TW491889B - Production of olefins - Google Patents

Abstract

A process for the catalytic cracking of an olefin-rich feedstock which is selective towards light olefins in the effluent, the process comprising contacting a hydrocarbon feedstock containing one or more olefins, with a MFI-type crystalline silicate catalyst having a silicon/aluminium atomic ratio of at least about 300 at an inlet temperature of from 500 to 600 DEG C, at an olefin partial pressure of from 0.1 to 2 bars and the feedstock being passed over the catalyst at an LHSV of from 10 to 30 h<SP>-1</SP> to produce an effluent with an olefin content of lower molecular weight than that of the feedstock.

Description

491889 V. Description of the invention (1) The present invention relates to a method for cracking olefin-rich hydrocarbon feedstock, which is selective for light olefins in the effluent. In particular, olefin feedstocks from refineries or petrochemicals can be selectively converted to redistribute the olefin content of the feedstock in the resulting effluent. It is known in the art to use zeolites for the conversion of long-chain stone butterflies to lighter products, such as in the catalytic de butterflying of petroleum feedstocks. Although not intended to be destabilized, at least some of the paraffin hydrocarbons are converted to olefins. It is known in these methods to use crystalline petrosates, such as MF type I crystalline petostates. The three letters r μ I ″ are not represented by the Structure Commission of the International Zeolite Association ) The special type of crystalline silicate structure established. Examples of MF I-type crystalline silicates are synthetic zeolites ZSM-5 and siliceous carbons (Si 1 i cai te) and MF I-type crystalline fossils known in other technologies. GB-A-1 323 7 1 0 published a dewaxing method using crystalline silicate catalysts, especially ZSM-5, to remove linear paraffin waxes and lightly branched paraffin waxes from hydrocarbon feedstocks. US-A-424 73 88 also discloses a method for catalytic hydrodewaxing of petroleum and synthetic hydrocarbon feedstocks using crystalline silicates of type ZSM_5. us —A —428452 9 and US-A-5 6 1 407 9 published similar dewaxing methods. The catalyst is a crystalline alumino-silicate, and the prior art documents noted above published a wide range of Si / A1 ratios and different reaction conditions for the disclosed dewaxing method. GB-A-2 1 85 753 published using silicon carbon-based catalysts to remove US-A-4 39425 1 published using the right-side cut from &gt; &amp; ^, crystalline silicate particles with aluminum-containing shell for clothing Hydrocarbon conversion. It is also known in the technical poor to perform hydrocarbon feeds containing straight-chain and / or lightly branched hydrocarbons,

491889 V. Description of the invention (2) In particular, the selective conversion of stone 躐 'into a mixture of lower molecular weight products containing a significant amount of olefins. Conversion is performed by contacting the feed with a crystalline silicate called siliceous carbon, as published in GB-A-2 0 75 045, US-A- 440 1 55 5 and US — A · &quot; 4 30 927 6 ° Siliceous carbons were published in US-A-4061 724. There are siliceous carbon catalysts with different silicon / aluminum atomic ratios and different crystal forms. EP-A-0 1 46 524 and 0 1 46 5 2 5 certified under the name of Cosden Technology, Inc. Published crystalline silica with monoclinic symptomatic carbon type and its manufacturing method. These silicates have a silicon to aluminum atomic ratio greater than 80. W0U7 / 0 487 1 published the use of steam to treat mesoporous zeolites, followed by treatment with acidic solutions to improve the selectivity of zeolites for catalytic cracking. '+ Lucas et al.'S paper entitled DeHalmization of rHZSM-5 Zeolite: Dealuminati〇n 〇f hzsm_5 zeolite. Effect of steaming on acidity and aromatization activity ”, Application Catalysis: General (Applied Catalysis A: General) 154 1997 221-240, published by Elsevier Science BV ·, published on these demineralized zeolites to convert acetone / n-butanol mixtures to hydrocarbons. For example, from US-A-4 1 71 25 7, it is more known to dewax petroleum distillates using crystalline silicate catalysts such as ZSM-5 to produce light olefin fractions, for example, C3 to C4 olefin fractions. . Typically, the reactor temperature reaches about 500 ° C, and the reactor uses a low hydrocarbon partial pressure that facilitates the conversion of petroleum distillates to propylene. Dewaxing cracks the paraffin chain and causes stickiness of the raw distillate

Page 7 491889 V. Description of the invention (3) The degree is reduced, but a small amount of olefin is also generated from cracking paraffin. EP A 0 3 0 5 72 0 discloses the production of gaseous olefins via catalytic conversion of hydrocarbons. EP B 0 3470 0 3 discloses a method for converting a hydrocarbon-containing feedstock into light olefins. WO-A-9 0/1 1 3 38 published a method for converting q-Q paraffin hydrocarbons into petrochemical feedstocks, especially a method of (: 2 to (: 4 olefins). Us —A —5040432 and porphyrin —A-〇 39 5345 Published from paraffin waxes with more than four carbon atoms to produce olefins. EP-A-0 511 (H 3 published the use of phosphorus-containing steam-activated catalysts and H-ZSM-5 to produce olefins from hydrocarbons. "―A —481〇 3 56 published the method of degassing on a stone-like catalyst to treat gas oil (gas 〇Us). GB-A-2 1 5684 5 published from propylene or a mixture of propylene-containing hydrocarbons to produce isobutene = : GB-A-2 1 598 33 published on the production of isobutyl by catalytic cracking of light distillates. It is known in the art that the crystalline silicates exemplified above, long-chain olefins tend to be worse than corresponding long-chain stones. It is known that when using crystalline silicate as the paraffin gate, the rr time is not stable. When the stream dryness Ik time is reduced, it is caused by the deposition and catalysis (carbon). "You think of using these known methods to crack heavy paraffin molecules into lighter ones. When you want to make propylene, not only is the yield low ' And crystalline silicate: catalyst

Frr.j: The propylene output can be added to about 7 ~ 8 from the FCC unit by introducing a known ZSM_5 catalyst into the early mash to "extrude" more propylene from the inflowing hydrocarbon feedstock to be cracked. Weight percent

Page 8 491889 V. Description of the invention (4) More dilute than acrylic. Not only is this increase in yield relatively small, but ZSM ~ 5 has low stability in FCC units. However, there is an increasing demand for polypropylene, especially for the manufacture of polypropylene.

Due to the growth of propylene derivatives, especially polypropylene, the petrochemical industry is currently engaged in the main exploitation of propylene. The traditional method of increasing propylene production is not entirely satisfactory. For example, another petroleum brain vapor cracking unit that produces about two ^ s of ethylene, which is propylene, produces propylene, because the raw materials are valuable and the capital investment is very high. The petroleum brain is a competitive raw material for radon gas crackers, which is the basis for the manufacture of gasoline in refineries. Propane dehydrogenation produces high yields of propylene, but the raw material (propane) is only practically costable for a limited number of years, making the process expensive and limiting the production of propylene. Propylene is made from FCC units, but it is made in very low yields, and it has been proven to be expensive and limited to increase yields. Another route called metathesis (i ^ e ^ athesis) or disproportionation allows propylene to be produced from ethylene and butene. This technology, which is often combined with a steam cracker, is expensive because it uses ethylene, which is at least as valuable as propylene, as a feedstock.

Therefore, there is a need for a high-yield propylene manufacturing method that can be easily integrated into a refinery or petrochemical plant and uses raw materials that are of little value to the market (there are few alternatives in the market). On the other hand, MF I type crystalline fossilates are also known catalysts for the accumulation of dilute hydrocarbons. For example, EP-A-0 03 1 675 is published to convert an olefin-containing mixture into gasoline on catalysts of &gt; ZSM ~ 5. As known to those skilled in the art, the operating conditions of the 'aggregation reaction are significantly different from those used for cleavage. / 、 型 上 ’In an oligomerization reactor, the temperature does not exceed about 400, and the high pressure

Page 9 491889 V. Description of the invention (5) Conducive to oligomerization. GB-A-2 1 56 844 published a method for isomerizing olefins on siliceous carbons as catalysts. US-A-4579 989 is published on a siliceous carbon-based catalyst to convert smoke into higher molecular weight hydrocarbons. US-A-4746762 is published on a crystalline petrolate catalyst to upgrade light olefins to produce hydrocarbons rich in Cs + liquids. US-A-5 0 0485 2 discloses a two-stage process for converting olefins into high-octane gasoline, in which in the first stage, olefins are agglomerated into c5 + olefins. US-A4171331 discloses a method for manufacturing gasoline, which includes a silicon-containing crystalline molecular sieve catalyst having a mesopore size of a raw material containing C6ene = 2, such as siliceous carbon, halogen-stabilized siliceous carbon, or zeolite On the oligo. Niu Sufang, 1 4 4 published a number of high-boiling hydrocarbons from normal gaseous hydrocarbons. The first step involves supplying normal gaseous olefins to a mesoporous carbene furnace i ΐ ϊ crystallite molecular sieve catalyst. us_a—4417088 published on dimerization and trimerization of Gao ΐΐΐ Ϊ shellfish / charcoal ° US-A_441 7086 published on thin smoke published on olefin = oligomerization method. GB-A-21 06131 and GB-A-2106132 "Building; Buddhist altars :: Ascending oligomerization of siliceous carbon-based catalysts in stone 3, # ^ 至 on stone evening carbons. GB_A-2 1 065 33 published gaseous state The violent polymerization of olefins on zeolite or shellfish. One of the objectives of the present invention and the value of the plant is to provide a raw material that uses the lower olefins existing in refineries and petrochemicals as raw materials and is The above-mentioned method of propylene. The method for catalytic conversion of olefins into lighter olefins, and especially the other aspect of the present invention, is to provide a method for producing a high propylene yield and a pure 7 / ¾1.

491889 V. Description of the invention (6) Another object of the present invention is to provide such a method capable of producing a thin smoke effluent at least in a chemical grade product. Yet another object of the present invention is to provide a method for producing an olefin having a stable olefin concentration over time and a stable product distribution. Yet another object of the present invention is to provide a method for converting an olefinic raw material, which has a high yield of olefins, regardless of the origin and composition of the olefinic raw material. The present invention provides a method for selectively catalytically decomposing light olefins in effluent. S-olefin-containing feedstocks, the method comprising combining one or more hydrocarbon feedstocks with a stone / atom atomic ratio of at least about 300 The MFI-type crystalline acid salt catalyst is contacted at an inlet temperature from 500 to 60 (rc), at a partial pressure of olefin from 01 to bar, and the raw material is contacted from 10 to 30 hours &lt; L] SV over 2 catalysts to produce effluents with lower olefin content than the raw materials. People in this 1 This, the sun and the moon can provide a logistics from the refining Wei and petrochemical plants The product) not only selectively cracks into light olefins, but also: A method for decomposing Shi Erj to acrylics. The raw materials rich in dilute hydrocarbons can be passed through a special § 丨 / a 1 atomic ratio M Eight

Yir 1,,,,,,,,,,,,,,,,,,,, silicate catalysts. This catalyst is prepared by crystallization using an organic precursor, and any subsequent steam spraying or dealumination process is performed at a temperature in the range of 5.0 to 600 t. May = olefin partial pressure of 1 mesh u ·· 1 to 2 bar and passing through the catalyst at ^ 10 to 30 hours-kLHSV, the olefin content in the propylene is at least 30 to 50%.乂 Raw material In this specification, the term "stone" is used to indicate the overall Si / Al atomic ratio of ^ 1889, invention description (7), which can be measured by chemical analysis. In particular, for the crystalline dream salt material, the stated Si / A1 ratio is not only applicable to the Si / A1 structure of the crystalline oxalate, but also applies to the overall material. -The raw materials can be supplied without dilution or with an inert gas such as nitrogen. In the latter case, the absolute pressure of the feedstock constitutes the distribution of the hydrocarbon feedstock under inert gas ^^. ', Will now only refer to the various aspects of the accompanying drawings, where: Figure 1 shows the conversion of olefin feedstock, propylene yield, and other components and the amount of silicon / aluminum in the catalytic cracking method of the present invention The relationship between the original. In the present invention, the cracking of olefins is performed by cracking olefins in a hydrocarbon stream into and selectively cracking them into propylene. It is preferred that the raw materials and streams have the same olefin weight content. Typically, the olefin content of the fluid is more preferably within the soil weight percentage of the soil based on the hydrocarbon content of the feedstock. The raw materials can be packaged as :; The feedstock can typically include from 10 to: any = and it can be diluted without diluent or diluted with diluent and the two are included in the normal chain coal from the C4K1Q carbon range: dilute hydrocarbon feedstock. "4 to .6 carbon range Better, A 2 and: t chain, smoke mixture 'in

In a particularly preferred embodiment of the invention, the candle raw materials are contained in a mixture of refining waste and I and / or ranges of normal and branched iron iron \ α solid square group compounds. On the blood sacrifice, the content of logistics has a self-esteem of about 180. . Boiling point, ...

491889 V. Description of the invention (8)

Gas Mixture Unit I mixture. This steam cracking unit can crack a wide variety of feedstocks' including ethane, propane, butane, petroleum naphtha, gas oil, fuel oil, and the like. In particular, the hydrocarbon feedstock may include C4 type products from a fluidized bed catalytic cracking (F c C) unit in a crude oil refinery used to convert heavy oil into gasoline and lighter products. Typically, this c4 type product from the FCC unit contains about 50 weight percent olefins. Alternatively, the hydrocarbon feedstock may include a type 04 product from a unit in a crude oil refinery used to make methyl tertiary butyl ether (MTBE), where methyl tertiary butyl ether is made from methyl alcohol and isobutylene. This C4 type product from the MTBE unit also typically contains about 50 weight percent olefins. These c4 type products are distributed at the exit of the respective FCC or MTBE units. The hydrocarbon feedstock may further include C4 type products from a petroleum brain vapor cracking unit in a petrochemical plant, in which the steam cracking unit will include C5 to (: 9 species with a boiling point range from about 15 to 180 ° C The petroleum brain vapor is cracked, and especially the C4 type product is produced. This c4 type product typically contains 40 to 50% by weight of 1,3-butadiene, about 25% of isobutene, and about 15% of butene. (In the form of butene and / or 2-butene) and about 10% of n-butane and / or isobutane. The olefin-containing hydrocarbon feedstock may also include from a steam cracking unit, after extraction of butadiene ( Raffinate 丨), or C4 type products after butadiene hydrogenation. Alternatively, the raw material may further include 〇4 type products rich in hydrogenated butadiene, which typically contains greater than 50 weight percent of c4 is an olefin Alternatively, the hydrocarbon source and feedstock may include pure olefin feedstocks prepared in petrochemical plants. Alternatively, the olefin-containing feedstocks may further include light cracked petroleum naphtha (LCN) (also known as light catalytic cracking essence (LCCS)) or derived from Steam cracker or lightly cracked petroleum

Page 13 491889 V. Description of the invention (9) Yue Shang's C 5 type products, knowing &amp; PΓΓ 0-AW in the refinery, the petroleum brain system is discussed in the crude oil refinement ^ [,. X Zao Wuzhi The effluent was fractionated. Both raw materials contain alkenes '&quot; ^ ,,' = alkenes. Raw materials can also be included from this FCC unit :: 1 'You know' or know from the vacuum S distillation in crude oil refineries for processing as early as 70 The viscosity-reducing petroleum brain of the residue-reducing unit. ... the olefin-containing feedstock may comprise a mixture of one or more of the aforementioned feedstocks. = Use of c5 type product as the thin smoke containing smoke according to the preferred method of the present invention, with = special plutonium, since in any case it is necessary to free the oil of the refinery to remove the C5 type. This is due to the presence of q in gasoline, which can increase the smelly milk level energy, and therefore increase the photochemical activity of gasoline. In the case of using lightly cracked petroleum naphtha as an olefin-containing raw material, the olefin content in the gasoline-free portion is reduced, so the vapor pressure is reduced, and the photochemical activity of gasoline is also reduced.

When S is converted into lightly cracked petroleum brain, C2 to roasted hydrocarbons can be produced according to the method of the present invention. Part L is very rich in olefins, especially isobutene, which is an important feed for MTBE units. When q-type products are converted, q to C3 olefins are produced on the one hand, and d. To olefins mainly containing isoolefins are produced on the other hand. The remaining C4 type products are rich in butane, especially isobutane, It is an important raw material of the alkylation unit of the refinery, in which an alkylate used in gasoline is prepared from a mixture of raw materials and raw materials. The products mainly containing isoolefins are used to produce the third amyl methyl ether (TAME). The important feed. \ The inventor surprisingly found that according to the method of the present invention, the olefin feedstock can be selectively cracked to redistribute the olefin content of the raw material in the effluent. The catalyst and method conditions are selected, and thus the method. For specific olefins in raw materials

Page 14 491889 V. Description of the invention (10) Smoke has a special yield based on dilute hydrocarbons. Industry type conditions, which makes the method suitable for acrylic; thin smoke meter and method regardless of the origin of olefin raw materials, for example, 6 mesh 5 目 yield, and type products, MT4 unit type c4 production from the FCC The M member of the unit has _ to wear calcite, and to use the "Xi" phase "to lightly crack the petroleum brain or come to i 1 and so on. This is based on previous techniques and is unbelievable by Aida. The olefins of raw materials _.,. In terms of olefins, it is typically from 3 () ·%. 5 The acrylic yield is defined as the weight of the dilute hydrocarbons in the effluent, and the yield of the thin smoke meter. For example, for 5. The weight of the total fluorene hydrocarbon rebate contains 20% by weight of propylene :: the raw material 'such as flow right. This is compared to the definition of the product 1 produced? The propylene yield is the stone soil and aromatic compounds Only mildly evil-like samples are included in the raw material according to a preferred aspect of the present invention for crystalline silicates of group MF I, which may be catalysts of stone X, k including any other silicate .. ....., siliceous carbon or one of the group, the best crystalline silicate has 10 oxygen and two stone / shaw atomic ratio The crystalline or crystalline fossilate of 1 疋 or 1 为 is a microporous crystalline helmet based on the structure of the pores by Α: 疑 炎 甘 # with oxygen ions linked to each other. (Such as A1, B, etc.) or tetravalent (such as organic materials: where X can be tri, acid crystal structure is determined by the tetrahedron e, Sl, etc.). The specific order of crystalline silicon is defined. ; &amp; The network structure is linked together to scare me ,,, or daily hard salt pores 1¾ P bow η &gt; the number of units, or by the formation of pores ^ :: small system by the tetrahedron Ning Lice atoms and their presence in pores

Page 15 491889 5. The nature of the cation in the description of the invention (11) is determined. It has a unique combination of the following properties:, internal surface area; uniform pores with one or more discontinuous sizes; ion exchange force; good thermal stability; and the ability to adsorb organic compounds. Since the pore size of these crystalline silicates is similar to many organic molecules of interest, they control the ingress and egress of reactants and products, so that they have a special selectivity for catalytic reactions. The crystalline silicate with MFI structure has a two-way intersecting pore system with the following pore diameters: straight channels along [〇1〇] · 0.5 · 3-0 · 56 nm, and [1 G 〇] Sinusoidal channel: 0 · 51-0 · 55 nm.

Crystalline silicate catalysts have structural and chemical properties and are used under special reaction conditions, so catalytic cracking can be easily performed. Different reaction paths may occur on the catalyst. At an inlet temperature of about 500 to 600, from 520 to 600 T: preferably, from 54 to 58. 〇 is even better, and the partial pressure of olefin from 0.1 to 2 bar is about the best atmospheric pressure, and the double bond movement of the olefin in the raw material can be easily achieved, resulting in double bond refining. In addition, this isomerization tends to reach thermodynamic equilibrium. Propylene can be produced directly, for example, via catalytic cracking of hexene or heavier olefin feedstocks. Catalytic cleavage of olefins is understood to include the production of shorter processes via bond cleavage. Ding Xin

The acidic part catalyzed by this is free from the saturates of the olefinizing agent. The catalysts preferably have high silicon / aluminum atoms greater than about 3000, and the agent has a relatively low acidity. The hydrogen transfer reaction is directly related to the strength and density of the catalyst, and it is better to suppress the reaction to avoid the formation of coal coke during the conversion process, otherwise it will sequentially reduce the catalyzability over time. This hydrogen transfer reaction tends to produce

.Page 16 491889 V. Description of the Invention (12) ΐί: Yu ::::: Diadiene and cyclic women's hydrocarbons, and aromatic compounds, their predecessors, especially ϊ. Cycloolefin-based aromatic compounds and coal-like coke = Then desorb ammonia at high temperature: --- 30 0 ^ 〇 ： 〇 ™ 〇r A feature of the present invention is that Two! H 'can obtain a high propylene yield from 30 to 5G%. The same son-in-law = olefin conversion rate, regardless of the origin and composition of the olefin feedstock, such a south ratio reduces the acidity of the catalyst, and thus makes the catalyst Ann 1 increased. According to the present invention, not only the high propylene production in terms of olefins needs to be achieved, but high purity propylene can be obtained in the C: 3 species of the effluent. The combined, and a high percentage of olefins are cracked into olefins instead of Cracking into: σ compounds. Propylene has a purity of at least 93%. In the feedstock, it is preferred that the olefins are cracked into olefins by weight percentage, or the initial olefins are stored at 85%. In addition, according to the present invention, in view of the fact that the activity of the catalyst is not gradually decreased or deposited on the catalyst compared to φ, it is better to have high stability in the catalytic & coal cracking coke sequence. The inventors have found that such coal coke 2 can cause the catalyst's ability to crack olefins at high propylene yields to decrease at any time. All of these expected results in the cracking procedure, the root 4 is remarkable, which can be achieved by providing the silicon / aluminum atomic ratio to + hair in a MF type crystalline silicate catalyst, combined with the required temperature and pressure ^ 'Approximately 300

nim p. 17 491889 V. Description of the invention (13). It has been found that the various preferred catalysts of the present invention can be counted ... 1 For example, until ten days, a stable yield of propidium is produced? : OK, where-when the reactor is operating, the other; = should continue. The catalyst of the present invention may also be :) pure catalyst or pure compound or mixture of 诏 仃 具有 具有 and having different composition. In the catalytic cracking method, choose food recipes, ginseng green ke, Shi-μ &amp; select method conditions to provide High selection of propylene 丨 The conversion rate of olefins in the son-in-law over time,

Sl / Al atom :) ,; =: chemical conversion: use of low acid density (ie, high and may be beneficial for these purposes;:; yes: and short contact time, 1W h All of these 4 method parameters are related to each other , And for the overall cumulative effect (ie, higher temperature offset or make up). The method of selecting the pendulum method eliminates the hydrogen transfer reaction from the entrance of L: Tian coal coke precursor. Because of &amp;, the method operation is Self-interval velocity, low pressure and high reaction temperature. The range of LHSV ΐο ^ is better. The range of partial pressure of lean smoke is from 0.1 to 2 bar, and even better. The best partial pressure of dilute hydrocarbon is atmospheric pressure (ie 1 Hydrocarbon feedstock is supplied under the total inlet pressure of the feedstock that is conveyed through the reactor: 氩 in argon "to the raw material can be undiluted 'or diluted in an inert gas, for example to 10 ρ in Duying. The total absolute in the reactor The range of pressure is from 0.5. The inventors found that using a low olefin partial pressure, such as atmospheric pressure, tends to reduce the occurrence of hydrogen transfer reactions in the cracking process, which is in accordance with 491889 V. Description of the invention (14) Ordering tendency The cracking of hydrocarbons generated from coal coke that reduces catalyst stability ranges from 500 to 600. The inlet of the raw material of t γ = low 520 to 60 (TC is better, from 540 to 58. 1 is even better, code ^^ 'from ° C to 57 0 ° C., 孓 上 为, force 560 can be in Fixed bed reaction 1, moving bed reactor or fluidized bed reaction is mid-stream. Typical fluid bed reactor is a type of FCC for catalytic cracking of fluidized bed. Typical moving bed reactor is continuous catalytic recombination type As discussed above, the process can be performed continuously using one to two pairs of "swing" reactors in parallel. Since the catalyst exhibits high stability to olefin conversion over an extended period, typically at least about ten days, the catalyst regeneration frequency Low. In particular, the catalyst can therefore have a lifespan of more than one year. "After the catalytic cracking process, the reactor effluent is sent to a fractionator, and the desired olefins are separated from the effluent. When the catalytic cracking method is used to produce propylene At that time, &amp; type products containing at least 93% propylene are fractionated and then purified to remove all contaminants such as sulfur species, polonium, etc. Heavier olefins larger than C3 can be recycled. According to In various aspects of the invention, not only can a variety of different olefin feedstocks be used in the cracking process, but the process of olefin conversion can be controlled through appropriate selection of process conditions and specific catalysts used to selectivity in the effluent produced To produce special olefin distribution. For example, 'According to one of the main aspects of the present invention, an olefin-rich stream from a refinery or petrochemical plant is cracked into light olefins, especially propylene. The light negative portion of the effluent' is the C2 and c3 type products, can contain more than 95% olefin

_ 丨 Drawing

Page 19 491889

5. Description of the invention (15) Hydrocarbon. This type of product is pure enough to form a chemical grade olefin feedstock. The inventors have discovered that one or more of these can be included in this method. The olefin content of the above olefin feedstock can be from 30 to 50% based on the propylene yield based on the olefin. In this method, the effluent has a different olefin distribution than the feedstock, but has essentially the same total olefin content. In another embodiment, the process of the present invention produces G to C3 olefins from a G olefin feed. The catalyst is a crystalline silicate with a silicon / aluminum ratio of at least 300, and the process conditions are an inlet temperature from 500 to 600 ° C, an olefin partial pressure from ο to 2 bar, and 10 to 30 hours-iiLHSV It produces an olefin effluent with an olefin content of at least 40% as C2 to (: 3 olefins). Another preferred embodiment of the present invention provides a method for producing C2 to C3 olefins from lightly cracked petroleum brain. Lightly cracked The petroleum brain is contacted with a crystalline silicate catalyst having a silicon / aluminum ratio of at least 300 to produce, via cracking, an olefin effluent in which at least 40% of the olefin content is present as q to h olefins. In this method, the method The conditions include an inlet temperature of 500 to 600.00, an olefin partial pressure of 0.00 to 2 bar, and an LHSV of 10 to 30 hours-1. Various aspects of the present invention refer to the following non-limiting Exemplary embodiments are described below. Example 1 In this example, the raw material containing 1-hexene is brought to an inlet temperature of about 5 8 0 X: an outlet hydrocarbon pressure of atmospheric pressure and an LHSV of about 25 hours -1. The supply and supply should be available in the reactor from cu Chemie ueticon, Switzerland. AG company on the ZSM-5 catalyst under the trade name ZEOCAT P2-2. This commercially available catalyst is prepared by crystallization using an organic precursor, and

Page 20 491889 V. Description of the invention (16) &quot; No subsequent steam spraying or dealumination process was performed. This catalyst has 5 〇,

Different Shi Xi / Ming atomic ratios of 2000, 300, and 490. The crystal size of each catalyst is from 2 to 5 microns, and the particle size is from 35 to 45 mesh. Many tests were performed and the composition of the effluent was checked for each test to obtain an indication of the sum of each olefin, saturates and aromatic compounds in the effluent for various S i / A 1 atomic ratios. The results of their tests on the logistics after 5 hours are illustrated in Figure 1. Fig. 1 shows the propylene yield in the effluent, the percentage conversion of the hexene olefin feedstock, and the sum of saturates, olefins, and aromatic compounds in the effluent after the olefin catalytic cracking process of the present invention. The four tests for increasing the propylene purity based on the amount of propylene of the 03 type in the effluent to increase the atomic ratio were 70%, 91%, 93%, and 97%.

For silicon / aluminum atom ratios in commercial catalysts from about 200 to 300, both the olefin yield in the effluent and the propylene yield in terms of olefins are lower than the expected values of 85% and 30%, respectively. . Propylene purity is also below the typical commercial expectations of 93%. This display requires increasing the Si / Ai atomic ratio of commercially available catalysts by spraying steam and de-mingling as described above and de-alumination as described above, typically increasing to more than 300. In contrast, when using this steam injection and dealumination process, the Si / A1 ratio produced is preferably greater than 180 to obtain the desired olefin content in the effluent, propylene yield in terms of olefins, and propylene At a Si / Al atomic ratio of greater than about 300 in commercially available catalysts that have not been sprayed with steam and pre-dealuminated, at least about 85% of the olefins in the feedstock are cracked into olefins or are present as starting olefins. Therefore, at an atomic ratio of more than 002 Si / Ai :, f, the olefins in the raw materials and effluents that substantially have the raw materials and effluents, the weight of olefins within 3 miles to within ± 15 weight percent of each other

491889 V. Description of invention (π) Quantity. In addition, at this Si / Al atomic ratio of at least about 300 in this commercially available untreated catalyst, the propylene yield in terms of olefin is at least about 30% by weight. At this Si / A1 atomic ratio of about 490 in this commercially available untreated catalyst, the olefin content of the effluent is greater than about 90 weight percent of the olefin content of the feedstock, and the propylene yield in terms of olefin is close to 40%. Example 2 In this example, various M F I type crystalline petrosates having different silicon / aluminum atomic ratios were used for catalytic cracking of olefin feedstock. MFI oxalates include zeolites of type ZSM-5, especially commercially sold under the trade name of H-ZSM-5, purchased from PQ Corporation (Pennsylvania 19482-0840 Valley Forge, PA, USA) ) Post # Box 840 Southpoint (Southpoint)) "Fo Shi. This crystalline fossilate has a particle size from 3 5-4 5 mesh and has not been modified by previous treatments. The crystalline silicate was charged into a reactor tube and heated to a temperature of about 5300 ° C. Thereafter, 1 gram of 1-hexene was injected into the reactor tube over a period of 60 seconds. The injection rate has a WHS V of 20 hours-1 and a catalyst to oil weight ratio of 3. The cracking process is carried out at an outlet hydrocarbon pressure of 1 bar (atmospheric pressure). Table 1 shows the yields in terms of weight percentages of the various costs in the resulting effluent, and the amount of coal coke produced on the catalyst in the reactor tube. It can be seen that for crystalline silicates with a low Si / Al atomic ratio, a significant degree of coal coke is formed on the catalyst h. When applied to a catalytic cracking process for olefins, the sequence will lead to poor stability of the catalyst over time. In contrast, it can be seen that for crystalline silicates with high silicon / aluminum atomic ratios,

491889 V. Description of the invention (18) The agent 'and this example are about 3 50. No coal coke is generated on the catalyst, so that the catalyst has a directional stability. It can be seen that for a catalyst with a high Si / A1 atomic ratio (350), the propylene yield in terms of olefins in the effluent is about 28.8, which is significantly higher than when using a low Si / A1 Atomic ratio of acrylic acid yield in two experiments. Therefore, it can be seen that the use of a catalyst having a Nanshixi / Ming atomic ratio will increase the propylene yield in terms of olefins in the catalytic cracking of olefins to produce other olefins. It has also been found that increasing the Si / A1 atomic ratio can reduce the formation of propane. Compared to Examples 1 and 2, in these comparative examples, a commercially available siliceous carbon-based catalyst that has not been subjected to steam injection and a process of dealumination by extraction is used for catalytic cracking of a raw material containing dilute. In the catalytic cracking process, the butene-containing feedstock has the composition detailed in Tables 2a and 2b. A catalytic cracking procedure was performed at an inlet temperature of 545 ° C, an outlet hydrocarbon pressure of atmospheric pressure, and an LHSV of 30 hours-1. Tables 2a and 2b show the analysis of propylene, the amount of isobutylene and n-butene present in the effluent. In Comparative Example 1, the catalyst includes a lithocene &lt; type having a silicon / aluminum ratio of about 120 and a crystal size from 4 to 6 microns and a surface area (BET) of 399 square meters per gram. Press the stone Xi quality carbon, wash the strips and keep the 3 5-4 5 net. The catalyst of the mesh part has not been subjected to any steam spraying and extraction process. In Comparative Example 2, Li et al. ☆☆ People &amp; t — Catalyzed d contains the same starting groups as in Comparative Example 1 ′, and has been in a 72% by volume stream and 28% by volume nitrogen. Of

V. Description of the invention (19) In the atmosphere, at a temperature of 550 ° C, under the name "48 hours, but the extraction process is not performed in order. The steam spraying procedure is performed under pressure. You can see the comparative examples and the , \ Fruit are shown in Table 2a and Li respectively. Shows stability. In other words, the catalytic sword Example 2, the catalyst has not been reduced. It is believed that this is due to the use of low stone in the catalyst at any time. Xi / Shaoyuan 2 coal coke: its sequential system has quite high acidity. The catalyst is caused by the formation of the catalyst. For Comparative Example 1, there is also a significant formation of Shizui * such as Bingyuan. Table 1 Gas # 59. 3 60 · 4 63. 8 Coal coke 4. 35 1. 44 0 Yield / wt% propane propene hydrazone-ZSM-5 [25] 28 58 H-ZSM-5 [40] 19.8 \ 〇 Η-ZSM-5 [350] 1.8 28.8 # gas = Η 2, to C4 dilute hydrocarbons and stone bugs 491889 V. Description of the invention (20) Comparative Example 1 Crystal silicate without modification T (° 549549 LHSVCh- 1) 30 TOS (h) 5 169 Feed conversion effluent n-butene conversion (%) 85. 2 55. 9 C! P1 0. 00 0. 41 0.997 C2 P2 0. 00 0. 51 0. 0000 02 0. 00 8. 64 0.8974 P3 0. 30 3. 80 0.3988 03 0. 10 2 0.36 8.47 53 C4 iP4 31.10 31. 57 30.7106 nP4 12.80 13. 27 13.0620 104 3. 70 5.14 1 3.4 608 n04 51.00 7. 76 22.4257 C5 iP5 + nP5 + cP5 0. 00 0. 93 0.4985 i05 + n05 + c05 0. 20 4. 11 6. 9 7 9 7 C6 C6 + 0. 80 3.5 0 2.9913 Olefins 02-06 55. 00 46. 01 5 2.24 Shikan P1-P6 44. 20 50. 49 44. 77 Unknown 0.80 3.5 0 2. 99 491889 V. Description of the invention (21) Table 2b Comparative Example 2 Crystal silicate was sprayed with steam T (°. 549 LHSV (h-!) 29. 6 TOS (h) 16 72 Conversion of n-butene from feed effluent (%) 73. 1 70. 1 Ci PI 0. 0000 0.2 0 22 0.1005 C2 P2 0. 0000 0.1011 0. 0000 02 0. 0000 2.7297 1. 7084 C3 P3 0.1000 0.4044 0.3015 03 0.3000 17.8949 14.2704 C4 iP4 33.4000 33.8689 33. 1 63 6 nP4 9.7000 10. 1001 10.1501 i04 2.4000 10.1101 10.7530 n04 53.2000 14.4684 15.9856 C5 i P5 + nP 5 + cP5 0.5000 0.5055 0.5025 i05 + n05 + c05 0.1000 7. 1782 8. 5421 C6 C6 + 0.40 0 0 2.4264 4.5223 Olefin 02 -06 56.00 52.38 51.26 Paraffin P1-P6 43.70 45.19 44. 22

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Claims (1)

491889 91 · 26-Case No. 87120161 Rev. _ Revised Master's Version 6. Scope of Patent Application-1 · A method for the selective catalytic cracking of olefin-rich hydrocarbons to light olefins in effluent, this The method comprises combining a hydrocarbon feedstock containing one or more olefins with an MF I-type crystalline silicate catalyst having a silicon / aluminum atomic ratio of 300 to 1000, at an inlet temperature from 500 to 600 ° C, and from The olefin was contacted at a partial pressure of 2 bar, and the raw material was catalyzed at an LHSV from 10 to 30 hours μ above M to produce an effluent having a lower molecular weight olefin content than the raw material. 2 · The method according to item 1 of the scope of patent application, wherein the catalyst is used The organic precursor was prepared by crystallization without any subsequent steam spraying or dealumination procedures. 3. The method according to item 2 of the patent application, wherein the catalyst comprises a ZSM-5 catalyst. 4. The method according to item 1 of the patent application range, wherein the raw materials include C4 to Cl0. 5. The method according to item 1 of the scope of patent application, wherein the method is selective for propylene in the effluent so that the effluent is rich in propylene. 6. The method of claim 5, wherein the propylene contains at least 93% of the C3 compound present in the effluent. ^ Shishen = The method of item 5 or 6 of the patent scope, in which the catalytic cracking is based on the content of propylene, which has from 30 to 50% of the propylene production brake U 2 in terms of olefins: patent scope 1 In the method of # 2, the catalytic cracking in # 2: The thin smoke of 2: to form lighter olefins, so that the olefin weight content of the raw materials and materials is within ± 15% of each other. 87120161.ptc p. 29 491889 87120161.ptc Page 30