Patent Application
20170312737
This application claims priority of Korean Patent Application No. 10-2016-0052323, filed on Apr. 28, 2016, in the KIPO (Korean Intellectual Property Office), the disclosure of which is incorporated herein entirely by reference.
The present disclosure relates to a method for manufacturing a diesel autothermal reforming catalyst and a diesel autothermal reforming catalyst manufactured by the same, more particularly to a method for manufacturing a diesel autothermal reforming catalyst which is loaded on a monolithic support with a large amount and can be used for a long period of time because cracking in a coating layer is decreased and a diesel autothermal reforming catalyst manufactured by the same.
A fuel cell is an electricity generation system which converts the chemical energy from hydrogen or a hydrocarbon-based material such as methanol or ethanol directly into electrical energy through a chemical reaction of hydrogen ions contained therein with an oxidizing agent.
Representative examples of the fuel cell include a polymer electrolyte membrane fuel cell (PEMFC) and a direct oxidation fuel cell. A direct oxidation fuel cell which uses methanol as a fuel is called a direct methanol fuel cell (DMFC).
In general, the polymer electrolyte membrane fuel cell has the advantages of high energy density and output. But, it requires additional devices such as a fuel reformer for reforming methane, methanol, natural gas, etc. to produce hydrogen as a fuel gas.
Fuel reforming can be classified into steam reforming, partial oxidation reforming and autothermal reforming. The steam reformer exhibits high hydrogen production efficiency but is disadvantageous in that response is slow because heat should be supplied since the associated reaction is an endothermic reaction.
The partial oxidation (PDX) reformer requires no heat supply and exhibits fast response because the associated reaction is an exothermic reaction. However, the hydrogen yield is not high. The autothermal reformer (ATR) can utilize the advantages of the two types of reformers. It is advantageous in that it requires less energy and exhibits fast response.
The autothermal reformer uses a catalyst for reforming of the fuel gas. In general, the catalyst is in powder form and is manufactured into spherical, cylindrical or pellet shapes depending on reaction conditions and states. For this, an additive such as a binder is necessary. In addition, the existing catalysts have the problems of low specific surface area and occurrence of differential pressure during the reaction.
Although a monolithic catalyst was proposed to solve these problems, it is has the problem of low reactivity due to gas mixing in the monolith and fast gas speed.
In order to solve these problems, Korean Patent Publication No. 10-2014-0048386 provides a fuel cell autothermal reforming catalyst in which a support body in the form of a metal foam, a metal net or a monolithic structure is used. However, a method for increasing the amount of the catalyst coated on the monolithic support and stably maintaining the coated catalyst has not been disclosed yet.
The present disclosure is directed to providing a method for increasing the amount of a catalyst loaded on a monolithic support and stably maintaining the coated catalyst layer.
In an aspect, the present disclosure provides a method for manufacturing a diesel autothermal reforming catalyst, which includes: a step of coating a catalyst material containing an organic solvent, a binder, a plasticizer and a catalyst powder on a monolithic support; and a step of heat-treating the catalyst material.
In an exemplary embodiment of the present disclosure, the catalyst material contains: 300-500 parts by weight of the organic solvent; 5-15 parts by weight of the binder; and 3-10 parts by weight of the plasticizer based on 100 parts by weight of the catalyst powder.
In an exemplary embodiment of the present disclosure, the heat treatment is performed at 500-900° C.
The present disclosure also provides a method for manufacturing a diesel autothermal reforming catalyst, which includes: a step of firstly coating gadolinium-doped ceria (CGO) on a monolithic support; and a step of secondly coating a catalyst layer on the gadolinium-doped ceria.
In an exemplary embodiment of the present disclosure, the catalyst layer contains a catalyst material supported on gadolinium-doped ceria (CGO).
In an exemplary embodiment of the present disclosure, the first coating and the second coating are performed by the method described above.
According to the present disclosure, by using a plasticizer together with an organic solvent and a binder, the loading amount of a catalyst on a monolithic support can be increased. In addition, the catalyst can be uniformly distributed on the monolithic support, with increased coating strength. Also, by providing gadolinium-doped ceria (CGO) on the support and the catalyst layer, the mechanical robustness of the monolithic catalyst can be improved by reducing cracking of the catalyst.
The above and other features and advantages will become more apparent to those of ordinary skill in the art by describing in detail exemplary embodiments with reference to the attached drawings, in which:
In the following description, the same or similar elements are labeled with the same or similar reference numbers.
The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “includes”, “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. In addition, a term such as a “unit”, a “module”, a “block” or like, when used in the specification, represents a unit that processes at least one function or operation, and the unit or the like may be implemented by hardware or software or a combination of hardware and software.
Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
Preferred embodiments will now be described more fully hereinafter with reference to the accompanying drawings. However, they may be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.
The present disclosure provides a method for manufacturing a diesel autothermal reforming catalyst, which uses diesel as a fuel, by coating a catalyst material containing an organic solvent, a binder, a plasticizer and a catalyst powder on a monolithic support and then drying and heat-treating the same.
In an exemplary embodiment of the present disclosure, the catalyst powder is a material in which a catalyst (Pt) is supported on gadolinium-doped ceria (CGO). The monolithic catalyst can be loaded uniformly and in large amount.
Referring to
In the present disclosure, the heat treatment may be performed specifically at 500-900° C. At lower temperatures, the effect of coating through heat treatment may be insignificant. And, at higher temperatures, the catalyst material may be deformed due to overheating.
Specifically, in an exemplary embodiment of the present disclosure, the catalyst material may contain: 300-500 parts by weight of the organic solvent; 5-15 parts by weight of the binder; and 3-10 parts by weight of the plasticizer based on 100 parts by weight of the catalyst powder. When the organic solvent is used in larger amounts, the loading amount of the catalyst may decrease. And, when the organic solvent is used in smaller amounts, the catalyst may not be coated on the entire monolithic support. And, when the amounts of the binder and the plasticizer are outside the above ranges, it may be difficult to achieve the effect desired by the present disclosure.
Referring to
Loading amount, coating strength, uniformity, etc. were evaluated for the following four coating methods.
[Coating Methods]
The monolithic support was immersed in 15-30% nitric acid for at least one day. The support was dried after washing the channel side with DI water.
As the catalyst powder, a material (Pt/CGO) in which a catalyst (Pt) was supported on gadolinium-doped ceria (CGO) was used. As the organic solvent, a mixture of xylene and butanol was used. As the binder, polyethylene glycol was used. As the plasticizer, polyvinylpyrrolidone was used. As a dispersing agent, Butvar (polyvinyl butyral) was used. The compositional ratios of the catalyst slurries prepared in this example are as follows.
After mixing the materials, ball milling was performed using zirconia balls.
After injecting the prepared slurry into the channels of the monolithic support, the support was turned upside down and air was blown to assist the injection of the catalyst slurry into the channels. Then, the support was dried in an oven for about 2 hours and then heat-treated at 800° C. Finally, a diesel autothermal reforming catalyst coated with the catalyst material was obtained.
Investigation of Catalyst Loading Amount
Referring to
Investigation of Catalyst Coating Strength
Referring to
Analysis of Coating Cross-Section
Referring to
Referring to
In addition, when the catalyst material was coated on a catalyst supported on gadolinium-doped ceria (CGO), cracking of the catalyst could be prevented by pre-coating gadolinium-doped ceria (CGO) between the monolithic support and the catalyst supported on gadolinium-doped ceria (CGO).
Referring to
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2016-0052323 | Apr 2016 | KR | national |
