Integrated device for preparing hydrogen by the recapitalization of dimethyl ether aqueous vapor and method

Abstract

The invention discloses an integrated dimethyl ether steam reforming hydrogen-production device and a method, belonging to the hydrogen-production equipment and the method. The invention utilizes a dual-jacketed membrane reactor to realize the coupling of an exothermic reaction and an endothermic reaction and the coupling of a catalytic reaction and a product separation. The invention is characterized in that the central tube of the double cannula is a hydrogen permeation membrane made of palladium silver alloy for in-situ separation of H2, the product of the reaction system; two reforming catalysts are filled in a jacket of the double cannula and the dimethyl ether steam reforming hydrogen production is carried out in the jacket of the tube side; a combustion supporting catalyst is filledin the shell side out of the double cannula to supply heat for the dimethyl ether steam reforming reaction. The invention has the advantages of greatly promoting the steam reforming reaction rate ofthe dimethyl ether, the heat utilization rate and the product purity. The invention obtains high purity hydrogen at lower reaction temperature and pressure, in which the conversion of dimethyl ether canreach 80%, the hydrogen recovery rate 85%, the hydrogen production rate 0.05 to 0.6 m<3> / h, the hydrogen purity 99.5% and the thermal efficiency of the system is above 80%.

Description

Technical field [0001] The invention relates to a device and a method for preparing hydrogen by using dimethyl ether as a raw material, in particular to an integrated dimethyl ether steam reforming hydrogen production device and a method. Background technique [0002] Hydrogen energy is regarded as the most promising energy source in this century because of its cleanness, high efficiency, and renewable energy. At present, it is still an ideal low-pollution or zero-pollution energy for vehicles. At present, the research and development of the mobile hydrogen production process of liquid hydrocarbons (such as methanol) based on chemical processes has become one of the current hot topics in the field of fuel cells. Using methanol as fuel can solve the problems of storage and transportation, but the specific energy density of methanol is still unsatisfactory, and it is more toxic. Once leaked, it will cause great harm to the human body and the environment. In addition, the infrastruc...

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Problems solved by technology

[0009] The steam reforming reaction of dimethyl ether produces hydrogen with high hydrogen content, and the reaction conditions are mild. The disadvantage is that the steam reforming reaction of dimethyl ether is a strong endothermic reaction, and the reaction itself and the vaporization of raw material water need absorption. Heat, when hydrogen production needs to burn part of the fuel for heating

Patents CN1126709C and CN1044896C propose a method for catalyzing hydrogen production by dimethyl ether in the presence of steam. In this patent, dimethyl ether is first hydrolyzed to produce a mixture containing carbon oxides and hydrogen, and then the reaction product is subjected to a water gas change reaction to make a large amount of carbon monoxide Converted into carbon dioxide, and the product is rich in carbon monoxide, which makes the hydrogen production process of dimethyl ether complicated and high in energy consumption; although the patent CN1123530C proposes a method of generating rich hydrogen by steam reforming dimethyl ether and using part of the hydrogen to oxidize for heat , but the patent preferably uses a fluidized bed reactor, the reaction operating pressure is high, the gas components in the reaction product are complex, and it is difficult to obtain hydrogen with high purity. The above patents are not suitable for mobile hydrogen production or hydrogen production from small hydrogen sources

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