CN105884568A - Technique for recovering propylene from off gas discharged by polypropylene device - Google Patents
Technique for recovering propylene from off gas discharged by polypropylene device Download PDFInfo
- Publication number
- CN105884568A CN105884568A CN201510018215.0A CN201510018215A CN105884568A CN 105884568 A CN105884568 A CN 105884568A CN 201510018215 A CN201510018215 A CN 201510018215A CN 105884568 A CN105884568 A CN 105884568A
- Authority
- CN
- China
- Prior art keywords
- tail gas
- gas
- propylene
- pressure
- coolant
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Landscapes
- Vaporization, Distillation, Condensation, Sublimation, And Cold Traps (AREA)
Abstract
The invention relates to a technique for recovering propylene from off gas discharged by a polypropylene device. The polypropylene device has a plurality of off gas (average propylene content being about 85%) discharging points, and the pressure and composition of off gas discharged from different discharging points are different. According to the technique, no off gas compressor is arranged, off gas with different pressure grades discharged by the polypropylene device is condensed through a refrigerant generated by a refrigerating unit, and 95% of propylene in off gas by mass is condensed; meanwhile, equilibrium flash vaporization is conducted with a condensate tank with the minimum pressure to enable light components including hydrogen and nitrogen in condensate to be flashed out almost completely, and then recovery of propylene is realized in the true sense. The pressure of off gas is fully utilized, and condensation is conducted according to different compositions of off gas, so that optimal condensation efficiency is realized. By conducting low-pressure flashing on obtained condensate, light components including hydrogen and nitrogen in condensate can be flashed out almost completely, so that recovery of propylene is realized in the true sense. The technique is high in efficiency, low in energy consumption, simple, practical, safe and reliable and is realized by improving an existing polypropylene process.
Description
Technical field
The present invention relates to the process of a kind of tail gas recycle propylene discharged from polypropylene plant.The method belongs to technical field of petrochemical industry.Utilize this invented technology, can simply, effectively and safely reclaim the propylene in polypropylene plant institute emission.
Background technology
Domestic polypropylene plant is generally divided into three kinds of techniques: liquid phase endless tube method, gas fluidized bed method, small scale bulk polymeric kettle method.These three technique, in actual production, all can discharge a certain amount of tail gas, and it is mainly composed of propylene.As a example by a set of 200,000 tons/year of liquid phase endless tube method polypropylene plants, its exhaust emissions has 3 points, see table:
Table-1 liquid phase endless tube method polypropylene plant exhaust emissions point situation
Calculating by upper table, three strands of tail gas amount to 600kg/h, and wherein propylene is 531kg/h.
If tail gas is not reclaimed, then this partial tail gas enters full factory gas train and uses as fuel gas.
After using the tail gas propylene recovery method of the present invention, propylene recovery rate takes 95% (wt), and polypropylene plant is annual based within 8000 hours, going into operation, 1 year recyclable propylene 4036t.If fuel gas price is based on 3000 yuan/t, propylene price is based on 8000 yuan/t, and 200 yuan/t of propylene recovery expense per ton, the propylene of recovery can increase value and be: 4036 × (0 8-0 3-0 02)-1,937 ten thousand yuan.Accordingly, there exist necessity that existing polymarization method for prodcing polyacrylates flow process is carried out to be improved and improve, come simple, reliable, safe, reclaim the propylene in tail gas at low cost.
Domestic polypropylene plant, has the employing method such as membrane separation process, pressure swing adsorption method Propylene recovery from tail gas, and these methods generally exist the problem that recovering effect is bad, contrast the present invention, and its investment is big, energy consumption is high, process is complicated.
According to statistics, China's polypropylene production in 2013 about 12,000,000 tons, in the tail gas that these polypropylene plants are discharged, potential propylene recovery amount is about 240,000 tons/year, and potential recovery value is about 1,200,000,000 yuan/year.Therefore, by the present invention, improve and improve China's existing polypropylene plant technological process, substantial amounts of propylene can be reclaimed and bring huge economic benefit and social benefit.
Summary of the invention
The mesh of the present invention is Propylene recovery from the tail gas that polypropylene plant is discharged.
Technical solution of the present invention: 1, to the tail gas containing steam, is first dried process；2, refrigeration unit is set, produces coolant, condensed the tail gas of different emission point with coolant by heat exchanger respectively.
It is described as follows:
A) to the tail gas containing steam, drying facility is set so that it is dew point temperature is less than the minimum temperature in condensation process.
B) refrigeration unit used is common handpiece Water Chilling Units or other unit, it is provided that coolant be chilled water or other medium；
C) initial temperature of coolant is between-19 DEG C to 5 DEG C, and such temperature range does not has particular/special requirement to the material of equipment, pipeline etc., and common refrigeration unit just can easily realize, and energy consumption is the highest:
D) coolant and the heat exchange in respective heat exchanger respectively of the tail gas of different emission points, the most propylene condensation in tail gas.Because its component of tail gas of different emission points is different with pressure, select to condense respectively, it is possible to use the pressure itself of tail gas, most effectively Propylene recovery；
E) condensed fluid that the tail gas of different emission points produces through coolant cooling, respectively enter respective condensate drum or hydrops groove that heat exchanger carries, finally converge to the minimum drainer of one of them pressure or hydrops groove, it is balanced flash distillation, so, light component such as the overwhelming majority (more than 96%, quality) hydrogen, nitrogen, C2 etc. in tail gas flashes to gas phase, and enters fuel gas system as fixed gas:
F) in the condensed fluid finally given, containing propylene more than 90% (quality), it is more than 99.7% (quality) containing propylene and propane, hydrogen, nitrogen, C2 component are few (less than 0 15%, quality), after pumped is boosted, can mix with the raw material propylene of polypropylene plant, it is also possible to deliver to gas fractionation unit.
Advantages of the present invention:
First, the initial temperature of coolant of the present invention is at-19 DEG C～5 DEG C, and equipment, pipeline etc. need not select low temperature resistant material, common refrigeration unit just can realize.
Second, the present invention utilizes the pressure of tail gas self, enables propylene to condense at a higher temperature, is not provided with tail-gas compressor, and process is simply effectively, energy consumption is low, it is low to invest.
3rd, the pressure that the present invention is directed to different emission point tail gas is different with composition, uses and condenses respectively, can obtain best propylene recovery effect, and the response rate can reach 95% (quality).
4th, the condensed fluid that the present invention obtains converges to be balanced flash distillation in the minimum condensate drum of pressure (or hydrops groove), light component substantially flash distillation is gone out, in the condensed fluid obtained, propylene content is more than 99.7% (quality) more than 90% (quality), propylene plus propane content, the light component total content such as hydrogen, nitrogen, C2, less than 0.15% (quality), is truly realized the recovery of propylene.
5th, for the tail gas containing moisture content, the present invention arranges drying facility, efficiently solves the frosting problem that tail gas aqueous is brought.
Accompanying drawing explanation 1
Fig. 1 is the process flow diagram of the present invention.
In figure: D-1AB be drying chamber, E-1 be PK-501 tail gas condenser, E-2 be E-701 tail gas condenser, E-3 be E-301 tail gas condenser, EH-1 be electric heater, V-1 be PK-501 tail gas condensing tank, V-2 be E-701 tail gas condensing tank, V-3 be E-301 tail gas condensing tank, V-4 be freezing water pot, P-1 be condensing propylene pump, P-2 be chilled water circulating pump, PK-1 be refrigeration unit.
Note: for ease of explanation, this process flow diagram device numbering relates to polypropylene plant, have references to the domestic liquid phase endless tube common numbering of method polypropylene plant, do not represent present invention process and be only applicable to the recovery of liquid phase endless tube method polypropylene plant tail gas, and apply to including gas fluidized bed method all have exhaust emissions and the polypropylene plant of propylene in tail gas need to be reclaimed.
Detailed description of the invention 1
A) PK-501 tail gas contains moisture, initially enters drying chamber D-1AB and removes moisture content, then with coolant in PK-501 tail gas condenser E-1 heat exchange, condensation, subsequently into PK-501 tail gas condensing tank V-1.Here, PK-501 tail gas is one tail gas that pressure is minimum；
B) E-701 tail gas and coolant are in E-701 tail gas condenser E-2 heat exchange, condensation, subsequently into E-701 tail gas condensing tank V-2；
C) E-301 tail gas and coolant are in E-301 tail gas condensing tank E-3 heat exchange, condensation, subsequently into E-301 tail gas condensing tank V-3；
D) fixed gas of E-701 tail gas condensing tank V-2 is discharged, and condensed fluid removes the PK-501 tail gas condensing tank V-1 that pressure is minimum；
E) fixed gas of E-301 tail gas condensing tank V-3 is discharged, and condensed fluid removes the PK-501 tail gas condensing tank V-1 that pressure is minimum；
F) pressure of PK-501 tail gas condensing tank V-1 is minimum, and it receives condensed PK-501 tail gas that E-1 comes and the condensed fluid that V-2, V-3 come, equilibrium flash, and fixed gas is discharged, and condensed fluid removes condensing propylene pump P-1:
G) condensed fluid is delivered to user by condensing propylene pump P-1；
H) refrigeration unit PK-1 provides coolant by freezing water pot V-4 and chilled water circulating pump P-2 to E-1, E-2, E-3.
Embodiment one:
The liquid phase endless tube method polypropylene plant of a set of annual output 200000 tons, the tail gas situation of its discharge chats " table-1 " before seeing.Condensation Propylene recovery process stream balance is shown in Table-2.
Table-2 material balance table (8000h that goes into operation in year meter)
| Sequence number | Name of material | t/h | t/d | t/a | Remarks |
| Charging | |||||
| 1 | PK-501 (tail gas 1) | 04 | 96 | 3200 | Containing propylene 88 3% (quality) |
| 2 | E-701 (tail gas 2) | 008 | 192 | 640 | Containing propylene 85 4% (quality) |
| 3 | E-301 (tail gas 3) | 012 | 288 | 960 | Containing propylene 91 2% (quality) |
| Add up to | 06 | 144 | 4800 | ||
| Discharging | |||||
| 1 | Condensed fluid | 0556 | 13344 | 4448 | Containing propylene 90 6% (quality) |
| 2 | Fixed gas | 0044 | 1056 | 352 | Containing propylene 61 7% (quality) |
| Add up to | 06 | 144 | 4800 |
Comparison " Fig. 1 "-process flow diagram, is described as follows:
PK-501 tail gas (gas steams the tail gas that off-gas compressor PK-501 discharges) temperature is 5 DEG C, pressure is 0 4MPa (gauge pressure, lower same), flow 400kg/h, containing saturated moisture content [0.23% (mol), 0.0958% (wt)], initially entering the D-1AB equipped with 3A molecular sieve desiccant, removing moisture content is less than-20 DEG C to dew point temperature.D-1A, D-1B handover operation, with nitrogen regeneration, every drying chamber is about 10 days equipped with about 750kg molecular sieve, regeneration period, and regenerative process is about 16 hours, nitrogen use level be about 200 mark sides/, time.
Dried PK-501 tail gas, in E-1 and coolant heat exchange, thermic load is 45kw, is cooled to-5 DEG C, is all condensed.Condensed fluid enters V-1, the condensed fluid mixed flash boiling come with V-2, V-3.
E-701 tail gas (tail gas that CO stripper condenser E-701 discharges) temperature is 50 DEG C, and pressure is 20MPa, flow 80kg/h, in E-2 and coolant heat exchange, thermic load is 8.3kw, is cooled to-5 DEG C, the gas phase having 75% (mol) is condensed, and gas-liquid mixture enters V-2.Fixed gas is discharged from V-2 top, and flow is 16kg/h；Condensed fluid drains into V-1 from V-2 bottom, and flow is 64kg/h.
E-301 tail gas (tail gas that propylene condenser E-301 is discharged) temperature is 25 DEG C, and pressure is 17MPa, flow 120t/h, in E-3 and coolant heat exchange, thermic load is 13.6kw, is cooled to-5 DEG C, the gas phase having 91% (mol) is condensed, and gas-liquid mixture enters V-3.Fixed gas is discharged from V-3 top, and flow is 7kg/h；Condensed fluid drains into V-1 from V-3 bottom, and flow is 113kg/h.
The operation pressure of V-1 is slightly below 0.4MPa.
The operation pressure of V-2 is slightly below 2.0MPa.
The operation pressure of V-3 is slightly below 1.7MPa.
Condensed fluid that V-2, V-3 are discharged enters V-1, owing to pressure reduces, flash distillation occurs, the light component overwhelming majority gasification such as hydrogen in condensed fluid, nitrogen.Because flash distillation, the temperature of V-1 is reduced to-10 DEG C, and the fixed gas flashed off is discharged from V-1 top, and flow is 21kg/h；Condensed fluid is extracted out by P-1 from V-1 bottom, and flow is 556kg/h.
The fixed gas that V-1, V-2, V-3 discharge, enters full factory gas train as fuel gas.
The condensed fluid of V-1, after P-1 extracts out (shaft power of pump is 1.1kw), boosts to 22MPa, delivers to gas fractionation unit.
Refrigeration unit PK-1 is refrigerating water sets, it is provided that coolant be the chilled water mixture of antifreeze (water with), the leaving water temperature of chilled water is-15 DEG C, and return water temperature is-5 DEG C, and refrigerating capacity is 67kw, and power consumption is 22kw.
Table-3 process energy consumption analysis
Note uses " petrochemical industry design energy consumption calculations method " SHT3110-2001 to calculate.
Claims (4)
1. the process of the tail gas recycle propylene discharged from polypropylene plant.Its product is
The main condensed fluid that the light component such as hydrogen, nitrogen is few containing propylene, can really realize propylene
Recovery.
It is characterized in that, specifically comprise the following steps that
A) tail gas of coolant condensation polypropylene plant difference emission point is utilized；
B) tail gas of different emission points, its composition, pressure are different, condense respectively with coolant；
C) to the tail gas containing moisture content, drying facility is set so that it is dew point temperature is less than condensation process
In minimum temperature；
D) condensed fluid that the tail gas of different emission points produces after being cooled down by coolant, converges to pressure minimum
The condensate drum (or hydrops groove) that tail gas is corresponding, is balanced flash distillation, obtains containing light component few
Product condensed fluid.
2. according to claim 1, during be not provided with tail-gas compressor.
3., according to claim 1, coolant is produced by refrigeration unit.
4., according to claim 1, collect the container of tail gas condensing liquid, can be single tank, also
It can be the hydrops groove of heat exchanger bottom setting.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510018215.0A CN105884568A (en) | 2015-01-14 | 2015-01-14 | Technique for recovering propylene from off gas discharged by polypropylene device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510018215.0A CN105884568A (en) | 2015-01-14 | 2015-01-14 | Technique for recovering propylene from off gas discharged by polypropylene device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN105884568A true CN105884568A (en) | 2016-08-24 |
Family
ID=56999017
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201510018215.0A Pending CN105884568A (en) | 2015-01-14 | 2015-01-14 | Technique for recovering propylene from off gas discharged by polypropylene device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN105884568A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105272807A (en) * | 2015-02-14 | 2016-01-27 | 陕西延长石油（集团）有限责任公司延安石油化工厂 | Multi-loop condensation technology for recovery of propylene in polypropylene device tail gas |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1450101A (en) * | 2002-10-31 | 2003-10-22 | 中国石化集团金陵石油化工有限责任公司 | Propene gas recovery device used in production of polypropene by bulk-polymenzation and process thereof |
| CN1660723A (en) * | 2004-12-27 | 2005-08-31 | 姜勇 | Technique for recovering propylene through rectification method in low temperature |
| CN105272807A (en) * | 2015-02-14 | 2016-01-27 | 陕西延长石油（集团）有限责任公司延安石油化工厂 | Multi-loop condensation technology for recovery of propylene in polypropylene device tail gas |
-
2015
- 2015-01-14 CN CN201510018215.0A patent/CN105884568A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1450101A (en) * | 2002-10-31 | 2003-10-22 | 中国石化集团金陵石油化工有限责任公司 | Propene gas recovery device used in production of polypropene by bulk-polymenzation and process thereof |
| CN1660723A (en) * | 2004-12-27 | 2005-08-31 | 姜勇 | Technique for recovering propylene through rectification method in low temperature |
| CN105272807A (en) * | 2015-02-14 | 2016-01-27 | 陕西延长石油（集团）有限责任公司延安石油化工厂 | Multi-loop condensation technology for recovery of propylene in polypropylene device tail gas |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105272807A (en) * | 2015-02-14 | 2016-01-27 | 陕西延长石油（集团）有限责任公司延安石油化工厂 | Multi-loop condensation technology for recovery of propylene in polypropylene device tail gas |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US9211484B2 (en) | Plant for recovering degraded heat transfer oil from a solar thermal facility and method for said recovery | |
| CN104759108A (en) | Three-stage continuous falling-film circulating evaporation concentration system with machinery vapor recompression | |
| CN105272807A (en) | Multi-loop condensation technology for recovery of propylene in polypropylene device tail gas | |
| CN1952569A (en) | Process and equipment for liquefying air-containing coal-bed gas | |
| WO2015011681A2 (en) | Evaporation-condensation desalination with a low temperature heat sink | |
| CN206930061U (en) | A kind of space division system | |
| CN105884568A (en) | Technique for recovering propylene from off gas discharged by polypropylene device | |
| CN102079552A (en) | Low-temperature multi-effect evaporation seawater desalination system with falling film condenser | |
| CN104986816A (en) | Process and apparatus for carrying out wastewater desorption and falling film evaporation on coking sewage | |
| CN105737457A (en) | Solvent recovery technology | |
| CN214780781U (en) | System for utilize alcohol tail gas to retrieve alcohol and high-purity carbon dioxide as raw materials | |
| CN104826348B (en) | A kind of steam condensed water waste heat that recycles processes the method extracting mixed liquor | |
| CN102115219B (en) | Utilization device, system and method of steam waste heat of vacuum device of seawater desalination system | |
| CN104085901A (en) | Device and method for cold recycling of ammonia in synthetic ammonia storage tank purge gas | |
| CN103463923B (en) | Device for separating and recycling tail gas generated in polypropylene production | |
| CN206121197U (en) | A MVR vapor recompression device for PA6 polymerization monomer is retrieved | |
| CN211752582U (en) | Distillation recovery system of ethylene glycol, diethylene glycol in ethylene glycol production waste liquid | |
| CN102492555B (en) | Method and device for high-efficiency energy-saving desolvation of fossilized animal/plant wax-containing solution | |
| CN108190838B (en) | Hydrogen fluoride multiphase gasification separation recovery system | |
| CN206342931U (en) | A kind of 2nd effect evaporator system that concentration is reclaimed suitable for Tea Polyphenols alcohol eluent | |
| CN106629936A (en) | Technology and system used for processing waste water | |
| CN110746024A (en) | Concentrated waste heat retrieval and utilization device of low temperature economizer waste water | |
| CN104629818B (en) | Vacuum carbonate desulphurization rich solution economic benefits and social benefits desorption technique and system | |
| CN202359095U (en) | Efficient and energy-saving desolventizer for solution containing fossilized animal and vegetable wax | |
| CN111939586A (en) | Vacuum sublimation evaporation cold-heat energy separation method distributed energy supply station |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20160824 |
|
| WD01 | Invention patent application deemed withdrawn after publication |