SU990758A1 - Process for removing iron carbonyls from olefin hydroformylation products - Google Patents

Description

(54) ATP: ON REMOVAL OF CARBONYL IRON FROM

OF PRODUCTS OF HYDROFORMING OF OLEFINS

2

This invention relates to an improved method for removing iron carbonyls from hydroforming products of olefins.

In the process of hydroformylation of olefins at elevated temperatures and pressure of synthesis gas, in the presence of cobalt carbonyls, aldehydes and alcohols are formed, which, during the solid phase, are freed from cobalt compounds.

Hydrophorehylation products, along with cobalt carbonylgmy, contain an example: due to carbonyl or acid corrosion of the iron compound. The presence of significant amounts of lightweight iron carbamates of iron causes such undesirable phenomena as clogging of equipment and pipelines, deterioration in the quality of commercial products (fundamentally, inconsistency with the standard in color), as well as premature loss of activity and decrease in the service life of the catalyst of the next stage of aldehyde hydrogenation.

There is a known method for removing iron carbonyls from hydroformylation products of olefins by thermal decomposition at elevated temperature 1. I However, this method requires elevated temperatures, allows loss of target products (up to 3-4%) and is associated with a multi-stage complex technology (dissolving precipitated metals). mineral acids and their regene1 aci).

There is a known method of removing iron carbonyls from hydroforming products of olefins by treating them with non-cyclic or cyclic unsubstituted saturated aliphatic hydrocarbons having two cumulated or conjugated double bonds or one triple bond (betadien, methylacetylene, acetylene, etc.). After the addition of these compounds, iron carbonyls are destroyed and the product is distilled. The iron compounds remain in the distillation bottom product 21.

The disadvantage of this method is the need to use hard-to-reach hydrocarbons, the duration of treatment (12 hours) and the possibility of contamination of aldehydes or solvent circulating in the oxoprocess, in the process of dispersing compounds that are undesirable for subsequent transformations of aldehydes or a house for the reaction of hydroformylates a n

The closest to the proposed 30 is a method of removing carbon

iron from the hydroformylation products of olefins, according to which iron pentacarbonyl is oxidized using trivalent cobalt salts. Co-salts in dissolved state are obtained either by oxidizing a solution of C salts (hydrogen dioxide or by treating the oxoproduct with oxygen-containing gas in the presence of water at pH 4-6. After separation of the water, the oxo product is distilled. The amount of water added to the oxo product is up to 5%, the process is carried out at atmospheric pressure. The optimum temperature is 1030 s 3.

After oxidation, the salts are removed by washing with water with the addition of small amounts of mineral acids. This leads to the formation of large amounts of wastewater. The presence of water makes it difficult to process the reaction mixture, and using hydrogen and mineral acids complicates the technology of the known process.

The purpose of the invention. The simplification of the process technology.

The goal is achieved by the way JTo removes iron carbonyls from olefins hydroformylation products by oxidizing with an oxygen-containing gas in the presence of cobalt α-compounds with subsequent targeting of the target products from the reaction mass, using a cobalt compound and an organic acid selected from the cobalt compound cobalt naphtanate group, cobalt 2-ethylhexenoate and cobalt butyrate, and the process is carried out at 30-100 ° C and a pressure of 1-7.

The process is carried out as follows.

Hydroforming products of olefins, containing target and by-products of the reaction, as well as organic solvent and iron carbonyls, are treated with oxygen-containing gas at 30-100 ° C and pressure of 1-7 atm in the presence of salts with a concentration of 0.05-0.30 May. % by Co). From the resulting reaction mixture, the desired products are distilled off at a temperature in a cube of 12O-2OO C. The bottom product containing iron compounds in soluble form is used for its intended purpose or sent for recycling. As a result of this purification, the products of hydroformylation of olefins with a concentration of carbonyl iron, in the initial state up to d, 02 wt.%, After treatment, contain no more than 0.0002 wt.%.

According to the proposed method, the iron carbonyls contained in the products of hydrophore-cleavage are removed from them efficiently and universally.

method. This method is applicable to virtually any oxosynthesis technology for the purification of not only the target products of hydroformylation, but also the circulating solvent, as well as individual fractions from the distillation stage. The technology carried out does not affect the quality or yield of aldehyde products. The proposed technology is a more advanced program — fewer stages, no hydrogen peroxide, water / mineral acids, and ultimately, wastewater polluted with mineral acid salts.

Example 1. 100 g of propylene hydroformylation products containing, in wt.%: Iron carbonyls 0.006 (in terms of iron); oil aldehydes 75.0 butyl alcohols, in the presence of 0.2 g of Co naphthenate (in terms of Co), are treated with 150 ml of air at 40 ° C and pressure of 3 temp for 20 minutes and distill the mixture at the bottom product. 80 g of cyfwapHoro distillate containing a mixture of oily aldehydes and butyl alcohols (77.0 g) and less than 0.0002% by weight of iron are obtained. The bottom product with 0.2 g of cobalt naphthenate (in terms of cobalt) and 0.0059 g of soluble iron salt is recycled to the process.

Example 2. 100 g of products of hydroformylation of ethylene, containing, wt%: iron carbonyls 0.01 (in terms of iron); n-propionic aldehyde and n-propyl alcohol 65.0, treated with 1000 ml of air at and at a pressure of 1 atm in the presence of 0.1 g of Co naphthenate (calculated as cobalt) for 25 minutes. The air-treated mixture is distilled at the temperature of the bottom product. 66.0 g of a mixture of n-propionaldehyde and n-propyl alcohol contain 0.0003% by weight of iron. A bottom product containing 0.1 g cobalt naphthenate and 0.0099 g soluble iron salt is recycled to the process.

Example 3. 500 g of the reaction mixture of the product of hydroformylation of butylene, containing 0.05% by weight of 2-ethylhexenoagent (based on Co) and 0.004% by weight of iron carbonyls (counting on iron) and 50% by weight of a mixture of aldehydes and Cg alcohols, are treated for 10 minutes at a pressure of 5 at 200 ml of oxygen. Target products are distilled at a temperature in the cube equal to The isolated mixture contains 250.0 g of aldehydes and alcohols Cd. and 0.0006 May. % iron. A bottoms product containing 0.25 g of cobalt 2-ethylhexenoate (in terms of cobalt) and 0.018 g of soluble iron salt is used as a source of cobalt catalyst in the hydroformylation process of butylene.

PRI me R 4. 1000 g of yellow oily aldehydes with a carbonyl iron content of 0.005 wt.% (In terms of iron) are treated with 200 ml of air at and at a pressure of 7 AT in the presence of 3g of cobalt butyrate cobalt (in terms of cobalt). distill aldehydes in the presence of 200 g of circulating solvent, (toluene). The distillate product contains 995 g of a mixture of oily aldehydes and 0.002 g of a nonvolatile metallic residue. A bottoms product containing a 15 solvent, a small portion of oxygen-containing compounds, 3 g of cobalt butyrate (in terms of cobalt) and 0.048 g of weight-soluble iron salt {in terms of iron) are recycled to the oxidation process.

Example 5 100 g of toluene circulating solvent in the process of hydroformylation of olefins containing 0.02 May. % carbonyls of iron (in terms of iron), treated with 500 ml of oxygen in the presence of 0.15 g of 2-ethylhexenoate C0 (in terms of cobalt) at a pressure of 3 ATA for 15 minutes Then toluene is distilled. Distilt (90 g of toluene) contains iron carbonyls of not more than 0.0004 wt.%. A bottom residue containing 0.15 g of 2-ethylhexenoate and 0.02 g of iron salt (in terms of iron) is recycled to the process of removing carbonyl iron from toluene.

Claims (3)

1. US Patent 3,903,172, cl. C 07 C 24/18, published 1974. 2. Patent of the GDR 121458, cl. C 07 C 45/10, published. 1974. 3. The patent of Germany 1107102, cl. C 07 C 45/10, published. 1957 (prototype).