CS201736B1 - Process for preparing ethylenoxide - Google Patents

Abstract

The invention relates to the production and production of otylene oxide by breaking the ethylene oxide on an etrlebozný catalyst gas. Line speed current or gas streams and / or a few otylene oxide in an amount of 0.3 to 0 vol. ea kept from the outlet and the reactor or reactors up to the spun and / or absorber ethylene oxide and water gas and / or vapor value 0.5 to 25 m / β, addition ea ensures uniformity flow in the pipe and the temperature of the ethylene the pipe is kept equal or at 30 ° C, as it is temperature of the gases and / or vapors in the respective pipe. In case of a decrease flow rate below 50% and / or pressure increase slope over 10 her compared to the baseline pressure drop from the oxidant outlet Reactor (s) and entry into a washing machine and / or an ethylene oxide absorber and other products and raw material supply stops.

Description

SUMMARY OF THE INVENTION The present invention relates to the production of an ocylene oxide by breaking an ethylene oxide onto an inert gas catalyst. The linear velocity of the stream (s) of gas and / or vapor is about 0.3 to 0 vol. e keeps from the outlet and the reactor or reactors up to the sputter and / or absorber of ethylene oxide and water to each of the products from the reaction gases and / or vapors at a value of 0.5 to 25 m / β; · At a value equal to or higher than 30 ° C, such as the temperature of the gases and / or vapors in the respective piping. If the flow rate falls below 50% and / or the pressure drop rises above 10% compared to the initial pressure drop from the oxidation reactor outlet (s) and the inlet to the scrubber and / or ethylene oxide absorber and the by-products, the feed is stopped.

201 736 i

SUMMARY OF THE INVENTION The present invention provides a process for producing ethylene oxide by feeding ethylene oxidation onto an elliptical catalyst in such a way that by modifying the technology and equipment ea significantly increases catalyst life, labor time and equipment production and high reliability and safety.

Catalytic oxidation of ethylene according to e + (3 - 2.5) O ₂ - with C 8 H 4 O + 2 (i - s) CO 2 + 2 (i - e) HgO where ε is selectivity and 0 <e <1 it is carried out on the surface of the etrieb at a temperature of 180 to 270 ° C. The aim is to maximize the selectivity to ethylene oxide, which can and, inter alia, be enhanced by the promoted silver catalyst with small amounts of electronegative elements C1, F, S, Se, P and TEMKIN. I., Kinetics and Catalysis 18, 544 (1977) and US Pat. 2,279,470 and 2,814,628}

V. Brit. pat. 518 823 and 779 102J, Salium with halides and sodium, Na, K, Li, Rb, Ce (US Pat.

671 764} jap. game. pat. prihl. 9307/1957) as well as compounds Ba, Ca and Ce (U.S. Pat.

825 70l). In addition, we believe, in particular, due to the silver catalyst carrier, a portion of the ethylene oxide can be isomerized to α-etaldehyde £ Twigg, Trans Faraday Soo. 42nd

284 (1946). Many processes for the production of ethylene oxide are known in which air or other oxygen-containing gas is used as the oxidizing agent, or oxygen itself. 3 «Amyoh is also a multiple variant of the equipment of R. R. Van Oesten, J. of the Institute of Petroleum 46, no. 443, 347 (1960)}. Marshal Sittig, Petrol. Ref. 41. č. 6175 (1965)} Prooeee Engng, October 1973, p. 6-7} Pajda A., Pajda E.i Chemik 24. 363 (1979)} Coneidine M, D .: Chemical and Process Technology Enoyolopedia, 440-445. Mo Gmw - Blil Book Co., New YorkJ. The reaction gases leaving the oxidation reactor are routed to the ethylene oxide aEParation, and to a variety of products, whereby the unconverted starting materials are generally re-inoculated. Some variants of equipment and technologies ea try to use reaction heat to preheat raw materials or produce steam. However, the known processes and apparatus have little regard for their design, fire engineer and apparatus solution, that as a main product, i. ethylene oxide, as well as by-products such as aoetaldehyde, water, eu at higher temperatures, although exposed to such conditions for a relatively short period of time, capable of interacting with each other * to higher molecular weight products. These already easily condense even at higher temperatures, extending aa ioh contact, reep. the reaction time and, moreover, the oxidative effect of unconverted oxygen may be significant. Thus, ethylene oxide can react with water to form ethylene glycol, and this in turn with other ethylene oxide molecules to polyglycols, aoetaldehyde to aoetaldol, crotonaldehyde, but also to oic acid, which can react with ethylene oxide and the like.

In addition, even higher olefins or paraffinic hydrocarbons in the feedstock or in the environment, these particularly prominent may be precursors of higher molecular weight compounds that can also be oxidized * to solid coke products that can drive gas pathways, generated by oxidation can get into the reaction circuit, poison the catalyst, reduce its lifetime, efficiency * and selectivity. These and other problems and deficiencies of the theology and apparatus are solved by the method and apparatus of the invention.

201 736

The process for the production of ethylene oxide by direct oxidation of ethylene with an oxygen-containing gas, preferably a mixture of oxygen, nitrogen and argon, is also possible in the presence of carbon dioxide, methane, otane and propane, on a silver catalyst, preferably in the presence of activators. to the mass, generally also with the addition of ethylene oxide oxidation inhibitors to carbon dioxide and water, at a temperature of 180 to 290 ° C, preferably 220 to 270 ° C and a pressure of 0.8 to 4 MPa, preferably at a pressure of 1.2 to 2, 5 MPa and subsequent isolation of ethylene oxide from the reaction product and, as a rule, by isolation and / or regeneration of the non-converted feedstocks according to the invention, is carried out such that the linearity of the streams or streams of gases and / or vapors containing 0.3 to 4 vol. , preferably from 0.6 to 2.5 fa by volume, is maintained from the exit of the reactor or reactors to the scrubber and / or absorber; yleneoxide and the other. products from reaction gases and / or vapors at a value of 0.5 to 25 m / s, except for the start-up and shutdown phases, preferably 8 to 18 m / s, while ensuring a uniform flow in the pipeline and maintaining the wall temperature of the pipeline at a value equal to or less than 30 ° C than the temperature of the gases A / or vapors in the associated piping, and in the event of a flow rate drop below 50? »and / or an increase in pressure drop above 10 fa compared to the initial pressure drop or reactors and inlet to the scrubber and / or absorber of ethylene oxide and by-products the feedstock is stopped.

It must be ensured that the linear outflow rate of the gases and / or the vapor of the reaction mixture are discharged from the reactor, besides the start-up and shutdown phases, when there is little ethylene oxide in the reaction gases, preferably 0.5 to 25 m / s. 15 m / s. If it is too low, the equipment (piping) is underutilized and deposits, prolonging the contact time of the reaction components with each other and with oxygen may be used, if too high, it will only be used to a small extent as a heat source, reduces washing machine efficiency and / or absorber.

Further, it is necessary to maintain the necessary temperature of the pipe walls in order to flow in it gases containing ethylene oxide mail either at the same temperature as the reaction gas or lower by at most 30 ° C. It is mainly to create conditions so that the temperature is not lower than the dew point of the lowest flowing components of the reaction gases. Make sure that the reaction rate of gases and / or vapors containing ethylene oxide does not drop the gas and vapor readiness to zero, so that there is no dead space equipment where condensation of gases and vapors can occur and thus de facto continuation of subsequent reactions, condensation and oxidation by forming liquid, semi-solid, elastic to solid products. These, in addition to the generation of generated gases and vapors, can further enhance their routes. If these conditions are not observed, some of the main and by-products are separated before the ethylene oxide and the by-products are separated in the washing machine and / or absorber. For reasons of complete production safety, especially for particularly long production cycles, it is advisable to check for possible fouling of the reaction gas path and / or the vapors discharged from the reactor, either by flow measurement or simply by pressure drop, by another reliable procedure.

The advantages of the method according to the invention are the operational reliability of the device, increased safety, long catalyst life, high ethylene conversion and selectivity.

201 736 to ethyl oxide, less sensitivity &apos; to possibly reduced purity of both the starting components and the re-spherical components.

Further advantages, as well as details of the epoch on. the devices are evident from the examples and the figure.

Example 1

Line 11 (see FIG.) Feeds ethylene through feedstock mixer 12 and gas (substantially pure oxygen) is passed through line 12 through feedstock mixer 10. From there, the mixed gases were fed through line 13 to the oxidation tube reactor 6 and preheating contained in silver catalyst in a mass of 8.9% by weight. silver with activators, at a pressure of 2 MPa with a volumetric coagulation of 2,700 h ^-1 and a temperature of 243 ° C. In addition, the reaction gases and / or vapors containing ethylene oxide as the main reaction product at 243 DEG C. are discharged via line 4, which has no dead spots, i.e. virtually no flow points, and is passed through heat exchanger 2 where they evacuate heat. while e and cooled to-1 <> 8 ⁹ C being preferred and then continue RES výmsnnlk heat KUE obtained was next cooled to 127 ° C being preferred and a RES heat exchanger 4 to a washing machine reakčnýoh gases and / or vapors, respectively. absorber 6, mainly ethylene oxide. In the washing machine respectively. at 20 to 28 ° C, the ethylene oxide and some of the incoming gases and / or vapors are washed. In the SalSom, the ethylene oxide solution is passed through the outlet 15 and is isolated, and the ethylene oxide-free gas mixture is passed from the scrubber head or from the scrubber head. of the absorber 6 via line 16 through a theohiologic separator 6 and 16 through a line 17 for sucking in the circulation compression ® ® 2t, whereby a part of the gas is evacuated through the exhaust gas 18? from the reaction circuit. From the discharge of the compressor 2, the gas mixture flows out. at a temperature of about 33 ° C through the outlet 24 o of the scrubber and / or absorber 8 for removing carbon dioxide and therefrom via a 19 oez heat exchanger 6 to the mixer 8 and therefrom with fresh ethylene to the mixer 10. inert gases.

From the mixer 10, the gas mixture, together with the fresh feedstocks fed to the circuit via lines 10 and 12, is fed via line 13 to an oxidation tubular reactor equipped with a preheater.

On average, a 10-molarity profile of a device blasting 10 months is 110 β ethylene oxide per 1 dm 2 catalyst per hour. In the outlet conduit 14 from the reactor 6, steppes of oxygenated organo-organic products are found.

Example 2

The procedure aa and &apos; except that part of the reaction gases and / or vapors are discharged from the oxidation tubular reactor via line 14, the additional heat is distributed to one or two taps 22 to 2 (° br) into the heat exchanger 6 or to the scrubber 8, that the linear gas can react with the reaction gases and / or

201 736 vapor and the content of the main reaction product - ethylene oxide, will drop below 0.2 m / s and short-term in at least 1 branch to zero. Within 6 months, a production of 100-110 g ethylene oxide per day is achieved. Catalyst per hour, but after 9 months there will be unevenness of production, temperature fluctuations in the reactor, reduced production to 40 g ethylene oxide per 1 dm @ 2 catalyst per hour, and substantially reduced catalyst activity. This can not be significantly increased by known regeneration processes, nor by raising the temperature to 265 ° C and modifying the reaction gas and / or vapor line 14 of Example 1, a maximum production of only 83 g ethylene oxide per 1 din catalyst per hour is achieved. simultaneous decrease in ethylene oxidation selectivity by approximately 10%. Branches in which the linearity drops below

0.2 m / s and short-term down to zero, they are progressively moved by the condensation and oxidation product 1, in the extreme case a mixture of solid and partially elastic and plastic condensation and oxidation products of the following composition: ash is formed. mainly composed of iron, calcium, medium, manganese, silicon and magnesium compounds; carbon 57.2 wt. and hydrogen 5.6% by weight. The infrared absorption spectrum indicates the presence of the -OH, CsO, C-0-0 groups, suggesting the presence of the polyaddition products of ethylene oxide mainly on acids, respectively. also aldols and aldehydes, as well as oxidized polyglycols.

Claims (1)

The process for the production of ethylene oxide by direct oxidation of ethylene with an oxygen-containing gas, preferably a mixture of oxygen, nitrogen and argon, optionally also in the presence of carbon dioxide, methane, ethane and propane, on silver catalysts, preferably in the presence of activators, usually on carriers and / or in the mass, generally also with the addition of ethylene oxide oxidation inhibitors to carbon dioxide and water, at a temperature of 180 to 290 ° C, preferably 220 to 270 ° 0 and a pressure of 0.8 to 4 MPa, preferably at a pressure of 1.2 to 2 5 MPa and subsequent isolation of ethylene oxide from the reaction product and generally by isolation and / or regeneration of the unconverted feedstock, characterized in that the linear velocity of the stream (s) of gas and / or vapors contains ethylene oxide in an amount of 0.3-4% by volume. preferably from 0.6 to 2.5% by volume, is maintained from the exit of the reactor or reactors to the scrubber and / or absorber of ethylene oxide and the h products from reaction gases and / or vapors to a value of 0.5 to 25 m / s, except for the start-up and shutdown phase, preferably 8 to 18 m / s, while ea ensures uniform flow in the pipe and the pipe wall temperature is maintains a value equal to or less than 30 ° C than the temperature of the gases and / or vapors in the pipeline, with an additional increase of 50% compared to the initial pressure drop from the oxidation reactor outlet if the flow rate falls below 50 # and / or or reactors and the inlet to the scrubber and / or absorber of ethylene oxide and by-products the feedstock is stopped.