CN102533334B

CN102533334B - Method for recycling releasing gases in liquid carbon dioxide production process

Info

Publication number: CN102533334B
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: 2013-12-04
Anticipated expiration: 2032-01-20
Also published as: CN102533334A

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, in order to reduce the foreign matter content in Liquid carbon dioxide, improve the purity of Liquid carbon dioxide; Carbonic acid gas mainly comprises separating of the impurity such as CO, H2, N2, CH4, O2 with the light constituent non-condensable gas, at present mainly adopt the method for liquefying and rectifying under middle pressure 2.2～4.0Mpa, shallow low temperature-15～-25 ℃ condition to be separated, obtaining purity from rectifier bottoms is the liquid carbon dioxide product more than 99%, and non-condensable gas reclaims after cold from tower top 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 the manufacture gas such as synthesis ammonia plant, hydrogen plant, petrochemical plant, gas plant; Liquid carbon dioxide drop a hint in except containing the components such as CO, H2, N2, CH4, O2, major part is CO2; In dropping a hint, the content of each component is respectively had any different according to the difference in CO 2 raw material gas source.Take the CO 2 raw material gas source as synthesis ammonia plant pressure swing adsorption decarbonization tail gas be example, in tail gas, the molar percentage of CO2 is 85-95%; 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, the 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 gasmeter import and export or suction port of compressor and then is recovered to ammonia production system; The 4th, burner is set specially, allocate emptying again after ignition dope burning into.Most of device employing second and the third method, wherein take and adopt the third method as maximum; First method causes waste because of contaminate environment simultaneously, only has the undemanding area of environmental requirement to adopt; The 4th kind of method is larger because of investment, and running cost is very high, and just possible in theory, seldom have enterprise to adopt.But second and third kind of method all has problems and deficiency, 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 be equally also the waste that has caused resource, the CO of the third method in dropping a hint, CH4, although H2 has obtained recovery, but the CH4 dropped a hint is the rare gas element in production of synthetic ammonia, CO2 is gas unnecessary in production of synthetic ammonia, this part rare gas element and unnecessary gas have equally also returned in production system, cause the production of synthetic ammonia unstripped gas to carry, the link energy consumptions such as pressurization obviously increase, in system, the quantity discharged of carbonic acid gas increases, CH4 returns to production system and finally will arrive ammonia synthesis system simultaneously, cause the amount that ammonia synthesis system is dropped a hint obviously to increase, bring certain side effect, therefore the economy of the third method is 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, using dropping a hint as the raw material recycle of synthetic ammonia of Liquid carbon dioxide production process, the value that lifting is dropped a hint, reach the purpose of energy-conservation, consumption reduction, synergy.

The object of the present invention is achieved like this: a kind of recoverying and utilizing method of dropping a hint of Liquid carbon dioxide production process, comprise following processing step: will produce the Liquid carbon dioxide collection of dropping a hint, be preheating to 50-200 ℃, being compounded into entering in the stove water vapor of producer gas generator uses as hybrid gasification agent, together enter producer gas generator, as the raw material recycle, turn waste into wealth.

The molar percentage of said mixed air agent is: the 1-30% that drops a hint, water vapor 70-99%; In producer gas generator under 1000-1500 ℃ of high temperature, CH4 and steam reaction generate CO and H2, CO2 and reacts with C and generate CO, and when saving and gasifying and use water vapor, H2, CO, CH4 have also obtained whole recyclings.

Said producer gas generator, comprise normal-pressure coal gas generating furnace 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 is dropped a hint and recycled normal-pressure coal gas generating furnace, also is applicable to recycle the pressing gas producer; The system of many producer gas generator operations, adopt the present invention, Liquid carbon dioxide can be dropped a hint after heating and be compounded into the entering in the stove water vapor of separate unit producer gas generator, also may be compounded into always entering in the stove water vapor of many producer gas generators and use as hybrid gasification agent; The molar percentage be mixed of dropping a hint in the mixed air agent is 1-30%, and optimum molar per-cent is 3-15%.

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

Embodiment

Below by embodiment, the invention will be further described.

Embodiment: adopt the present invention to be applied to take lump coal as 250,000 tons of synthetic ammonia installations of raw material atmospheric fixed bed gas-producer annual output.

Synthetic ammonia pressure swing adsorption decarbonization tail gas CO2 content is 88%; The Liquid carbon dioxide scale is 100,000 ton/years, 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 dropped a hint, C0, H2, N2, CH4 is respectively 71%, 9.0%, 7.5%, 10.0%, 2.5%.

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

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

Claims

1. the recoverying and utilizing method of dropping a hint of a Liquid carbon dioxide production process, the Liquid carbon dioxide middle main ingredient CO that drops a hint ₂, CO, H ₂, N ₂, CH ₄Molar percentage be respectively 60-80%, 6-12%, 5-10%, 6-12%, 2-4%, the Liquid carbon dioxide 30-50% that total amount is CO 2 raw material gas that drops a hint; It is characterized in that comprising following processing step: will produce the Liquid carbon dioxide collection of dropping a hint, and be preheating to 50-200 ℃, and be compounded into entering in the stove water vapor of producer gas generator and use as hybrid gasification agent, and together enter producer gas generator, as the raw material recycle; The molar percentage of said mixed air agent is: the 1-30% that drops a hint, steam 70-99%; In producer gas generator under 1000-1500 ℃ of high temperature, CH ₄Generate CO and H with steam reaction ₂, CO ₂React with C and generate CO, saving gasification with in water vapor, the H in dropping a hint ₂, CO, CH ₄Whole recyclings have also been obtained.

2. a kind of recoverying and utilizing method of dropping a hint of Liquid carbon dioxide production process according to claim 1, it is characterized in that said producer gas generator, comprise normal-pressure coal gas generating furnace and pressing gas producer, also comprise the system of many producer gas generator operations.