[go: up one dir, main page]

CN107201254B - A kind of desulfurization refining method of mixed liquefied petroleum gas - Google Patents

A kind of desulfurization refining method of mixed liquefied petroleum gas Download PDF

Info

Publication number
CN107201254B
CN107201254B CN201610150711.6A CN201610150711A CN107201254B CN 107201254 B CN107201254 B CN 107201254B CN 201610150711 A CN201610150711 A CN 201610150711A CN 107201254 B CN107201254 B CN 107201254B
Authority
CN
China
Prior art keywords
petroleum gas
liquefied petroleum
extraction
catalytic cracking
coking
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN201610150711.6A
Other languages
Chinese (zh)
Other versions
CN107201254A (en
Inventor
潘光成
赵杰
李涛
赵丽萍
常春艳
吴明清
陶志平
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Sinopec Research Institute of Petroleum Processing
China Petroleum and Chemical Corp
Original Assignee
Sinopec Research Institute of Petroleum Processing
China Petroleum and Chemical Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Sinopec Research Institute of Petroleum Processing , China Petroleum and Chemical Corp filed Critical Sinopec Research Institute of Petroleum Processing
Priority to CN201610150711.6A priority Critical patent/CN107201254B/en
Publication of CN107201254A publication Critical patent/CN107201254A/en
Application granted granted Critical
Publication of CN107201254B publication Critical patent/CN107201254B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G, C10K; LIQUEFIED PETROLEUM GAS; ADDING MATERIALS TO FUELS OR FIRES TO REDUCE SMOKE OR UNDESIRABLE DEPOSITS OR TO FACILITATE SOOT REMOVAL; FIRELIGHTERS
    • C10L3/00—Gaseous fuels; Natural gas; Synthetic natural gas obtained by processes not covered by subclass C10G, C10K; Liquefied petroleum gas
    • C10L3/12—Liquefied petroleum gas
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
    • C10G11/00—Catalytic cracking, in the absence of hydrogen, of hydrocarbon oils
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
    • C10G70/00—Working-up undefined normally gaseous mixtures obtained by processes covered by groups C10G9/00, C10G11/00, C10G15/00, C10G47/00, C10G51/00
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
    • C10G70/00—Working-up undefined normally gaseous mixtures obtained by processes covered by groups C10G9/00, C10G11/00, C10G15/00, C10G47/00, C10G51/00
    • C10G70/04—Working-up undefined normally gaseous mixtures obtained by processes covered by groups C10G9/00, C10G11/00, C10G15/00, C10G47/00, C10G51/00 by physical processes
    • C10G70/048—Working-up undefined normally gaseous mixtures obtained by processes covered by groups C10G9/00, C10G11/00, C10G15/00, C10G47/00, C10G51/00 by physical processes by liquid-liquid extraction
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
    • C10G70/00—Working-up undefined normally gaseous mixtures obtained by processes covered by groups C10G9/00, C10G11/00, C10G15/00, C10G47/00, C10G51/00
    • C10G70/04—Working-up undefined normally gaseous mixtures obtained by processes covered by groups C10G9/00, C10G11/00, C10G15/00, C10G47/00, C10G51/00 by physical processes
    • C10G70/06—Working-up undefined normally gaseous mixtures obtained by processes covered by groups C10G9/00, C10G11/00, C10G15/00, C10G47/00, C10G51/00 by physical processes by gas-liquid contact
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
    • C10G2300/00—Aspects relating to hydrocarbon processing covered by groups C10G1/00 - C10G99/00
    • C10G2300/20—Characteristics of the feedstock or the products
    • C10G2300/201—Impurities
    • C10G2300/202—Heteroatoms content, i.e. S, N, O, P
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
    • C10G2300/00—Aspects relating to hydrocarbon processing covered by groups C10G1/00 - C10G99/00
    • C10G2300/20—Characteristics of the feedstock or the products
    • C10G2300/201—Impurities
    • C10G2300/207—Acid gases, e.g. H2S, COS, SO2, HCN
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
    • C10G2400/00—Products obtained by processes covered by groups C10G9/00 - C10G69/14
    • C10G2400/26—Fuel gas

Landscapes

  • Chemical & Material Sciences (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Production Of Liquid Hydrocarbon Mixture For Refining Petroleum (AREA)

Abstract

The invention provides a method for refining mixed liquefied petroleum gas. The refining method provided by the invention is that the coking liquefied petroleum gas from a coking device is introduced into a riser reactor of a catalytic cracking device to carry out cracking reaction with catalytic cracking feed, then the coking liquefied petroleum gas is distilled from a fractionation system in the catalytic cracking device to form mixed liquefied petroleum gas mixed with the catalytic liquefied petroleum gas, then the mixed liquefied petroleum gas is sent to a hydrogen sulfide extraction device and a mercaptan extraction device to respectively remove hydrogen sulfide and mercaptan, and the sulfur content of the desulfurized liquefied petroleum gas product is not more than 10 mug/g. The refined mixed liquefied petroleum gas can be fractionated to obtain propylene products meeting the sulfur content requirement, and can be used as a raw material for producing low-sulfur MTBE.

Description

Desulfurization refining method of mixed liquefied petroleum gas
Technical Field
The present invention belongs to the field of refining hydrocarbon material.
Background
Liquefied Petroleum Gas (LPG) is an important petroleum refinery product, which mainly comprises catalytic LPG gas from a catalytic cracking unit and coking LPG gas from a coking unit, and is a mixture of mainly carbon-three hydrocarbons and carbon-four hydrocarbons. Uses of liquefied petroleum gas include use as a fuel for domestic or automotive use, and use as a chemical feedstock, for example, as a feedstock for methyl tert-butyl ether (MTBE) from which commercial propylene and synthetic gasoline antiknock agents are extracted. Liquefied petroleum gas usually needs to be desulfurized and refined to be used as a target product.
Unrefined liquefied petroleum gas contains harmful sulfides, mainly hydrogen sulfide and mercaptans, mainly methyl mercaptan, and other small amounts of sulfides including carbonyl sulfide (COS), sulfide, and the like. In comparison, the sulfide in the coking liquefied petroleum gas is more complex and higher than that in the catalytic liquefied petroleum gas, especially the proportion of non-mercaptan sulfur is large, and in addition, the coking liquefied petroleum gas is easy to carry coke powder from a coking device, and the amount of unstable diene and the amount of relatively heavy hydrocarbon components are more than that of the catalytic liquefied petroleum gas, so the coking liquefied petroleum gas is more difficult to carry out desulfurization refining than the catalytic liquefied petroleum gas.
The current industrialized refining method for liquefied petroleum gas desulfurization mainly comprises a continuous process of hydrogen sulfide extraction for removing hydrogen sulfide and mercaptan extraction for removing mercaptan. The hydrogen sulfide extraction is mostly performed by an alcohol amine extraction method, and the mercaptan extraction is mostly performed by an alkali liquor extraction method. The alcohol amine extraction is to contact alcohol amine compound (such as methyldiethanolamine and MDEA) solution with liquefied gas and absorb hydrogen sulfide in the liquefied gas, and the alcohol amine solution after absorbing the hydrogen sulfide is continuously used after desorption treatment. The alkali liquor extraction is to contact inorganic alkali liquor with liquefied gas after hydrogen sulfide is removed by alcohol amine extraction, and to absorb mercaptan in the liquefied gas, and the alkali liquor after mercaptan absorption is recycled after regeneration treatment. The liquefied petroleum gas after removing hydrogen sulfide and mercaptan becomes a refined product.
In order to obtain olefins which meet the sulfur content requirements (e.g., propylene, for the production of polypropylene, it is generally desirable that the sulfur content be no greater than 3mg/m3) And MTBE with low synthetic sulfur content (under the national five-gasoline standard, the sulfur content of the MTBE is generally required to be not more than 10 mu g/g), and the sulfur content of refined liquefied petroleum gas is generally required to be not more than 10 mu g/g or even lower by refineries. For the coking liquefied petroleum gas with high sulfur content and a large amount of non-mercaptan sulfur, the requirement of such low sulfur content after refining is difficult to achieve, and even the coking liquefied petroleum gas with the sulfur content of no more than 343mg/m is produced3The required civil liquefied petroleum gas product is difficult.For this reason, refineries generally separate a coker liquefied petroleum gas from a catalytic liquefied petroleum gas for desulfurization and purification, and usually perform gas fractionation on the purified catalytic liquefied petroleum gas to concentrate propylene, and use the liquefied petroleum gas from which hydrocarbons are separated as a raw material for synthesizing MTBE (extraction of an isobutylene component and etherification with methanol to produce MTBE), while using the purified coker liquefied petroleum gas only as a blended domestic fuel. Thus, olefins (propylene and isobutylene) in the coker liquefied petroleum gas are not utilized much better.
In a refinery, coking liquefied petroleum gas and catalytic liquefied petroleum gas are combined together to perform the continuous two-step desulfurization refining, but the outstanding problem in the operation is that non-mercaptan sulfur in the coking liquefied petroleum gas is difficult to remove, so that the sulfur content of the refined product is still relatively high, and as a result, the refined product is probably used only as civil fuel, the olefin resource is difficult to effectively utilize, the consumption of the alcohol amine in the alcohol amine extraction unit and the consumption of the alkali liquor in the alkali liquor extraction unit are both serious, and the operation cost is higher.
In the prior art, an alkali liquor extraction process is generally adopted in a liquefied petroleum gas mercaptan extraction process, and mainly comprises three steps of alkali liquor extraction, oxidation and reverse extraction, wherein the alkali liquor extraction step is to contact the liquefied petroleum gas with alkali liquor so that mercaptan in the liquefied petroleum gas is transferred into the alkali liquor, the alkali liquor oxidation step is to oxidize mercaptan absorbed by the alkali liquor into disulfide under a catalytic oxidation condition, and the reverse extraction step is to separate the oxidized alkali liquor from the disulfide in a reverse extraction manner of an organic solvent, so that the alkali liquor is recycled. Generally, for the back extraction of disulfide, low-sulfur hydrocarbon oil is mostly used as a solvent, such as hydrogenated naphtha, gasoline, light diesel oil and the like, and the back extraction solvent is treated by hydrogenation after being used. This is disadvantageous for refineries with no or insufficient hydrogen source. Moreover, naphtha, gasoline, light diesel oil and the like usually contain a certain amount of aromatic hydrocarbon, sometimes even have high aromatic hydrocarbon content, when the catalyst is used as a reverse extraction solvent, the catalyst is easy to generate a certain emulsification phenomenon with contacted alkali liquor, is not beneficial to the separation of a hydrocarbon phase and an alkali phase, and further influences the alkali extraction desulfurization effect of the liquefied petroleum gas.
It can be seen from the prior art that when the hydrocarbon material to be refined contains a high content of sulfides or a large proportion of non-thiolated sulfides in the contained sulfides, which are difficult to extract by lye, it is generally difficult to obtain the effect of deep desulfurization using conventional lye extraction techniques.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provides a desulfurization refining method which comprises the step of mixing coking liquefied petroleum gas and catalytic liquefied petroleum gas together, so that the sulfur content of the mixed liquefied petroleum gas after refining is not more than 10 mu g/g.
The refining method comprises the following continuous steps:
(1) introducing coking liquefied petroleum gas from a coking device into a catalytic cracking riser reactor of a catalytic cracking device, and carrying out cracking reaction with a catalytic cracking raw material entering a catalytic cracking riser, wherein relatively macromolecular hydrocarbon components and sulfides in the coking liquefied petroleum gas are respectively converted into relatively micromolecular hydrocarbons and sulfides;
(2) the coking liquefied petroleum gas subjected to cracking reaction and the catalytic liquefied petroleum gas formed by cracking the catalytic cracking raw material flow out from a fractionation system of a catalytic cracking device together, enter a hydrogen sulfide extraction unit to extract and remove hydrogen sulfide, then flow into a mercaptan extraction unit to remove mercaptan, and the desulfurized mixed liquefied gas becomes a low-sulfur liquefied petroleum gas product, wherein the sulfur content is not more than 10 mu g/g.
Wherein the coked liquefied petroleum gas from the coking device is injected into the catalytic cracking reactor through a nozzle.
Preferably, the hydrogen sulfide extraction unit adopts an alcohol amine extraction mode, and comprises an alcohol amine extraction process and an alcohol amine desorption process.
Wherein, the mercaptan extraction unit adopts an alkali liquor extraction mode and comprises three processes of alkali liquor extraction, alkali liquor oxidation and reverse extraction. Wherein the processes of alkali liquor extraction and alkali liquor oxidation can be processed according to the prior art. According to the method of the invention, in the reverse extraction process, the reverse extraction solvent can adopt low-sulfur hydrocarbon oil, such as hydrogenated naphtha, gasoline, light diesel oil and the like, and the reverse extraction solvent is treated by hydrogenation after being used. Preferably, a part of the desulfurized mixed fossil oil gas is separated out to be used as a reverse extraction solvent in the reverse extraction process, and the disulfide in the regenerated alkali liquor is removed through reverse extraction and then returned to the catalytic cracking riser reactor for treatment.
The refining method also comprises the steps of washing and coalescing the desulfurized mixed liquefied petroleum gas, and then obtaining the product.
In the present invention, if not otherwise stated, the catalytic cracking process, the alcohol amine extraction process, the alcohol amine desorption process, the alkali liquor extraction process, the alkali liquor oxidation and reverse extraction process, and the water washing and coalescence treatment process are all performed in a known manner, and the operation conditions of the respective processes are kept unchanged.
The coking liquefied petroleum gas is introduced into the catalytic cracking device for cracking reaction, so that relatively macromolecular hydrocarbon components and sulfides in the coking liquefied petroleum gas are respectively converted into relatively micromolecular hydrocarbons and sulfides, simultaneously, non-volatile pollutants (such as coke powder) carried in the coking liquefied petroleum gas are removed, the coking liquefied petroleum gas and the catalytic cracking liquefied petroleum gas flow out together after being treated by a fractionation system of the catalytic cracking device, and the mixed liquid fossil oil and the catalytic liquefied petroleum gas are relatively reduced in sulfur content and proportion of non-mercaptan sulfur and are relatively easy to remove compared with a direct mixture of the coking liquefied petroleum gas and the catalytic liquefied petroleum gas.
The coking liquefied petroleum gas is treated by the catalytic cracking device and is combined into the desulfurization and refining device of the catalytic liquefied petroleum gas for refining, and the refined catalytic liquefied petroleum gas is subjected to gas fractionation to extract propylene, so that the yield of the propylene in a refinery and the yield of MTBE products can be improved (more MTBE is produced by providing more isobutene components), the operation process is simplified, and the operation cost is reduced.
In the invention, the desulfurized liquefied petroleum gas is used as the reverse extraction solvent in the mercaptan extraction device, and because the desulfurized liquefied petroleum gas does not contain aromatic hydrocarbon components which are easy to emulsify with alkali liquor, the effect is obvious when disulfide generated in the regeneration process of the alkali liquor is removed, and the desulfurized liquefied petroleum gas is returned to the catalytic cracking cue tube reactor for treatment after being used, so that materials outside the device are not needed to be used as the reverse extraction solvent, and additional hydrogenation treatment is not needed, and the operation is more convenient.
Drawings
Fig. 1 schematically shows a preferred embodiment of the present invention.
FIG. 2 is a schematic flow diagram of an extraction desulfurization refining method in the prior art.
Fig. 1 is intended to generally represent the flow of a preferred embodiment of the present invention and is not intended to give details regarding vessels, heaters, coolers, pumps, compressors, valves, process control equipment, etc., which are essential equipment to those skilled in the art.
Coking raw materials of an oil refinery enter a coking device 4 for treatment through a pipeline 3, the obtained coking liquefied petroleum gas is introduced into a riser of a catalytic cracking device 2 through a pipeline 5 and is subjected to catalytic cracking reaction together with catalytic cracking raw materials entering the catalytic cracking device 2 through a pipeline 1, so as to obtain mixed liquefied petroleum gas, the mixed liquefied petroleum gas enters an alcohol amine extraction device 7 through a pipeline 6 to remove hydrogen sulfide (an alcohol amine desorption device is not shown), enters a conventional alkali liquor extraction device through a pipeline 8, is subjected to mercaptan removal through an alkali liquor extraction unit 9 and is discharged through a pipeline 10 to obtain a refined liquefied petroleum gas product. The alkali liquor which is discharged from the alkali liquor extraction unit 9 and absorbs mercaptan flows into an alkali liquor oxidation unit 12 through a pipeline 11, and under the action of air (not shown) and an oxidation catalyst, the mercaptide in the alkali liquor is oxidized into disulfide, so that the alkali liquor is regenerated. The regenerated alkali liquor mixed with disulfide after releasing air is mixed with a part of refined liquefied petroleum gas which is branched from the pipeline 10 and flows through the pipeline 14 through the pipeline 13 to be subjected to back extraction operation in the back extraction unit 15, the disulfide is back extracted into the part of the refined liquefied petroleum gas, the part of the refined liquefied petroleum gas mixed with disulfide is discharged through the pipeline 16 after being separated from the regenerated alkali liquor and is returned to the catalytic cracking device 2 for recycling treatment, and the separated regenerated alkali liquor (not shown) is returned to the alkali liquor extraction unit 9 for recycling use.
Fig. 2 is a prior art process. Different from the schematic diagram 1 of the invention, the coking liquefied petroleum gas from the coking device 3 is mixed with the catalytic cracking petroleum gas from the catalytic cracking device 2 through a pipeline 5 in a pipeline 6, and then the hydrogen sulfide is removed through the extraction of conventional alcohol amine and the mercaptan is removed through the extraction of conventional alkali liquor to obtain a refined liquefied petroleum gas product. Wherein, in the reverse extraction unit 15, the material (such as hydrogenated naphtha) outside the process is generally used as the reverse extraction solvent (flowing in through the line 14), and is generally sent out to the device (such as naphtha hydrogenation device) outside the process for additional treatment through the line 16 after the reverse extraction operation is completed.
Detailed Description
The present invention will be further described with reference to examples. The examples are intended to be generally representative of the flow of a preferred embodiment of the invention and are not intended to provide details regarding vessels, heaters, coolers, pumps, compressors, valves, process control equipment, etc., which are essential to those skilled in the art. The examples given are intended to illustrate the invention and are not intended to limit the invention in any way.
Example 1
The sulfur content of the coking liquefied petroleum gas produced by a coking device in a certain refinery is reduced to about 3000mg/m after the treatment of alcohol amine3The sulfur content is reduced to 200mg/m after the extraction by alkali liquor3～300mg/m3Left and right.
The refinery produces catalytic liquefied petroleum gas from catalytic cracking unit, and the sulfur content is reduced to about 200mg/m after alcohol amine treatment3Then the sulfur content is reduced to 5mg/m after the extraction by alkali liquor3。
According to the present invention, the coking liquefied petroleum gas produced from the coking unit is connected to the riser reactor of the catalytic cracking unit through a pipeline and is injected through a nozzle, and the coking liquefied petroleum gas and the catalytic cracking raw material generate a cracking reaction in the riser together. Then distilling a mixed liquefied petroleum gas from a fractionation system of the catalytic cracking unit, the mixed liquefied petroleum gas including a cracked-treated coked liquefied petroleum gas and a gas produced by cracking a catalytic cracking feedstockThe catalytic liquefied petroleum gas of (1). The sulfur content of the mixed fossil oil after alcohol amine extraction is about 250mg/m3Then the sulfur content is reduced to 10mg/m after the extraction by alkali liquor3。
In the reverse extraction link of the mercaptan extraction unit, desulfurized liquefied petroleum gas is used as a solvent for reverse extraction of disulfide, the volume ratio of the reverse extraction solvent to alkali liquor is 3:7, and the desulfurized liquefied petroleum gas is discharged to a catalytic cracking reactor for treatment when the sulfur content is accumulated to be about 6000 mu g/g-10000 mu g/g.
It can be seen that if the coking liquefied petroleum gas is not treated by catalytic cracking, the sulfur content can only be reduced to 200mg/m after the coking liquefied petroleum gas is extracted by alcohol amine and alkali liquor3～300mg/m3On the other hand, if the catalyst is pretreated by catalytic cracking, the sulfur content can be reduced to 10mg/m after the same alcohol amine extraction and alkali liquor extraction3The following shows the advantageous effects of the present invention.
Example 2
This example is used to illustrate the effect of using liquefied petroleum gas after desulfurization by alkali extraction as a reverse extraction solvent for removing disulfide in alkali solution.
In this example, sodium hydroxide solution was used as 20% by mass of the alkali solution in the alkali extraction unit for liquefied petroleum gas, and 200 μ g/g to 500 μ g/g of sulfonated cobalt phthalocyanine (commercially available product) was dissolved in the alkali solution, and the alkali solution having absorbed mercaptans was oxidized and regenerated as an oxidation catalyst.
The operation steps of the extraction, desulfurization and refining are as follows:
contacting sodium hydroxide alkali liquor with liquefied petroleum gas after hydrogen sulfide removal by alcohol amine solution (40% MDEA solution) in an extraction system, transferring mercaptan in the liquefied petroleum gas into the alkali liquor, and feeding the desulfurized liquefied petroleum gas into a tank area, wherein the volume ratio of the alkali liquor to the liquefied petroleum gas is 2:8, the temperature is 40 ℃, and the pressure is 1.4 MPa; separating the alkali liquor absorbing the mercaptan from the liquefied gas and then treating the alkali liquor and the liquefied gas in an oxidation system, wherein air serving as an oxidant is injected into the oxidation system according to twice the theoretical amount of oxidized mercaptan, the pressure of the oxidation system is 0.35MPa, the temperature of the oxidation system is 55 ℃, and the mercaptan sodium salt in the alkali liquor is oxidized into disulfide so as to regenerate the alkali liquor; mixing redundant air and disulfide with the oxidized alkali liquor, releasing air tail gas, and then putting the mixture into a reverse extraction system to contact with a reverse extraction solvent, wherein desulfurized liquefied petroleum gas is used as the reverse extraction solvent, the volume ratio of the desulfurized liquefied petroleum gas to the alkali liquor is 3:7, the reverse extraction solvent is recycled, the pressure of the reverse extraction system is 1.4MPa, and the temperature is 40 ℃; returning the alkali liquor after the back extraction to the extraction system for recycling.
For comparison, refined gasoline product (sulfur content not greater than 50 mug/g, distillation range 33-200 ℃) from refinery is used as reverse extraction solvent, and other technological parameters are similar, except that the pressure of the reverse extraction system is reduced to 0.35 MPa.
Table 1 gives the measurement data of the residual disulfide sulfur content in the regenerated alkali solution after back extraction, and the sulfur content is measured as follows: petroleum ether (without sulfur) with the temperature of 90-120 ℃ is fully mixed with the reversely extracted alkali liquor by the same mass, so that the disulfide remained in the reversely extracted alkali liquor is transferred into the petroleum ether, then the sulfur content in the petroleum ether is measured after standing and separating, and the sulfur content value is the sulfur content of the disulfide remained in the reversely extracted alkali liquor.
TABLE 1
Figure BDA0000942763890000071
It can be seen from the data in table 1 that, when the desulfurized liquefied petroleum gas is used as the stripping solvent, the content of disulfide sulfur in the alkali solution after stripping is much lower than that when refined gasoline is used as the stripping solvent, which indicates that the effect of using desulfurized liquefied petroleum gas as the stripping solvent is better. It has also been found in operation that when refined gasoline is used as the stripping solvent, the amount of disulfide remaining in the lye after stripping is sometimes considerable, possibly due to the emulsification with the lye taking place.
It can be inferred that when the desulfurized liquefied petroleum gas is used as the reverse extraction solvent, the effective utilization rate of the alkali liquor is higher, and the discharge of the alkali liquor is less.

Claims (7)

1. A desulfurization refining method of mixed liquefied petroleum gas comprises the following steps:
(1) introducing coking liquefied petroleum gas from a coking device into a catalytic cracking riser reactor of a catalytic cracking device, and carrying out cracking reaction with a catalytic cracking raw material entering a catalytic cracking riser, wherein relatively macromolecular hydrocarbon components and sulfides in the coking liquefied petroleum gas are respectively converted into relatively micromolecular hydrocarbons and sulfides;
(2) the coking liquefied petroleum gas subjected to cracking reaction and the catalytic liquefied petroleum gas formed by cracking the catalytic cracking raw material flow out from a fractionation system of a catalytic cracking device together, enter a hydrogen sulfide extraction unit to extract and remove hydrogen sulfide, then flow into a mercaptan extraction unit to extract and remove mercaptan, and the sulfur content of the desulfurized mixed fossil oil is not more than 10 mu g/g.
2. The process of claim 1, characterized in that the coker liquefied petroleum gas is injected through a nozzle into a catalytic cracking riser reactor of a catalytic cracking unit.
3. The method of claim 1, wherein the desulfurized mixed liquefied petroleum gas is subjected to water washing and agglomeration treatment, and then is formed into a product.
4. The method of claim 1, characterized in that the hydrogen sulfide extraction unit adopts an alcohol amine extraction mode, including alcohol amine extraction and alcohol amine desorption processes.
5. The method of claim 1, wherein the mercaptan extraction unit adopts a lye extraction mode, and comprises three processes of lye extraction, lye oxidation and reverse extraction.
6. The method of claim 5, wherein a portion of the desulfurized mixed fossil oil is removed as a stripping solvent for a stripping process.
7. The method of claim 6, characterized in that the part of the desulfurized mixed liquefied petroleum gas is returned to the catalytic cracking riser reactor after being stripped of the disulfides in the regenerated alkali liquor by back extraction.
CN201610150711.6A 2016-03-16 2016-03-16 A kind of desulfurization refining method of mixed liquefied petroleum gas Active CN107201254B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201610150711.6A CN107201254B (en) 2016-03-16 2016-03-16 A kind of desulfurization refining method of mixed liquefied petroleum gas

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201610150711.6A CN107201254B (en) 2016-03-16 2016-03-16 A kind of desulfurization refining method of mixed liquefied petroleum gas

Publications (2)

Publication Number Publication Date
CN107201254A CN107201254A (en) 2017-09-26
CN107201254B true CN107201254B (en) 2021-01-08

Family

ID=59903539

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201610150711.6A Active CN107201254B (en) 2016-03-16 2016-03-16 A kind of desulfurization refining method of mixed liquefied petroleum gas

Country Status (1)

Country Link
CN (1) CN107201254B (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108939750A (en) * 2018-06-25 2018-12-07 珠海恒基达鑫国际化工仓储股份有限公司 A kind of condensate Deodor technique
CN111569624B (en) * 2019-02-19 2022-06-03 中国石油天然气股份有限公司 Device and method for treating malodorous gas containing mercaptan

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1478865A (en) * 2002-08-29 2004-03-03 中国石油化工股份有限公司 Method for increasing propylene production and reducing olefin content in gasoline by using C4 fraction
JP2006316154A (en) * 2005-05-12 2006-11-24 Idemitsu Kosan Co Ltd Liquefied petroleum gas for LP gas type fuel cell, desulfurization method thereof and fuel cell system
CN101962566A (en) * 2009-07-21 2011-02-02 宁波中一石化科技有限公司 Mercaptan removed alkali liquid oxidation regeneration method and device thereof

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101665710B (en) * 2008-09-02 2014-03-26 李莉 Method and device for catalytic conversion of light Hydrocarbon

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1478865A (en) * 2002-08-29 2004-03-03 中国石油化工股份有限公司 Method for increasing propylene production and reducing olefin content in gasoline by using C4 fraction
JP2006316154A (en) * 2005-05-12 2006-11-24 Idemitsu Kosan Co Ltd Liquefied petroleum gas for LP gas type fuel cell, desulfurization method thereof and fuel cell system
CN101962566A (en) * 2009-07-21 2011-02-02 宁波中一石化科技有限公司 Mercaptan removed alkali liquid oxidation regeneration method and device thereof

Also Published As

Publication number Publication date
CN107201254A (en) 2017-09-26

Similar Documents

Publication Publication Date Title
CN101815565B (en) Improved separation process
US4199440A (en) Trace acid removal in the pretreatment of petroleum distillate
CN103189117B (en) Separation process
CN104370708B (en) The method of the thick product of a kind of purifying methyl tertiary butyl ether and the method for production methyl tertiary butyl ether
CN102851068B (en) Gasoline desulfurization method
HU205164B (en) Continuous process for extracting mercaptan from basic material with high olefin content
CN101100616A (en) Combined process for removing mercaptan from gasoline
CN101275085B (en) Combined method for gasoline desulfurization
JP2021514022A (en) Additives for supercritical water processes to upgrade heavy oils
CN103911177B (en) A kind of saturated liquid hydrocarbon deep desulfurization method
CN107201254B (en) A kind of desulfurization refining method of mixed liquefied petroleum gas
CN107201255B (en) A kind of desulfurization refining method and device of mixed liquefied petroleum gas
US8894845B2 (en) Alkali metal hydroprocessing of heavy oils with enhanced removal of coke products
CN104403688A (en) Deep desulfurization and refining combined technology for liquefied petroleum gas
CN102851069B (en) Gasoline desulfurization method
CN105218325B (en) Preparation process of low-sulfur methyl tert-butyl ether
CN108424786B (en) Separation method of gasoline fraction and gasoline desulfurization method
CN108329946B (en) A kind of method for separating gasoline fraction and gasoline desulfurization method
CN102604672B (en) Method for producing low-sulfur gasoline
CN105567313B (en) A kind of production method of high-octane rating low-sulphur oil
US9453167B2 (en) Methods and apparatuses for processing hydrocarbon streams containing organic nitrogen species
CN103740405A (en) Alkali cleaning-extraction-hydrogenation combined process for producing low-sulfur-content gasoline
CN119463936A (en) A method and system for continuous deep desulfurization of liquefied petroleum gas
CN103193603B (en) MTBE adsorbs the renovation process of desulfurization solvent
CN220579201U (en) A system for extraction and demercaptanization of light oil

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant