JPS5962345A - Catalyst for methane synthesis and its manufacture - Google Patents

Abstract

PURPOSE:To develop a catalyst for CH4 synthesis from CO and H2 causing no deterioration of activity even at high temps., by supporting the specified quantity of BaO and Ni on an alumina carrier. CONSTITUTION:As a catalyst used for CH4 synthetic reaction from CO and H2, a carrier such as gamma-alumina or the like is impregnated with an aqueous solution of BaNO3 or Ba(OH)2. The salt is heated, decomposed, and supported on the alumina carrier as BaO by 0.3-9.0wt%. Then, the carrier is impregnated with the aqueous solution of Ni(NO3)2, which is heated and supported as Ni by 3-30wt% basing on the total amount of alumina and Ni. This catalyst is used for the CH4 synthesis from CO and H2, and does not lower its catalyst activity even at high temperatures caused by the exothermic reaction at the synthesis.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a catalyst for methane synthesis by hydrogenation of carbon oxide and a method for producing the same, and more specifically to a catalyst for methane synthesis using a high concentration CO gas containing alumina, nickel and barium oxide, and a method for producing the same. Regarding the manufacturing method.

Considering the current energy situation, the method of producing alternative natural gas by converting highly concentrated CO gas obtained by gasifying heavy oil or coal into methane is a very promising process. In recent years, many reports have been published on methane synthesis from coal gasification gas. Particularly in the United States, full-scale research is being conducted, and even in Japan, there are rare projects aimed at producing high-calorie gas as part of the Sunshine Project.This methane synthesis reaction is a reaction that involves the generation of a large amount of reaction heat. Therefore, it is very important to effectively utilize the heat of reaction as an energy source from the economical point of view of the methane synthesis process. In order to effectively utilize this reaction heat, it is most preferable to carry out the reaction at a high temperature, but if the catalyst normally used for methane synthesis reaction is used with such a high concentration of CO gas, sintering due to heat and steam in the atmosphere may occur. It is known that the catalyst deteriorates significantly due to the formation of carbonaceous matter and other causes.

Furthermore, carbonaceous matter produced by bonding of carbon atoms on the catalyst sometimes causes clogging of the reaction tube, making the reaction physically impossible.

A number of methods that have been proposed in the past to solve these problems are to constantly remove reaction heat and maintain temperature control of the catalyst layer in order to avoid high-temperature reactions. However, in this method, the advantage of recovering and effectively utilizing the reaction heat is lost.

An object of the present invention is to provide a catalyst for methane synthesis that does not cause deterioration in activity even at high temperatures, and a method for producing the same, in order to recover and effectively utilize this reaction heat.

This object of the invention is achieved by the following catalyst.

That is, the catalyst of the present invention is a catalyst for producing methane characterized by comprising alumina, nickel, and barium oxide.

The catalyst of the present invention is composed of alumina, nickel and barium oxide, and the preferred content of nickel is 3 to 30% by weight, economically preferably 5 to 15% by weight, based on the total amount of nickel and alumina. .

The content of barium oxide is 0.6 to alumina.
A range of 9.0% by weight is preferable; if it is less than 6% by weight, there is no effect of containing barium oxide, and if it is contained in excess of 9% by weight, the solubility of barium nitrate and barium hydroxide is low. Therefore, it is difficult to incorporate barium oxide using a normal impregnation method, and it is added by a cross-wire method before molding the carrier, but the effect of barium oxide inclusion is not so great, and for this reason, it is added in an amount exceeding 9% by weight. It lacks merit.

In the present invention, the catalyst for methane production is obtained by supporting a barium salt solution such as barium nitrate or barium hydroxide and a nickel salt bath solution such as nickel nitrate on an alumina carrier by a conventionally known method such as an impregnation method, a kneading method, or a precipitation method. can be obtained.

In this case, add a barium salt solution and thermally decompose the Ba
There are two methods: (1) adding a nickel salt solution to the O-containing alumina support afterwards, (2) adding a nickel salt solution to the O-containing alumina support, and (2) adding a nickel salt solution to the O-containing alumina support at the same time.
Six methods can be adopted, method (3) for supporting O,
In particular, method (1) in which BaO is supported on an alumina carrier and then NiO is supported is preferred.

Furthermore, the alumina used in the present invention is γ-
Alumina is preferably used.

Hereinafter, the present invention will be specifically explained based on Examples, Comparative Examples, and Experimental Examples.

Comparative Example 1 Molded alumina carrier (r-alumina, water absorption rate 0.75
cc/f) 100 t was placed in a 5'00 cc beaker, and the alumina carrier was stirred and heated to 2.53 m.
It was impregnated with 75 cc of an ol/1-nickel nitrate solution dropwise at room temperature. Thereafter, it was dried in a conventional dryer and calcined in air at 500° C. for 6 hours in an electric furnace to obtain catalyst A having a nickel content of 10% by weight.

Example 1 The same alumina carrier 1002 used in Comparative Example 1 was
Pour into a 00cc beaker and add 0.26 mot/, l-
It was impregnated with 75 cc of barium nitrate solution dropwise at room temperature. After being allowed to stand at room temperature for 12 hours, it was dried in a conventional manner and fired in air at 800° C. for 6 hours in an electric furnace, so that the alumina carrier contained BaO in a filtrate amount.

On this alumina support containing 3% by weight of BaO, 2,5
In the same manner as in Example 1, 75 cc of a 3rnol/1 nickel nitrate solution was dripped onto the carrier to impregnate it. After standing still for 12 hours, it was dried in a conventional manner and heated to 500% in the air in an electric furnace.
C. for 6 hours to obtain catalyst B.

Examples 2 to 4 By changing the concentration of the barium nitrate solution in Example 1,
(J content is 0.6% by weight and 1.5% by weight, and
．． 3 r rnot/l- barium nitrate solution 150c
By impregnating 100f of carrier alumina with c in two parts, the carrier alumina was made to contain 9% by weight of BaO.

These 0.6 wt%, 1.5 wt%, 9 wt% f3a
Ni was added to O-containing alumina 1007 in the same manner as in Example 1.
O was supported on the catalysts, and these catalysts were designated as catalysts C, D, and E, respectively.

Example 5 Catalyst A prepared in Comparative Example 1 was placed in a 500 cc beaker, and 0.26 rnoL/, 6 barium nitrate solution 75
cc was impregnated dropwise at room temperature. After standing at room temperature for 12 hours, it was dried using a conventional method, heated to 500°C in the air in an electric furnace,
After firing for 6 hours, Catalyst F containing 6 parts by weight of BaO based on alumina was obtained.

EXAMPLES The surface area reduction rates of catalysts A to E obtained in Comparative Example 1 and Examples 1 to 4 were determined by sintering in a steam atmosphere using a conventional fixed bed flow reactor.

In the measurement force method, 22 of each catalyst was packed into a stainless steel reaction tube with an inner diameter of 16, and the pressure was 10 Kq/,..., H250t/hrH2080cc/hr, H2080cc/hr at a G1 temperature of 600°C.
20/H2-2 (molar ratio) and treated for 24 hours, and the surface area reduction rate of each catalyst before and after treatment was calculated as S/
8o as shown in Figure 1.

From FIG. 1, it can be seen that the inclusion of BaO in the catalyst is effective against sintering of the catalyst.

1” Tsukikai λ Catalyst A obtained in Comparative Example 1 and Example 1.5.

For B and F, changes in methanation activity when no steam was added were examined.

The reaction was carried out using a conventional high-pressure flow-type fixed bed reactor, and 0.22 of each catalyst was packed into a stainless steel reaction tube with an inner diameter of 'l6rrtrh, and the pressure was 10 K9/(,p'
The reaction was carried out at a gas temperature of 650°C for 100 hours, resulting in H260t/hr, CO20t/hr, and GH8v-2.
Determine the CO conversion rate at 70,000 hr-1 and apply the result to the second
Shown in the figure.

It can be seen from FIG. 2 that the deterioration of the catalyst is significantly reduced by containing BaO in the catalyst.

Table 1 shows the changes in physical properties of catalysts A, B, and F before and after the reaction, and by incorporating BaO into the catalyst,
It can be seen that carbon precipitation is effectively suppressed.

Examples Comparison' For catalysts A and B obtained in Comparative Example 1 and Example 1, changes in methanation activity when steam was added were investigated. The reaction apparatus was the same as in Experimental Example 2.

First, 022 of each catalyst was packed into a stainless steel reaction tube with an inner diameter of 16 mm, and the pressure was 10 Ky/c, p.
s H2O32, 1cc/hrXH20/Co = 2
C molar ratio), and the CO conversion rate at GH3V=270.00 units hr (dry gas basis) was determined. The CO conversion rate at this time was 100%. Next, after reacting for 100 hours at an inlet gas temperature of 600°C, the CO conversion rate was determined when the inlet gas temperature was lowered to 350°C again.

The inlet gas temperature after this high temperature reaction treatment at 600°C is 650°C.
The effect of BaO inclusion was evaluated based on the CO conversion rate at °C, the surface area reduction rate, and the amount of carbon precipitation.

The results are shown in Table 2.

Table 2 However, Table 2 shows that the inclusion of BaO suppresses sintering due to steam under high temperature conditions and prevents deterioration of activity.

As explained above, there is great promise in producing high-calorie gas by methanizing high-concentration CO gas such as heavy oil or coal gasification gas, but it has not yet been used under such reaction conditions. No suitable catalyst was available. The catalyst of the present invention, which is composed of alumina, nickel and barium oxide, exhibits little deterioration even under such reaction conditions, and has the advantage of being particularly heat resistant at high temperatures and high pressures in a steam atmosphere and having little carbon precipitation. Therefore, since the reaction can be carried out at a high temperature, the heat can be recovered as high-temperature steam, and energy efficiency can be improved.

[Brief explanation of drawings]

Figure 1 shows the surface area reduction rate (S/So) in Experimental Example 1.
A diagram showing the relationship between and BaO content (weight ratio), and the second
The figure shows the CO conversion rate (%) and reaction time (h
It is a figure showing the relationship with r). Patent Applicant JGC Corporation Agent Patent Attorney Tatsuo Ito Agent Patent Attorney Satoshi Ito Figure 1 0 2 4 6 8
IQBoo Mi4 [UP, (wt'/,)Fig.2 0 20 40 60 80
100 Anti-Civilization (hr) ・Electric medium A ○Resolution B ◇Unfriendly F Continued from page 1 0 Inventor Noon Yamada Inside Kinuura Research Institute, JGC Corporation, 2-110 Kununosaki-cho, Handa City 0 Inventor Akio Furuta 2-110 Shuunosaki-cho, Handa-shi, JGC Corporation Kinuura Research Institute Procedural Correction Teeth (Voluntary) 5 August 1981 Commissioner of the Japan Patent Office Kazuo Wakasugi '1. Indication of $f'r 1982 Patent Application No. 171059 2 Name of the invention Catalyst for methane synthesis and its manufacturing method 3 Relationship with the case of the person making the amendment Patent applicant address 2 Otemachi, Chiyoda-ku, Tokyo Chome 2-1 Name (/
I41) JGC Corporation Representative Shino 1) Osamu Osamu 4, Agent 105 Address Toranomon Electric Building, 2-8-1 Toranomon, Minato-ku, Tokyo Telephone (501) 9370 Subject of amendment: [Invention] ``Detailed Explanation Column'', Contents of the Amendment ■ In Mei Ia, page 6, line 4, ``Example'' is corrected to ``I Comparative Example''. ■ “Alumina 1 oog” in line 12 of the same page of the same book,
Corrected to "Alumina 1009". ■ After "'Bad" on page 8, line 10, "wo"
join.

Claims (1)

[Claims] 1. A catalyst for methane synthesis by hydrogenation of carbon oxide, characterized by comprising alumina, nickel, and barium oxide. 2. The above i permit, wherein the content of nickel is 3 to 60 parts by weight with respect to the total amount of alumina and nickel, and the content of barium oxide is 0.3 to 9.0 parts by weight with respect to alumina. A catalyst for producing methane by hydrogenating carbon oxide according to claim 1. 3. A method for producing a catalyst for methane storm synthesis by hydrogenation of carbon oxide, which comprises first supporting barium oxide and then supporting nickel oxide on alumina.