Liquefied gas hydrogenation olefin removal and desulfurization device

Abstract

The utility model discloses a liquefied gas hydrogenation olefin removal and desulfurization device which mainly comprises a feed pump, a reaction heating furnace, a hydrofining reactor, a reaction effluent / mixed feed heat exchanger, a reaction effluent air cooler, a reaction effluent cooler, a low-pressure separator, a circulating hydrogen compressor, a liquefied gas booster pump, a liquefied gas desulfurization tower and a fine desulfurization tank, the system is characterized in that the feed pump is communicated with the reaction effluent / mixed feed heat exchanger, the reaction effluent / mixed feed heat exchanger is communicated with the reaction heating furnace, the reaction heating furnace is communicated with the hydrofining reactor, the hydrofining reactor is communicated with the reaction effluent / mixed feed heat exchanger, and the hydrofining reactor is communicated with the reaction effluent / mixed feed heat exchanger. The reaction effluent / mixed feed heat exchanger is communicated with a reaction effluent air cooler, the reaction effluent air cooler is communicated with a reaction effluent cooler, the reaction effluent cooler is communicated with a low-pressure separator, the low-pressure separator is communicated with a recycle hydrogen compressor and a liquefied gas booster pump, the liquefied gas booster pump is communicated with a liquefied gas desulfurization tower, and the liquefied gas desulfurization tower is communicated with a liquefied gas desulfurization tower. And the liquefied gas desulfurization tower is communicated with the fine desulfurization tank.

Description

TECHNICAL FIELD

[0001] The present application relates to liquefied gas hydrogenation refining technology in the field of petrochemical industry, and particularly relates to a liquefied gas hydrogenation deolefin desulfurization device. BACKGROUND

[0002] Liquefied gas is a basic chemical raw material in the petrochemical industry. The liquefied gas obtained from oil refineries mainly includes one or two of propane, propylene, butane and butene, and also contains a small amount of pentane, pentene and trace amounts of sulfide impurities. The liquefied gas associated with oil and gas fields basically does not contain olefins, and its main components are ethane, propane, butane and other alkanes, but contains a small amount of hydrogen sulfide and organic sulfur. C3 and C4 hydrocarbons in liquefied gas are important raw materials for light hydrocarbon processing industry chain, which can be used to produce ethylene, propylene, maleic anhydride, succinic anhydride, BDO, PBS, MTBE, acrylonitrile, epoxy propane and other chemical products. When liquefied gas is used as raw material for alkanes cracking device, olefins will polymerize, cyclize, condense and coking in the cracking furnace, as raw material for alkanes dehydrogenation device, olefins will cause catalyst carbon deposition, as raw material for n-butane to maleic anhydride device, olefins will cause hot spots in the catalyst bed and reactor temperature runaway; and sulfur in liquefied gas will cause catalyst poisoning in downstream devices and product unqualified and other influences. The raw material liquefied gas involved in the present application is mainly the by-product liquefied gas of catalytic cracking, coking and other devices and the light hydrocarbon by-product of oil and gas fields. After deolefin desulfurization refining, liquefied gas can be used as a chemical raw material with higher value.

[0003] The sulfides contained in liquefied gas are mainly hydrogen sulfide and mercaptans, and also contain a small amount of carbonyl sulfur, sulfide and disulfide to varying degrees. Among them, hydrogen sulfide is basically removed by alcohol amine solution absorption method, while the removal of mercaptans has always been a difficulty in liquefied petroleum gas desulfurization, and is also the focus of research and development at home and abroad.

[0004] US patent US2882224 discloses the earliest process developed by UOP for refining light oil products with alkaline solution, Merox process. The basic principle of the technology is to add sulfonated cobalt phthalocyanine or polyphthalocyanine cobalt catalyst in NaOH aqueous solution to make mercaptan in liquefied gas react with NaOH to form sodium mercaptide which is transferred to the alkaline solution. Under the action of sulfonated cobalt phthalocyanine catalyst, mercaptide is oxidized to disulfide by air, and after separation, the alkaline solution can be regenerated and recycled. The technology needs to consume a large amount of caustic soda and catalyst, and the alkaline solution needs to be replaced frequently, not only causing a large amount of alkali residue discharge, but also the process has insufficient desulfurization depth, and the disulfide in the oxidized regenerant alkaline solution is difficult to separate, thus often causing the total sulfur content of the refined liquefied gas to exceed the standard. In view of the above problems, UOP has continuously improved the Merox technology, and so far has formed a series of liquefied petroleum gas desulfurization processes, which are disclosed in patents US2988500, US3108081, US4049572, US4626341. The overall technical progress is to reduce the amount of caustic soda and improve the desulfuration rate.

[0005] Chinese patent 103965984A discloses a method for catalytic desulfurization of liquefied petroleum gas. In the method, liquefied gas is mixed with hydrogen and then subjected to thioetherization reaction in a reactor to convert mercaptan in liquefied petroleum gas into high-boiling thioether compounds, and part of diene is selectively saturated. The method needs to remove hydrogen sulfide and carbonyl sulfur before treatment, and the diene in liquefied gas cannot be completely saturated, which is not suitable for liquefied gas refining that needs to remove olefins and hydrogen sulfide.

[0006] In order to solve the problem of alkaline solution discharge, Chinese patent CN1702157A discloses a method for refining liquefied petroleum gas. The method first removes hydrogen sulfide in liquefied gas with alcohol amine solution, then generates hydrogen sulfide and carbon dioxide by hydrolysis to remove carbonyl sulfur, and removes hydrogen sulfide by flowing through a desulfurizer bed. Liquid oxygen supplementing agent of tert-butyl hydroperoxide is added to oxidize mercaptan into disulfide. Finally, refined liquefied petroleum gas and heavy fraction enriched in disulfide are obtained by gas fractionation and rectification. Although the method can completely convert mercaptan in liquefied petroleum gas by controlling the amount of added oxygen supplementing agent, the decomposition of tert-butyl hydroperoxide produces isobutyl alcohol, which brings difficulties to the separation and purification of liquefied petroleum gas products, and may have adverse effects on further processing and utilization. In addition, hydrogen sulfide, carbonyl sulfur and mercaptan in liquefied gas need to be removed by three methods, which has complex process, large device area and high energy consumption.

[0007] Chinese patent CN117757537 A discloses a liquefied gas deep desulfurization method, which first removes hydrogen sulfide in liquefied gas by using alcohol amine solution, then liquefied gas and hydrogen enter the reactor for hydrogen desulfurization reaction, and after desulfurization, liquefied gas enters the separator for gas-liquid separation, and the separated liquid phase enters the alcohol amine absorption tower to absorb sulfides generated in the reaction. The method uses two alcohol amine solution processes to remove hydrogen sulfide, which is long but cannot guarantee deep removal of hydrogen sulfide, and the catalyst of the method has the characteristics of low olefin saturation rate, which is not suitable for liquefied gas refining requirements that require deep olefin removal and desulfurization.

[0008] Chinese patent CN115216333 A discloses a liquefied gas deep desulfurization method, in which liquefied gas and hydrogen are subjected to selective desulfurization reaction in a fluidized bed reactor, the reaction gas is discharged from the top of the reactor and enters the alcohol amine absorption tower to remove hydrogen sulfide, and the liquefied gas desulfurization product is obtained. The reactor temperature of the method is 50-150℃, the reaction gas directly entering the alcohol amine absorption tower will cause serious foaming in the tower, the reaction pressure is 0.3MPa-2.0MPa, and at a lower pressure, liquefied gas and hydrogen are both in gas phase and are difficult to separate, which requires deep cooling means to condense liquefied gas into liquid, and the method does not have the implementability of industrial application.

[0009] Olefin hydrogenation saturation is the most effective method for removing olefins, and Chinese patent CN106753561 A discloses a liquefied gas hydrogenation method for preparing ethylene cracking material, in which liquefied gas and hydrogen pass through the hydrogenation reactor in parallel flow, and olefin saturation reaction is carried out in the reactor. The method can remove olefins in liquefied gas, but is not suitable for processing sulfur-containing liquefied gas, on the one hand, sulfur compounds in liquefied gas will cause poisoning of noble metal catalyst, on the other hand, the method does not involve removal of sulfur components in liquefied gas. Utility model content

[0010] The utility model aims at providing a liquefied gas hydrogenation deolefin desulfurization device, and the liquefied gas is subjected to olefin saturation and mercaptan conversion reactions under the conditions of hydrogenation refining catalyst and hydrogen, raw materials for downstream light hydrocarbon deep processing devices are produced, and device energy consumption, investment and land occupation are reduced.

[0011] In order to achieve the above-mentioned purpose, the technical scheme adopted by the utility model is:

[0012] The utility model relates to a liquefied gas hydrogenation deolefin desulfurization device which mainly comprises a feed pump, a reaction heating furnace, a hydrogenation refining reactor, a desulfurization reactor, a reaction effluent / mixed feed heat exchanger, a reaction effluent air cooler, a reaction effluent cooler, a low-pressure separator and a circulating hydrogen compressor.

[0013] The utility model relates to a liquefied gas hydrogenation deolefin desulfurization device further characterized in that the hydrogenation refining reactor is a fixed bed reactor, and the liquefied gas and hydrogen in the reactor are in a gaseous state.

[0014] The utility model relates to a liquefied gas hydrogenation deolefin desulfurization device further characterized in that the desulfurization reactor is a gas-phase high-temperature adsorption desulfurization device, and the operating temperature of the desulfurization reactor is 210-320 DEG C.

[0015] The utility model relates to a liquefied gas hydrogenation deolefin desulfurization device further characterized in that the desulfurization reactor is provided with one or two desulfurization reactors, and when two desulfurization reactors are provided, they can be connected in series or in parallel.

[0016] The utility model relates to a liquefied gas hydrogenation deolefin desulfurization device further characterized in that the desulfurization reactor is filled with zinc oxide or iron oxide desulfurizer, and the volume space velocity of the gaseous phase feed of the desulfurization reactor relative to the desulfurizer is 200-1000 h -1 .

[0017] The utility model relates to a liquefied gas hydrogenation deolefin desulfurization device further characterized in that the reaction effluent / mixed feed heat exchanger is provided with multiple heat exchangers connected in series, and is divided into a feed vaporization zone and a temperature rising zone.

[0018] The utility model relates to a liquefied gas hydrogenation deolefin desulfurization device further characterized in that the reaction gas is cooled by an air cooler and a coolant medium cooler, the operating temperature of the low-pressure separator is 20-45 DEG C, the operating pressure is 2.0-3.0 MPAG, the low-pressure separator is provided with separation internals, and the gas-liquid two-phase separation is strengthened to reduce the amount of light hydrocarbons carried in the circulating hydrogen and the amount of hydrogen carried in the refined liquefied gas product.

[0019] Compared with the prior art, the utility model has the following advantages:

[0020] 1) Hydrofining reactor for olefin saturation, hydrodesulfurization reaction, removal of olefins and mercaptans and other impurities in liquefied gas.

[0021] 2) High temperature gas phase desulfurization reactor is used, and the sulfur capacity is 2-3 times of that of low temperature adsorption, so that the consumption of desulfurizer is greatly reduced.

[0022] 3) Hydrodesulfurization and adsorption desulfurization hydrogen process is used, so that the process is shortened, and the equipment investment and land occupation are reduced.

[0023] 4) The reaction effluent increases the cooling of the refrigerant medium, strengthens the separation effect of the circulating hydrogen and the refined liquefied gas, and improves the hydrogen purity in the circulating hydrogen. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 It is a schematic view of a liquefied gas hydrogenation deolefin desulfurization device.

[0025] The reference signs shown in the figure are: 1-feeding pump; 2-reaction effluent / mixed feed heat exchanger; 3-reaction heating furnace; 4-hydrofining reactor; 5-desulfurization reactor; 6-reaction effluent air cooler; 7-reaction effluent cooler; 8-low pressure separator; 9-circulating hydrogen compressor; 10-gas phase distributor; 11-inertial separator; 12-momentum defoamer. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings Figure 1 Further description of the present application:

[0027] As Figure 1 shown, the liquefied gas hydrogenation deolefin desulfurization device of the utility model comprises a feeding pump 1, a reaction effluent / mixed feed heat exchanger 2, a reaction heating furnace 3, a hydrofining reactor 4, a desulfurization reactor 5, a reaction effluent air cooler 6, a reaction effluent cooler 7, a low pressure separator 8 and a circulating hydrogen compressor 9; the hydrofining reactor 4 is provided with a gas phase distributor 10 at the inlet; the low pressure separator 8 is provided with an inertial separator 11 at the inlet, and is provided with a momentum defoamer 12 at the gas phase outlet.

[0028] The outlet of the feed pump 1 is communicated with the cold side inlet of a reaction effluent / mixed feed heat exchanger 2, the cold side outlet of the reaction effluent / mixed feed heat exchanger is communicated with a reaction heating furnace 3, the reaction heating furnace 3 is communicated with the top inlet of a hydrofining reactor 4, the bottom outlet of the hydrofining reactor 4 is communicated with the top inlet of a desulfurization reactor 5, the bottom outlet of the desulfurization reactor 5 is communicated with the hot side inlet of the reaction effluent / mixed feed heat exchanger 2, the hot side outlet of the reaction effluent / mixed feed heat exchanger 2 is communicated with a reaction effluent air cooler 6, the reaction effluent air cooler 6 is communicated with a reaction effluent cooler 7, the reaction effluent cooler 7 is communicated with a low-pressure separator 8, the gas phase outlet of the low-pressure separator 8 is communicated with the inlet of a recycle hydrogen compressor 9, and the outlet of the recycle hydrogen compressor 9 is communicated with the cold side inlet of the reaction effluent / mixed feed heat exchanger 2.

[0029] The liquefied gas hydrogenation deolefin desulfurization device of the utility model refers to the process of Figure 1 The raw material liquefied gas is pressurized by a feed pump 1, mixed with recycle hydrogen, heated by a reaction effluent / mixed feed heat exchanger 2 and a reaction feed heating furnace 3, and then sent to a hydrofining reactor 4.

[0030] The above is only a typical embodiment of the utility model, and those skilled in the art can make proper modification and improvement on the basis of the embodiment, but the utility model has the same essence, and also falls within the protection scope of the utility model.

Claims

1. A liquefied gas hydrodeolefinization desulfurization apparatus mainly consisting of a feed pump, a reaction heating furnace, a hydrofining reactor, a desulfurization reactor, a reaction effluent / mixed feed heat exchanger, a reaction effluent air cooler, a reaction effluent cooler, a low-pressure separator, and a recycle hydrogen compressor; characterized by: The reaction heating furnace is communicated with a hydrofining reactor, the hydrofining reactor is communicated with a desulfurization reactor, the desulfurization reactor is communicated with a reaction effluent / mixed feed heat exchanger, the reaction effluent / mixed feed heat exchanger is communicated with a reaction effluent air cooler, the reaction effluent air cooler is communicated with a reaction effluent cooler, the reaction effluent cooler is communicated with a low-pressure separator, and the low-pressure separator is communicated with a recycle hydrogen compressor.

2. The liquefied gas hydrodeolefinization desulfurization apparatus according to claim 1, characterized by: The hydrofining reactor is a fixed bed reactor, and the liquefied gas and hydrogen in the reactor are in a gas phase state.

3. The liquefied gas hydrodeolefinization desulfurization apparatus according to claim 1, characterized by: A feed gas phase distributor is arranged at the inlet of the hydrofining reactor, and the mixed liquefied gas uniformly enters the catalyst area of the reactor through the feed gas phase distributor.

4. The liquefied gas hydrodeolefinization desulfurization apparatus according to claim 1, characterized by: The reaction effluent / mixed feed heat exchanger is provided with multiple series connections, and is divided into a feed vaporization zone and a temperature rising zone.

5. The liquefied gas hydrodeolefinization desulfurization apparatus according to claim 1, characterized by: The low-pressure separator is provided with a separation inner part, so as to strengthen the gas-liquid two-phase separation, reduce the light hydrocarbon carrying amount in the recycle hydrogen and the hydrogen carrying amount in the refined liquefied gas product.

6. The liquefied gas hydrodeolefinization desulfurization apparatus according to claim 1, characterized by: The desulfurization reactor is a gas phase high-temperature adsorption desulfurization, and the desulfurization reactor is provided with one or two.

7. The liquefied gas hydrodeolefinization desulfurization apparatus according to claim 6, characterized by: The desulfurization reactor is filled with zinc oxide or iron oxide desulfurizer.

Images