CN112342053B

CN112342053B - Method for treating waste liquid of co-production process of epoxypropane by co-oxidation method

Info

Publication number: CN112342053B
Application number: CN201910720920.3A
Authority: CN
Inventors: 陈学峰; 魏晓丽; 龚剑洪; 张久顺
Original assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Current assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Priority date: 2019-08-06
Filing date: 2019-08-06
Publication date: 2022-05-17
Anticipated expiration: 2039-08-06
Also published as: CN112342053A

Abstract

The invention relates to the field of catalytic cracking, and discloses a method for treating waste liquid in a co-oxidation co-production process of propylene oxide, wherein the method comprises the following steps: sequentially contacting the co-production process waste liquid of the propylene oxide and the heavy raw oil with a catalytic cracking catalyst to carry out catalytic cracking reaction to obtain a reaction product and a spent catalyst; separating the reaction product from the spent catalyst, regenerating the spent catalyst, and using the regenerated catalyst as the catalytic cracking catalyst. The treatment method for treating the waste liquid of the co-oxidation process and co-production process of the propylene oxide can convert the waste liquid of the co-oxidation process and co-production process of the propylene oxide, which is basically worthless, into high-value products through a mature process, so that the resources are recycled, the treatment difficulty of the waste liquid of the co-oxidation process and co-production process of the propylene oxide is not increased by adopting the treatment method of the catalytic cracking, and the yield of the propylene and the butylene is improved.

Description

Method for treating waste liquid of co-production process of epoxypropane by co-oxidation method

Technical Field

The invention relates to a method for treating waste liquid of co-production process of propylene oxide by a co-oxidation method.

Background

Propylene Oxide (PO), also called methyl ethylene Oxide and Propylene Oxide, is the third largest Propylene derivative second to polypropylene and acrylonitrile, and is an important basic organic chemical synthesis raw material. The current industrialized production processes of propylene oxide include chlorohydrin process, co-oxidation process, cumene oxidation process, and direct hydrogen peroxide oxidation process. The chlorohydrin method is most widely applied, has low requirement on the raw material propylene, good product selectivity, large operation load elasticity and short production process flow, and greatly reduces the capital construction cost, but the chlorohydrin method has low product quality, needs to consume a large amount of water resources in the production process, generates a large amount of waste water and waste residues, and can discharge 40-50 tons of high-salinity sewage and 1-1.5 tons of waste residues per 1 ton of propylene oxide produced. Compared with a chlorohydrin method, the co-oxidation method has great advantages in solving the problems of three-waste pollution, high corrosion and environmental protection, greatly improves the production scale of a single set of device, can share part of cost for co-production products (styrene, tert-butyl alcohol, methyl tert-butyl ether or cumene peroxide), and has stronger market competitive advantage.

However, in the production process of propylene oxide coproduced with methyl tert-butyl ether (PO/MTBE), high-concentration waste liquid is discharged in the production process, and from the result analysis, most of main organic pollutants in the waste liquid are formic acids, esters, alcohols, aldehydes, acetone, butanone, hydrocarbons and the like, and in addition, part of pollutants such as propylene oxide, pyrazoles, furans, pyrans and the like are also contained. The byproducts are generally used as fuel of a heating furnace in public works, but waste liquid with water is easy to cause heating furnace fluctuation and the fuel economy is low, and if the part of ketones, alcohols or ethers can be further processed and utilized, the overall benefit of the process is greatly improved.

A large amount of high-concentration wastewater exists in the process of preparing olefin by alcohol dehydration, and the wastewater is firstly treated into low-concentration wastewater by means of extraction, steam stripping and the like at present and then subjected to biochemical treatment, however, the treatment method has high cost and complex flow. The high concentration waste water in the process of preparing ethylene by cracking ethanol contains ethanol, ether, ethylene, C3 and hydrocarbon organic waste water. For example, the method disclosed in CN105036437A adopts a process in which an anionic polyacrylamide solution is added to a high-concentration wastewater from the dehydration of ethanol to produce ethylene at a certain ratio for flocculation, precipitation, filtration, and finally rectification. For another example, CN104230618A discloses a process for recycling water resources in the production of ethylene by ethanol dehydration, in which a first-stage separation tower is used to separate high-concentration wastewater, and then steam stripping, inorganic salt blending, mechanical filtration, anaerobic treatment, flocculation, precipitation, filtration and other means are used to achieve recycling. The wastewater from the dimethyl ether production by methanol cracking also contains high concentration organic compounds. For example, CN101376550 discloses a method in which wastewater is separated into two streams of wastewater rich in organic matters and wastewater poor in organic matters by distillation, and then the wastewater rich in organic matters is subjected to membrane separation to recover organic matters, and the wastewater poor in organic matters is subjected to biochemical treatment. The above-mentioned wastewater treatment method is applicable to the treatment of high-concentration wastewater containing PO/MTBE, but the treatment process is long, the cost is high, and it is difficult to reuse useful substances in wastewater.

CN106336061A discloses a treatment method for high-concentration wastewater from cracking PO byproduct TBA to prepare isobutene, which adopts hydrogenolysis method to decompose ethers and esters in the wastewater into alcohol compounds, aldehyde ketone generates alcohol, olefin is hydrogenated to generate saturated alkane, the COD of the wastewater is reduced to below 500ppm by means of azeotropic distillation of micromolecule alcohol and water, water insolubilization of macromolecule alcohol and alkane, flash evaporation, coagulation separation and the like, and then the wastewater is discharged after biochemical treatment.

CN103086874A discloses a method for utilizing tertiary butanol co-produced by a propylene and isobutane co-oxidation process propylene oxide production device. The method comprises the steps of vaporizing a tert-butyl alcohol solution containing acetone, which is a byproduct of the device, forming a mixed gas with air, diluent gas and the like in a certain proportion, preheating, and then carrying out first-stage oxidation, adjusting the composition and temperature of an oxidation product obtained by the first-stage oxidation, and then carrying out second-stage oxidation, wherein an oxidation product obtained by the second-stage oxidation is absorbed to obtain a crude methacrylic acid aqueous solution which can be used for refining.

CN103936574A discloses a method for preparing high-purity methyl isobutyl ketone by using industrial by-product waste liquid acetone. The method directly passes the industrial byproduct, namely the waste liquid acetone and hydrogen through a fixed bed tubular reactor filled with a heterogeneous catalyst, and the acetone and impurities difficult to separate are respectively converted into MIBK and substances easy to separate from the product. Rectifying and purifying the reaction product to obtain the high-purity methyl isobutyl ketone.

The method for treating the high-concentration waste liquid in the production of the propylene oxide can realize the recycling of valuable components in the waste liquid, but is only limited to a certain component, the separation and subsequent product refining processes are long, a newly-built device and investment are required, the cost is high, and the method is not economical for improving the benefit of resource recycling. If the low-value waste liquid can be converted into a high-value product through a simple and mature process, the method is more economical and effective.

Disclosure of Invention

The invention aims to provide a novel method for treating the waste liquid of the co-production process of the propylene oxide by the co-oxidation method, which can realize the recycling of valuable components in the waste liquid and improve the yield of the low-carbon olefin propylene and butylene on the premise of not increasing the treatment difficulty of the waste liquid.

The inventor of the invention finds that the co-oxidation method co-production process waste liquid of the propylene oxide contains more oxygen-containing compounds of C3 and C4, and the co-oxidation method co-production process waste liquid of the propylene oxide and the heavy raw oil are contacted with a catalytic cracking catalyst in sequence to carry out catalytic cracking, namely, the device is slightly modified on the basis of utilizing a mature heavy raw oil catalytic cracking process device, and the oxygen-containing compounds of C3 and C4 in the co-oxidation method co-production process waste liquid of the propylene oxide are converted into low-carbon olefin products of propylene and butylene with higher values through a proper feeding sequence and a proper reaction environment, and the catalytic cracking of the heavy raw oil is not influenced. On the one hand, the method realizes the recycling of the waste liquid resource of the co-production process of the basically worthless propylene oxide so as to produce high-value chemical raw materials, greatly improves the economic benefit of the co-oxidation co-production process device of the propylene oxide, and on the other hand, does not increase the treatment difficulty of the waste liquid of the co-production process of the propylene oxide.

Preferably, the invention adopts the riser reactor to carry out catalytic cracking on the co-production process waste liquid of the propylene oxide co-oxidation method and the heavy raw oil, slightly changes the device on the basis of utilizing the riser reactor used for the catalytic cracking of the heavy raw oil, realizes effective treatment on the co-production process waste liquid of the propylene oxide co-oxidation method through the arrangement of a proper feed inlet position and a reaction environment, and can further improve the yield of the low-carbon olefin products propylene and butylene.

In order to achieve the purpose, the invention provides a method for treating waste liquid in a co-oxidation process co-production process of propylene oxide, wherein the method comprises the following steps: co-producing process waste liquid and heavy raw oil by co-oxidation of propylene oxide, and contacting with a catalytic cracking catalyst in sequence to perform catalytic cracking reaction to obtain a reaction product and a spent catalyst; separating the reaction product from the spent catalyst, regenerating the spent catalyst, and using the regenerated catalyst as the catalytic cracking catalyst.

Preferably, the co-oxidation process co-production process waste liquid and the heavy raw oil of the propylene oxide are fed into the riser reactor to contact with the catalytic cracking catalyst for catalytic cracking reaction, and the feed inlet of the co-oxidation process co-production process waste liquid of the propylene oxide is arranged at the upstream of the feed inlet of the heavy raw oil according to the flow direction of reaction materials in the riser reactor.

By adopting the treatment method to process the co-oxidation method co-production process waste liquid of the propylene oxide, the co-oxidation method co-production process waste liquid of the propylene oxide which is basically worthless can be converted into a high-value product through a mature process, the resource recycling is realized, and the yield of the propylene and the butylene can be simultaneously improved on the premise of not increasing the treatment difficulty of the co-production process waste liquid of the propylene oxide, for example, as can be seen from the comparison between the example 1 and the comparative example 1, the yield of the propylene is improved by 4.4 percent; the yield of the butene is improved by 16.7 percent.

The treatment method provided by the invention is not only suitable for PO/MTBE process units, but also suitable for other process units which adopt a co-oxidation method to prepare PO co-production products, and can be realized by slightly changing mature catalytic cracking process units, thereby greatly reducing the investment cost.

The treatment method provided by the invention not only solves the problem of reasonable and efficient utilization of the co-oxidation process waste liquid of the propylene oxide, especially the PO/MTBE waste liquid, but also solves the problem of petrochemical raw material shortage, and improves the economic benefit and social benefit of the petrochemical industry.

Drawings

FIG. 1 is a schematic view of a process flow of an embodiment of the present invention, including a schematic structural view of an embodiment of the system of the present invention.

Description of the reference numerals

1-a riser reactor; 2-a regenerator; 3-a settler; 4-a stripping section;

5- (outlet end of riser reactor 1) first cyclone;

6- (outlet end of riser reactor 1) second cyclone;

7- (a gas outlet of the first cyclone separator 5 and the second cyclone separator 6 is communicated with a large oil gas pipeline 19) is used for collecting gas;

8-a first to-be-regenerated catalyst inclined pipeline;

9-a first to-be-regenerated slide valve;

10-a second spent catalyst inclined pipeline;

11- (connecting the regenerator 2 with the riser reactor 1) a third regenerated catalyst inclined pipeline;

12- (connecting the regenerator 2 with the riser reactor 1) a fourth regenerated catalyst inclined pipeline;

13-a second regenerative spool valve;

14- (for the riser reactor 1 to convey pre-lift medium) pre-lift medium line;

15- (for riser reactor 1 feed) heavy feed oil line;

16- (for riser reactor 1 to deliver mist steam) mist steam line;

a feeding pipeline for co-producing process waste liquid by a co-oxidation method of 17-propylene oxide;

18-stripping steam line;

19-large oil gas line;

20- (regenerator 2) main wind inlet line;

21-an air distributor;

22-regenerator cyclone;

23- (communicating with the gas outlet of the cyclone 22) flue gas duct.

Detailed Description

The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value, and such ranges or values should be understood to encompass values close to those ranges or values. For ranges of values, between the endpoints of each of the ranges and the individual points, and between the individual points may be combined with each other to give one or more new ranges of values, and these ranges of values should be considered as specifically disclosed herein.

According to the invention, the treatment method of the co-production process waste liquid of the propylene oxide by the co-oxidation method comprises the following steps: co-producing process waste liquid and heavy raw oil by co-oxidation of propylene oxide, and contacting with a catalytic cracking catalyst in sequence to perform catalytic cracking reaction to obtain a reaction product and a spent catalyst; separating the reaction product from the spent catalyst, regenerating the spent catalyst, and using the regenerated catalyst as the catalytic cracking catalyst.

According to the invention, the co-production process waste liquid of the propylene oxide is contacted with the catalytic cracking catalyst before the heavy raw oil, so that the oxygen-containing compounds of C3 and C4 in the waste liquid can be sufficiently catalytically cracked under the harsh catalytic cracking condition to be converted into the low-carbon olefin product.

According to the present invention, the catalytic cracking reaction of the co-production process waste liquid of propylene oxide prior to the contact of the heavy raw oil with the catalytic cracking catalyst can be carried out in various reaction apparatuses known in the art capable of carrying out catalytic cracking. In view of ensuring the full reaction of the co-oxidation process waste liquid of the propylene oxide, the co-oxidation process waste liquid of the propylene oxide and the heavy raw oil are fed into the riser reactor to contact with a catalytic cracking catalyst for catalytic cracking reaction, and the feed inlet of the co-oxidation process waste liquid of the propylene oxide is arranged at the upstream of the feed inlet of the heavy raw oil according to the flow direction of reaction materials in the riser reactor.

According to the present invention, such riser reactors are well known to those skilled in the art. For example, the riser reactor may be a constant diameter riser reactor or a variable diameter riser reactor, preferably a constant diameter riser reactor, and the variable diameter riser reactor may be, for example, a constant linear velocity riser reactor.

The riser reactor can be provided with a plurality of feed inlets, the feeding proportion of each feed inlet can be the same or different, and different feed inlets and feeding positions can be arranged according to different feeding. According to a specific embodiment of the present invention, the feed inlet comprises: a feed inlet for co-production process waste liquid and a feed inlet for heavy raw oil by a propylene oxide co-oxidation method. The riser reactor can comprise a pre-lifting section and at least one reaction zone from bottom to top, and the number of the reaction zones can be 2-8, preferably 2-3, in order to enable the raw materials to be fully reacted and meet different target product quality requirements. Preferably, the co-oxidation process waste liquid of the propylene oxide and the heavy raw oil are introduced into the riser reactor from different feed inlets of the riser reactor. Further preferably, the feed inlet for co-production process waste liquid by the propylene oxide co-oxidation method is upstream of the feed inlet for heavy raw oil according to the flow direction of the reaction materials in the riser reactor. That is, the flow direction of the reaction materials in the riser reactor flows from bottom to top, so that the feed inlet of the co-production process waste liquid by the epoxypropane co-oxidation method is arranged below the feed inlet of the heavy raw oil. Further preferably, in order to sufficiently catalyze and crack the oxygen-containing compounds of C3 and C4 in the co-production process waste liquid of propylene oxide co-oxidation process to convert the oxygen-containing compounds into low-carbon olefin products, the distance between the feed inlet of the co-production process waste liquid of propylene oxide co-oxidation process and the feed inlet of the heavy raw oil accounts for 2-20% of the height of the riser reactor according to the flow direction of the reaction materials in the riser reactor, and more preferably 3-15%. In order to realize the catalytic cracking reaction of the co-oxidation process co-production process waste liquid of the propylene oxide and the heavy raw oil which are sequentially contacted with the catalytic cracking catalyst, the feed inlet of the catalytic cracking catalyst is positioned at the lower part of the feed inlet of the co-oxidation process co-production process waste liquid of the propylene oxide, preferably at the bottom of the riser reactor.

According to the present invention, the co-production process waste liquid of propylene oxide includes waste liquid in various processes for preparing Propylene Oxide (PO) and co-producing products by using a co-oxidation method, for example, the co-production process waste liquid of propylene oxide may be at least one selected from co-production process waste liquid of methyl tert-butyl ether by using a co-oxidation method of propylene oxide, co-production process waste liquid of styrene by using propylene oxide, co-production process waste liquid of tert-butyl alcohol by using a co-oxidation method of propylene oxide, and co-production process waste liquid of cumene peroxide by using a co-oxidation method of propylene oxide. The inventor of the invention finds that the treatment method is more suitable for the conversion of the co-production of methyl tert-butyl ether process waste liquid (PO/MTBE) by the co-oxidation method of propylene oxide, and thus embodies the treatment effect of the treatment method. Wherein the PO/MTBE waste stream contains, but is not limited to: based on the total weight of the PO/MTBE waste liquid, the PO/MTBE waste liquid contains 10-30 wt% of water, 10-30 wt% of hydrocarbons and 40-80 wt% of oxygen-containing compounds; based on the total weight of the oxygen-containing compounds, the oxygen-containing compounds comprise 10-85% of ketone compounds, 0-50% of alcohol compounds, 0-30% of ether compounds and 0-10% of aldehydes and ester compounds.

The types of heavy feedstocks are well known to those skilled in the art in accordance with the present invention. For example, the heavy feedstock may be heavy hydrocarbons and/or various animal and vegetable oil-type feedstocks rich in hydrocarbons. The heavy hydrocarbon may be a mixture of one or more selected from the group consisting of petroleum hydrocarbons, mineral oils and synthetic oils. The petroleum hydrocarbon can be one or more of vacuum wax oil, atmospheric residue, vacuum wax oil blending part vacuum residue and other hydrocarbon oil obtained by secondary processing. The hydrocarbon oil obtained by the secondary processing may be, for example, one or more of coker gas oil, deasphalted oil, and furfural refined raffinate oil. The mineral oil may be a mixture of one or more selected from coal liquefaction oil, oil sand oil and shale oil. The synthetic oil can be distillate oil obtained by F-T synthesis of coal, natural gas or asphalt. The various animal and vegetable oils rich in hydrocarbon can be various animal and vegetable oils. Preferably, the heavy feedstock is selected from one or more of vacuum wax oil, atmospheric resid, vacuum resid, coker wax oil, coker resid, and fischer-tropsch wax oil.

According to the present invention, the conditions for the catalytic cracking reaction generally include reaction temperature and reaction time. Under the feeding sequence that the co-production process waste liquid of the propylene oxide co-oxidation method and the heavy raw oil are sequentially contacted with the catalytic cracking catalyst, in order to further ensure the full reaction of the two and further improve the yield of the low-carbon olefin propylene and butylene, the conditions of the catalytic cracking reaction comprise: the reaction temperature (outlet temperature, the same below) is 560 ℃ and 750 ℃, the reaction time is 1-10 seconds, and the reaction pressure (gauge pressure, the same below) is 0.05-1 MPa. Preferably, the reaction temperature is 580-720 ℃ and the reaction time is 2-6 seconds. More preferably, the reaction temperature is 600 ℃ to 680 ℃ and the reaction time is 2 to 4 seconds. The weight ratio of the catalytic cracking catalyst to the heavy feedstock oil may be 1 to 100, preferably the weight ratio of the catalytic cracking catalyst to the heavy feedstock oil is 5 to 50, more preferably the weight ratio of the catalytic cracking catalyst to the heavy feedstock oil is 10 to 40.

According to the present invention, preferably, the processing method further includes: the co-oxidation method co-production process waste liquid of the propylene oxide is preheated to 350-450 ℃, more preferably 380-420 ℃ before the co-production process waste liquid of the propylene oxide is contacted with the catalytic cracking catalyst, and then is sent into the riser reactor to be contacted with the catalytic cracking catalyst.

According to the invention, the conditions of the catalytic cracking reaction further comprise: the feeding weight ratio of the co-production process waste liquid of the propylene oxide co-oxidation method to the heavy raw oil per unit time is preferably (0.05-0.5):1, and the weight ratio of the atomized water vapor to the heavy raw oil can be (0.01-1): 1.

The catalytic cracking catalyst is a catalyst capable of catalytically cracking the co-production process waste liquid and heavy raw oil by the epoxypropane co-oxidation method. The catalytic cracking catalyst is commercially available or may be prepared according to methods known to those skilled in the art. In particular, the catalytic cracking catalyst contains a zeolite, an inorganic oxide, and optionally a clay. According to the present invention, the catalytic cracking catalyst preferably contains 1 to 60 wt% of zeolite, 5 to 99 wt% of inorganic oxide and 0 to 70 wt% of clay, on a dry basis and based on the total weight of the catalytic cracking catalyst. More preferably, the zeolite contains 50 to 100 wt% of a medium pore zeolite and 0 to 50 wt% of a large pore zeolite, on a dry basis and based on the total weight of the zeolite, in order to increase the yield of propylene and butenes; further preferably, on a dry basis and on a zeolite basisThe zeolite contains 70 to 95 weight percent of a medium pore zeolite and 5 to 30 weight percent of a large pore zeolite, based on the total weight of the zeolite. The medium and large pore zeolites are defined as conventional in the art, i.e., the medium pore zeolite has an average pore size of 0.5 to 0.6nm and the large pore zeolite has an average pore size of 0.7 to 1 nm. The medium pore zeolite may be a zeolite having an MFI structure, such as a ZSM-series zeolite and/or a ZRP zeolite, which may also be modified with a nonmetallic element such as phosphorus and/or a transition metal element such as iron, cobalt, nickel, as described in more detail in U.S. Pat. No. 5,232,675, and the ZSM-series zeolite is selected from one or more mixtures of ZSM-5, ZSM-11, ZSM-12, ZSM-23, ZSM-35, ZSM-38, ZSM-48 and other zeolites of similar structure, as described in more detail in US3,702,886. The large pore zeolite may be selected from one or more of rare earth Y (rey), rare earth hydrogen Y (rehy), ultrastable Y and high silicon Y. The inorganic oxide may be silicon dioxide (SiO) as a binder₂) And/or alumina (Al)₂O₃). The clay, as a matrix (carrier), may be kaolin and/or halloysite.

According to the invention, a reaction product and a spent catalyst are obtained after catalytic cracking reaction, the reaction product and the spent catalyst are separated, the obtained spent catalyst is regenerated, and the regenerated catalyst is used as the catalytic cracking catalyst. The obtained reaction product is separated into fractions such as dry gas, liquefied gas, pyrolysis gasoline, pyrolysis diesel oil and the like through a subsequent separation system, then the liquefied gas is further separated through gas separation equipment to obtain propylene, butylene and the like, and the method for separating propylene and butylene from the reaction product is conventional in the art, and the method is not limited in the invention and is not described in detail herein.

The process for regenerating the spent catalyst according to the invention is well known to the person skilled in the art. Preferably, the obtained spent catalyst is contacted with oxygen-containing gas in a regenerator for coke-burning regeneration. In the regeneration process, an oxygen-containing gas is generally introduced from the bottom of the regenerator, after the oxygen-containing gas, such as air or oxygen, is introduced into the regenerator, the spent catalyst is contacted with the oxygen-containing gas for burning and regeneration, the flue gas generated after the spent catalyst is burned and regenerated is subjected to gas-solid separation at the upper part of the regenerator, and the flue gas enters a subsequent energy recovery system. According to the invention, when the co-production process waste liquid of the propylene oxide and the heavy raw material are contacted with the catalytic cracking catalyst in the riser reactor in sequence for catalytic cracking reaction, preferably, the regenerated catalyst is returned to the riser reactor to be used as the catalytic cracking catalyst. The conditions for regeneration are well known to those skilled in the art and may include, in particular: the regeneration temperature is 550-750 ℃, preferably 600-730 ℃, and more preferably 650-700 ℃; the apparent linear velocity of the oxygen-containing gas is 0.5 to 3 m/s, preferably 0.8 to 2.5 m/s, more preferably 1 to 2 m/s; the average residence time of the spent catalyst is from 0.6 to 3 minutes, preferably from 0.8 to 2.5 minutes, more preferably from 1 to 2 minutes.

According to the invention, the processing method further comprises: before returning the regenerated catalyst to the riser reactor for use as the catalytic cracking catalyst, the regenerated catalyst from the regenerator is fed to a degassing tank for degassing and then fed to the riser reactor for use as the catalytic cracking catalyst, an oxygen-containing gas obtained by degassing in the degassing tank is returned to the regenerator, and the regenerated catalyst in the degassing tank is subjected to removal of impurities such as the oxygen-containing gas by a stripping gas such as water vapor.

The invention will be further illustrated by means of a specific embodiment in conjunction with fig. 1, but the invention is not limited thereto.

As shown in fig. 1, the process flow of the treatment method provided by the present invention comprises: the pre-lifting medium enters from the bottom of the riser reactor 1 through a pre-lifting medium pipeline 14, the regenerated catalyst from a fourth regenerated catalyst inclined pipeline 12 enters the bottom of the riser reactor 1 after being regulated by a second regeneration slide valve 13, and moves upwards in an accelerated manner along the riser reactor under the lifting action of the pre-lifting medium, firstly contacts with PO/MTBE waste liquid from a co-oxidation process waste liquid feeding pipeline 17 of propylene oxide to react, and then continues to move upwards. The preheated heavy raw oil in the heavy raw oil pipeline 15 is atomized by the atomizing steam in the atomizing steam pipeline 16 and brought into the riser reactor to contact with the catalyst for reaction. The generated reaction product oil gas and the inactivated spent catalyst enter a second cyclone separator 6 in the settler 3 to realize the separation of the spent catalyst and the reaction product oil gas, the reaction product oil gas enters a gas collection chamber 7, and catalyst fine powder returns to the settler 3 through a dipleg. Spent catalyst in settler 3 flows to stripping section 4 and contacts steam from stripping steam line 18. The reaction product oil gas extracted from the spent catalyst enters a gas collection chamber 7 after passing through a cyclone separator. The stripped spent catalyst enters the regenerator 2 after being regulated by a first spent slide valve 9, air from a main air inlet pipeline 20 enters the regenerator 2 after being distributed by an air distributor 21, coke on the spent catalyst in a dense bed layer at the bottom of the regenerator 2 is burned off to regenerate the inactivated spent catalyst, and flue gas enters a subsequent energy recovery system through an upper gas flue gas pipeline 23 of a cyclone separator 22 of the regenerator. Wherein the pre-lifting medium may be dry gas, water vapor or a mixture thereof. The regenerated catalyst circulates to the bottom of the riser reactor 1 through a fourth regenerated catalyst inclined pipeline 12, the catalyst circulation amount can be controlled through a second regenerated slide valve 13, gas returns to the regenerator 2 through a third regenerated catalyst inclined pipeline 11, and reaction product oil gas in the gas collection chamber 7 enters a subsequent separation system through a large oil gas pipeline 19.

The present invention will be described in detail below by way of examples.

In the following examples and comparative examples, the co-oxidation co-production process waste liquid of propylene oxide is PO/MTBE waste liquid, and the heavy raw oil is daqing atmospheric residue, and the properties thereof are shown in table 1 and table 2, respectively.

The catalytic cracking catalyst used in the following examples and comparative examples is commercially available under the designation RAG.

In the following examples and comparative examples, the COD content in the wastewater was determined by the potassium dichromate method (GB/T11914-.

Comparative example 1

The tests were carried out on a pilot plant of a riser reactor. The raw oil is heavy raw oil, the preheated heavy raw oil (preheated to 230 ℃) enters the bottom of a riser reactor to carry out catalytic cracking reaction, a reaction product and a spent catalyst enter a closed cyclone separator from the outlet of the reactor, the reaction product and the spent catalyst are quickly separated, and the reaction product is cut according to the distillation range in a separation system, so that fractions such as propylene, butylene, pyrolysis gasoline and the like are obtained.

The spent catalyst enters a stripping section under the action of gravity, hydrocarbon products adsorbed on the spent catalyst are stripped by steam, and the stripped spent catalyst enters a regenerator and is in contact with air for regeneration; the regenerated catalyst enters a degassing tank to remove oxygen-containing gas adsorbed and carried by the regenerated catalyst; the degassed regenerated catalyst returns to the riser reactor for recycling; the operating conditions and the product distribution are listed in Table 3.

Example 1

The experiment was carried out according to the scheme of FIG. 1. The raw materials comprise: PO/MTBE waste liquid and heavy raw oil. The catalytic cracking reaction is carried out on a medium-sized device of an equal-diameter riser reactor. The preheated PO/MTBE waste liquid (preheated to 390 ℃) enters the lower part of the riser reactor, and the preheated heavy raw oil (preheated to 230 ℃) enters the lower part of the riser reactor from a feed inlet above a PO/MTBE waste liquid feed inlet to carry out catalytic cracking reaction. The pre-lifting medium enters from the bottom of the riser reactor through a pre-lifting medium pipeline, the regenerated catalyst from a fourth regenerated catalyst inclined pipe pipeline enters the bottom of the riser reactor after being regulated by a second regeneration slide valve, and moves upwards in an accelerating manner along the riser reactor under the lifting action of the pre-lifting medium, firstly contacts with PO/MTBE waste liquid from a co-oxidation process co-production process waste liquid feeding pipeline of propylene oxide to react, then continues to move upwards, and continues to contact with the heavy raw oil preheated by a heavy raw oil pipeline through atomization steam atomization of an atomization steam pipeline and is brought into the riser reactor to react with the catalyst. The distance between the feeding hole of the PO/MTBE waste liquid and the feeding hole of the heavy raw oil accounts for 4% of the height of the riser reactor, and the feeding weight ratio of the PO/MTBE waste liquid to the heavy raw oil per unit time is 0.1: 1.

And the reaction product and the spent catalyst enter a closed cyclone separator from the outlet of the riser reactor, the reaction product and the spent catalyst are quickly separated, and the reaction product is cut in a separation system according to the distillation range, so that fractions such as propylene, butylene, pyrolysis gasoline and the like are obtained. The spent catalyst enters a stripping section under the action of gravity, hydrocarbon products adsorbed on the spent catalyst are stripped by steam, the stripped catalyst enters a regenerator and is in contact with air for regeneration, the regeneration temperature is 700 ℃, the apparent linear speed of the air is 1.2 m/s, and the average residence time of the spent catalyst is 1.5 minutes. The regenerated catalyst enters a degassing tank to remove air adsorbed and carried by the regenerated catalyst, and the degassed regenerated catalyst returns to the riser reactor for recycling. The operating conditions and the product distribution are listed in Table 3.

Example 2

The PO/MTBE waste liquid and the heavy raw oil were fed into the riser reactor to contact the catalytic cracking catalyst successively according to the method of example 1, except that the distance between the feed port of the PO/MTBE waste liquid and the feed port of the heavy raw oil was 10% of the height of the riser reactor according to the flow direction of the reaction material in the riser reactor. The operating conditions and the product distribution are listed in Table 3.

Example 3

PO/MTBE waste liquid and heavy raw oil were fed into the riser reactor to be successively brought into contact with a catalytic cracking catalyst in the same manner as in example 1, except that the feed weight ratio per unit time of the PO/MTBE waste liquid to the heavy raw oil was 0.3: 1. The operating conditions and the product distribution are listed in Table 3.

Example 4

PO/MTBE waste liquid and heavy feed oil were fed into the riser reactor to be successively subjected to contact reaction with a catalytic cracking catalyst in accordance with the method of example 1, except that the operating conditions were changed, and the specific operating conditions and product distribution were as shown in Table 3.

TABLE 1

Composition of raw materials	By weight%
		Water (W)	7.49
Methanol	0.68
		Acetone (II)	41.22
Acetic acid	3.93
		Ethylene glycol	5.04
Tert-butyl alcohol	13.44
		Isobutyric acid	2.17
1-tert-butyl-2-propanol	9.45
		Formic acid butyl ester	0.23
Ethylene glycol Ether	1.68
		Hydrocarbons	14.67

TABLE 2

TABLE 3

The water-oil weight ratio refers to the ratio of the weight of atomized water vapor to the weight of heavy raw oil; the catalyst oil weight ratio refers to the ratio of the weight of the catalyst to the weight of the heavy feed oil.

As can be seen from the results of table 3, the yields of propylene and butene in comparative example 1 were 11.21 wt% and 13.63 wt%, respectively. In example 1, the yields of propylene and butene were 16.18 wt% and 15.91 wt%, respectively. The yields of propylene and butene were 15.78 wt% and 15.12 wt%, respectively, in example 2, 16.34 wt% and 16.26 wt%, respectively, in example 3, and 16.58 wt% and 16.30 wt%, respectively, in example 4. In addition, the COD content in the wastewater is increased by less than 150 mg/L. Therefore, the treatment method provided by the invention realizes the recycling of valuable components in the waste liquid, the increase of COD content in the waste liquid is not obvious, and the method for treating the co-oxidation process waste liquid of the propylene oxide by catalytic cracking does not increase the treatment difficulty of the waste liquid, and meanwhile, the yield of the low-carbon olefin products of propylene and butylene is obviously improved.

The preferred embodiments of the present invention have been described in detail, however, the present invention is not limited to the specific details of the above embodiments, and various simple modifications may be made to the technical solution of the present invention within the technical idea of the present invention, and these simple modifications are within the protective scope of the present invention.

It should be noted that the various technical features described in the above embodiments can be combined in any suitable manner without contradiction, and the invention is not described in any way for the possible combinations in order to avoid unnecessary repetition.

In addition, any combination of the various embodiments of the present invention is also possible, and the same should be considered as the content of the present invention as long as it does not depart from the gist of the present invention.

Claims

1. A treatment method for co-production process waste liquid of propylene oxide by a co-oxidation method is characterized by comprising the following steps:

co-producing process waste liquid and heavy raw oil by co-oxidation of propylene oxide, and sequentially contacting with a catalytic cracking catalyst according to the flow direction of reaction materials in a riser reactor to perform catalytic cracking reaction to obtain a reaction product and a spent catalyst; the conditions of the catalytic cracking reaction include: the reaction temperature is 560 ℃ and 750 ℃, the reaction time is 1-10 seconds, the weight ratio of the catalytic cracking catalyst to the heavy raw oil is 1-100, the weight ratio of the co-oxidation process co-production process waste liquid of the propylene oxide to the heavy raw oil in unit time is (0.05-0.5) to 1, and the weight ratio of the atomized water vapor to the heavy raw oil is (0.01-1) to 1; according to the flow direction of reaction materials in the riser reactor, the distance between a feed inlet of the waste liquid of the co-oxidation process co-production process of the propylene oxide and a feed inlet of the heavy raw oil accounts for 2-20% of the height of the riser reactor;

separating the reaction product from the spent catalyst, regenerating the spent catalyst, and using the regenerated catalyst as the catalytic cracking catalyst.

2. The treatment method according to claim 1, wherein the co-production process waste liquid of propylene oxide is at least one selected from co-production process waste liquid of methyl tert-butyl ether by co-oxidation process of propylene oxide, co-production process waste liquid of styrene by co-oxidation process of propylene oxide, co-production process waste liquid of tert-butyl alcohol by co-oxidation process of propylene oxide, and co-production process waste liquid of cumene peroxide by co-oxidation process of propylene oxide;

the heavy raw oil is selected from one or more of vacuum wax oil, atmospheric residue oil, vacuum residue oil, coker wax oil, coker residue oil and Fischer-Tropsch wax oil.

3. The treatment method as claimed in claim 1, wherein the reaction temperature is 580-720 ℃, the reaction time is 2-6 seconds, and the weight ratio of the catalytic cracking catalyst to the heavy raw oil is 5-50.

4. The treatment method as claimed in claim 3, wherein the reaction temperature is 600-680 ℃, the reaction time is 2-4 seconds, and the weight ratio of the catalytic cracking catalyst to the heavy raw oil is 10-40.

5. The process of claim 1, 3 or 4, wherein the catalytic cracking catalyst contains a zeolite, an inorganic oxide and optionally a clay;

on a dry basis and based on the total weight of the catalytic cracking catalyst, the catalytic cracking catalyst contains 1-60 wt% zeolite, 5-99 wt% inorganic oxide, and 0-70 wt% clay;

the zeolite contains 50 to 100 wt% of a medium pore zeolite and 0 to 50 wt% of a large pore zeolite, on a dry basis and based on the total weight of the zeolite.

6. The process of claim 5 wherein the zeolite comprises from 70 to 95 weight percent of the medium pore size zeolite and from 5 to 30 weight percent of the large pore size zeolite, on a dry basis and based on the total weight of the zeolite.

7. The treatment process of claim 5, wherein the medium pore zeolite is a ZSM-series zeolite and/or a ZRP zeolite, and the large pore zeolite is selected from one or more of rare earth Y, rare earth hydrogen Y, ultrastable Y, and high silicon Y;

the inorganic oxide is silicon dioxide and/or aluminum oxide;

the clay is kaolin and/or halloysite.

8. The treating method according to any one of claims 1 to 4, wherein the co-oxidation process waste liquid of propylene oxide and the heavy raw oil are fed into the riser reactor to contact with a catalytic cracking catalyst for catalytic cracking reaction, and the feed inlet of the co-oxidation process waste liquid of propylene oxide is upstream of the feed inlet of the heavy raw oil according to the flow direction of the reaction materials in the riser reactor.

9. The treatment method according to claim 8, wherein the distance between the feed inlet of the co-oxidation process waste liquid and the feed inlet of the heavy raw oil of the propylene oxide accounts for 3-15% of the height of the riser reactor according to the flow direction of the reaction materials in the riser reactor;

the feed inlet of the catalytic cracking catalyst is positioned at the lower part of the feed inlet of the waste liquid of the co-oxidation process co-production process of the propylene oxide.

10. The process of claim 9, wherein the catalytic cracking catalyst feed inlet is located at the bottom of the riser reactor.

11. The processing method according to any one of claims 1 to 4, further comprising: preheating the co-oxidation method co-production process waste liquid of the propylene oxide to 350-450 ℃ before the co-oxidation method co-production process waste liquid of the propylene oxide contacts the catalytic cracking catalyst.

12. The treatment method as claimed in claim 11, wherein the co-oxidation process waste liquid of propylene oxide is preheated to 380-420 ℃ before contacting the co-oxidation process waste liquid of propylene oxide with the catalytic cracking catalyst.

13. The process according to claim 8, wherein the spent catalyst is subjected to coke-burning regeneration by contacting it with an oxygen-containing gas in a regenerator.

14. The processing method of claim 13, wherein the processing method further comprises: and (3) before the regenerated catalyst is returned to the riser reactor to be used as the catalytic cracking catalyst, the regenerated catalyst is sent to a degassing tank for degassing, and oxygen-containing gas obtained after degassing is returned to the regenerator.