A kind of preparing propylene from methanol by product technological method for processing
Technical field
The invention belongs to aromatic hydrocarbons chemical technology field, be specifically related to a kind of preparing propylene from methanol by product technological method for processing.
Background technology
Propylene is the second largest petrochemical industry basic material being only second to ethene, and its maximum purposes produces polypropylene.The propylene of current more than 95% produces the byproduct of ethene and the byproduct of refinery FCC apparatus from steam cracking.But due to the unstable of world oil supply and the predicament of China's shortage petroleum resources, the source of the important source material propylene of development needed for petrochemical complex is greatly limited.Exploitation through preparing propylene from methanol (MTP) technique by coal, is not only conducive to the efficiency utilization realizing coal, can also alleviates the situation that state's inner propene is in short supply.Therefore, preparing propylene from methanol obtains in China and develops rapidly in recent years, and by the end of the year 2012, the coal-based propylene annual capacity of China will have reached 1,360,000 tons, accounts for about 7% of China's propylene production capacity.
MTP technique, except production propylene product, goes back the liquefied hydrocarbon (C that by-product is a large amount of
5 +) and liquefied gas.Liquefied hydrocarbon output large (being about 40% of propone output), the impurity few (without sulphur, without nitrogen) of MTP technique, product component is mainly isoparaffin, alkene and aromatic hydrocarbons, there is very large appreciation potential, but current processing mode is taken out as blended gasoline component.The liquefaction tolerance of by-product is relatively few, and product component is mainly propane and butane, because output is relatively little, sells and does not become scale.Along with developing rapidly of MTP technique, seek the processing and utilization approach of by product, to promote the value of by product extremely urgent.
Because the aromaticity content in MTP liquefied hydrocarbon by product is higher, therefore by carrying out catalytic reforming to it, be more rational processing scheme by the non-aromatic aromatic hydrocarbons being converted into high added value wherein.In addition, by product liquefied gas also can be translated into aromatic hydrocarbons by the technology of aromizing.
CN1032697C discloses a kind of catalytic modification of poor quality gasoline-aromatization method, and the method Raw is introduced into first reactor, 300 ~ 550 DEG C, 0.05 ~ 1.2MPa, mass space velocity be 0.2 ~ 1.0h
-1conditions of non-hydrogen under react, product after gas-liquid separation, C
5 +liquid obtains gasoline fraction by fractionation, is less than C
4gas after preheating, enter second stage reactor, at 480 ~ 650 DEG C, 0.05 ~ 1.5MPa, volume space velocity 20 ~ 2000h
-1condition under carry out aromatization, aromatization products, after gas-liquid separation, obtains the gas and the aromatic hydrocarbons mixture that are rich in hydrogen.
CN101747933A discloses a kind of petroleum naphtha and light-hydrocarbon aromatized method for modifying, and the method is by petroleum naphtha and C
3~ C
5lighter hydrocarbons contact with aromatized catalyst under hydro condition and carry out aromatization modification reaction, 250 ~ 600 DEG C, the volume ratio of hydrogen and petroleum naphtha is 20 ~ 400.Low-octane petroleum naphtha and low-carbon (LC) hydro carbons can be converted into stop bracket gasoline and high-quality liquefied gas by the method.
One Pt/ZSM-5 catalyzer is disclosed by C in USP4835336
6-C
12non-aromatic hydrocarbon is converted into the method for aromatic hydrocarbons, in order to improve arenes selectivity and suppress hydrogenolysis, this catalyzer needs to carry out prevulcanized before use, although this technique has higher aromatics yield, but because adopting noble metal catalyst and needing prevulcanized, cause manufacturing cost higher.
The Cyclar technique (USP4642402) that British Petroleum Company p.l.c. (BP) and earth oil company (UOP) are developed jointly, low-molecular-weight alkane such as propane and butane is utilized to replace petroleum naphtha to carry out aromatization, the gasoline yield being rich in aromatic hydrocarbons can reach 62 ~ 67%, but this technological reaction temperature is higher.
Current inferior patrol and liquefied gas complete processing are mainly for catalytic gasoline and low-carbon alkanes raw material, and the complete processing for MTP by product is not also reported.MTP by product character is special, and value-added space is large, and especially liquefied hydrocarbon by product, is converted into the light aromatics of high added value by the non-aromatic hydrocarbon in liquefied hydrocarbon according to ZSM-5 molecular sieve catalyzer, bring considerable economic benefit by for enterprise.Meanwhile, utilize liquefied gas through aromatization technology that the liquefied gas of by-product is also converted into aromatic hydrocarbons, just solve the marketing problem of liquefied gas simultaneously.But the Determination of Alkane Content of the liquefied gas of MTP by-product is higher, the liquefied gas through aromatization being rich in alkane is very endothermic reaction, need in production process constantly to carry out concurrent heating, and aromatization of methanol reaction is very exothermic process, liquefied gas through aromatization and aromatization of methanol technology are coupled, the external heat source of aromatization process needs can be saved, thus reduce system energy consumption.
Summary of the invention
The invention provides a kind of complete processing of MTP by product, this technique adopts two sections of aromatization of gas technology that non-aromatic in liquefied hydrocarbon is converted into aromatic hydrocarbons, utilize methyl alcohol and liquefied gas coupling aromatization technology that by product liquefied gas is also converted into aromatic hydrocarbons, the advantage that to have that aromatics yield is high, energy consumption is low, economic benefit is rised in value large simultaneously.
The present invention is a kind of preparing propylene from methanol by product technological method for processing, it is characterized in that:
By coal through the liquefied hydrocarbon by product of preparing propylene from methanol MTP technique after alkene aromizing and alkane aromatization two sections of fixed-bed reactor, be isolated to dry gas, liquefied gas, C
5 +non-aromatic and aromatic hydrocarbons; Dry gas and aromatic hydrocarbons discharge reaction system as product, C
5 +the non-aromatic alkane aromatization reaction device that returns continues reaction, liquefied gas enters aromatization reactor together with the liquefied gas of MTP process by-product, thermal source needed for liquefied gas through aromatization is provided by the mode of extraneous methanol, under molecular sieve catalyst effect, be converted into the hydrocarbon mixture product based on aromatic hydrocarbons, hydrocarbon mixture product enters deethanizing column and is separated after water-and-oil separator; Aromatization of gas, liquefied gas through aromatization technology combine by this technique, effectively MTP by product are converted into aromatic hydrocarbons; By this technique, the actual gaining rate of aromatic hydrocarbons of the liquefied hydrocarbon by product of MTP can reach 50 ~ 140%, and the aromatics yield of liquefied gas through aromatization can reach 30 ~ 45%;
MTP by product technological method for processing comprises the steps:
1) the liquefied hydrocarbon by product from MTP technique is heated to after temperature of reaction through preheater, enter into and be equipped with in the fixed-bed reactor of molecular sieve catalyst, be 0.1 ~ 2.0MPa at working pressure, temperature is 260 ~ 380 DEG C, and raw materials quality air speed is 0.5 ~ 8.0h
-1condition under carry out alkene aromatization; Catalyzer is through the modified nano-ZSM-5 molecular sieve catalyzer of hydrothermal treatment consists, and the hydrothermal treatment consists temperature of ZSM-5 molecular sieve is 300 ~ 800 DEG C;
2) one section of alkene aromatization reaction products is after heating, enter metal-modified ZSM-5 molecular sieve catalyzer is housed alkane aromatization reaction device in, be 0.1 ~ 2.0MPa at working pressure, temperature of reaction is 380 ~ 520 DEG C, and raw materials quality air speed is 0.5 ~ 4.0h
-1condition under carry out the aromatization of alkane; Catalyzer is metal-modified nano-ZSM-5 molecular sieve catalyzer, and modified metal is one or more in Zn, Ni, La, Mo, Cu, Fe, Mn, Cr, and the total charge capacity of metal is 0.5 ~ 8.0wt%;
3) reaction product of two sections of alkane aromatizations product after deethanizing column, debutanizing tower, Aromatics Extractive Project tower is divided into dry gas, liquefied gas, C
5 +non-aromatic and aromatic hydrocarbons;
4) step 3) is separated the C obtained
5 +non-aromaticly return two sections of alkane aromatization reaction devices and continue reaction, the liquefied gas by product of liquefied gas product and MTP technique jointly enters in liquid gas aromatization reaction device and reacts; Pass into a certain amount of methyl alcohol through preheating in liquid gas aromatization reaction device, the heat effect utilizing methanol conversion to produce directly supplements liquefied gas through aromatization institute heat requirement; Reaction conditions is: temperature 400 ~ 550 DEG C, pressure 0.1 ~ 3.0MPa, and the mol ratio of methyl alcohol and liquefied gas is 0.5:1 ~ 5:1, and raw materials quality air speed is 0.5 ~ 5.0h
-1; Used catalyst is metal-modified ZSM-5 molecular sieve catalyzer, and modified metal is one or more in Ga, Ni, Zn, Cu, Re, Sn, La, Tb, and metal total loading amount is 1.0 ~ 8.0wt%;
5) the hydrocarbon mixture component that liquefied gas through aromatization obtains enters deethanizing column and is separated after water-and-oil separator.
According to MTP by product technological method for processing of the present invention, it is characterized in that:
From the liquefied hydrocarbon by product of MTP technique after alkene aromizing and alkane aromatization two sections of fixed-bed reactor, be isolated to dry gas, liquefied gas, C
5 +non-aromatic and aromatic hydrocarbons; Dry gas and aromatic hydrocarbons discharge reaction system as product, C
5 +the non-aromatic alkane aromatization reaction device that returns continues reaction, liquefied gas enters aromatization reactor together with the liquefied gas of MTP process by-product, thermal source needed for liquefied gas through aromatization is provided by the mode of extraneous methanol, under molecular sieve catalyst effect, be converted into the hydrocarbon mixture product based on aromatic hydrocarbons, hydrocarbon mixture product enters deethanizing column and is separated after water-and-oil separator; Aromatization of gas, liquefied gas through aromatization technology combine by this technique, effectively MTP by product are converted into aromatic hydrocarbons; By this technique, the actual gaining rate of aromatic hydrocarbons of the liquefied hydrocarbon by product of MTP can reach 65 ~ 120%, and the aromatics yield of liquefied gas through aromatization can reach 32 ~ 40%;
MTP by product technological method for processing comprises the steps:
1) the liquefied hydrocarbon by product from MTP technique is heated to after temperature of reaction through preheater, enter into and be equipped with in the fixed-bed reactor of molecular sieve catalyst, be 0.5 ~ 1.0MPa at working pressure, temperature is 280 ~ 340 DEG C, and raw materials quality air speed is 1.0 ~ 5.0h
-1condition under carry out alkene aromatization.Catalyzer is through the modified nano-ZSM-5 molecular sieve catalyzer of hydrothermal treatment consists, and the hydrothermal treatment consists temperature of ZSM-5 molecular sieve is 450 ~ 650 DEG C;
2) one section of alkene aromatization reaction products is after heating, enter metal-modified ZSM-5 molecular sieve catalyzer is housed alkane aromatization reaction device in, be 0.5 ~ 1.0MPa at working pressure, temperature of reaction is 380 ~ 480 DEG C, and raw materials quality air speed is 1.0 ~ 3.0h
-1condition under carry out the aromatization of alkane.Catalyzer is metal-modified nano-ZSM-5 molecular sieve catalyzer, and modified metal is one or more in Zn, Ni, La, Cr, and the total charge capacity of metal is 2.0 ~ 6.0wt%;
3) reaction product of two sections of alkane aromatizations product after deethanizing column, debutanizing tower, Aromatics Extractive Project tower is divided into dry gas, liquefied gas, C
5 +non-aromatic and aromatic hydrocarbons;
4) step 3) is separated the C obtained
5 +non-aromaticly return two sections of alkane aromatization reaction devices and continue reaction, the liquefied gas by product of liquefied gas product and MTP technique jointly enters in liquid gas aromatization reaction device and reacts.Pass into a certain amount of methyl alcohol through preheating in liquid gas aromatization reaction device, the heat effect utilizing methanol conversion to produce directly supplements liquefied gas through aromatization institute heat requirement.Reaction conditions is: temperature 440 ~ 520 DEG C, pressure 0.5 ~ 2.0MPa, and the mol ratio of methyl alcohol and liquefied gas is 1:1 ~ 3:1, and raw materials quality air speed is 0.5 ~ 3.0h
-1.Used catalyst is metal-modified ZSM-5 molecular sieve catalyzer, and modified metal is one or more in Ga, Ni, Zn, Sn, La, and metal total loading amount is 2.0 ~ 6.0wt%;
5) the hydrocarbon mixture component that liquefied gas through aromatization obtains enters deethanizing column and is separated after water-and-oil separator.
The present invention has following advantage: (1) adopts alkene aromizing and alkane aromatization technology that non-aromatic in liquefied hydrocarbon is at utmost converted into aromatic hydrocarbons, unreactedly non-aromaticly returns alkane aromatization reaction device, has higher aromatics yield; (2) the liquefied gas by product of the liquefied gas this technique produced and MTP technique carries out aromizing jointly, and utilize the heat release of aromatization of methanol to supplement the heat absorption of liquefied gas through aromatization, system energy consumption is lower.
Accompanying drawing explanation
Fig. 1 is MTP by product technological method for processing schematic flow sheet provided by the invention.In figure: 1-raw materials furnace and heating; 2-alkene aromatization reactor; 3-alkene aromatization products process furnace; 4-alkane aromatization reaction device; 5-deethanizing column; 6-debutanizing tower; 7-Aromatics Extractive Project tower; 8-liquid gas aromatization reaction device; 9-water-and-oil separator; 10-methanol preheater.
Embodiment
In order to further illustrate MTP by product complete processing of the present invention, below in conjunction with accompanying drawing, process of the present invention is described.
As shown in Figure 1, MTP liquefied hydrocarbon by product is heated to through process furnace 1 and enters alkene aromatization reactor 2 after temperature of reaction and react, and reaction product enters alkane aromatization reaction device 4 again and carries out alkane aromatization reaction after process furnace 3 heats.Alkane aromatization reaction product obtains dry gas, liquefied gas, C through deethanizing column 5, debutanizing tower 6 after being separated with Aromatics Extractive Project tower 7
5 +non-aromatic and aromatic hydrocarbons.Dry gas and aromatic hydrocarbons discharge system as product, C
5 +the non-aromatic alkane aromatization reaction device 4 that returns proceeds reaction, the liquefied gas by product of liquefied gas and MTP technique jointly enters liquid gas aromatization reaction device 8 and reacts, pass into a certain amount of methyl alcohol through preheater 10 preheating in aromatization reactor 8, product returns deethanizing column 5 and is separated after water-and-oil separator 9.
Embodiment 1
(1) MTP liquefied hydrocarbon by product aromizing
First MTP technique liquefied hydrocarbon by product enters one section of alkene aromatization reactor, and catalyzer is the nano-ZSM-5 molecular sieve through 450 DEG C of hydrothermal treatment consists modifications, is 280 DEG C in temperature of reaction, and pressure is 0.5MPa, and mass space velocity is 1.0h
-1condition under react.Then enter two sections of alkane aromatization reaction devices, catalyzer is the ZSM-5 molecular sieve catalyzer of Zn, Ni modification, and wherein the charge capacity of ZnO is the charge capacity of 2.0wt%, NiO is 1.0wt%.Reaction conditions is temperature is 380 DEG C, and pressure is 0.5MPa, and mass space velocity is 1.0h
-1.MTP liquefied hydrocarbon by product feedstock property is as shown in table 1, and reaction result is as shown in table 2.
(2) MTP liquefied gas by product aromizing
Adopt MTP liquefied gas by product and methyl alcohol to be raw material, liquefied gas feedstock property is as shown in table 3.Enter fixed-bed reactor after liquefied gas and methanol mixed, catalyzer adopts the ZSM-5 molecular sieve catalyzer of Zn modification, and wherein the charge capacity of ZnO is 2.0wt%.Be 440 DEG C in temperature of reaction, pressure is 0.5MPa, and the mol ratio of methyl alcohol and liquefied gas is 1:1, and raw materials quality air speed is 0.5h
-1condition under react, reaction result is as shown in table 4.
Embodiment 2
(1) MTP liquefied hydrocarbon by product aromizing
First MTP technique liquefied hydrocarbon by product enters one section of alkene aromatization reactor, and catalyzer is the nano-ZSM-5 molecular sieve through 550 DEG C of hydrothermal treatment consists modifications, is 300 DEG C in temperature of reaction, and pressure is 1.0MPa, and mass space velocity is 2.0h
-1condition under react.Then enter two sections of alkane aromatization reaction devices, catalyzer is the ZSM-5 molecular sieve catalyzer of Zn, Ni, La modification, and the charge capacity of ZnO is the charge capacity of 2.0wt%, NiO is 1.0wt%, La
2o
3charge capacity be 1.0wt%.Reaction conditions is temperature is 420 DEG C, and pressure is 1.0MPa, and mass space velocity is 1.0h
-1, reaction result is as shown in table 2.
(2) MTP liquefied gas by product aromizing
Adopt MTP liquefied gas by product and methyl alcohol to be raw material, liquefied gas feedstock property is as shown in table 3.Fixed-bed reactor are entered, the ZSM-5 molecular sieve catalyzer that catalyzer adopts Ga, Ni composite modified, Ga after liquefied gas and methanol mixed
2o
3charge capacity be the charge capacity of 0.5wt%, NiO be 3.5wt%.Be 460 DEG C in temperature of reaction, pressure is 1.0MPa, and the mol ratio of methyl alcohol and liquefied gas is 2:1, and raw materials quality air speed is 1.5h
-1condition under react, reaction result is as shown in table 4.
Embodiment 3
(1) MTP liquefied hydrocarbon by product aromizing
First MTP technique liquefied hydrocarbon by product enters one section of alkene aromatization reactor, and catalyzer is the nano-ZSM-5 molecular sieve through 600 DEG C of hydrothermal treatment consists modifications, is 340 DEG C in temperature of reaction, and pressure is 0.5MPa, and mass space velocity is 4.0h
-1condition under react.Then enter two sections of alkane aromatization reaction devices, catalyzer is the ZSM-5 molecular sieve catalyzer of Zn, Cr modification, and the charge capacity of ZnO is 2.0wt%, Cr
2o
3charge capacity be 3.0wt%.Reaction conditions is temperature is 450 DEG C, and pressure is 0.5MPa, and mass space velocity is 3.0h
-1, reaction result is as shown in table 2.
(2) MTP liquefied gas by product aromizing
Adopt MTP liquefied gas by product and methyl alcohol to be raw material, liquefied gas feedstock property is as shown in table 3.Fixed-bed reactor are entered, the ZSM-5 molecular sieve catalyzer that catalyzer adopts Ga, Ni, Sn composite modified, wherein Ga after liquefied gas and methanol mixed
2o
3the charge capacity of charge capacity to be the charge capacity of 1.5wt%, NiO be 4wt%, Sn be 0.5wt%, be 480 DEG C in temperature of reaction, pressure is 2.0MPa, and the mol ratio of methyl alcohol and liquefied gas is 2:1, and raw materials quality air speed is 2.0h
-1condition under react, reaction result is as shown in table 4.
Embodiment 4
(1) MTP liquefied hydrocarbon by product aromizing
First MTP technique liquefied hydrocarbon by product enters one section of alkene aromatization reactor, and catalyzer is the nano-ZSM-5 molecular sieve through 650 DEG C of hydrothermal treatment consists modifications, is 340 DEG C in temperature of reaction, and pressure is 1.0MPa, and mass space velocity is 3.0h
-1condition under react.Then enter two sections of alkane aromatization reaction devices, catalyzer is the ZSM-5 molecular sieve catalyzer of Ni, La modification, and the charge capacity of NiO is 3.0wt%, La
2o
3charge capacity is 1.0wt%, and reaction conditions is temperature is 480 DEG C, and pressure is 1.0MPa, and mass space velocity is 3.0h
-1, reaction result is as shown in table 2.
(2) MTP liquefied gas by product aromizing
Adopt MTP liquefied gas by product and methyl alcohol to be raw material, liquefied gas feedstock property is as shown in table 3.Enter fixed-bed reactor after liquefied gas and methanol mixed, the ZSM-5 molecular sieve catalyzer that catalyzer adopts Zn, Sn composite modified, wherein the charge capacity of ZnO is 4.5wt%, SnO
2charge capacity be 0.5wt%.Be 520 DEG C in temperature of reaction, pressure is 2.0MPa, and the mol ratio of methyl alcohol and liquefied gas is 3:1, and raw materials quality air speed is 3.0h
-1condition under react, reaction result is as shown in table 4.
Table 1MTP liquefied hydrocarbon by product PONA composition
Carbon number |
Normal paraffin |
Isoparaffin |
Alkene |
Naphthenic hydrocarbon |
Aromatic hydrocarbons |
Amount to |
4.00 |
0.00 |
0.01 |
0.09 |
0.00 |
0.00 |
0.10 |
5.00 |
1.63 |
13.81 |
6.36 |
1.18 |
0.00 |
22.98 |
6.00 |
0.50 |
6.69 |
6.43 |
6.47 |
0.29 |
20.38 |
7.00 |
1.36 |
0.94 |
8.41 |
3.00 |
4.61 |
18.32 |
8.00 |
0.34 |
2.91 |
4.96 |
1.48 |
19.08 |
28.77 |
9.00 |
0.00 |
0.46 |
0.78 |
0.40 |
7.19 |
8.83 |
10.00 |
0.00 |
0.00 |
0.00 |
0.00 |
0.55 |
0.55 |
11.00 |
0.00 |
0.07 |
0.00 |
0.00 |
0.00 |
0.07 |
Add up to |
3.83 |
24.89 |
27.03 |
12.53 |
31.72 |
99.99 |
Table 2 embodiment 1 ~ 4MTP liquefied hydrocarbon by product two sections of aromatization results
Note: aromatics yield=liquid yield arenes selectivity; Aromaticity content in the actual gaining rate of aromatic hydrocarbons=(in liquid yield arenes selectivity-raw material aromaticity content)/raw material.
Table 3MTP liquefied gas by product composition
Component |
Propane |
Propylene |
Trimethylmethane |
Normal butane |
Just, iso-butylene |
Trans-2-butene |
Cis-2-butene |
C5+ |
Content wt% |
17.10 |
0.23 |
39.31 |
10.91 |
19.52 |
6.84 |
4.25 |
1.84 |
Table 4 embodiment 1 ~ 4 liquefied gas and aromatization of methanol reaction result