JPH02280836A - Preparation of catalyst for dimethyl ether synthesis - Google Patents

Abstract

PURPOSE:To obtain the title catalyst which suppresses reactions to produce by-products by precipitating a composite hydroxide of copper, zinc, and aluminum on a metal oxide or hydroxide carrier and stabilizing by sintering. CONSTITUTION:A composite hydroxide of copper, zinc, and aluminum as an active component for methanol synthesis is precipitated on an oxide or a hydroxide of aluminum, titanium, etc., having a methanol dehydration activity. Then, the precipitation product is filtered and sintered for stabilization. A catalyst prepared by this method accelerates methanol synthesis reaction and methanol dehydration reaction and suppresses by-product formation in the dehydration reaction in synthesis of dimethyl ether from CO and H2.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a catalyst for producing dimethyl ether from hydrogen and carbon oxide.

[Conventional technology]

Generally, the process of synthesizing gasoline from synthesis gas such as CO, H, etc. has not yet been fully established and has many problems. For example, in the FT process, products are produced over a wide range, so it is necessary to reform the products in order to obtain a gasoline fraction, and in addition, in the MTG process (synthesis gas → methanol → gasoline), methanol synthesis is It has problems such as low methanol yield due to thermodynamic plateau control. - In gasoline synthesis via dimethyl ether as a reaction intermediate, the dimethyl ether conversion reaction of synthesis gas is not bound by thermodynamic equilibrium control;
It is a process that has been attracting attention in recent years because it can produce dimethyl ether in high yield.

In general, catalysts for producing methanol from CO%H are widely referred to as steel-zinc systems. On the other hand, Co.

Catalysts for converting H into dimethyl ether include FT reaction catalysts, but they have poor selectivity and short lifespans. Furthermore, since dimethyl ether is produced by completely dehydrating methanol, one method is to mix a methanol synthesis catalyst and a methanol dehydration catalyst.
It has problems such as a short catalyst life due to side reactions such as C precipitation, and is currently not practical as a catalyst.

[The problem that the invention attempts to solve]

The reasons for the deterioration of the mixed catalyst are that the optimal reaction conditions of the methanol synthesis catalyst and the methanol dehydration catalyst are different;
When both catalysts are mixed in the same reactor and dimethyl ether t-S is produced from Co and islands through the sequential reaction of methanol synthesis reaction and methanol dehydration reaction, side reactions such as dimethyl ether decomposition reaction and F-T reaction are noticeable. It is thought that the catalyst deteriorates rapidly due to C precipitation, wax adhesion, etc.

In view of the above-mentioned state of the art, the present invention has been made to provide a catalyst that allows the sequential reactions of methanol synthesis reaction and methanol dehydration reaction to occur more quickly when dimethyl ether is produced from Co, H, and can particularly suppress side reactions occurring during the latter reaction. The aim is to provide a manufacturing method for

[Means for solving line problems]

The present invention relates to a method for producing a catalyst for synthesizing dimethyl ether from hydrogen and carbon monoxide, in which gold Jf411! has methanol dehydration activity! A method for producing a catalyst for dimethyl ether synthesis, which comprises precipitating a composite hydroxide of steel, zinc, and aluminum, which is an active ingredient in methanol synthesis, on a compound case or a hydroxide carrier and stabilizing it by calcination. be.

In producing the catalyst of the present invention, it is preferable to use at least one oxide or hydroxide selected from aluminum, titanium, tin, iron, and zirconium as a carrier.

[For production]

According to the present invention, it is possible to produce a catalyst in which the methanol synthesis reaction conditions and the methanol dehydration reaction conditions are the same.

The method for producing the catalyst of the present invention will be explained in more detail.

1. tl that has methanol dehydration reactivity! An acidic water bath solution that uses a catalyst oxide or hydroxide as a carrier and contains methanol synthesis active ingredients such as copper, zinc, and aluminum (nitrates, sulfates, and chlorides).

This is carried out by adding the above-mentioned carrier to a water solution such as acetate, and adding an alkaline water bath solution such as sodium carbonate, acidic sodium carbonate, ammonia, or caustic soda water bath solution.

At this time, the upper api carrier becomes the core during precipitation formation.

The oxide or hydroxide of the acid catalyst used in the production of the catalyst of the present invention is preferably as fine as possible. Furthermore, when precipitating composite hydroxides of copper, zinc, aluminum, etc. on an acidic carrier, the precipitates should be deposited as much as possible inside the pores of the substrate, so that the entire surface layer of the substrate is covered with the precipitates. It is preferable.

The quantitative relationship of the active ingredients copper, zinc, and aluminum is as follows: atomic ratio of 100 parts for steel, 400 to 10 parts for zinc, and 1 part for aluminum.
00 to 2 are preferred.

The catalyst of the present invention will be explained in detail in the following examples.

[Example 1] Copper nitrate (Cu(NO3)2 ・3H20: α5 mol
], zinc nitrate [Zn(Nose, -6H,O:α2
25 mob], aluminum nitrate (ht(Nos)
s: αO 75 mol) f 2 t T/C of the same water. To the obtained acidic water bath solution, α 1 mol of 7-k1203 finely ground to 300 mesh or less was added and stirred. This suspended acidic aqueous solution was designated as A.

10,000, soak 0g of NalC in water, adjust IM image density,
This alkaline water bath liquid is designated as Bg.

Ay and B solutions were kept at 80°C, and AQ and B were placed in separate beakers kept at 80°C to maintain pH = 7 during neutralization.
g at a constant rate.

Constantly stir the precipitate that forms during the dropping of both liquids to improve the dispersibility of the dropped liquid. The dropping time was 50 minutes, and then aging was performed for 2 hours.

After aging, the precipitate is filtered, washed so that Na ions and No31 ions are not detected, and dried at 100° C. for 24 hours. Furthermore, the dried hydroxide was calcined at 300C for 5 hours and used as a catalyst for dimethyl ether synthesis. This catalyst is catalyst a
shall be.

[Example 2] A catalyst for dimethyl ether synthesis was prepared in the same manner as in Example 1, except that α2 mol of anatase form Tie ground to 300 mesh or less was added to Solution A of Example 1. Let us say that this catalyst is used as a catalyst. Furthermore, iron oxide (FexOs) finely ground to 300 mesh or less is added to liquid A.
)stin oxide (Snow), zirconium oxide (Zr
O2 positive crystal type) was added to each jr (L 1mol, (L2mO
The catalyst was prepared in the same manner as in Example 1 by adding 2 mol of 1, [L] to obtain catalyst C1, catalyst d, and catalyst e.

[Example 3] Nitrate fRm<α5 mol), zinc nitrate (12mob
), Aluminum nitrate A ((L 1 mob) 1 was dissolved in 2 tons of the same water, and r-Az, os was cooled to prepare an acidic water bath solution A' in the same manner as in Example 1. Next catalyst ft-Tokuji.Furthermore, nitric acid steel (12mob
), zinc nitrate ([L2mol), aluminum nitrate (α
Catalyst gt-1 was prepared in the same manner as in Example 1 using nitrate steel (αS 5 mob ), zinc nitrate ((L 1 mob )%, aluminum nitrate (105
y4 catalyst was prepared in the same manner as in Example 1 using Mob) T-.

[Example 4] Using the same preparation method as in Example 1, γ-At and O were added to solution A.

(L 2 mol, (L 05 mob) was added to an acidic suspension to obtain catalyst 1,j.

[Example 5] Aluminum hydroxide (At
An acidic suspension containing α1 mol and α2 m04 of (oH)m) was prepared to give t to the catalyst.

[Comparative Example 1] Cu0-ZrO-A120H-based methanol synthesis catalyst (C
u:Zn:At=100 near 5:25 (atomic ratio)] and r
- Methanol dehydration catalyst which is At2o3'i70:30
(weight ratio) of fine powders of 300 mesh or less were mixed to obtain catalyst m.

[Experimental Example 1] An activity evaluation test for the dimethyl ether synthesis reaction of the friend catalysts a to m obtained in Examples 1 to 5 and Comparative Example 1 was conducted under the following conditions.

GH8V 8000h" Reaction temperature 250℃ Reaction pressure 50 kg/ctn"G Catalyst is 16-28 mesh and 2 cc
After filling a microreactor and performing reduction treatment with %H, 3%/Nl gas, raw material gas was supplied and initial activity evaluation was performed. Table 1 shows the initial activity evaluation results for each catalyst.

From the above results, catalysts a to t obtained according to the present invention are catalysts m
It can be seen that the initial CO conversion rate is higher than that of

[Experimental Example 2] Catalysts a and m used for initial activity evaluation were used as catalysts for durability testing. The reaction conditions are as follows.

Temperature 250℃, pressure 50kp/cIr? G, GH8
V 4000h-”H@/Co:2 The activity results are shown in Table 2.

Table 2 As shown in Table 2, it can be seen that the catalyst prepared according to the present invention is significantly more durable than the conventional mixed catalyst.

Claims (1)

[Claims] 1. In a method for producing a catalyst for synthesizing dimethyl ether from hydrogen and carbon monoxide, copper, which is an active component for methanol synthesis, is placed on a metal oxide or hydroxide carrier having methanol dehydration activity; A method for producing a catalyst for dimethyl ether synthesis, characterized by precipitating a composite hydroxide of zinc and aluminum and stabilizing it by calcination. 2. The method for producing a catalyst according to claim 1, wherein the catalyst carrier has a composition of at least one oxide or hydroxide selected from aluminum, titanium, tin, iron, and zirconium. .