CN88100604A - Load type cu-zn base methyl alcohol-disolving catalyzer - Google Patents

Abstract

With the aluminium oxide is carrier, and copper, zinc are the 1st composition, and nickel is the 2nd composition, and alkali metal or alkali earth metal are the 3rd composition, and a kind of supported non-precious metal catalyst system that adopted immersion process for preparing.For methanol decomposition reaction, this catalyst system has good low-temperature reactivity, selectivity and resistance to elevated temperatures.In 100 hours continuous running, catalyst performance stabilised.

Description

The invention belongs to chemical method, Preparation of Catalyst field, a kind of base metal carbinol resolving catalyst system with premium properties is provided.

Rich coal resources in China.Coal is changed into liquid methanol act as a fuel and industrial chemicals, have wide practical use to replace oil.Moreover, can be under the effect of catalyst and cryogenic conditions with Methanol Decomposition, catabolite hydrogen (H ₂) and carbon monoxide (CO) in chemical industry, metallurgy, mechanical industry, aspects such as internal combustion engine and fuel cell have been widely used.Methanol Decomposition is the endothermic reaction, and available waste heat is as the heating source of catalyst bed.

Methanol Decomposition generates H under catalyst action ₂In the time of with CO, also follow and carry out multiple side reaction (exothermic reaction), generate dimethyl ether (CH ₃OCH ₃), methane (CH ₄), water (H ₂O), carbon dioxide (CO ₂), free charcoal (C) etc.In order to suppress side reaction, catalyst should have good selectivity.When utilizing I. C. engine exhaust used heat for heating source, delivery temperature can be high to 800 ℃, thereby catalyst should have heat resistance.

Carbinol resolving catalyst now commonly used be copper-based catalysts and VIII family metallic catalyst [for example: United States Patent (USP) 4,499,863(1985); United States Patent (USP) 4,431,566(1984); Day disclosure special permission communique, clear 57-68140(1982); Catalyst (day) Vol.27, No.8,563(1985); Catalyst (day) Vol.28, No.3,195(1986); The energy and energy-conservation, No.4,16(1985)].Copper-based catalysts commonly used is the CuZn industrial catalyst of the synthetic usefulness of methyl alcohol.This catalyst has good low temperature active and good selectivity, but it is heat-resisting, anti-wear performance is poor.Accessory substance methyl formate (the HCOOCH that more amount is arranged under 250 ℃ of left and right sides temperature in addition, ₃) generate.In the VIII family metallic element, platinum (Pt), palladium (Pd), rhodium (Rh), nickel (Ni) have high reaction activity and high and heat resistance to Methanol Decomposition, but under hot conditions when reaction easily generate CH ₄Deng accessory substance.In addition, noble metal itself is uneconomical.

The objective of the invention is to prepare a kind of base metal carbinol resolving catalyst system with premium properties.Use this system, Methanol Decomposition can be generated H selectively ₂And CO, and suppress CH significantly ₃OCH ₃, CH ₄, CO ₂, HCOOCH ₃Generation Deng accessory substance.Catalyst system of the present invention in addition also should have good low-temperature reactivity, good resistance to elevated temperatures and feature such as stable performance in long-term the use.

Catalyst of the present invention is to have heat resistance, high-intensity aluminium oxide (Al ₂O ₃) be carrier, be principal component with copper, zinc (Cu, Zn), nickel (Ni), alkali metal or alkaline-earth metal (Me) they are adding ingredient, with the support type CuZn-Ni-Me-Al of immersion process for preparing ₂O ₃The non-precious metal catalyst system.The retrieval U.S. " chemical abstracts " is (1967-1987) (CA), does not see the bibliographical information that the catalyst of same composition is arranged with catalyst system of the present invention.

Content of the present invention is described in detail as follows.

Catalyst is the Al with φ 2-4mm ₂O ₃Particulate vector is put into nitrate aqueous solution dipping, the drying of required metal element content and is made after 550 ℃ of roastings of air.Get 15 milliliters of catalyst and pack in the stainless steel reactor, handle back feeding methanol vapor (liquid air speed LHSV=5.6h through reduction ^-1), preliminary treatment is 3 hours under 310 ℃ of bed temperatures.Subsequently, measuring conversion of methanol and product down at different bed temperature (calling reaction temperature in the following text) forms.According to measured conversion ratio and product composition data the performance of catalyst is made an appraisal.

The present inventor has at length studied the performance of above-mentioned catalyst in the methanol decomposition reaction.Result of study shows that the content of each composition is in following ranges in the catalyst system of the present invention, and promptly 0.3＜CuZn total amount＜6.0(mM/1 restrains Al ₂O ₃), 0.20＜Cu/Zn＜50(mol ratio), 0.05＜Ni＜4.0(mM/1 gram Al ₂O ₃), 0.1＜Me＜3.0(Me is alkali metal, alkali earth metal, as Na, K, Mg, Ca) (mM/1 gram Al ₂O ₃) condition under, methanol decomposition reaction is had good low temperature active and selectivity.CH ₃OCH ₃, CH ₄, CO ₂, HCOOCH ₃Deng accessory substance do not generate or growing amount seldom, product mainly is H ₂And CO.And this catalyst system has heat resistance and service life preferably.

Example 1:

Containing CuZn total amount 2 mMs/1 gram Al ₂O ₃, the Cu/Zn=0.43(mol ratio), Ni measures 0.5 mM/1 gram Al ₂O ₃Reach on the different catalyst of adding ingredient Me, carry out methanol decomposition reaction.Conversion of methanol and product composition is listed in table 1 during 300 ℃ of reaction temperatures.

All have good reactivity when as shown in Table 1, methyl alcohol reacts on each catalyst and decompose selectivity.Conversion of methanol 〉=82% during 300 ℃ of reaction temperatures; Contain a small amount of CH in the product when removing with Mg ₃OCH ₃(3.5%) outside, when using remaining to add element (Na, K, Ca) in the product by-products content be H basically seldom ₂And CO.

Example 2:

To contain CuZn total amount 2 mMs/1 gram Al ₂O ₃, the Cu/Zn=2.33(mol ratio), Ni and K content are 0.5 mM/1 gram Al ₂O ₃Catalyst respectively 550 ℃, 650 ℃ and 750 ℃ of roasting temperatures 3 hours, carry out methanol decomposition reaction by preceding method then.The relation of conversion of methanol and sintering temperature is listed in table 2 under the differential responses temperature.

All has good low temperature active when as shown in Table 2, methyl alcohol reacts on the baked catalyst in 550-750 ℃ of temperature range.When sintering temperature more than 650 ℃ the time, though the low temperature active of methyl alcohol reaction has decline slightly, drop-out value is little, and actively keeps stable.

Table 1:

Example 3:

Get with table 2 in numbering 5 have urging of same composition, identical preparation condition to do 15 milliliters of agent, after reduction is handled, at liquid methanol air speed (LHSV) 5.6h ^-1, 380 ℃ of furnace temperature condition under the Methanol Decomposition of carrying out 100 hours turn round continuously, its result is as follows.

Initial reaction stage, methanol conversion was 85% when reaction temperature was 275 ℃, and reaction temperature rises gradually subsequently, and methanol conversion is low gradually.Methanol conversion is stabilized in 80% after a few hours running, and reaction temperature is stabilized in 296 ℃, and product has only H ₂And CO.Till experiment in 100 hours finished, methanol conversion and product composition did not all change in running after this.In addition, found no carbon deposit through 100 hours on the used catalyst.

The catalyst carrier that the present invention uses, particle-removing shape Al ₂O ₃Outward, also can be strip, cellular and tabular Al ₂O ₃

Catalyst of the present invention can be with carrier disposable dipping preparation in the slaine mixed aqueous solution of required composition, also can be that carrier is flooded preparation successively in succession in the individual metallic saline solution of required composition.

Claims (5)

1, a kind ofly is used for (H with Methanol Decomposition Cheng Qing ₂) and the catalyst system of carbon monoxide (CO), it is characterized in that with Al ₂O ₃Being carrier, is principal component with copper, zinc (Cu, Zn), and nickel (Ni), alkali metal or alkaline-earth metal (Me) are adding ingredient, by the supported non-precious metal catalyst system of immersion process for preparing.

2, catalyst system according to claim 1 is characterized in that Al ₂O ₃The shape of carrier can be graininess, strip, cellular or tabular.

3, catalyst system according to claim 1 is characterized in that each component content: 0.3＜CuZn total amount＜6.0(mM/1 gram Al ₂O ₃), 0.20＜Cu/Zn＜50(mol ratio), 0.05＜Ni＜4.0(mM/1 gram Al ₂O ₃), 0.1＜Me＜3.0(mM/1 gram Al ₂O ₃) (Me is alkali metal or alkali earth metal).

4, catalyst system according to claim 1, it is characterized in that also can being that carrier is flooded preparation successively in succession in each other aqueous metal salt of required composition with carrier disposable dipping preparation in the slaine mixed aqueous solution of required composition.

5, catalyst component according to claim 3 is characterized in that Me is a kind of element among alkali metal Na, the K or the mixture of the two; Or a kind of element among alkali earth metal Mg, the Ca or the mixture of the two; Or the mixture of above-mentioned alkali metal and alkali earth metal.