JP2007212207A - Life estimation method of catalyst - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily and certainly estimate the life of a catalyst in a short time. <P>SOLUTION: The life estimation method of the catalyst, which is charged in a catalyst bed to perform predetermined chemical reaction with respect to the raw material supplied to the catalyst bed, includes a step (A) of performing respective chemical reaction tests under a steady condition with respect to a plurality of test objects a, b, c and d changed in the filling ratio of the catalyst in the catalyst bed, a step (B) of respectively acquiring the life data of the test objects a, b, c and d from the result of the chemical reaction test of the test objects a, b, c and d, a step (C) of acquiring an approximate straight line 5 showing the correlation between the filling ratio of the catalyst of the respective test objects a, b, c and d and the life data of the respective test objects a, b, c and d and a step (D) of acquiring a life estimation at the time of the 100% filling ratio of the catalyst from the approximate straight line 5. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for estimating the lifetime of a catalyst that performs a predetermined chemical reaction with a supplied raw material, and in particular, based on the respective lifetime data acquired for each of a plurality of test specimens having different catalyst filling rates. The present invention relates to a catalyst life estimation method for obtaining an estimated life when the catalyst filling rate is 100%.

  In various reaction devices such as a reformer of a fuel cell, a catalyst is widely used to promote a chemical reaction with a raw material supplied to a catalyst layer. The catalyst gradually deteriorates as the usage time elapses, eventually loses its activity, and does not perform a predetermined function. Therefore, the catalyst needs to be regenerated or exchanged before it loses its activity. For this purpose, it is necessary to estimate the life of the catalyst.

Conventionally, as a method of estimating the life of the catalyst, for example, the temperature at a plurality of points between the inlet and the outlet of the raw material with respect to the catalyst layer is measured, and it is detected that the peak point of the temperature distribution appears in the vicinity of the outlet. There is known a method of estimating that the entire catalyst has deteriorated due to the above (for example, see Patent Document 1).
JP-A-60-147226

  However, in order to estimate the life of the catalyst by the method described in Patent Document 1, it is necessary to continue the chemical reaction test until the entire catalyst deteriorates. Therefore, the work for estimating the life of the catalyst is very laborious and time consuming, which is extremely uneconomical.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a catalyst life estimation method that can be carried out reliably and efficiently in a short time.

  In order to achieve the above object, the present invention provides a catalyst life estimation method for performing a predetermined chemical reaction with a raw material supplied to the catalyst layer, which is a catalyst charged in the catalyst layer. A step of performing a chemical reaction test on each of a plurality of test bodies in which the catalyst filling rate in the catalyst layer is changed under a steady condition, and (B) each of the test bodies based on a result of the chemical reaction test of each of the test bodies. Respectively, (C) obtaining an approximate line indicating a correlation between the catalyst filling rate of each test specimen and the life data of each test specimen, and (D) from the approximate straight line. And a step of obtaining an estimated life when the filling rate of the catalyst is 100%.

  Then, the step (A) may include mixing alumina balls with the catalyst in the catalyst layer and changing the filling rate of the catalyst between 30% and 60%.

  The catalyst may be filled in a catalyst layer of a fuel cell reformer.

  According to the present invention, since the life of the entire catalyst can be estimated based on a test piece with a low catalyst filling rate and a short life, there is no need to continue the chemical reaction test until the entire catalyst deteriorates. In addition, various excellent effects can be obtained such that the lifetime of the catalyst can be estimated reliably and efficiently in a short time.

  Hereinafter, a catalyst life estimation method according to an embodiment of the present invention will be described with reference to the drawings. In the following description, the case where the present invention is applied to a catalyst filled in a catalyst layer of a fuel cell reformer will be described as an example.

  A fuel cell is an electrochemical reaction between reformed gas (hydrogen) and oxidant gas (air) that converts the chemical energy of the fuel directly into electrical energy, and is mainly composed of hydrocarbons such as natural gas. In order to reform the raw material to be reformed gas (hydrogen), a reformer is provided. The reformer is provided with a catalyst layer filled with a catalyst, and a predetermined chemical reaction is performed between the catalyst filled in the catalyst layer and the raw material.

  When estimating the catalyst life by the catalyst life estimation method according to the present embodiment, first, the ratio (hereinafter referred to as “filling rate”) with respect to the amount (100%) of the catalyst filled in the catalyst layer. )) Respectively, test specimens a, b, c and d comprising 60%, 50%, 40% and 30% pellet catalysts and alumina balls having the same shape as the pellet catalysts were mixed. Fill the catalyst layer.

In this manner, with the test specimens a, b, c, d filled in the catalyst layers, the gas flow rate, steam / carbon ratio, SV value, etc. are set to be the same, The raw material is supplied to a chemical reaction test between the raw material and each of the specimens a, b, c, and d. As shown in FIG. 1, the results of the chemical reaction tests are shown in FIG. 1, where the x-axis is the test time (h) and the y-axis is the hydrogen (H ₂ ) concentration (mol%). Separately, it represents a change with time in the hydrogen (H ₂ ) concentration. From FIG. 1, the approximate straight line 1 when the filling rate is 60%, y = −0.0002x + 52.213, the approximate straight line 2 when the filling rate is 50%, y = −0.0008x + 51.405, the filling rate An approximate straight line 3 when the rate is 40%, y = −0.001x + 51.863, an approximate straight line 3 when the filling rate is 30%, and y = −0.0031x + 52.087 are obtained.

Thus, when each test specimen a, b, c, d chemically reacts with the raw material, the catalyst is thermally deteriorated and the activity is lowered. The catalyst layer moves from the raw material inlet to the outlet. In FIG. 1, when the hydrogen (H ₂ ) concentration (mol%) flowing out from the outlet of the catalyst layer decreases to a predetermined ratio (X%) of the initial performance value, each specimen a, b, c, d, the test time (h) from the start of the chemical reaction test to the time when the performance is reduced by X% based on the approximate straight lines 1, 2, 3, and 4 of the specimens a, b, c, and d. Acquired as life data of specimens a, b, c, and d, respectively.

  Next, as shown in FIG. 2, the x-axis is the filling rate (%), the y-axis is the performance X% reduction time (h), and the respective life data are represented for each of the specimens a, b, c, and d. Then, an approximate straight line 5 indicating the correlation between the catalyst filling rate of each test specimen a, b, c, d and the life data of each test specimen a, b, c, d is obtained from FIG. At this time, the lower the packing rate of the catalyst, the faster the sintering moves from the inlet to the outlet of the raw material of the catalyst layer. X% decrease time is shortened and becomes a proportional straight line.

  Thereafter, the approximate straight line 5 is extended obliquely upward to the right to obtain an estimated life when the filling rate of the catalyst is 100%, and this estimated life is taken as the life time of the catalyst. Thereby, it is possible to evaluate whether or not the lifetime of the catalyst achieves the target lifetime (in this embodiment, 40,000 hours as shown in FIG. 2).

  Thus, according to the catalyst lifetime estimation method according to the above-described embodiment, the lifetime of the entire catalyst is estimated based on the test specimens a, b, c, d having a low catalyst filling rate and a short lifetime. Therefore, it is not necessary to perform a chemical reaction test until the entire catalyst deteriorates, and the life of the catalyst can be estimated reliably and efficiently in a short time.

  In the above-described embodiment of the present invention, the test is performed with the catalyst filling rate set to 60%, 50%, 40%, and 30%. The filling rate can be arbitrarily set as long as the minimum amount of catalyst necessary for the chemical reaction test can be secured.

  The number of test specimens at that time is not limited to the above-described four pieces, and can be arbitrarily set as long as there are at least two specimens.

  Furthermore, in the above-described embodiment, the case where the lifetime of the catalyst charged in the catalyst layer of the fuel cell reformer is estimated has been described. However, this is merely an example, and the present invention includes a denitration device, etc. Needless to say, the present invention can also be applied to a catalyst filled in a catalyst layer of another reactor.

In life estimation method of the catalyst according to the embodiment of the present invention, specimen separately hydrogen (H ₂₎ is a graph showing the time course of concentration. In the catalyst lifetime estimation method according to the embodiment of the present invention, it is a diagram showing the correlation between the catalyst filling rate of each test specimen and the life data of each specimen.

Explanation of symbols

a Specimen with a catalyst filling rate of 60% b Specimen with a catalyst filling rate of 50% c Specimen with a catalyst filling rate of 40% d Specimen with a catalyst filling rate of 30% 5 Approximate line

Claims (3)

In a catalyst life estimation method for filling a catalyst layer, and performing a predetermined chemical reaction with a raw material supplied to the catalyst layer,
(A) performing a chemical reaction test on each of a plurality of test bodies in which the packing ratio of the catalyst in the catalyst layer is changed under a steady condition;
(B) a step of obtaining lifetime data of each test specimen from the result of the chemical reaction test of each test specimen,
(C) obtaining an approximate line indicating the correlation between the catalyst filling rate of each test specimen and the life data of each test specimen;
(D) obtaining an estimated life when the packing rate of the catalyst is 100% from the approximate line;
A method for estimating the life of a catalyst, comprising: 2. The catalyst life estimation according to claim 1, wherein the step (A) includes mixing alumina balls with the catalyst in the catalyst layer and changing a filling rate of the catalyst between 30% and 60%. Method. The catalyst life estimation method according to claim 1 or 2, wherein the catalyst is filled in a catalyst layer of a fuel cell reformer.

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