CN201261716Y - A device that uses non-equilibrium plasma to eliminate volatile organic compounds and simultaneously produce hydrogen - Google Patents

Abstract

The utility model relates to a device which utilizes non-equilibrium plasma to eliminate volatile organic compounds and simultaneously produce hydrogen. The difference forms a breakdown arc column. Driven by the rotating airflow introduced by the tangential air guide tube, the arc column rotates at a high speed between the central electrode and the outer electrode of the cylinder, and is quickly pushed downstream and extinguished while rotating. At the same time, the arc column Ignite again at the narrowest point between the electrodes, and repeat the above process to form a sliding arc rotating discharge, thereby producing a rotating discharge unbalanced plasma flow with low pressure, low temperature expansion, and a large area of glow and corona. This unbalanced plasma The bulk flow contains a large number of high-energy electrons and active particles such as O, O ₂ ^- , O ₃ , H, OH, HO _{2 ,} etc., through the bombardment of high-energy particles and the oxidation of active particles to break the C-H bond to eliminate organic matter and generate hydrogen.

Description

A kind of device that utilizes nonequilibrium plasma to eliminate volatile organic matter hydrogen manufacturing simultaneously

Technical field

The utility model relates to a kind of device that utilizes nonequilibrium plasma to eliminate volatile organic matter hydrogen manufacturing simultaneously, belongs to environmental technology and exhaust-gas resource field.

Background technology

The mass production of industrial chemicals, paint, coating, lubricated wet goods chemical preparations being extensive use of in the external coating operation, also have the burning of industrial waste, the discharging of motor-vehicle tail-gas etc., cause a large amount of volatile organic matters (volatile organic compounds, VOCs) be discharged in the atmosphere, cause atmospheric pollution.Some volatile organic matter (as Chlorofluorocarbons (CFCs)) trace the time just is enough to damage the ozone layer, and causes that ultraviolet radiation increases with the earth to heat up.Even more serious is that the VOCs molecule can be subjected to the irradiation with radiation of 280～730nm wavelength and form radical, generates via a succession of atmospheric photochemical reaction at last and contains ozone (O ₃), peroxynitric acid second vinegar ester derivative air pollutant such as (PAN), these materials can stimulate eyes, respiratory mucosa and harmful to human.Moreover, some volatile organic matter (as vinylbenzene) even have strong carinogenicity and genotoxicity.In China part city, because polluting the cancer and the respiratory system disease that cause, volatile organic matter obviously increases, constituting a serious threat of human body.Therefore, VOCs waste gas being carried out effective purifying treatment is a problem demanding prompt solution in China.The treatment process that both at home and abroad the VOVs waste gas pollution control and treatment is adopted mainly contains absorption, directly burning, catalyticcombustion etc. at present, absorption method mainly adopts sorbent material such as gac to adsorb, and main drawback is that sorbent material need regularly replace, the expense height, produce discarded sorbent material secondary pollution; Directly combustion method face energy consumption big, produce NO _xDeng problems such as secondary pollutants; And problem such as Production by Catalytic Combustion Process faces that catalyzer is easily poisoned, equipment complexity, energy consumption are big.Therefore, economical, administer VOCs waste gas efficiently, except that improving conventional art, need develop new technology.

Along with the continuous development and perfection of plasma technique, plasma technique is applied to various fields more and more widely.Plasma body is called as the 4th attitude of material, contain abundant particles such as highly active atom, molecule, ion, electronics and free radical in its space, the various chemical substances that are in plasma state have extremely strong chemically reactive, therefore, plasma body also receives much concern in Application for Field such as chemical industry, environmental protection.Plasma body can be divided into thermal equilibrium plasma body and nonequilibrium plasma according to its particle temperature.Thermal equilibrium plasma body (as arc-over) electronics equates that with heavy particle temperature is approaching reach 5000～20000 ℃, power input is very high, and selectivity of chemical equation is very low and wayward, and serious in addition quenching causes the electrode erosion phenomenon, and energy efficiency is very low.Nonequilibrium plasma (as normal pressure glow discharge, corona discharge, dielectric barrier discharge etc.) power input is low, electronic temp can be up to 5000 ℃ near normal temperature for heavy particle temperature, in this case, plasma body is not energy to be provided but to produce to reaction system to excite or to strengthen the Activity of Chemical Reaction species, have very high selectivity and energy efficiency, operation and do not need quenching at low temperatures, be proved can be able to effectively be used for the removal of multiple gaseous pollutants such as VOCs.Its shortcoming is that plasma density is lower, is difficult in high flow condition and is issued to high conversion, is difficult to realize the industry amplification.

Traditional thermal equilibrium plasma body and nonequilibrium plasma can not satisfy the non-equilibrium property that plasma chemistry is used required high-energy and height simultaneously, promptly have highly non-equilibrium property and high electronic temp, electron density simultaneously.Therefore the plasma body of seeking a kind of comprehensive both advantages has bigger challenge.The beginning of the nineties in last century, Frenchman Czernichowski A. etc. proposed to produce the normal atmosphere nonequilibrium plasma with air stream drives and the cutter type electrode gliding arc discharge scheme of cooling off electric arc, it has had the characteristic of thermal equilibrium plasma body and nonequilibrium plasma concurrently, physical study shows that the plasma body zone that this method produces shows tangible non-equilibrium property, input electric energy more than 80% is the very high nonequilibrium plasma of a kind of capacity usage ratio (French Patent 2639172) by the raising of nonequilibrium plasma stimulating chemical reaction efficient.After this, foreign study personnel such as France, Russia, the U.S. have also carried out a series of research work at the gliding arc discharge this respect.Research not only comprises the physical theory analysis of gliding arc discharge plasma body, but also its be applied to the air stream contamination thing control, produce field (Krawczyk K. such as synthetic gas, organic solvent purification, et al.Plasma Chem.Plasma Process.2003,24 (2): 155-167.; Fridman A., et al.J.Prog.Energy and Comb.Sci., 1999,25:211-231.).Domestic, the research of gliding arc discharge is in the starting stage, certain research is being arranged aspect the gliding arc discharge physical property, research mainly concentrates on the gliding arc discharge physical property aspect (Lin Lie of the pure air stream drives of direct current, Wu Chengkang. nucleosynthesis and plasma physics, 2000,20 (2): 121-124.); But domestic aspect the control of pollutent research very few, mainly be the research that Du Changming etc. carries out the single phase ac gliding arc discharge, and its is used remove multiple organic pollutant (Du Changming such as toluene, polycyclic aromatic hydrocarbons and carbon black granules, Deng. Proceedings of the CSEE .2006,26 (1): 77-81.).To sum up the investigation of domestic and foreign literature data finds that gliding arc discharge Cement Composite Treated by Plasma volatile organic matter has unique advantage, and not only treatment capacity is big but also simple to operate, the clearance height; Find also that simultaneously traditional gliding arc discharge device has following problem in science to need to be resolved hurrily at present: the 1. oxynitride NO of higher concentration _xDischarging; 2. energy consumption is higher; 3. importing the performance of power supply and the structure of electrode remains further to be explored; 4. research emphasis concentrates on the elimination of volatile organic matter, does not consider resource utilization.

Summary of the invention

At above-mentioned present situation, the purpose of this utility model is to provide that a kind of discharge space is evenly distributed, the plasma discharging body region is big, oxynitride NO _xThe quantity discharged nonequilibrium plasma that utilizes few, that realize the volatile organic matter resource utilization is eliminated the device of volatile organic matter hydrogen manufacturing simultaneously.

For reaching above-mentioned purpose, technical solution of the present utility model is: a kind of device that utilizes nonequilibrium plasma to eliminate volatile organic matter hydrogen manufacturing simultaneously, this device comprise the nonequilibrium plasma reactor, to the high-voltage power supply 1 of plasma reactor power supply; The nonequilibrium plasma reactor is the tubular housing of a sealing, comprise outer cover 10, establish cylindrical center's electrode 4 on the described tubular housing medullary ray, the narrowest place 11 distances are established between a type Laval that contracts (daraf(reciprocal of farad) you) jet pipe outer electrode 6, two electrodes in 0.5～5mm scope in the central electrode outside; Central electrode is fixed in the tubular housing by center electrode insulation cover 7 and sealed adapter sleeve 8, and an end is connected with high-voltage power supply simultaneously, and central electrode is fixed in the tubular housing by outer electrode insulation covering 9, and links to each other with high-voltage power supply by wiring screw rod 5; On tubular housing, be provided with tangential airway 3, contain volatile organic compounds stream 2 and tangentially enter tubular housing from tangential airway.

Described high-voltage power supply 4 is boosted and the exchanging or umformer of current-limiting function for having, and the voltage control of output is in 5～20kV scope, and watt level is determined according to nonequilibrium plasma reactor power size.

Described central electrode 4 and outer electrode 6 adopt copper or stainless material, and the concrete size of two electrodes is determined according to the size of nonequilibrium plasma reactor power and off gas treatment amount.

Described center electrode insulation cover 7 and outer electrode insulation covering 9 adopt polytetrafluoroethylmaterial material to make.

Utilize above-mentioned nonequilibrium plasma generation device, the method that the nonequilibrium plasma of generation is eliminated volatile organic matter hydrogen manufacturing simultaneously is:

1) tangentially introduces tubular housings by tangential airway 3 containing volatile organic compounds stream 2, form air-flow around the central electrode rotation;

2) connect high-voltage power supply 4, regulate the high-pressure side output voltage of high-voltage power supply 4, utilize interelectrode potential difference the narrowest place 11 between electrode to form and puncture the arc light post, the arc light post is high speed rotating between the driving lower edge cylindrical center electrode 4 of air-flow of rotation and Laval jet pipe outer electrode 6, in rotation, pushed to the downstream fast, because more downstream, distance between electrodes is big more, when reaching certain distance, the thermosteresis of arc light post makes electric arc carry out the transition to nonequilibrium state by equilibrium state, and when the continuation of arc light post was mobile downstream, interelectrode distance further enlarged, last owing to be subjected to the restriction of power, the arc light post can't be kept and extinguish; Meanwhile, puncture the arc light post again between electrode the narrowest place 11 light, and repetition said process, form slip arc light rotating electric-discharging 12, thereby produce low pressure, low-temperature expansion state, have the rotating electric-discharging nonequilibrium plasma stream 13 in big area aura and corona zone, comprise in this nonequilibrium plasma stream a large amount of high-energy electrons and O, ₂ ^-, O ₃, H, OH, HO ₂The isoreactivity particle disconnects c h bond to eliminate organism by high-energy particle bombardment and active particle oxidation to produce hydrogen simultaneously, and can avoid oxynitride NO _xGeneration; At last, the hydrogen air communication after nonequilibrium plasma purifies is crossed outlet 14 discharges.

Characteristics of the present utility model are: 1. make to contain the volatile organic matter air-flow and be in the inflated with low pressure state, cause that temperature descends (theoretical minimum temperature T ≈-100 ℃), temperature is reduced to and can produces discharge; 2. this discharge is a kind of low temperature discharge, produces discharge in the zone of non-calorifics equilibrium state, and this temperature that produces electrical discharge zone is less than or equal to the temperature of surrounding environment; 3. avoid the formation of high-temperature electric arc, and then avoided oxynitride NO _xGeneration; 4. transfer electric energy at low pressure, cold condition and produce the long lifetime free radical, as the H base, its life-span can reach following 10 times of normal atmosphere; 5. this discharge exists more aura and corona zone, can produce more O ₃, oxidisability particles such as OH, O, strengthen the degraded of organic deep oxidation; 6. energy consumption is little, and electrode can automatically cleaning, not perishable and ablation, long service life; 7. the selectivity of chemical reaction is good, can produce hydrogen when eliminating volatile organic matter.

A kind of device that utilizes nonequilibrium plasma to eliminate volatile organic matter hydrogen manufacturing simultaneously described in the utility model can be applied to emission control of volatility organic exhaust gas and resource utilization in the environmental engineering, also can be used for the hydrocarbon polymer reformation hydrogen production in chemistry and the energy project.

Description of drawings

Accompanying drawing is a structural representation of the present utility model.

Among the figure, 1 high-voltage power supply, 2 contain volatile organic compounds stream, 3 tangential airways, 4 central electrodes, 5 wiring screw rod, 6 outer electrodes, 7 center electrode insulation covers, 8 sealed adapter sleeves, 9 outer electrode insulation coverings, 10 outer covers, the narrowest place between 11 electrodes, 12 rotating electric-dischargings, 13 plasma flows, 14 outlets.

Embodiment

Below in conjunction with drawings and Examples the utility model is further described.

With reference to the accompanying drawings, making cylindrical center's electrode 4 and Laval jet pipe outer electrode 6 used materials is brass; The long 280mm of central electrode, diameter 8mm; The long 110mm of outer electrode, outside diameter 68mm, the interval 3mm of minimum place between two electrodes; Volatile organic waste gas 2 is for containing 5000ppm toluene, flow 20m ³/ h, the output voltage of ac high voltage source 1 is controlled at 10kV; This moment, the toluene elimination factor reached more than 90%, and capacity usage ratio is about 1200g/kWh, and the concentration that detects hydrogen in the exhaust simultaneously is about 1000ppm.

Claims (4)

1. A device that utilizes non-equilibrium plasma to eliminate volatile organic compounds to produce hydrogen simultaneously, is characterized in that comprising: non-equilibrium plasma reactor, high-voltage power supply (1) for powering plasma reactor; non-equilibrium plasma reactor It is a closed tubular cavity, including an outer cover (10), a cylindrical central electrode (4) is set on the center line of the tubular cavity, and a retractable Rafal nozzle external electrode (6) is set outside the central electrode. The distance between the narrowest part (11) between the electrodes is in the range of 0.5-5mm; the central electrode is fixed in the tubular cavity through the central electrode insulating sleeve (7) and the sealing connection sleeve (8), and the central electrode is fixed through the outer electrode insulating sleeve (9) In the tubular cavity; a tangential air guide pipe (3) is provided on the tubular cavity, and the exhaust gas flow (2) containing volatile organic compounds enters the tubular cavity from the tangential air guide pipe along a tangential direction. 2. A device for simultaneously producing hydrogen by using non-equilibrium plasma to eliminate volatile organic compounds according to claim 1, characterized in that: the high-voltage power supply (4) is an AC or DC transformer, the output voltage is controlled in the range of 5 ~ 20kV. 3. A device for simultaneously producing hydrogen by using non-equilibrium plasma to eliminate volatile organic compounds according to claim 1, characterized in that: the central electrode (4) and the outer electrode (6) are made of copper or stainless steel . 4. A device for simultaneously producing hydrogen by using non-equilibrium plasma to eliminate volatile organic compounds according to claim 1, characterized in that: the central electrode insulating sleeve (7) and the outer electrode insulating sleeve (9) are made of poly Made of tetrafluoroethylene material.