JP2941022B2 - Method for producing liquid hydrocarbons from CO2 and H2 - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an industrial method for obtaining liquid hydrocarbons usable as a liquid fuel from CO ₂ and H ₂ at once.

2. Description of the Related Art In recent years, global warming due to the accumulation of CO ₂ has become a serious environmental problem, and there is an urgent need to reduce CO ₂ emissions. If CO ₂ can be converted to useful components such as liquid fuel and recycled, the problem of global warming and the saving of petroleum resources can be achieved all at once.

For obtaining a methanol by catalytic hydrogenation of CO ₂ <Synthesis of methanol by catalytic hydrogenation CO _2> have been made various proposals, also progressed the study of methanol synthesis catalyst therefor. Examples of the catalyst for this purpose include oxide catalysts, metal catalysts, and alloy catalysts as listed below.

Oxide-based catalyst _{ZnO, ZrO 2, Cu / ZnO} , Cu / oxide, Cr 2 O 3 / ZnO, Cu / ZnO / oxide, Cu / Zno / Al 2 O 3, ZnO / oxide metal catalyst Pd, Pt or Re Supports as follows: Al ₂ O ₃ , T
hO ₂ , SiO ₂ , La ₂ O ₃ , Nb ₂ O ₅ , MgO, Sm ₂ O ₃ , TiO ₂ , ZrO ₂ , Nd
Supported on ₂ O ₃ , Y ₂ O ₃ , In ₂ O _3, etc. Alloy catalyst Al-Cu-Zn Raney alloy, rare earth-Cu alloy, Nd-Cu
Etc. The synthesis catalysts of hydrocarbons from <Liquid hydrocarbon synthesis of hydrogen from methanol> methanol, in _{JP-A-53-58499, M 2 / n O:} Al 2 O 3: (8~50) SiO 2 (M is a cation having a valence of n), and there is a report using a crystalline aluminosilicate zeolite catalyst having a specific X-ray powder diffraction pattern and a specific n-hexane adsorption ability.

The present inventors have filed a series of applications as shown below.

& JP 57-63135 discloses crystalline aluminosilicate zeolite catalyst, _{i.e., M 2 / n O: Al} 2 O 3: (8~70) SiO 2 (M is a cation of valence n) has a composition of Using a catalyst having a specific X-ray powder diffraction pattern and a specific crystalline morphology.

Patent Document 1: JP-A-57-144038 Crystalline aluminosilicate zeolite catalyst, that is, SiO ₂ / Al ₂ O ₃ = 8 to 70, OH ⁻ / SiO ₂ = 0.2 to 1.6, H ₂ O / SiO ₂ = 10 to 30, M / SiO ₂ = 0.2 to 1.7, R / SiO ₂ = 0.0086 to 0.20, R / M + R = 0.0005 to 0.40, K ₂ O / M ₂ O = 0.05 to 0.3 (where R is A tetraalkylammonium cation wherein the alkyl group is methyl or ethyl and M is the valence n
And a catalyst obtained by adding an aggregate or a crystal growth nucleus supporting a metal or a metal oxide to a mixture which is a cation and an alkali metal ion).

JP-A-59-62348 Amine-modified high silica zeolite catalyst, that is, Si / A
Uses a high silica zeolite with a molar ratio of 100 to 3200, treated with organic amine vapor having a molecular size that does not easily enter the catalyst pores.

JP-A-59-62349 A high silica zeolite catalyst, that is, a liquid A comprising an aqueous solution containing an Al salt, a nitrogen-containing organic cation and an inorganic acid, a liquid B comprising an aqueous silicate solution, and a liquid C comprising an aqueous ion conditioner solution The catalyst is manufactured by a specific method using the liquid.

& JP 59-136386 discloses high silica zeolite catalyst, i.e., a composition molar ratio, Si / Al = 15 or _{^{higher, OH - / SiO 2 = 0.3~1.0}} , H 2 O / SiO 2 = 30~100, R / R + M = 0.05~0.15, NaCl / H 2 O = 0.01~0.06 ( wherein, R quaternary alkylammonium cation, M
Is a Na or K ion) when the methanol is contacted with a high silica zeolite catalyst represented by the following formula:
A small amount of olefin or alcohol or alcohol precursor that easily produces olefin in the reaction process.

JP-A-60-12135 Metallosilicate catalyst, that is, in the high silica zeolite catalyst, instead of Al, Ga, Ti, Zr, Ge, La, Mn,
Use catalyst with Cr, Sc or V.

In addition, the Journal of Cat
alyst, 98 , 491-501 (1986) discloses a method for obtaining hydrocarbons from methanol using an H-type iron-silicate catalyst.

Problems to be Solved by the Invention Various studies have been made on the synthesis of methanol by catalytic hydrogenation of CO ₂ as described above, and various studies have been made on the synthesis of hydrocarbons from methanol as described above. .

However, the use of the reactants obtained by catalytic hydrogenation of CO ₂ as raw materials for the synthesis of hydrocarbons is still in an unsuccessful stage. This is because the output gas after the first-stage catalytic hydrogenation of CO ₂ contains a large amount of unreacted substances (especially H ₂ ), so that the hydrogenation is carried out during the second-stage hydrocarbon synthesis reaction. Is the priority, and the intended reaction does not proceed smoothly.

Among the above-mentioned catalysts for synthesizing liquid hydrocarbons from methanol, the crystalline aluminosilicate zeolite catalyst disclosed in JP-A-53-58499 has a C ₁ -C ₄ even when methanol is used as a starting material. Only hydrocarbons are obtained.

Crystalline aluminosilicate zeolite catalyst disclosed in JP 57-63135 and JP 57-144038 discloses, even with methanol as the starting material, only to hydrocarbon virtually C ₁ -C ₄ without conversion, the selectivity of C ₅ or more, a liquid hydrocarbon about 5-9% and less.

Amine-modified high silica zeolite catalyst disclosed in JP-A-59-62348, JP-A-59-62349 and JP-A-59-1
When using a high-silica zeolite disclosed in 36386 JP, C ₅ or more aliphatic substantial amounts and aromatic hydrocarbons which was used metallosilicate catalyst disclosed in JP-A-60-12135 Similarly, when C ₅ or more aliphatic and aromatic hydrocarbons considerable amount can be obtained. However, according to studies by the present inventors, even with these catalysts, the inclusion of a large amount of H ₂ in addition to methanol in the starting material occurs preferentially hydrogenated olefin selectivity and liquid hydrocarbons Hydrogen selectivity decreases significantly.

Journal of Catalyst, 98, The method according to 491-501 (1986), H-type iron - although to obtain hydrocarbons from methanol using a silicate catalyst can be applied to methanol containing H ₂ in a large amount There is no disclosure as to whether or not.

In this background, the present invention has been made to provide an industrial method for obtaining a liquid hydrocarbon usable as a liquid fuel from CO ₂ and H ₂ at once.

Preparation of liquid hydrocarbons from CO ₂ and H ₂ means the present invention for solving the problems, CO ₂ and H 2 at a mixing ratio of ₂ molar ratio: 8-7: CO ₂ in the range of 3 and a mixed gas of H ₂ as a main component is supplied to the first reactor, the first to be converted to a gas rich in methanol by contact with the _{CuO-ZnO-Cr 2 O 3} -Al 2 O 3 based catalyst reduction treatment A second step of continuously supplying a gas derived from the first step to a second reactor and converting the gas into a component rich in liquid hydrocarbons by contact with an H-type Fe-silicate catalyst; and CuO-ZnO-Cr ₂ O ₃ prepared by reducing treatment in the first step
-Al ₂ O ₃ based composition CuO 15 to 35 wt% of the pre-reduction treatment of the catalyst, ZnO 20 to 50 wt%, Cr ₂ O ₃ 0.6~ 5% by weight, an Al ₂ O ₃ 25 to 40 wt%, and CuO-ZnO-Cr ₂ O was the reduction treatment ₃ -Al ₂ O ₃
The system catalyst was gelled by contacting an aqueous solution of a water-soluble salt of Cu, Zn, Cr and Al with NH ₃ gas in a stationary state, dried, calcined, and further reduced with H ₂ before use. It is characterized by being a thing.

 Hereinafter, the present invention will be described in detail.

Source gas As the source gas, a mixed gas containing CO ₂ and H ₂ as main components is used.

Of these, CO ₂ is produced from combustion gas, natural gas, petroleum refinery gas, ammonia synthesis by-product gas, coke oven gas, etc. discharged from power plants and steelworks, using membrane separation, pressure swing separation, absorption separation, etc. Can be obtained separately.

H ₂ is, H ₂ obtained by electrolysis of water, such as H ₂ supplied from other processes or other plant in the plant can be used.

The mixing ratio of CO ₂ and H ₂ is theoretically set to 1: 3 in molar ratio, but a range of 2: 8 to 7: 3 is acceptable. When containing CO, the ratio of CO ₂ may be appropriately adjusted and then supplied as a source gas.

Note that the source gas may contain components other than CO ₂ and H ₂ , such as N ₂ , CO, H ₂ O, hydrocarbons, alcohols, etc., as long as the gist of the present invention is not impaired. However, it is desirable to remove sulfur-containing compounds and nitrogen oxides that may become catalyst poisons and O _{2 that} may delay the reaction rate to below the allowable limit.

First Step The first step is performed when the mixing ratio of CO ₂ and H ₂ is 2: 8 to 7:
A mixed gas mainly composed of CO ₂ and H ₂ in the range of 3 is supplied to the first reactor, and the reduced CuO—ZnO—Cr ₂ O ₃ —Al ₂
This is a step of converting into a gas rich in methanol by contact with an O ₃ -based catalyst.

The catalyst used in this first step, that is,
The _{CuO-ZnO-Cr 2 O 3} -Al 2 O 3 catalyst, used as prepared in the following manner.

That is, first, a water-soluble salt (eg, nitrate) of Cu, Zn, Cr and Al is dissolved in water to prepare an aqueous solution. The order of salt addition is arbitrary. It is desirable that the salt concentration be as high as possible.

Next, this aqueous solution is brought into contact with NH ₃ gas in a stationary state to cause gelation. The temperature of the aqueous solution is usually from room temperature to about 70 ° C., preferably about 50 to 60 ° C. NH ₃ catalyst with gas, a method using NH ₃ gas, NH ₃
A method of evaporating NH ₃ gas from water is used. In any case, it is preferable that the aqueous solution itself is not substantially stirred and the NH ₃ gas is absorbed from the surface of the aqueous solution. The gelation is carried out at normal pressure, but slight pressure may be used.

After gelation, after drying, at high temperature (for example, 300
(At about ~ 500 ° C) and perform tableting, crushing, sieving, etc. as necessary.

Thereafter, a reduction treatment is performed with H ₂ (usually using H ₂ diluted with an inert gas such as N ₂₎ before further use.

The above-mentioned method has a significantly higher activity than a catalyst obtained by the ordinary coprecipitation method using the same material.

The composition of the pre-reduction treatment of the reduction-treated _{CuO-ZnO-Cr 2 O 3} -Al 2 O 3 type catalyst, when the total amount of the components to 100 wt%, CuO 15 to 35 wt%, ZnO. 20 to 50 wt%, Cr ₂ O ₃ 0.6~ 5% by weight, is set to Al ₂ O ₃ 25 to 40 wt%, optimal CO ₂ conversion and methanol selectivity is obtained in such a composition.

The above catalyst can be modified by further adding Pd. Modification with Pd contributes to an increase in CO ₂ conversion and an increase in methanol selectivity. The addition of Pd
The Al ₂ O ₃ component of the O—ZnO—Cr ₂ O ₃ —Al ₂ O ₃ based catalyst is reduced, and the reduced amount of Al ₂ O ₃ (usually using γ-alumina) is subjected to the usual impregnation method. Impregnated with a water-soluble salt of Pd and dried, and then thermally decomposed and reduced with hydrogen to obtain CuO-ZnO.
-Cr ₂ O ₃ -Al in ₂ O ₃ catalyst may be physically mixed. The amount of Pd added is about 0.5 to 8% by weight of the whole catalyst, especially 1 to 7%.
It is appropriate to occupy the weight%. When the ratio is too small, the effect of adding Pd is not sufficiently obtained, while when the ratio is too large, the effect is accompanied by sintering of Pd. There is a possibility of reduction, and the cost of the catalyst becomes extremely high, which impairs practicality. Note that Rh or Ru can be used instead of Pd, but Rh
In the case of, there is a reaction inhibitory action, the CO ₂ conversion rate decreases, and Ru
Although remarkably improves CO ₂ conversion, methane is liable to be generated due to a marked decrease in methanol selectivity, and thus is less practical than Pd.

Reduction treatment of _{CuO-ZnO-Cr 2 O 3} -Al 2 O 3 catalyst (including those with added Pd) is used diluted with H ₂ in an inert gas such as N _2, temperature 200 to 600 ° C. The treatment is performed for several minutes to several hours (for example, 10 minutes to 5 hours).

The inside of the first reactor is packed with the above catalyst as a fixed bed or a fluidized bed. Note that the above reduction treatment is performed using CuO-ZnO
-Cr ₂ O ₃ -Al ₂ a O ₃ catalyst may be performed after filling the reactor. This reactor is configured to be heatable.

The reaction pressure in the first step is about 20 to 120 atm, especially 3
About 100 to 100 atm, reaction temperature is 150 to 300 ° C, especially 200 to 280
C is appropriate. If the pressure is too low, the CO ₂ conversion and methanol selectivity decrease, and if the pressure is too high, there is a disadvantage in terms of equipment cost and energy cost. If the temperature is too low, the CO ₂ conversion and methanol selectivity decrease, and if the temperature is too high, the methanation reaction occurs preferentially and there is an energy disadvantage.

A part of the product obtained through the first step can be recycled before the first reactor.

Second step In the second step, the gas derived from the first step is continuously supplied to the second step.
This is a step of supplying to a reactor and converting it into a component rich in liquid hydrocarbons by contact with an H-type Fe-silicate catalyst.

Here, the H-type Fe- silicate catalyst structure code of the International Zeolite Association is a kind of zeolite having a crystal structure of the MFI type, H portion of Si element was isomorphous replacement in Fe _n [Fe _n Si _(96-n) O ₁₉₂ ] (here, 0.2 <n <4) zeolite having weak acid properties.

The catalyst used in the second step, i.e. H-shaped Fe- silicate catalyst, a water-soluble Fe salt, containing a nitrogen-containing organic cations and inorganic acid solution G ₁ and silicate solution G ₂ and the ion modifier vigorous stirring was added to the aqueous solution G _3, the resulting precipitate gel crushed to be separated, then which was hydrothermal synthesis in an inert gas atmosphere, after washing the obtained crystals were dried,
After firing at a higher temperature, an ion exchange reaction is performed using an aqueous solution of ammonium nitrate, washing and drying are performed, and then firing is performed in air. Here, as the nitrogen-containing organic cation, tetrapropylammonium bromide, tetramethylammonium hydroxide,
Tetraethylammonium hydroxide or the like is used, sulfuric acid or the like is used as an inorganic acid, and sodium chloride or the like is used as an ion adjuster.

When you get a large H-type Fe- silicate catalyst of the Fe content is more silicon salt solution and ammonia water of SiO ₂ content was admixed to an aqueous solution of water-soluble Fe salt, an operation similar to the formed precipitate gel per above It should be applied.

The inside of the second reactor is filled with the above catalyst as a fixed bed or a fluidized bed. This reactor is configured to be heatable.

The reaction pressure in the second step is usually set to normal pressure,
If necessary, the reaction may be performed under increased or reduced pressure. The reaction temperature is suitably from 250 to 400 ° C, especially about 270 to 350 ° C. If the temperature is too low, the conversion will be low, and if the temperature is too high, it will be energetically disadvantageous and the liquid hydrocarbon selectivity will decrease.

In the reaction of the second step, a lower olefin, a part of a product derived from the second reactor, a cyclic olefin or an olefin-producing easy alcohol can be additionally supplied before the second reactor, whereby the liquid Hydrocarbon selectivity is improved.

Here, examples of the lower olefin include ethylene, propylene, butylene, and isobutylene. Since the output from the second reactor also contains a lower olefin,
This lower olefin will be utilized. Examples of the cyclic olefin include cyclohexene. Examples of the olefin-producing alcohol include ethanol, isopropanol, allyl alcohol, and cyclohexanol, and these alcohols are converted to olefins on the catalyst surface.

Action In the first step, a reaction of mainly CO ₂ + 3H ₂ → CH ₃ OH + H ₂ O takes place, and various by-products (hydrocarbons such as CO and methane, alcohols of C _{2 to} C ₄ , A mixture of dimethyl ether and the like, especially CO and CH ₄ ) and a large amount of unreacted substances are present.

When a catalyst to which Pd is added is used as the catalyst in the first step, the CO ₂ conversion and the methanol selectivity are improved at the same pressure.

In the second step, a C ₂ -C ₆ saturated or unsaturated aliphatic hydrocarbon is synthesized from methanol, and an aromatic component is also produced. For H-type Fe- silicate catalyst having a moderately weak acid, even though the intermediate of H ₂ unreacted some large excess is hardly subjected to hydrogenation. Even when a lower olefin, a part of the product derived from the second reactor, a cyclic olefin or an olefin-producing alcohol is additionally added before the second step, the hydrogenation of the olefin is not promoted, but rather, the reaction proceeds autocatalytically. It is believed that oligomerization is promoted.

EXAMPLES Next, the present invention will be further described with reference to examples.

Example 1 Production of Catalyst for First Step A catalyst for the first step was produced as follows.

_{Cu (NO 3) 2 · 3H} 2 O, Zn (NO 3) 2 · 6H 2 O, Cr (NO 3)
_{3 · 9H 2 O, Al (} NO 3) 3 · 9H 2 O and water, respectively 3.82
g, 7.57 g, 0.29 g, 11.83 g, and 50.0 g were weighed, and these salts were dissolved in water to prepare 73.5 g of a high-concentration aqueous solution. The percentages of each component are as follows.

_{Cu (NO 3) 2 · 3H} 2 O 5.2 _{wt% Zn (NO 3) 2 ·} 6H 2 O 10.3 _{wt% Cr (NO 3) 3 ·} 9H 2 O 0.4 _{wt% Al (NO 3) 3 ·} 9H 2 O 16.1 68.9% by weight of water 68.9% by weight Total 100% by weight 73.5 g of this aqueous solution was put in a tray and allowed to stand in a constant temperature bath at a temperature of 60 ° C. Further, a tray containing 150 ml of 28% by weight ammonia water in the constant temperature bath was placed in the tray. And left for 15 minutes. Thereby, the volatilized NH ₃ gas was absorbed into the aqueous solution, and the aqueous solution gelled.

After the obtained gel was dried at a temperature of 120 ° C. overnight, the temperature was raised from room temperature to 150 ° C. over 30 minutes in an air atmosphere, and then from 150 ° C. to 350 ° C. over 2 hours.
Baking at 0 ° C. for 3 hours.

After leaving the calcined product to cool, it was compressed into tablets, crushed, and sieved to obtain a 10 to 24 mesh portion.

Accordingly, CuO 25.0 wt% ZnO 41.5 wt% Cr ₂ O ₃ 1.2 wt% Al ₂ O ₃ 32.3 _{wt% CuO-ZnO-Cr 2 O} 3 having a composition of -Al ₂ O ₃ catalyst was obtained.

Then, the catalyst was filled into a stainless steel tube, and 1% by volume H ₂ gas diluted with N ₂ was passed through at a flow rate of 100 ml / min, and reduced at room temperature to 500 ° C. for 1 hour, and further reduced at 500 ° C. for 30 minutes. Processed.

Production of Catalyst for Second Step A catalyst for the second step was produced as follows.

_{FeCl 3 · 6H 2 O 0.22g,} H 2 SO 4 3.38ml, tetrapropylammonium bromide 5.75 g, NaCl 11.95 g and water 60
an aqueous solution G ₁ consisting ml, water glass 69 g, and an aqueous solution G ₂ consisting of water _{45ml, NaCl40.6g, H 2 SO 4} 1.55ml, tetrapropylammonium bromide 2.16 g, NaOH 2.4 g and water
It was added to an aqueous solution consisting of 208 ml and stirred vigorously at room temperature while maintaining the pH at 9-11. The resulting precipitated gel was separated by centrifugation and crushed for 1 hour.

Separately, water _{60ml, FeCl 3 · 6H 2 O} 0.23g, H 2 SO 4 3.38ml,
An aqueous solution consisting of 7.53 g of tetrapropylammonium bromide, an aqueous solution consisting of 45 ml of water and 6.0 g of water glass,
A mixed aqueous solution was prepared by adding to an aqueous solution consisting of 104 ml of water and 26.3 g of NaCl, and a supernatant of the aqueous solution was obtained.

The above crushed material and the above supernatant liquid are mixed and put into an autoclave, and the atmosphere in the autoclave is 3k with N ₂ gas.
g / cm ² G The temperature was raised from room temperature to 160 ° C at a rate of 1.5 ° C / min, and further raised to 210 ° C at a rate of 12 ° C / min. The obtained crystals were washed with distilled water until Cl ions were no longer detected, dried at 120 ° C. for 3 hours, and calcined at 540 ° C. for 3.5 hours in an air stream. This was subjected to ion exchange reaction twice using a 1M aqueous solution of ammonium nitrate, washed with distilled water, dried at 100 ° C. overnight, and further calcined in air at 540 ° C. for 3.5 hours. Thereby, H-type Fe-
A silicate catalyst was obtained.

The first reactor made of stainless steel reaction inside diameter 10mm was packed with the above-described reduction treatment was _{CuO-ZnO-Cr 2 O 3} -Al 2 O 3 catalyst 1.8 ml.

A second reactor made of stainless steel having an inner diameter of 10 mm was filled with 3.6 ml of the above H-type Fe-silicate catalyst.

The first reactor and the second reactor were connected in series, and each was set in an oven. In addition, a cylinder filled with a mixed gas of 25% by volume of CO _{2 and} 75% by volume of H ₂ , a stop valve, a pressure reducing valve, a needle valve, a flow meter, a pressure gauge, a thermocouple, a temperature recorder, a gas sampler, a heater, etc. are attached. did. For analysis, a gas chromatograph equipped with an integrator was installed.

While supplying the mixed gas from the cylinder to the first reactor,
The reaction was performed under the following conditions. The entire amount of the gas discharged from the first reactor was sent to the second reactor except for the sampling amount for analysis.

First reactor pressure 80 atm, temperature 250 ° C, space velocity 4700hr- ¹ Second reactor pressure 1 atm, temperature 300 ° C, space velocity 1680hr ^-1 The gas derived from the first reactor was sampled and analyzed. The CO ₂ conversion was 32.1%. Methanol selectivity is 24.9% (77.6Cwt%), CO selectivity is 7.2% (22.4Cw
t%) and only traces of methane were produced.

The analysis results of hydrocarbons in the product discharged from the second reactor were as follows. The methanol conversion was 32.1% and the hydrocarbon selectivity was 77.6% in one pass.

C ₁ component 0.4% C ₂ component (saturated) 0.0% C ₂ component (unsaturated) 8.1% C ₃ component (saturated) 3.1% C ₃ component (unsaturated) 17.3% C ₄ component (saturated) 9.8% C ₄ component (unsaturated) 15.8% C ₅ components 14.5% C ₆ or more components (aliphatic) 28.2% aromatics 2.8% C ₅ components, C ₆ or higher component (aliphatic) and the total amount of aromatic components, i.e. gasoline components 45.5%.

Example 2 Example 1 was repeated except that propylene was added from the front part of the second reactor to the methanol in the gas discharged from the first reactor in an amount of 47.2 Cwt times (in terms of carbon content).

At this time, the analysis result of the hydrocarbon in the product derived from the second reactor was as follows.

C ₁ Component 0.0% C ₂ components (saturated) 0.0% C ₂ components (unsaturated) 1.6% C ₃ components (saturated) 3.2% C ₃ components (unsaturated) 5.5% C ₄ component (saturated) 10.6% C ₄ components (Unsaturated) 17.7% C ₅ component 25.4% C ₆ or more component (aliphatic) 33.0% Aromatic component 3.0% The total amount of C ₅ component, C ₆ or more component (aliphatic) and aromatic component, that is, gasoline component 61.4%.

Example 3 The reaction of Example 1 was repeated, except that the pressure in the first reactor was changed to 50 atm.

When the gas derived from the first reactor was sampled and analyzed, the CO ₂ conversion was 20.5%. Methanol selectivity is 10.5% (51.2Cwt%), CO selectivity is 10.0% (48.8Cwt
wt%) and traces of methane.

Example 4 In the structure of the catalyst for the first step of Example 1, an Al salt was used.
Created a _{CuO-ZnO-Cr 2 O 3} -Al 2 O 3 catalyst with reduced to 2/3. That is, a predetermined amount of the following reagent was weighed to prepare an aqueous solution, and gelling, drying, baking, tableting, pulverization, and sieving were performed in the same manner as in Example 1.

_{Cu (NO 3) 2 · 3H} 2 O 3.82g Zn (NO 3) 2 · 6H 2 O 7.57g Cr (NO 3) 3 · 9H 2 O 0.29g Al (NO 3) 3 · 9H 2 O 7.89g water 65.0 for g total 84.6 g Al ₂ O ₃ of the remaining components 1/3, was supported Pd by conventional impregnation method γ-Al ₂ O _3. That is, Pd (NO ₃ ) ₃
An aqueous solution was prepared by dissolving 0.69 g in 1.0 g of water,
It was impregnated with 0.55 g of Al ₂ O ₃ , dried, further thermally decomposed, and then reduced with hydrogen.

This was mixed above _{CuO-ZnO-Cr 2 O 3} -Al 2 O 3 catalyst and mechanically. The supported amount of Pd was adjusted to 6.0% by weight of the whole catalyst.

Accordingly, CuO 23.7 wt% ZnO 38.9 wt% Cr ₂ O ₃ 1.1 wt% Al ₂ O ₃ 30.3 wt% Pd 6.0 _{wt% CuO-ZnO-Cr 2 O} 3 having a composition of -Al ₂ O ₃ -Pd catalyst was gotten.

The catalyst thus obtained was reduced in the same manner as in Example 1 before use.

The reaction of Example 1 was repeated, except that the pressure in the first reactor was set to 50 atm, and the other conditions were the same as in Example 1.

When the gas derived from the first reactor was sampled and analyzed, the CO ₂ conversion was 30.3%. Methanol selectivity is 18.9% (62.4Cwt%), CO selectivity is 11.4% (37.6Cwt
wt%), and no methane was detected.

The analysis results of hydrocarbons in the product discharged from the second reactor were as follows. The methanol conversion was 33.0%, and the hydrocarbon selectivity was 80.0% in one pass.

C ₁ component 0.4% C ₂ component (saturated) 0.0% C ₂ component (unsaturated) 8.0% C ₃ component (saturated) 3.2% C ₃ component (unsaturated) 18.3% C ₄ component (saturated) 8.8% C ₄ component (unsaturated) 15.9% C ₅ components 14.4% C ₆ or more components (aliphatic) 28.3% aromatics 2.7% C ₅ components, C ₆ or higher component (aliphatic) and the total amount of aromatic components, i.e. gasoline components 45.4%.

Effect of the Invention According to the present invention, the CO ₂ conversion and methanol selectivity in the first step are large, and in the second step, unreacted H 2 is present in a large excess in the product derived from the first step. Not easily hydrogenated. Therefore, CO ₂ and H ₂
Thus, a liquid hydrocarbon that can be used as a liquid fuel can be industrially obtained at once.

Therefore, according to the present invention, it is possible to reduce the emission of CO ₂ , which is a cause of global warming, into the atmosphere, and to save oil resources.

──────────────────────────────────────────────────の Continuation of front page (51) Int.Cl. ⁶ Identification symbol FI C07C 31/04 C07C 31/04 // C07B 61/00 300 C07B 61/00 300 (56) References JP-A-55-60588 ( JP, A) JP-A-60-94931 (JP, A) JP-A-58-41713 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C10G 2/00 B01J 23/86 , 23/89 C07C 1 / 20,29 / 154,31 / 04

Claims (3)

(57) [Claims] 1. The mixing ratio of CO ₂ and H ₂ is from 2: 8 to 7: 3 in molar ratio.
In the range of CO ₂ and H ₂ by supplying a mixed gas mainly composed into the first reactor, CuO-ZnO-Cr ₂ reduction treatment O ₃ -Al ₂
A first step of converting the gas into a methanol-rich gas by contact with an O ₃ -based catalyst;
A second step of supplying to the reactor and converting it into a component rich in liquid hydrocarbons by contact with an H-type Fe-silicate catalyst; and the CuO—ZnO—Cr ₂ O subjected to the reduction treatment in the first step. ₃ −A
l ₂ O ₃ based composition CuO 15 to 35 wt% of the pre-reduction treatment of the catalyst, ZnO 20 to 50 wt%, Cr ₂ O ₃ 0.6~ 5% by weight, an Al ₂ O ₃ 25 to 40 wt%, and and the reduction treatment _{CuO-ZnO-Cr 2 O 3} -Al 2 O 3
The system catalyst was gelled by contacting an aqueous solution of a water-soluble salt of Cu, Zn, Cr and Al with NH ₃ gas in a stationary state, dried, calcined, and further reduced with H ₂ before use. A method for producing a liquid hydrocarbon from CO ₂ and H ₂ , characterized in that: 2. In the second step, before the second reactor, a lower olefin, a part of a product derived from the second reactor, a cyclic olefin or an olefin-producing alcohol is additionally supplied. The method according to claim 1. 3. A reduction treatment was _{CuO-ZnO-Cr 2 O 3} -Al 2 O 3 based catalysts, process of Claim 1 is intended further containing 0.5 to 8% by weight of Pd with respect to the entire catalyst.