CN104401994A

CN104401994A - Treatment method for abandoned dichlorodifluoromethane

Info

Publication number: CN104401994A
Application number: CN201410715701.3A
Authority: CN
Inventors: 夏正付
Original assignee: Individual
Current assignee: Individual
Priority date: 2014-11-28
Filing date: 2014-11-28
Publication date: 2015-03-11

Abstract

The invention relates to a treatment process for abandoned dichlorodifluoromethane. The process comprises the following steps: (1) mixing zirconium sulfate, titanic acid and tungstic acid according to a mole ratio of zirconium to titanium to tungsten of 1 to (0.5-0.6) to (0.1-0.3), adding water for granulating, and performing spray-drying at 200-300 DEG C to prepare catalyst granules with the diameters of 0.1-10 mm; (2) putting the granules into a tubular reactor, wherein the volume of the catalyst granules accounts for 25-40% the total volume of the tubular reactor; (3) introducing dichlorodifluoromethane and steam into the tubular reactor according to a volume ratio of 1 to (3-6), keeping the temperature of the tubular reactor at 250-300 DEG C, and controlling the contact time to be 3-10 minutes; (4) absorbing the steam by 90-98% concentrated sulfuric acid for tail gas after catalytic hydrolysis, absorbing hydrogen chloride gas by absolute ethanol, absorbing hydrogen fluoride gas by a sodium hydrogen carbonate solution, and absorbing carbon dioxide gas by a sodium carbonate solution. Compared with the prior art, the process has the characteristics that the energy consumption is low, the dichlorodifluoromethane hydrolysis efficiency is high, and a hydrolysis product can be reutilized. Therefore, the process has a wide application prospect in the field of waste treatment and resource.

Description

A kind for the treatment of process of discarded freonll-11

Technical field

The present invention relates to and relate to field of Environment Protection, especially relate to a kind for the treatment of process of discarded freonll-11.

Background technology

Freonll-11 (CFCs) is the synthesis twenties in last century " safe refrigeration agent ".It has many characteristics such as good chemical stability, easily interconvertibility, non-corrosiveness and high-insulativity, is therefore widely used in the every field of modern production life.The CFCs character in troposphere be discharged in air is very stable, Absorbable organic halogens exists tens of to upper a century, but after it slowly rises and enter stratosphere, can be decomposed under the effect of intense UV rays, the chlorine atom that decomposition discharges, with ozone meeting chain-react, destroys ozone molecule.Estimate that a chlorine atom can destroy tens thousand of ozone molecules according to science.The ozonosphere of earth surface can absorb the ultraviolet in solar radiation; the ecotope of preserving our planet; the ability that ozone molecule is its ultraviolet radiation-absorbing by the result consumed in a large number weakens greatly; the ultraviolet arriving earth surface is caused obviously to increase; many-sided serious harm is brought to human health and ecotope, as: human immune system's disease, respiratory tract disease obviously increases; plant-growth is impaired, marine organisms kind quantity minimizing etc.

If discarded freonll-11 is discharged in environment, following two aspects are mainly contained to the harm that environment and people cause:

1. Ozone hole.Because ozonosphere protection earth surface is not by the uviolizing that the sun is strong, animals and plants circle in biosphere will be affected after destruction, mankind's patient with canceroderm particularly can be made to increase.The content of freonll-11 R11 and R12 in air is in increase, and ozone concn, in reduction, even makes to have occurred Ozone hole above the Antarctic.The appearance of Ozone hole, can cause: make microbial death; Plant-growth is obstructed, and especially farm crop such as cotton, beans, growth that is melon and some vegetables comes to harm; Make the planktonic organism in ocean dead, cause dying off with the marine organisms of these planktonic organisms for food; Make the fry in ocean dead, the fishery underproduction; Make the blindness of animal and human; Humans and animals immunizing power is reduced.

According to analysis, Stratospheric ozone depletion ten thousand/, global cataractous sickness rate, by increase by 0.6 ~ 0.8%, namely means and therefore causes blind number by increase by 1 ten thousand to 1.5 ten thousand people.

2. Greenhouse effect.Another harm of the freonll-11 increase of concentration in an atmosphere is " Greenhouse effect ", the Typical sources of the Greenhouse effect of original earth surface is the carbonic acid gas in air, but freonll-11 also has similar characteristic mostly, and its Greenhouse effect effect is thousands of times of carbonic acid gas.Greenhouse effect make the temperature of earth surface rise, and cause global climate unusual.If the speed that earth surface temperature raises continues development, scientists is predicted: to the year two thousand fifty, global temperatures is by rising 2-4 degree Celsius, iceberg, polar region, north and south will significantly be melted, cause that sea level rise, make some island countries and coastal cities be submerged among seawater, comprising international big city: New York, Shanghai, Tokyo and Sydney.

Just because CFCs is to the very big destruction of atmospheric ozone layer, countries in the world have taken action the production and application limiting CFCs, and propose the various schemes of progressively eliminating CFCs.

At present, usage quantity is more than 1,000,000 tons CFCs product year in the world, one of how economic, harmless discharge important topic becoming environment protection realizing CFCs efficiently, and therefore, the innoxious decomposition technique of exploitation CFCs becomes the task of top priority.Conventional CFCs innoxious process for treating comprises combustion heat decomposition method, catalytic decomposition, photocatalysis Decomposition method, chemical reagent degestion, sonolysis method and plasma decomposition etc.Chinese patent (CN201110320425.7) discloses a kind of hydrothermal decomposition to process the method for discarded freonll-11, alkali lye, oxygenant, freonll-11 are put into reaction system together and carries out hydro-thermal reaction, product after freonll-11 hydrolysis is immediately by alkali liquor absorption, finally obtain the mixed rock containing carbonate and fluorine chlorine, there is the feature of quick and high efficient reaction but to there is product be mixing salt, economic worth is little, the shortcoming do not utilized completely; Chinese patent (CN200810058719.5) discloses a kind of method improving freonll-11 rate of decomposition in freonll-11 combustion hydrolytic process, but the decomposition efficiency of CFCs can not reach completely (98%), and dangerous secondary compound can be produced; Publication (CN1049295) describes a kind of catalytic decomposition of chlorofluoro-alkane, and the method not only exists the problem of the easy inactivation of catalyzer, and the efficiency of its catalytic decomposition freonll-11 also needs further to be improved; There is the process problem of residual chemical agents in chemical reagent degestion; Chinese patent (CN200810058719.5) discloses a kind of microwave plasma decomposition Freon innocent treatment method, the decomposition efficiency of freonll-11 can reach more than 99%, obtain good effect, but equipment carbon distribution easily occurs the method, the stability of operation has much room for improvement.

Process for freonll-11 adopts combustion method process mostly, at about 800-1200 DEG C, freonll-11 is burnt, the additive methods such as microwave decomposition method, plasma method are also had what study, but microwave decomposition method and plasma method cost too high, combustion method can produce new pollutent again, and cannot reclaim active substance, causes the wasting of resources.

Summary of the invention

The present invention is the problems referred to above solving prior art, provides a kind of method that energy consumption is low, freonll-11 hydrolysis efficiency is high, hydrolysate can recycle.

The method of catalytic hydrolysis freonll-11 of the present invention, its scheme comprises the following steps:

(1) zirconium sulfate, metatitanic acid, wolframic acid to be added water granulation after mixing according to zirconium, titanium, tungsten mol ratio 1:0.5-0.6:0.1-0.3, be prepared at 200-300 DEG C of spraying dry the granules of catalyst that diameter is 0.1-10mm;

(2) be placed in tubular reactor by particle, the volume of granules of catalyst accounts for the 25-40% of tubular reactor cumulative volume;

(3) freonll-11 and water vapour are passed in tubular reactor according to volume ratio 1:3-6, maintain between temperature 250-300 DEG C in tubular reactor, duration of contact is 3-10min simultaneously simultaneously simultaneously.

(4) the 90-98% vitriol oil of the tail gas after catalytic hydrolysis absorbs water vapour, and dehydrated alcohol absorbing hydrogen chloride gas, absorbs hydrogen fluoride gas with sodium hydrogen carbonate solution, carrys out absorbing carbon dioxide gas with sodium carbonate solution.

Preferably, granules of catalyst is natural packing state; Pressure in reaction process is 0.5-2atm; Tail gas after catalytic hydrolysis passes into the 90-98% vitriol oil again and absorbs water vapour after interchanger is cooled to 100-105 DEG C; Being used for absorbing hydrofluoric sodium hydrogen carbonate solution is saturated sodium bicarbonate.The percent hydrolysis of final freonll-11 is higher than 99.5%

The chemical reaction mode (for modal F-12) of its hydrolysis:

Discarded Freon gas is under the environment of high-temperature vapor and the effect of catalyzer, be hydrolyzed, obtain the gases such as carbonic acid gas, hydrogen fluoride, hydrogenchloride, these gases are through various material absorbing, achieve the harmless treatment of freonll-11, the product of simultaneously stability can be used as chemical products and sells, and achieves the recycling of freonll-11.

Compared with prior art, the present invention has the advantages that energy consumption is low, freonll-11 hydrolysis efficiency is high, hydrolysate can recycle, and specifically comprises following advantage:

1., because its temperature of reaction only has 250-350 DEG C, lower than the temperature of reaction of existing method, reduce energy consumption.

2. the percent hydrolysis of freonll-11 is high, and adopt present method, the percent hydrolysis of freonll-11 is generally higher than 99.5%.

3. be hydrolyzed the hydrogen fluoride, hydrogenchloride etc. that obtain after absorbing, to can be used as Chemicals sell, namely decrease its harm to environment, achieve again its recycling.

Embodiment

Below provide some embodiments of the present invention, to help understanding the present invention further, but protection scope of the present invention is not limited in these embodiments.

Embodiment 1

(1) zirconium sulfate, metatitanic acid, wolframic acid to be added water granulation after mixing according to zirconium, titanium, tungsten mol ratio 1:0.55:0.15, be prepared at 280 DEG C of spraying dry the granules of catalyst that diameter is 8mm;

(2) be placed in tubular reactor by particle natural packing, the stacking volume of granules of catalyst accounts for 30% of tubular reactor cumulative volume;

(3) freonll-11 and water vapour are passed in tubular reactor according to volume ratio 1:4, maintain the temperature 265 DEG C in tubular reactor, pressure is 1atm, and duration of contact is 8min simultaneously simultaneously simultaneously.

(4) 98% vitriol oil of the tail gas after catalytic hydrolysis absorbs water vapour, and dehydrated alcohol absorbing hydrogen chloride gas, absorbs hydrogen fluoride gas with saturated sodium bicarbonate solution, carrys out absorbing carbon dioxide gas with sodium carbonate solution.The percent hydrolysis of final freonll-11 is 99.6%.

Embodiment 2

(2) be placed in tubular reactor by particle natural packing, the stacking volume of granules of catalyst accounts for 35% of tubular reactor cumulative volume;

(3) freonll-11 and water vapour are passed in tubular reactor according to volume ratio 1:4, maintain the temperature 285 DEG C in tubular reactor, pressure is 1atm, and duration of contact is 8min simultaneously simultaneously simultaneously.

(4) 98% vitriol oil of the tail gas after catalytic hydrolysis absorbs water vapour, and dehydrated alcohol absorbing hydrogen chloride gas, absorbs hydrogen fluoride gas with saturated sodium bicarbonate solution, carrys out absorbing carbon dioxide gas with sodium carbonate solution.The percent hydrolysis of final freonll-11 is 99.7%.

Embodiment 3

(1) zirconium sulfate, metatitanic acid, wolframic acid to be added water granulation after mixing according to zirconium, titanium, tungsten mol ratio 1:0.5:0.15, be prepared at 300 DEG C of spraying dry the granules of catalyst that diameter is 8mm;

(3) freonll-11 and water vapour are passed in tubular reactor according to volume ratio 1:5, maintain the temperature 300 DEG C in tubular reactor, pressure is 1.5atm, and duration of contact is 8min simultaneously simultaneously simultaneously.

(4) 98% vitriol oil of the tail gas after catalytic hydrolysis absorbs water vapour, and dehydrated alcohol absorbing hydrogen chloride gas, absorbs hydrogen fluoride gas with saturated sodium bicarbonate solution, carrys out absorbing carbon dioxide gas with sodium carbonate solution.The percent hydrolysis of final freonll-11 is 99.8%.

Claims

1. a treatment process for discarded freonll-11, is characterized in that, the method comprises the following steps:

2. discard the treatment process of freonll-11 as claimed in claim 1, it is characterized in that, granules of catalyst is natural packing state.

3. discard the treatment process of freonll-11 as claimed in claim 1, it is characterized in that, the pressure in reaction process is 0.5-2atm.

4. discard the treatment process of freonll-11 as claimed in claim 1, it is characterized in that, the tail gas after catalytic hydrolysis passes into the 90-98% vitriol oil again and absorbs water vapour after interchanger is cooled to 100-105 DEG C.

5. discard the treatment process of freonll-11 as claimed in claim 1, it is characterized in that, being used for absorbing hydrofluoric sodium hydrogen carbonate solution is saturated sodium bicarbonate.