Patent Issued for CO Shift Reaction Apparatus and Gasification Gas Refining System (USPTO 9238208)
By a News Reporter-Staff News Editor at Journal of Engineering -- From
Alexandria, Virginia
, VerticalNews journalists report that a patent by the inventors Seiki, Yoshio (
Tokyo
, JP);
Fujii, Shuji (
Tokyo
, JP); Higashino, Koji (
Tokyo
, JP);
Yoshida, Kaori (
Tokyo
, JP); Yushima, Masaki (
Hiroshima
, JP), filed on February 8, 2013, was published online on January 19, 2016.
The patent's assignee for patent number 9238208 is MITSUBISHI HEAVY INDUSTRIES, LTD. (
Tokyo
, JP).
News editors obtained the following quote from the background information supplied by the inventors: "In recent years, the effective use of coal has received attention, and from now on, it is predicted that the demand for a clean coal utilization process will be increased. In order to convert coal into a high value-added energy medium, advanced technologies such as a technology of gasifying coal and a technology of refining the gasified coal are used.
"In a process of refining coal gasification gas (gasification gas) made by gasifying coal, which has received attention as one of technologies to cope with such a system, as in the following reaction formula (1), a CO shift reaction in which carbon monoxide (CO) reacts with water to produce hydrogen (H.sub.2) and carbon dioxide (CO.sub.2) is applied (for example, refer to Patent Literatures 1 and 2). CO+H.sub.2O.fwdarw.H.sub.2+CO.sub.2 (1)
"A power generation plant which applies refined gas obtained by subjecting gasification gas to the CO shift reaction as described above and refining the resultant, as gas for the turbine, and a chemical product synthesis plant which uses the refined gas as a raw material for synthesizing chemical products such as methanol and ammonia has been suggested. As the power generation plant which uses and applies the gasification gas to power generation, for example, a coal gasification combined power generation (Integrated coal Gasification Combined Cycle (IGCC)) system has been suggested (for example, refer to Patent Literatures 3 and 4). The IGCC system is referred to as a system in which coal is converted into combustible gas in a gasification furnace at a high temperature and a high pressure to produce gasification gas and the gasification gas is used as the raw material in a gas turbine and a steam turbine for combined power generation.
"In order to refine the coal gasification gas and produce the refined gas, a CO shift catalyst which accelerates the reaction in which CO contained in the gasification gas is reformed and converted into CO.sub.2 (CO shift reaction) is used. The coal gasification gas is allowed to pass through a CO shift reaction apparatus having a plurality of reactors provided with CO shift catalyst layers filled with the CO shift catalyst, and the CO shift reaction as in the above formula (1) occurs in the presence of the CO shift catalyst in the reactors of the CO shift reaction apparatus, thereby producing reformed gas.
"In general, in order to produce the reformed gas by the CO shift reaction in the reactor, the CO shift catalyst needs to be limited to a predetermined temperature range (for example, 250.degree. C. to 350.degree. C.) in which the CO shift catalyst is usable. Therefore, the CO shift reaction apparatus is provided with a plurality of groups of a reactor and a cooler and is adjusted to allow the reaction to proceed while the temperature of the CO shift catalyst is in the predetermined temperature range (250.degree. C. to 350.degree. C.)."
As a supplement to the background information on this patent, VerticalNews correspondents also obtained the inventors' summary information for this patent: "Technical Problem
"Here, since the CO shift reaction is an exothermic reaction, the gasification gas is heated by the CO shift reaction in the CO shift reaction apparatus and thus the CO shift catalyst is heated. When the temperature of the CO shift catalyst is increased and the temperature of the CO shift catalyst exceeds a predetermined temperature, the CO shift catalyst deteriorates and needs to be replaced in early stages. Therefore, in a case where the CO shift reaction is allowed to proceed while the CO shift catalyst is in the predetermined temperature range (for example, 250.degree. C. to 350.degree. C.), the CO shift reaction apparatus needs to use a number of reactors and coolers in order to suppress the deterioration of the CO shift catalyst.
"In addition, the size of the cooler is generally determined and manufactured based on the gas flow rate in the plan of the original design. Accordingly, there may be cases where the coal gasification gas cannot be sufficiently cooled due to variations in the gas flow rate and the gas composition of the coal gasification gas. Therefore, when the gas flow rate and the gas composition of the coal gasification gas are in a range that is too distant from the conditions of the original design, there may be cases where the cooler cannot cool the coal gasification gas while the CO shift catalyst is in the predetermined temperature range.
"Accordingly, the appearance of a CO shift reaction apparatus is desirable, which is capable of allowing a CO shift catalyst to be in a predetermined temperature range even in a case where the gas flow rate and the gas composition of gasification gas vary, thereby suppressing the deterioration of the CO shift catalyst, efficiently and stably producing reformed gas, and flexibly coping with variations in the gas flow rate and the gas composition in coal gasification gas.
"The present invention has been made taking the forgoing problems into consideration, and an object thereof is to provide a CO shift reaction apparatus and a gasification gas refining system capable of efficiently producing reformed gas while suppressing the deterioration of a CO shift catalyst, and flexibly coping with variations in the gas flow rate and the gas composition in coal gasification gas.
"Solution to Problem
"According to a first aspect of the present invention in order to solve the problems, there is provided a CO shift reaction apparatus including: a plurality of reactors, each having CO shift catalyst layers filled with a CO shift catalyst which reforms CO in gas containing CO; at least one gas supply line which supplies the gas to each of the reactors; at least one first gas flow rate control unit which is provided in the gas supply line and adjusts a gas supply amount of the gas supplied to each of the reactors; a gas discharge line which discharges processing gas in which CO in the gas is at least partially reformed, from the reactors; at least one gas separation line which connects the gas supply line to the gas discharge line and extracts a part of the processing gas in the gas discharge line; and at least one second gas flow rate control unit which is provided in the gas discharge line and adjusts a gas supply amount of the processing gas supplied to the gas discharge line and the gas separation line.
"According to a second aspect of the present invention, there is provided the CO shift reaction apparatus according to the first aspect, wherein lengths of the CO shift catalyst layers are different from each other.
"According to a third aspect of the present invention, there is provided a gasification gas refining system including: the CO shift reaction apparatus according to the first or second aspect, which converts CO in gasification gas produced by gasifying coal as a raw material in a gasification furnace into CO.sub.2 in the presence of the CO shift catalyst; a wet flue gas processing apparatus which purifies the gasification gas after being subjected to a CO shift reaction in the CO shift reaction apparatus; and a refining apparatus which performs refinement by removing carbon dioxide and hydrogen sulfide from the gasification gas after being purified by the wet flue gas processing apparatus.
"Advantageous Effects of Invention
"According to the present invention, the reformed gas can be efficiently produced while suppressing the deterioration of the CO shift catalyst, and variations in the gas flow rate, the gas composition, and the like of coal gasification gas can be flexibly coped with.
"Accordingly, an increase in the lifespan of the CO shift catalyst becomes possible and the catalyst performance of the CO shift catalyst can be held for a longer term. Therefore, a gas refining process can be performed more efficiently and stably."
For additional information on this patent, see: Seiki, Yoshio; Fujii, Shuji; Higashino, Koji; Yoshida, Kaori; Yushima, Masaki. CO Shift Reaction Apparatus and Gasification Gas Refining System.
U.S.
Patent Number 9238208, filed February 8, 2013, and published online on January 19, 2016. Patent URL:
http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=9238208.PN.&OS=PN/9238208RS=PN/9238208
Keywords for this news article include: Chemicals, Chemistry, Technology, Carbon Dioxide, Carbon Monoxide, MITSUBISHI HEAVY INDUSTRIES LTD..
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