JPS58210853A - Catalyst for synthesis of hydrocarbon from mixed gas of carbon monoxide and hydrogen - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a catalyst for synthesizing hydrocarbons of 04 or less for use in high-energy gas fuels from a mixed gas of -m carbon and hydrogen.

-Ninkel (N1) catalyst for methanation reaction is a catalyst for synthesizing hydrocarbons of 04 or less as a high-energy fuel from a mixed gas of carbon oxide (CO) and hydrogen (N2), and is disclosed in U.S. Patent No. 42 +16135. Nickel is supported on niobium oxide (Nb205). Further, a catalyst for synthesizing high molecular weight hydrocarbons (olefins) in which ruthenium (Ru) is supported on niobium oxide (NbzO5) is known in German Patent Publication No. 2845294.

However, as will be described later, the catalytic activity of the former decreases at low temperatures and is not very good, and the latter have the disadvantage that their activity is not as high when used for the purpose of high-energy fuel synthesis.

The present inventors aimed to solve these conventional difficulties.

As a result of intensive research, we were able to discover all the catalysts with extremely high activity. That is, the gist is that rhodium (Rh)e is supported on niobium oxide (Mb20s).

The catalyst of the present invention has two reaction conditions: low temperature and low pressure.

Moreover, it is characterized by high selectivity, making it truly optimal as an energy-saving catalyst.

It can be said to be an extremely promising catalyst for the autochemical use of carbon monoxide, which accompanies the conversion of raw materials from petroleum to coal.

The present invention will be further explained below.

The catalyst of the present invention and the catalyst of the US patent (N i -N I
)2Q), its activity is 220-240℃
The catalyst of the present invention is several tens of times as large as the N i -Nb206 catalyst. In the experimental examples shown in Figure 1 and Table 1, the hydrogen partial pressure under the experimental conditions of the catalyst of the present invention is about twice that of the N1-NbzOs catalyst.
It has twice the activity. Therefore, the catalyst of the present invention has the advantage that sufficient activity can be obtained at 200 to 240 DEG C. under normal pressure, and energy loss for synthesis can be saved. Paraffin was the most common reaction product.

Next, the catalyst of the present invention is niobium 18112 (Nb20s
) as a carrier 1, that is, compared to the commonly used At203 carrier and SiO2 carrier,
In the case of the 2O5 carrier, as is clear from the H/Rh value in Table 2, it shows extremely high activity even though the dispersion of Rh metal on its surface is very low.

1 active point calculated taking into account the degree of dispersion of Isen metal 7
The number of reaction molecules of ζri is At203-supported R at 220°C.
540 times that of the h catalyst and 405 times that of the 5i02-supported Rh catalyst. (Table 3) Furthermore, the Nb2O5-supported Rh catalyst is characterized by high selectivity for C3 compounds as well as methane production among the hydrocarbons produced.

This selectivity varies greatly depending on the component ratio of CO and N2. As can be seen from Table 4, Co/N2-1 reduces methane production, increases selectivity to C2-C4 compounds, and also produces methanol. At Co/N2 = 2, the selectivity to methanol is the same as above.

In addition, the activity of the Nb205-supported Rh catalyst appears with good reproducibility, and almost no decrease in activity is observed even when the usage time is extended to about 30 hours.

The effects of the present invention will be illustrated below by way of examples.

Example Nb2os supported Rh catalyst was niobic acid (made by CBMM).
NbzOs ・nHzO) was suspended in distilled water, washed, filtered through an IP filter and dried at 100°C for 24 hours, and then a predetermined amount was added to an aqueous solution of rhodium nitrate (Rh(NO3)31t at 50%).
0-1 dissolved in distilled water] and evaporated to dryness on a water bath. This supported catalyst i 5 Fl was calcined at 0° C. for 2 hours. The carrier (Nbz Os
) alone had a surface area of 42m27y. Also A/
! A Rh catalyst supported on O3 and 5i02 was prepared by similarly supporting Rh on At203 and 5i02 by the above method and calcined at 500°C for 2 hours, and by hydrolyzing ethylorone ricade.Of course: i'00°C Obtained by firing. The Rh content was 2.3 wt% in all cases.

These catalysts were reduced for 2 hours at 300° C. in a hydrogen stream before use.

After reducing the catalyst at 0.25 V in a hydrogen stream at 300° C. for 2 hours, the reaction was carried out in a normal pressure flow reactor. The reactant is C
O:N2=3:20, CO flow is 1.34
X I O' mol/min, space velocity (GH3
V)=2760hr'. Analysis of the reaction products was performed by gas chromatography.

In addition, the reaction in the circulation system is carried out in a closed circulation reactor with an internal volume of 36 d, using a catalyst t1.25F at 80 rr + mHg of I (2
After reducing at 300℃ for 2 hours using
A reaction was carried out by adding N2 at a predetermined pressure to 0 mmHg. The product was wrapped once in liquid nitrogen, and after a predetermined period of time, a portion of the product was all introduced into a gas chromatograph (7 analyzes were conducted. The results are shown in Table 1).

Table 2 Results of chemisorption experiment Table 3 Number of reactive molecules per active site (Number of reacted CO molecules/rn i n/Rh)

[Brief explanation of the drawing]

The figure shows the catalyst of the present invention (Rh-Nb205) and N i -N
Graph showing comparison of activity with b205 catalyst. 2130 260 240 220 200
1aO good 51 friends (C)

Claims (1)

[Claims] A catalyst for hydrocarbon synthesis from a mixed gas of carbon and hydrogen, which is characterized by supporting rhodium on niobium oxide.