses the production of hydrogen and carbon by the thermal decomposition of methane on nickel catalyst. Japanese patent JP 11228102 A2 discloses reactors for the thermal decomposition of methane to form carbon and hydrogen.
Hydrogen production by catalytic cracking of methane or natural gas and other hydrocarbons below 900° C. is disclosed in a few publications [Zhang, T and Amiridis, M. D., Applied Catalysis A: General, Volume 167; pages 161-172, 1998; Muradov, N. Z. Energy Fuels, Volume 12, pages 41-48, 1998; Kuvshinov, G. G., et al, Hydrogen Energy Progress XI Proceedings of the World Hydrogen Energy Conference,. 11
th
, Volume 1, pages 655-660, edited by Veziroglu, T., 1996; Muradov, N. Z., Proceedings of US DOE Hydrogen Program Review, volume 1, page 513-535, 1996].
While the hydrogen produced in the above prior art processes, based on catalytic cracking or thermo-catalytic decomposition of methane and other hydrocarbons, is free from carbon monoxide and carbon dioxide, the rate of deactivation of the catalyst is high due to the carbon formed and deposited on the catalyst accompanied by an increase in the pressure drop across the catalyst bed. This makes the above processes unsuitable for hydrogen production on a commercial scale.
Choudhary and Goodman recently report a process for the production of carbon monoxide free hydrogen involving step wise methane stream reforming [Choudhary, T. V. and Goodman, D. W., Catalysis Letter, volume 59, page 93-94, 1999]. In this process, methane pulse and water pulses are alternately passed over a pre-reduced nickel based catalyst at 375° C. When methane pulse is passed over the catalyst, the methane from the pulse decomposes to hydrogen en and carbon, leaving the carbon deposited on the catalyst. When the water pulse is passed over the catalyst with carbon deposited thereon, the carbon on the catalyst reacts with steam to form CO
2
, hydrogen and methane. In this process, although the carbon monoxide free hydrogen is produced by, the catalytic cracking of methane and the carbon deposited on the catalyst is removed by the cyclic operation of the methane and water pulses in the same reactor, the process is not operated in steady state and hydrogen production is not continuous. It is therefore not practical or economical to produce carbon monoxide free hydrogen on large scale by this transient process involving cyclic operation of the methane and water pulses.
In view of the above mentioned drawbacks and limitations of prior art processes, there is a pressing need to develop a continuous process for the production of carbon monoxide-free hydrogen by catalytic decomposition of methane or natural gas at low temperature of below 600° C., thereby avoiding the carbon build up on the catalyst by its periodic removal.
OBJECTS OF THE INVENTION
It is an object of the invention to provide a low temperature process for the continuous production of hydrogen from methane or methane rich hydrocarbons and steam.
It is yet another object of the invention to provide a process for the continuous production of hydrogen from methane or methane rich hydrocarbons and steam that is cost effective.
It is a further object of the invention to provide a process for the continuous production of hydrogen that is carbon monoxide or carbon dioxide free and is useful as a fuel.
It is another object of the invention to provide a process for the production of hydrogen that is carbon monoxide or carbon dioxide free in while avoiding build up of carbon on the catalysts.
It is another object to provide a low temperature process for the continuous production of hydrogen from methane or methane rich hydrocarbons and steam that avoids the problem of high cost involved in the removal of carbon monoxide from hydrogen at low concentrations and is therefore cost effective.
SUMMARY OF THE

Affiliated with

Also associated with

Rating

Low temperature process for the production of hydrogen does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Low temperature process for the production of hydrogen, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Low temperature process for the production of hydrogen will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3002464