JP2009220082A - Manufacturing method for water vapor reforming catalyst for lpg, and water vapor reforming catalyst for lpg - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a water vapor reforming catalyst for a liquefied petroleum gas being excellent in activity at a low temperature area. <P>SOLUTION: A mixture solution in which a ruthenium compound becoming an active metal and a nickel compound becoming an additive are dissolved and a suspension in which a powdery aerosil alumina becoming a catalyst carrier is suspended are mixed, and after the mixture is dried, it is granulated to a granular form and the granulated substance is subjected to reduction treatment by a hydrogen gas stream under a temperature atmosphere of a predetermined or higher. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a catalyst production method and a catalyst suitable for use in steam reforming of liquefied petroleum gas (LPG), and more particularly, to a method for producing a steam reforming catalyst for LPG and a catalyst excellent in activity in a low temperature region. It is to provide.

  Ruthenium-containing catalysts have been widely used for steam reforming of hydrocarbons in recent years because they exhibit excellent catalytic performance such as high activity and excellent carbon deposition resistance even under low steam / carbon ratio operating conditions.

Regarding the ruthenium-containing catalyst, a catalyst in which ruthenium is supported on a zirconia support (Patent Document 1), or zirconia having alumina as a support and zirconia sol as a precursor is supported as a co-catalyst, and ruthenium is an active component. Or a solution containing a ruthenium compound, a zirconium compound, and an alkaline earth metal or rare earth element compound is brought into contact with the support, whereby the ruthenium component is converted to the zirconium component on the support. A device (Patent Document 3) or the like carried in a highly dispersed state in the vicinity has been proposed.
JP-A-2-002879 Japanese Patent Laid-Open No. 5-220397 JP-A-8-196907

  When hydrogen production is carried out by steam reforming of hydrocarbons, particularly liquefied petroleum gas, energy saving and high durability of the production process are desired. With conventional reforming catalysts, it is difficult to obtain a reformed gas with a hydrogen concentration exceeding its equilibrium composition. In order to obtain a reformed gas with a predetermined high concentration of hydrogen, the reformed catalyst is modified in a temperature range exceeding 600 ° C. In addition, the steam / carbon (S / C) ratio needs to be 3.0 or more in order to suppress the carbon deposition that causes the blockage of the system. As a result, it is difficult to save energy by reducing the amount of heat input for reforming. Further, in the hydrogen separation membrane reformer, when the temperature exceeds 600 ° C., there is a problem that the durability of the separation membrane is remarkably lowered.

  In view of such a point, an object of the present invention is to provide a steam reforming catalyst for liquefied petroleum gas having excellent activity in a low temperature region.

  In order to achieve the above object, according to the present invention described in claim 1, in the production of a steam reforming catalyst for LPG, a ruthenium compound serving as an active metal, a nickel compound serving as an additive, and a mixed solution dissolved therein This is mixed with a suspension of powdered aerosil alumina in the form of a catalyst carrier, dried, and then granulated into granules. It is characterized by being reduced by a hydrogen gas stream.

  The invention described in claim 2 is characterized in that, in addition to the structure of claim 1, a lithium compound is added as a second additive together with a nickel compound so that aerosil alumina is dissolved and mixed in the solution. In the invention of claim 3, the mixing ratio of the ruthenium compound in the invention of claim 1 or 2 is 0.5 to 1.0 wt%, the mixing ratio of the nickel compound is 0.5 to 1.0 wt%. It is characterized by being.

  In the present invention, a ruthenium compound serving as an active metal, a nickel compound serving as an additive, and a mixed solution are mixed with a suspension obtained by suspending powdered aerosil alumina serving as a catalyst carrier. Since it is dried and sized and subjected to reduction treatment with hydrogen gas in a temperature atmosphere above a predetermined temperature to obtain a steam reforming catalyst for LPG, the active metal is supported on the support in a more highly dispersed state. Can be made.

  In the steam reforming catalyst for LPG of the present invention formed by the above-described method, methanation of carbon monoxide and carbon dioxide that occurs as a sequential reaction of steam reforming can be suppressed, and a conventional reforming catalyst is used. A hydrogen concentration higher than the equilibrium composition of steam reforming can be obtained. As a result, reforming can be performed at a lower temperature, the amount of input heat in the reforming process can be reduced, energy can be saved, and hydrogen used in the reformer can be reduced. It is possible to reduce the heat damage to the separation membrane and extend the life of the hydrogen separation membrane.

  In addition, since the steam reforming catalyst for LPG of the present invention formed by the above-described method can be reformed with a smaller S / C ratio than the conventional catalyst, the amount of heat required for vaporization can be reduced. Can save energy.

  Furthermore, in the steam reforming catalyst for LPG of the present invention formed by the above method, the hydrogen concentration can be increased by increasing the space velocity (SV) value. Thereby, reduction of the catalyst amount can also be expected.

FIG. 1 is a flowchart illustrating the procedure of a method for producing a steam reforming catalyst for LPG according to the present invention.
First, an operation (S1) of dissolving a ruthenium compound as an active metal and a nickel compound as an additive in ion-exchanged water, and aerosil alumina consisting of powder having a surface area of about 100 cm ² / g as ion-exchanged water are used as ion-exchanged water. After the suspension, the operation of boiling once and then cooling to a predetermined temperature (80 ° C.) or so (S2) is performed in parallel.

  Next, the ion-exchanged water in which the ruthenium compound and the nickel compound are dissolved, and the ion-exchanged water once boiled and suspended after suspending the Aerosil alumina are further mixed (S3), and the mixed solution is evaporated. To be consolidated (S4).

  Next, the solidified product is further heated and dried at a temperature of about 60 ° C. (S5), and the dried product is granulated (S6).

  The sized granule is further subjected to a reduction treatment by flowing hydrogen gas for 2 hours under an atmosphere at a temperature of 550 ° C. or higher (S7) to obtain an LPG steam reforming catalyst.

  A solution prepared by dissolving 0.25088 g of ruthenium chloride as a ruthenium compound and 0.55585 g of nickel nitrate as a nickel compound in 50 ml of ion exchange water is prepared. On the other hand, 9.8 g of aerosil alumina is suspended in 250 ml of ion exchange water and then boiled, and then cooled to about 80 ° C. is prepared.

  The ion-exchanged water obtained by dissolving the ruthenium compound and the nickel compound is mixed with the heated and cooled solution after suspending the aerosil alumina, and after sufficiently stirring and mixing, the water is evaporated and the ruthenium compound and The nickel compound is consolidated in a state of being dispersed in aerosil alumina.

  The solidified product obtained by evaporating moisture is dried in a drier set at a temperature of about 60 ° C. for 6 hours, and then sized into granules having a particle size of about 1.4 to 2.0 mm. This sized product is allowed to act for 5 hours with hydrogen gas set at a flow rate of about 40 cc / min in an atmosphere at a temperature of 600 ° C. or higher to obtain a catalyst. The composition of this catalyst is 1 wt% of the active metal ruthenium and 1 wt% of the additive nickel. It is assumed that ruthenium and nickel are alloyed during the reduction treatment.

FIG. 2 is a test apparatus for a steam reformer.
This test apparatus is comprised of an inner cylinder (2) that houses the reforming catalyst (1) and a heater (3) that heats the inner cylinder (2). The reforming catalyst accommodating portion (6) is formed by supporting the catalyst stopper (4) via the stopper support cylinder (5). In the figure, symbol (7) is quartz wool filled on the inflow side of the reforming catalyst housing (6), symbol (8) is a recondensing device arranged in the outlet gas passage (9), and symbol (10) is the catalyst layer. A temperature detector constituted by a thermocouple for detecting the temperature, reference numeral (11), is a temperature detector for detecting the temperature outside the inner cylinder. The catalyst stopper (4) and the stopper support cylinder (5) are both made of a stainless steel mesh plate.

The steam reforming catalyst prepared by the above-mentioned method is filled in the test apparatus, and propane gas and steam are mixed under the conditions of space velocity: 2,000 / h, pressure: 0.53 MPaG, S / C: 2.8. The concentration of the derived hydrogen gas was measured by changing the temperature through a test apparatus that maintained the temperature. The results are shown in Table 1.
As a comparative example, the concentration of the derived hydrogen gas was measured when a catalyst containing granular alumina as a carrier and 5% ruthenium as an active metal was used. Incidentally, the hydrogen gas concentration in the equilibrium state under the same temperature condition was also compared.

  FIG. 3 shows the relationship between the elapsed time and the hydrogen concentration.

  As a result, in the catalyst according to the present invention, it was confirmed that the hydrogen concentration was increased by about 1 to 1.5% in each temperature zone. Incidentally, the carbon monoxide concentration in the derived gas using the catalyst of the present invention showed a value about 1% higher than the carbon monoxide concentration in the equilibrium state. This is probably because the catalyst according to the present invention suppresses the methanation reaction.

As a result, in order to obtain an equivalent hydrogen concentration, the catalyst according to the present invention can reduce the processing temperature. And lowering the treatment temperature can contribute to the reduction of the input heat amount, and the durability of the hydrogen separation membrane can be improved.
Further, in the catalyst according to the present invention, the ruthenium content is about 1/5 as compared with the conventional ruthenium-containing catalyst, so that the amount of expensive ruthenium can be reduced.

  In order to investigate the effect of the space velocity on the hydrogen concentration, the space velocity was changed, and the temperature change was made in a test apparatus that maintained the conditions of processing temperature: 600 ° C., pressure: 0.53 MPaG, S / C: 2.8. The concentration of the derived hydrogen gas was measured. The results are shown in Table 2.

  As a result, when the conventional ruthenium-containing steam reforming catalyst is used, the hydrogen concentration is constant regardless of the change in the space velocity, whereas in the catalyst according to the present invention, when the space velocity increases, It was confirmed that the hydrogen concentration increased. Thereby, in order to obtain the equivalent hydrogen concentration, the amount of catalyst can be reduced, and the cost required for steam reforming can be reduced.

  In the above embodiment, the composition of the catalyst includes 1 wt% of the active metal ruthenium and 1 wt% of the additive nickel, but the mixing ratio of ruthenium is 0.5 to 1.0 wt%, When the mixing ratio of the nickel compound is in the range of 0.5 to 1.0 wt%, the above-described effects can be achieved. Further, as the second additive, a lithium compound may be added at an upper limit of about 0.5 wt%.

  The present invention can be used for hydrogen production technology using liquefied petroleum gas as a raw material.

It is a flow explaining the procedure of the steam reforming catalyst manufacturing method for LPG which concerns on this invention. It is a figure which shows the test apparatus of a steam reformer. It is a graph which shows the relationship between hydrogen concentration and elapsed time.

Claims (6)

  A ruthenium compound as an active metal, a nickel compound as an additive, a mixed solution and a suspension in which aerosil alumina of powder as a catalyst carrier is suspended are mixed, and after drying this mixture, A process for producing a steam reforming catalyst for LPG, characterized in that the granulated particles are sized and the sized particles are reduced by a hydrogen gas stream in a temperature atmosphere of a predetermined temperature or higher.   The method for producing a steam reforming catalyst for LPG according to claim 1, wherein a lithium compound is added as a second additive together with the nickel compound, and aerosil alumina is dissolved and mixed in the solution.   The method for producing a steam reforming catalyst for LPG according to claim 1 or 2, wherein the mixing ratio of the ruthenium compound is 0.5 to 1.0 wt%, and the mixing ratio of the nickel compound is 0.5 to 1.0 wt%.   The method for producing a steam reforming catalyst for LPG according to claim 2, wherein the mixing ratio of the lithium compound is 0.1 to 0.5 wt%.   The method for producing a steam reforming catalyst for LPG according to claim 1, wherein the ruthenium compound is ruthenium chloride and the nickel compound is nickel nitrate.   A steam reforming catalyst for LPG, in which a ruthenium compound serving as an active metal and a nickel compound serving as an additive are supported on aerosil alumina serving as a catalyst carrier.

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