SU718449A1

SU718449A1 - Method of styrene preparation

Info

Publication number: SU718449A1
Application number: SU782658203A
Authority: SU
Inventors: Дилгам Бабир Оглы Тагиев; Зульфугар Гусейн Кули Оглы Зульфугаров; Эльмира Багир Кызы Шарифова; Алевсер Бахтияр Оглы Мамедов
Original assignee: Институт Неорганической И Физической Химии Ан Азербайджанской Сср
Priority date: 1978-08-09
Filing date: 1978-08-09
Publication date: 1980-02-29

Description

Изобретение относится к области нефтехимического синтеза, в частности к способу получения стирола - ценного мономера для получения синтетического каучука. .The invention relates to the field of petrochemical synthesis, in particular to a method for producing styrene, a valuable monomer for producing synthetic rubber. .

Известен способ получения стирола окислительным дегидрированием этилбензола на катализаторе,, содержащем фосфаты щелочноземельных металлов. При температуре 500°С, подаче смеси 'θ этилбензола (17 мл/ч), воздуха (185 мл/мин) и паров воды (104 мл/ч) конверсия этилбензола - 54,6% [1]. Выход стирола 50,0%, селективность реакции 91,6%. Недостатком такого 15 способа является низкий выход стирола .A known method of producing styrene by the oxidative dehydrogenation of ethylbenzene on a catalyst containing alkaline earth metal phosphates. At a temperature of 500 ° C, feeding a mixture of θ ethylbenzene (17 ml / h), air (185 ml / min) and water vapor (104 ml / h), the conversion of ethylbenzene is 54.6% [1]. The yield of styrene is 50.0%, the selectivity of the reaction is 91.6%. The disadvantage of this 15 method is the low yield of styrene.

Известен также способ получения алкенилароматических углеводородов, например стирола, окислительным де- 20 гидрированием этилбензола в присутствии окиси кремния при 400-700°С. Конверсия этилбензола (ЭБ) в стирол 45% [2].·There is also a known method for producing alkenyl aromatic hydrocarbons, for example styrene, by oxidative dehydrogenation of ethylbenzene in the presence of silica at 400-700 ° C. The conversion of ethylbenzene (EB) to styrene is 45% [2]. ·

Цель изобретения - повышение вы- хода целевого продукта.The purpose of the invention is to increase the yield of the target product.

Поставленная цель достигается описываемым способом получения стирола окислительным дегидрированием этилбензола при повышенной температуре в присутствии катализатора на основе окиси кремния, дополнительно содержащего окись стронция в количестве 7-14% от веса катализатора. Предпочтительно процесс проводить при 475-525°С.The goal is achieved by the described method of producing styrene by oxidative dehydrogenation of ethylbenzene at elevated temperature in the presence of a catalyst based on silicon oxide, additionally containing strontium oxide in an amount of 7-14% by weight of the catalyst. Preferably, the process is carried out at 475-525 ° C.

Процесс проводят на установке' про· точного типа (кварцевый реактор с диаметром 2 мм, длиной 40 см, объем катализатора 10 см³) при 475-525°С, мольном соотношении ЭБ и 0₂ от 1:1,2 до 1:2,скорости подачи этилбензола 4-7 мл/ч и с использованием в качест ве катализатора стронцийсиликата.The process is carried out on a flow-through installation (quartz reactor with a diameter of 2 mm, length 40 cm, catalyst volume 10 cm ³ ) at 475-525 ° С, molar ratio of EB and 0 ₂ from 1: 1.2 to 1: 2 an ethylbenzene feed rate of 4-7 ml / h and using strontium silicate as a catalyst.

Синтез стронцийсиликатного.катализатора осуществляют методом совместного осаждения. 8,3 г азотнокислого стронция растворяют в 300 мл дистиллированной во^ке и добавляют 10 г концентрированной H₂S0₄. Полученный раствор смешивают с 100 г силиката натрия, растворенного в 400 мл воды. Полученный гидрогель в течение 2 ч оставляют в (450 мл) 2,5%-ном аммиачном растворе и промывают дистиллированной водой до отсутствия ионов SC/j². Пасту 24 ч держат при комнатной температуре, потом формуют в маленькие цилиндры 30 (длина 3-5 мм, диаметр 1-2 мм) , 2-3 дня высушивают при комнатной температуре и подвергают ступенчатой прокалке в воздухе при 80, 150, 250, 450, 550°С (по 2-3 ч) и обработке 100%-ным водяным паром при 650°С. Полученный катализатор является рент- j геноаморфным, имеет удельную поверхность 170 м^г/г и химический со- .The synthesis of strontium silicate catalyst is carried out by the method of co-deposition. 8.3 g of strontium nitrate was dissolved in 300 ml of distilled ke ^ and 10 g of concentrated H ₂ S0 _4. The resulting solution was mixed with 100 g of sodium silicate dissolved in 400 ml of water. The resulting hydrogel is left in a (450 ml) 2.5% ammonia solution for 2 hours and washed with distilled water until there are no SC / j ² ions. The paste is kept at room temperature for 24 hours, then molded into small cylinders 30 (length 3-5 mm, diameter 1-2 mm), dried for 2-3 days at room temperature and subjected to stepwise calcination in air at 80, 150, 250, 450 , 550 ° C (2-3 hours each) and treatment with 100% water vapor at 650 ° C. The resulting catalyst is X-ray amorphous, has a specific surface area of 170 m ^g / g and chemical co.

став, вес.%: СгО 7, Б10_г 93. Аналогичным образом синтезированы другие образцы.becoming, wt.%: CrO 7, B10 _g 93. Other samples were synthesized in the same way.

В присутствии синтезированных катализаторов и при указанных условиях выход жидкого катализата составляет’' не менее 90% от пропущенного этилбензола, количество стирола 56,8- , 68,8%, бензола 0,1-0,4%, толуола 0,1-0,4% и С02. 3,0-4,5%.In the presence of synthesized catalysts and under the indicated conditions, the yield of liquid catalysis is `` at least 90% of the missed ethylbenzene, the amount of styrene 56.8-, 68.8%, benzene 0.1-0.4%, toluene 0.1-0 , 4% and CO2. 3.0-4.5%.

Пример 1. В качестве катализатора используют стронцийсиликат, содержащий 7 вес.% SrO и 93 вес.%Example 1. As a catalyst using strontium silicate containing 7 wt.% SrO and 93 wt.%

SiCL·. 20SiCL 20

Результаты проведения процесса з присутствии указанного катализатора представлены в таблице.The results of the process in the presence of the specified catalyst are presented in the table.

Температу- ра, °C Temperature ra ° C г-*'·— ЭБ g - * ' EB :СЦ 2 : SC 2 [ Скорость подачи этилбензола мп/ч [Ethylbenzene feed rate mp / h Конверсия, % Conversion% .Вы- ход • сти- рола, '% .You- move • style roll '% Се- лективность, % Se- lectivity,% 25 30 25 thirty 475 475 1: 1: 1,5 1,5 5 5 62,2 62,2 56,8 56.8 91, 3 91, 3 35 35 500 500 1 : 1 : 1,2 1,2 5 5 63,4 63,4 58,8 58.8 92,7 92.7 • • 500 500 1: 1: 1,7 1.7 7 7 65,6 65.6 60,8 60.8 92,7 92.7 40 40 515 515 1: 1: 2 2 5 5 70,0 70.0 .65,2 .65,2 93,1 . 93.1. 525 525 1: 1: 2 2 4 4 73,5 73.5 68,8 68.8 93,6 93.6

При мер 2. В качестве катализатора используют стронцийсиликат, содержащий 14 вес.% SrO и 86 вес.% SiO_a. При 510°С, соотношении ЭБ:О_гравном 1:1,8 и скорости подачи этилбензола 5 мл/ч выход стирола - 64% при конверсии этилбензола 68,7%. Селективность процесса 93%.Example 2. As a catalyst, strontium silicate containing 14 wt.% SrO and 86 wt.% SiO _{a is used} . At 510 ° C, an EB: O _g ratio of 1: 1.8 and an ethylbenzene feed rate of 5 ml / h, the styrene yield is 64% with an ethylbenzene conversion of 68.7%. The selectivity of the process is 93%.

Из приведенных примеров видно,что предлагаемый способ окислительного дегидрирования _:этилбензола превосходит по выходу стирола известный способ. При температурах 475-525°С, соотношении ЭБ:О_г от 1:1,2 до 1:2 и объемной скорости по жидкости 0,40,7 ч~* выход стирола составляет 56,868,8% при конверсии этилбензола 62,273,5% и селективности процесса 91,393,6%. Процесс проводится без разбавителей, что упрощает технологию процесса. Катализаторами служат дешевые и легкосинтезируемые стронцийсиликаты.From the above examples it is seen that the proposed method of oxidative dehydrogenation _: ethylbenzene surpasses the known method in the yield of styrene. At temperatures of 475-525 ° C, a ratio of DL: O _r from 1: 1.2 to 1: 2, and a space velocity of fluid 0,40,7 h ~ yield of styrene is at 56,868,8% ethylbenzene conversion 62,273,5% and a process selectivity of 91.393.6%. The process is carried out without diluents, which simplifies the process technology. The catalysts are cheap and easily synthesized strontium silicates.

Claims

The invention relates to the field of petrochemical synthesis, in particular, to a method for producing styrene, a valuable monomer for the preparation of synthetic rubber. A known method for producing styrene by the oxidative dehydrogenation of ethylbenzene on a catalysts, containing alkaline earth metal phosphates. At a temperature of 500 ° C, a mixture of ethylbenzene (17 ml / h), air (185 ml / min) and water vapor (104 ml / h ethylbenzene conversion - 54.6%) 1. The yield of styrene is 50.0%, the selectivity of the reaction is 91 , 6%. The disadvantage of this method is the low yield of styrene. Also known is a method of producing alkenyl aromatic hydrocarbons, such as styrene, by oxidative dehydrogenation of ethyl benzene in the presence of silicon oxide at 400-700 C. Conversion of ethyl benzene (EB) to styrene 45% 2. Purpose of the invention - increase in the yield of the target product. The goal is achieved by the described method to produce styrene by oxidative dehydrogenation of ethylbenzene at elevated temperature in the presence of silica-based catalysts, additionally containing strontium oxide in a quantity of 7-14% by weight of the catalyst. Preferably, the process is carried out at 475-525 ° C. type (quartz reactor with a diameter of 2 mm, length 40 cm, volume of catalyst 10 cm) at 475-525 ° С, molar ratio of EB and Og from 1: 1.2 to 1: 2, ethylbenzene feed rate 4-7 ml / h and using strontium silicate as catalyst. Synthesis of strontium silicate catalyst is carried out by co-precipitation. 8.3 g of strontium nitrate are dissolved in 300 ml distilled and 10 g of concentrated is added. The resulting solution is mixed with 100 g of sodium silicate dissolved in 400 ml of water. The obtained hydrogel is left in (450 ml) 2.5% ammonia solution for 2 hours and washed with distilled water until there are no ions 50. The paste is kept at room temperature for 24 hours, then molded into small cylinders (3-5 mm long, diameter 1-2 mm), dried for 2-3 days at room temperature and subjected to stepped dressing in air at 80, 150, 250, 450, (2-3 hours each) and treatment with 100% water vapor at 650С . The resulting catalyst is reagent amorphous, has a specificity of 170 and a chemical composition, weight,%: CrO 7, SiO 93. Other samples are synthesized in a similar way. In the presence of synthesized talizators and under the specified conditions, the yield of liquid catalyzate was not less than 90% of the missed ethylbenzene, the amount of styrene was 56.868, 8%, benzene 0.1-0.4%, toluene 0.1-0.4% and CO 2 . 3.0-4.5%. An example, Strontium silicate containing 7 wt.% SrO and 93 wt.% SiOp is used as a catalyst. The results of the process in the presence of the specified catalyst are presented in the table. Example 2. Strontium silicate containing 14 wt.% SrO and 86 wt.% SiOg is used as a catalyst. When the ratio of EE; O is 1: 1.8 and the feed rate of ethylbenzene is 5 ml / h, the styrene yield is 64% with ethylbenzene conversion 68.7%. The selectivity of the process is 93%. From the above examples, it can be seen that the proposed method of oxidative dehydrogenation: Ethylbenzene exceeds the known method in the yield of styrene. At temperatures of 475-525 ° C, a ratio of 36: 0 from 1: 1.2 to 1: 2 and a bulk velocity of 0.40, 7 hours, the styrene yield is 56.868, 8% with ethylbenzene conversion of 62.273, 5% and selectivity process 91,393, 6%. The process is carried out without diluents, which simplifies the process technology. The catalysts are cheap and easily synthesized strontium silicates. Claim 1. The method for producing styrene by oxidative dehydrogenation of ethylbenzene at elevated temperature in the presence of silicon oxide as a catalyst, characterized in that, in order to increase the yield of the target product, catalysts, additionally containing strontium oxide, are used in the amount of 7-14% of catalyst weight. 2. The method according to claim 1, that is, so that the process is carried out at 475-525 ° C. Sources of information taken into account in the examination 1. Japan Patent 45-13091, cl. 16 C 12, pub. 1970.

2. US patent 3497564, cl. 260-650, published. 1970 (prototype).