CN102533334A

CN102533334A - Method for recycling releasing gases in liquid carbon dioxide production process

Info

Publication number: CN102533334A
Application number: CN2012100174837A
Authority: CN
Inventors: 景玉国
Original assignee: HEBEI KAIYUE CHEMICAL INDUSTRIAL Co Ltd
Current assignee: HEBEI KAIYUE CHEMICAL INDUSTRIAL Co Ltd
Priority date: 2012-01-20
Filing date: 2012-01-20
Publication date: 2012-07-04
Anticipated expiration: 2032-01-20
Also published as: CN102533334B

Abstract

The invention relates to a method for recycling releasing gases in liquid carbon dioxide production process, and belongs to the technical field of comprehensive utilization of production in the chemical industry. The invention adopts the technical scheme that the method comprises the following processing steps: collecting releasing gases during liquid carbon dioxide production, preheating to 50 DEG C to 200 DEG C, adding into water vapor feed of a gas producer to form a mixed gasifying agent, and feeding into the gas producer to recycle the releasing gases as raw materials. Most of the liquid carbon dioxide production enterprises have gas producer facilities. The method achieves the effect of recycling the releasing gases in liquid carbon dioxide production by utilizing the existing gas producer device and process conditions, needs fewer added equipment, has strong practicability and operability, less investment and low cost, and recycles the releasing gases in liquid carbon dioxide production process as raw materials to achieve the effect of turning waste into treasure. Compared with the prior art, on the premises of no energy consumption addition and no side effect, the method can reduce the consumption of coal raw material for synthetic ammonia by 3% to 10%, reduce the consumption of vapor by 3% to 10% and reduce the consumption of dynamic electricity by 1% to 5%.

Description

A kind of recoverying and utilizing method of dropping a hint of Liquid carbon dioxide production process

Technical field

The present invention relates to a kind of recoverying and utilizing method of dropping a hint of Liquid carbon dioxide production process, belong to Chemical Manufacture comprehensive utilization technique field.

Background technology

In the Liquid carbon dioxide production process,, improve the purity of Liquid carbon dioxide in order to reduce the foreign matter content in the Liquid carbon dioxide; Carbonic acid gas and light constituent non-condensable gas mainly comprise separate impurities such as CO, H2, N2, CH4, O2; Press the method for liquefying and rectifying under 2.2～4.0Mpa, shallow low temperature-15～-25 ℃ condition to separate in mainly being employed at present; Obtaining purity from rectifier bottoms is the liquid carbon dioxide product more than 99%, and non-condensable gas reclaims behind the cold from cat head emptying; This part gas of emptying is referred to as Liquid carbon dioxide and drops a hint.

The main source of CO 2 raw material gas is manufacture gas such as synthesis ammonia plant, hydrogen plant, petrochemical plant, gas plant; Except that containing CO, H2, N2, CH4, O2 etc. the component, major part was CO2 during Liquid carbon dioxide was dropped a hint; Each components contents is respectively had any different according to the difference in CO 2 raw material gas source in dropping a hint.With the CO 2 raw material gas source is that synthesis ammonia plant pressure swing adsorption decarbonization tail gas is example, and the molar percentage of CO2 is 85-95% in the tail gas; The drop a hint molar percentage of middle main ingredient CO2, C0, H2, N2, CH4 of Liquid carbon dioxide is respectively 60-80%, 6-12%, 5-10%, 6-12%, 2-4%.The total amount of dropping a hint is about the 30-50% (V/V) of CO 2 raw material gas.At present, processing that Liquid carbon dioxide is dropped a hint and recycling mainly contain following four kinds of methods: the one, and direct emptying; The 2nd, this part gas is guided to roasting kiln, three wastes stove or boiler combustion byproduct steam; The 3rd, this part gas is turned back to the import and export of coal gas gas holder or suction port of compressor and then is recovered to ammonia production system; The 4th, burner is set specially, allocate emptying again after the ignition dope burning into.Most of device employing second and the third method serve as maximum to adopt the third method wherein; First method causes waste simultaneously because of contaminate environment, has only the undemanding area of environmental requirement to adopt; The 4th kind of method is bigger because of investment, and running cost is very high, and just possible in theory seldom has enterprise to adopt.But second and third kind method all has problems and is not enough; The subject matter of second method is: the CO in dropping a hint, CH4, H2 etc. produce the top quality raw material of synthetic ammonia, and acting as a fuel, to burn equally also be the waste that has caused resource; Though the CO during the third method is dropped a hint, CH4, H2 have obtained recovery, the CH4 in dropping a hint is the rare gas element in the production of synthetic ammonia, and CO2 is a gas unnecessary in the production of synthetic ammonia; This part rare gas element and unnecessary gas have equally also returned in the production system; Cause link energy consumptions such as the conveying of production of synthetic ammonia virgin gas, pressurization obviously to increase, emission amount of carbon dioxide increases in the system, and CH4 returns production system and finally will arrive ammonia synthesis system simultaneously; The amount that causes ammonia synthesis system to drop a hint obviously increases; Bring certain spinoff, so the economy of the third method is relatively poor, dropping a hint, it is lower to reclaim the benefit of bringing.

Summary of the invention

The recoverying and utilizing method of dropping a hint that the purpose of this invention is to provide a kind of Liquid carbon dioxide production process; Guide to producer gas generator uses as the raw material of producing coal gas dropping a hint; With dropping a hint of Liquid carbon dioxide production process as the raw material recycle of synthetic ammonia; The value that lifting is dropped a hint reaches energy-conservation, consumption reduction, synergic purpose.

The objective of the invention is to realize like this: a kind of recoverying and utilizing method of dropping a hint of Liquid carbon dioxide production process; Comprise following process step: will produce the Liquid carbon dioxide collection of dropping a hint; Be preheating to 50-200 ℃, be compounded into going in the stove water vapor of producer gas generator and use, together get into producer gas generator as hybrid gasification agent; As the raw material recycle, turn waste into wealth.

The molar percentage of said mixed vaporized chemical is: the 1-30% that drops a hint, water vapor 70-99%; Under 1000-1500 ℃ of high temperature, CH4 and steam reaction generate CO and generate CO with H2, CO2 with the C reaction in producer gas generator, and when saving was gasified with water vapor, H2, CO, CH4 had also obtained whole recyclings.

Said producer gas generator comprises normal pressure gas producer and pressing gas producer, also comprises the system of many producer gas generator operations.The present invention is applicable to the production Liquid carbon dioxide dropped a hint and recycles the normal pressure gas producer, also is applicable to and recycles the pressing gas producer; The system of many producer gas generator operations; Adopt the present invention; Can Liquid carbon dioxide be dropped a hint and be compounded into the going in the stove water vapor of separate unit producer gas generator after the heating, also may be compounded into always going in the stove water vapor of many producer gas generators and use as hybrid gasification agent; The molar percentage that is mixed of dropping a hint in the mixed vaporized chemical is 1-30%, and optimum molar per-cent is 3-15%.

Positively effect of the present invention: all there is the producer gas generator facility in the manufacturing enterprise that much produces Liquid carbon dioxide, and the present invention utilizes existing producer gas generator device and processing condition, realizes producing recovery and efficient utilization that Liquid carbon dioxide is dropped a hint; Newly-increased equipment is less; Have very strong practicality and exploitativeness, less investment, cost are low, with dropping a hint as the raw material recycle of Liquid carbon dioxide production process; Turn waste into wealth; Compare with background technology, do not increasing energy consumption and do not bringing under the prerequisite of spinoff, the feed coal that can reduce synthetic ammonia consumes 3-10%, reduces water vapor consumption 3-10%, reduces power current consumption 1-5%.

Embodiment

Through embodiment, the present invention is described further below.

Embodiment: adopt the present invention to be applied to produce 250000 tons of synthetic ammonia installations per year for the raw material atmospheric fixed bed gas-producer with lump coal.

Synthetic ammonia pressure swing adsorption decarbonization tail gas CO2 content is 88%; The Liquid carbon dioxide scale is 100,000 tons/year, and the amount that Liquid carbon dioxide is dropped a hint is 5000-6000 Nm3/h, and the molar percentage of the main ingredient CO2 that drops a hint, C0, H2, N2, CH4 is respectively 71%, 9.0%, 7.5%, 10.0%, 2.5%.

Daily output ammonia 730-750 ton, carbonic acid gas dropped a hint to be heated to 145 ℃ and to be compounded into always to go in the stove water vapor.

Under embodiment the same terms; Adopt background technology; The consumption of ton ammonia feed coal is that 1230-1250kg, ton ammonia power current consume 1180-1200kwh, and going into the consumption of stove water vapor is 65-66t/h: in an embodiment, adopt the present invention's technology; Under the prerequisite of not bringing spinoff; The consumption of ton ammonia feed coal is that 1180-1200kg, ton ammonia power current consume 1150-1170kwh: going into the consumption of stove water vapor is 61-62t/h: the feed coal that reduces synthetic ammonia consumes 3-4%, reduces water vapor consumption 4-5%, reduces power current and consumes 2-3%, and economic benefit of the present invention and social benefit are all very significantly.

Claims

1. the recoverying and utilizing method of dropping a hint of a Liquid carbon dioxide production process; It is characterized in that comprising following process step: will produce the Liquid carbon dioxide collection of dropping a hint; Be preheating to 50-200 ℃; Be compounded into going in the stove water vapor of producer gas generator and use, together get into producer gas generator, as the raw material recycle as hybrid gasification agent.

2. according to the recoverying and utilizing method of dropping a hint of the said a kind of Liquid carbon dioxide production process of claim 1, it is characterized in that the molar percentage of said mixed vaporized chemical is: the 1-30% that drops a hint, steam 70-99%; Under 1000-1500 ℃ of high temperature, CH4 and steam reaction generate CO and generate CO with H2, CO2 with the C reaction in producer gas generator, and when saving was gasified with water vapor, the H2 in dropping a hint, CO, CH4 had also obtained whole recyclings.

3. according to the recoverying and utilizing method of dropping a hint of claim 1 or 2 said a kind of Liquid carbon dioxide production processes; It is characterized in that said producer gas generator; Comprise normal pressure gas producer and pressing gas producer, also comprise the system of many producer gas generator operations.