JPS59196829A - Method for selective hydrogenation of acetylenic compound - Google Patents

Abstract

PURPOSE:To improve the performance of the Pd-based solid catalyst for the hydrogenation of an acetylenic compound in a fraction composed mainly of olefinic hydrocarbons, by desulfurizing the fraction with a metal oxide prior to the hydrogenation process. CONSTITUTION:A fraction composed mainly of 3-4C olefinic hydrocarbons (obtained e.g. by the cracking of petroleum) is desulfurized with a metal oxide to the state essentially free from sulfur compound, and the acetylenic compound in the fraction is selectively hydrogenated in liquid phase under pressure, in the presence of a Pd-based catalyst. The metal oxide is e.g. zinc oxide, lead oxide, chromium oxide, iron oxide, copper oxide, etc., preferably zinc oxide, and is optionally supported on a carrier such as alumina. EFFECT:The stability of the catalyst can be improved. USE:Raw material for rubbers, plastics and other chemical industry products.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a fraction (hereinafter referred to as C3, fraction) which is mainly composed of olefinic hydrocarbons having 3 to .1 carbon atoms and is obtained by clarification of petroleum products. ) in a method for selectively hydrogenating an acetylene compound under pressurized liquid phase conditions, using a solid catalyst as a catalyst;
The present invention relates to a method for desulfurizing a C3,-4 fraction using a metal oxide as a desulfurizing agent and carrying out the reaction substantially in the absence of sulfur compounds in the reaction system.

The C3-4 fraction obtained by talunking of petroleum products mainly contains propylene, 1,3-butadiene/isobutyne, n-butene (butene-1, butene-2), propane,
It consists of butanes, and contains small amounts of acetylene compounds such as acetylene, menal acetylene, ethylacetylene, and vinyl acetylene as small wires, and
In some cases, allene (propadiene) as an impurity,
It may also contain diene compounds such as methyl allene.

When this C5-4 fraction is separated and used as a raw material for rubber, flask snacks, and other chemical industries, the acetylene compounds contained as impurities pose various obstacles.
It must be removed by appropriate treatment in advance so that the concentration is below a certain level.

Conventionally, as a method for removing acetylene compounds in the C3-4 fraction, hydrogenation of olefins and diolefins, which are the main components, is suppressed as much as possible under gas phase or liquid phase conditions in the presence of a catalyst. A method of selectively hydrogenating is being used.

However, in the conventionally known methods, it is very difficult to selectively and sufficiently hydrogenate only the acetylene compound while suppressing the hydrogenation of the main components, auxiliary refins and diolefins &i, as much as possible. 1. In the case of a C4 fraction in J, in general, there are few or no claws in the anti-Li> property of the acetylene compound in the mixture with 1,3-butadiene, and the concentration of the acetylene compound that should not be hydrogenated is the concentration of butadiene. It is very difficult to suppress the hydrogenation of butadiene as much as possible and to selectively hydrogenate only the acetylene compound in an amount of 1 gL, because the hydrogenation of butadiene is extremely low compared to the hydrogenation rate of the acetylene compound. For example, in the gas phase method, the reaction is usually carried out at a crystallinity of about 150 to 200°C, but the reaction at such high temperatures causes severe hydrogenation and formation of butadiene. Damage to the catalyst is inevitable, and catalyst deterioration due to adhesion of polymeric substances is also significant. On the other hand, in the liquid phase method, usually 10
F) Since the reaction is carried out at a relatively low temperature below ℃, there are few drawbacks such as deterioration of the catalyst due to the gas phase θ and I. It is also necessary to avoid a static point in which it is necessary to use a large amount of hydrogen, which increases the hydrogenation rate of butadiene.

In the case of a liquid phase method, compared to a gas phase method, catalyst deterioration is small, but for C3-4 fractions: [Depending on the raw state, the catalyst may be used for a long period of time] [In the case of polymers, moisture, Catalyst poisoning components such as sulfur compounds gradually accumulate, and catalyst activity 1<IE
When the power is lowered, there are cases where the loss of power increases. In particular, sulfur compounds are often present in the C3-4 fraction in the form of hydrogen sulfur, dichloromethane, carbonyl butane sulfide, and carbon disulfide.

Due to the presence of sulfur compounds, e.g. total sulfur concentration of 1 wtpp
Even if the palladium-based catalyst is used for a long period of time, it does not cause inverse activity and low F, so it is desired to develop an effective desulfurization method.

In view of the current situation, the present inventors conducted extensive research to develop an effective method for selectively hydrogenating acetylene compounds in C3-4 fractions, and as a result, they discovered that palladium It has been found that an excellent effect can be produced by removing trace amounts of We H:/j compounds by treating the C3-4 fraction to be subjected to the reaction using a metal oxide catalyst.

When selective hydrogenation of acetylene compounds in the C34 fraction is carried out using a haladium thread catalyst, C34 without desulfurization agent treatment is used.
Even if the reaction is carried out using the 3-4 fraction, initially the catalyst performance, that is, the activity, selectivity, and stability are relatively good.
When used for a long period of time, stability may be affected! There is point L.

However, when the de(i4e) C3.

Is Balajiuno/thread catalyst affected by sulfur compounds? Although it is known that the catalyst according to the present invention has a high performance of 41+l, it is less than the normal catalyst.
It was also observed that -1 has an aspect sensitive to sulfur f)+ (compounds).

The desulfurization conditions when carrying out the method of the present invention are not necessarily strictly limited, but generally the following J: eel strip f'
j(・-).

The desulfurization temperature is in the range of O to so'c, preferably 5 to 60 C, and the desulfurization force is in the range of 2 to 30 kg/ff1G, preferably 3 to 20! 9. /GwfG range, L J-1,
S V l ~ 1.0 (,) hr-1, preferably 2
= 60 hr-1, the concentration of sulfur compounds is in the range of 0.01 to 10 (wtpprr+), preferably 0.1-5Cwtr) pm as a total sulfur concentration, and the desulfurization system is substantially The desulfurization crystallinity and desulfurization pressure are set to maintain the liquid phase.

Desulfurization agents include metal oxides such as lead oxide, lead oxide, chromium oxide, copper oxide, and iron oxide (total of 1 type).
It is possible to use the ``warrior system'' of Shunf Hibi.

Among these, zinc oxide can be preferably used.

As a desulfurizing agent, 1) 14 oxides or composite oxides of 11i9 may be used, but these may be further added to 41 in a suitable pressed body.
You may hold one and use it. As the 111 body, known materials such as alumina, silica, silica-alumina, titanium oxide, activated carbon, and aluminum can be used, and alumina can be particularly preferably used.

Commercially available metal oxides and composite oxides can be used for desulfurization.
You can also do 1. There are no restrictions on the method for producing the desulfurizing agent, and any method commonly used for this type of compound may be used as appropriate. As an example of removing oxidized yarn, it can be prepared by the following method.

Alumina (U body is impregnated with a predetermined amount of acid such as lead acetate or lead nitrate or a solution of water-soluble salts, then dried,
The lead oxide-aluminum composite oxide is produced by firing at an appropriate temperature to obtain the desired desulfurization agent.

The catalyst used in the invention contains radium or baradium as the main component and other metals as co-catalysts.
Preference is given to those containing, for example, copper, silver, gold, tin, lead, cadmium or non-metallic acid salts of lead, organic acid bases. Various metal oxides, etc. are used as the carrier (two types are possible, but alumina is preferable, especially 7'-A
, e 0 77-Al2O3, θ-A120. Na
31 is preferred. As for the catalyst composition, the ratio of radium to 1 body is 0.05 to 5-111%, preferably 0.
The ratio of the cocatalytic component to palladium is 01 to 10 as the atomic ratio of the metal. Preferably 05
It is in the range of ~8. There are no particular restrictions on the method for preparing the catalyst, and any method commonly used for this type of catalyst may be used as appropriate. - For example, it can be prepared by the following method. Palladium chloride, palladium nitrate, alumina press
[Acid resistance] After impregnating a predetermined amount of a solution of acid or water-soluble salts such as radium or sodium palladium chloride, this palladium salt is treated with a suitable reducing agent such as hydrogen, hydrazine, formaldehyde, or sodium formate. Then, iζV is converted into metallic radium using a dry or wet method.

Next, the alumina supporting metallic palladium is thoroughly washed with water and dried in vacuum. When using a co-catalyst component, it is generally immersed in a solution containing soluble salts of the metal at a predetermined concentration to support these salts, and then subjected to a reduction treatment if necessary. Vacuum drying yields the desired catalyst.

There are no strict limitations on the reaction conditions when carrying out the method of the invention, and the reaction is generally carried out under the following conditions.

The reaction temperature is in the range of 0 to 80°C, preferably 5 to 60°C, and the reaction pressure is in the range of 2 to 3 Qkg/crjG, preferably C;
The molar ratio of H2 and acetylene compound is in the range of 01 to 15, preferably 05 to 10, LH3V is in the range of 2-80 hr-1, preferably * L < Ha4
-40 hr, and the reaction system is set to have a dielectric wetness and J:ib'r5f which can maintain the reaction system substantially in a liquid phase.

J]2 used in the present invention may be pure or may be diluted with an inert gas such as methane.

There is no particular limitation on the f-shift fJ of the 04 acetylene r-hyde compound in the C3-4 fraction used in the present invention, but the total concentration of the coexisting various 'γ acetylene compounds is 05~:3w.
Hydrogenation removal IJJ' is possible even in the range of t%.

The anti++6 type reaction when carrying out the method of the present invention is a fixed bed reaction, and either a flowing type or an overflow type can be adopted to carry out a fixed bed reaction in a liquid phase. Further, as the reactor, either a wet type or an adiabatic type can be used.

According to the method of the present invention, selective hydrogen removal is promoted, the removal rate of acetylenes is very high, and hydrogenation of the main component mono- or diolefin, which occurs as a vernier core, is significantly reduced. It has the excellent advantage of minimizing losses and ensuring a stable reaction over a long period of time.

Hereinafter, the method of the present invention will be explained in more detail by showing typical examples. However, these are merely examples, and it goes without saying that the present invention is not limited thereto.

Example 1 (1) Origin (hydrocarbon composition) A C4 fraction having the following composition was used as raw material 1.

Butanes 8.9 wt%, butenes 220-vt%
, Isobutine 25. ], wt%, ], ] 3-butadiene 429 wt%, 1,2-butadiene 0.2 w
t%, ethyl acetylene 0.2 wt%, vinyl acetylene (1.7 wt%, methyl acetylene and + propadiene 6y, H7, H1 total sulfur?, ff ii'i]
, -3 wjppm (2) Desulfurization conditions Desulfurization agent' lno % desulfurization temperature J! E: 20℃, pressure +6kg/cntG, LHS V: 2 hr-
1(3) Hydrogenation conditions catalyst: I) d -P b (CH3COO)2-A
/? 203P b / P d original P ratio = 2 Pd containing f ratio (for humans 6203) = 0.3 s wt%
Wetness, 20℃, pressure crab 8ky1074G, 1-■2 molar ratio: 5 (to C4 acetylene), L)■SV 15
hr-1, reactor type: adiabatic type This C4 fraction was subjected to a hydrogenation reaction of 04 acetylenes under desulfurization conditions and hydrogenation conditions, and the results are shown in the table.

Example 2 Example 1 except that the hydrogenation conditions were changed as follows:
The hydrogenation reaction was carried out in exactly the same manner. The results are shown in the table.

Catalyst, p dz n (Ci(3Coo)2 Ad20
3Z n / P d atomic ratio -2 1? d content (outer I Al2O3) - o35 wt%
Example 3 A hydrogenation reaction was carried out in exactly the same manner as in Example J except that the desulfurization conditions for the C4 fraction were changed as follows.

The results are shown in the table.

Desulfurization agent 10%PbO-Al2O3, desulfurization 1XIlh degree, 2o...c, pressure crab 6! ? /ff1G, LH8
V: 2 hr-1 Example 1 Hydrogenation reaction 1ia was carried out in exactly the same manner as in Example 1 except that the desulfurization conditions for the C4 fraction were changed as follows.

The results are shown in the table.

Desulfurization agent: Cu-Cr-oxide, desulfurization fill/(U
' 20° (/, 1■E crab 6kg/ff1G,,L
J-ISV: 2 hr-1J, 1! Example J Hydrogenated anti-tljs was carried out in exactly the same manner as in Example 1, except that the C4 fraction was not desulfurized. The results are shown in the table.

Claims (1)

[Claims] A desulfurizing agent in a method of selectively hydrogenating acetylene compounds in a fraction mainly composed of olefinic hydrocarbons having 3 to 4 carbon atoms under pressurized liquid phase conditions in the presence of a palladium thread solid catalyst. A method characterized in that the fraction is desulfurized using a metal oxide as a metal oxide, and the hydrogenation reaction is completed in a state in which there is substantially no sulfur compound present in the reaction system.