CN102516022B - Comprehensive processing method of vinyl chloride synthetic gas - Google Patents

Comprehensive processing method of vinyl chloride synthetic gas Download PDF

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CN102516022B
CN102516022B CN201110400976.4A CN201110400976A CN102516022B CN 102516022 B CN102516022 B CN 102516022B CN 201110400976 A CN201110400976 A CN 201110400976A CN 102516022 B CN102516022 B CN 102516022B
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chloride
mercury
synthetic gas
vinyl chloride
hydrochloric acid
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CN102516022A (en
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胡启阳
李新海
郭华军
王志兴
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Central South University
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Central South University
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Abstract

The invention discloses a comprehensive processing method of vinyl chloride synthetic gas. Under the effect of a mercuric chloride catalyst, acetylene gas and hydrogen chloride are subject to a reaction, such that crude vinyl chloride synthetic gas is produced; the crude vinyl chloride synthetic gas is subject to mercury removing by using a high-concentration chloride containing hydrochloric acid; hydrogen chloride is absorbed by using water; the crude vinyl chloride synthetic gas is then subject to steps such as alkali washing and dehydration, such that refined vinyl chloride is obtained, and requirements of mercury recovering, qualified industrial hydrochloric acid production and vinyl chloride refining are directly achieved.

Description

A kind of method of comprehensive treating process vinyl chloride synthetic gas
Technical field
The present invention relates to a kind of method of comprehensive treating process vinyl chloride synthetic gas, for product separation, purifying treatment with there is valency (poisonous) thing recovery method, belong to chemical field.
Background technology
Polyvinyl chloride is one of five large general-purpose plastics, is widely used in the key areas such as industry, agricultural, national defence, chemical building material.At present, China's polyvinyl chloride aggregated capacity is about 1,800 ten thousand tons, and wherein calcium carbide route production capacity is about 1,400 ten thousand tons, accounts for the more than 75% of aggregated capacity; Actual generated by polyvinyl chloride by calcium carbide output accounts for 65% of polyvinyl chloride ultimate production.
What calcium carbide route was produced polyvinyl chloride use is activated carbon supported mercuric chloride catalyst (10-12% mercury chloride).At present, China's calcium carbide route is produced polyvinyl chloride and is consumed mercuric chloride catalyst over 7000 tons, approximately 800 tons of the usage quantitys of mercury chloride, and approximately 580 tons of the usage quantitys of mercury, account for 60% left and right that national mercury is used total amount.
The mercury whereabouts of generated by polyvinyl chloride by calcium carbide production process is mainly useless mercury catalyst, mercurous waste active carbon, mercurous waste hydrochloric acid, waste lye etc., accounts for respectively mercury chloride and uses 36%, 8%, 51%, 5% of total amount.At present, useless mercury catalyst and useless mercury gac are processed producer by the Hazardous wastes that has qualification and are recycled, the mercury chloride rate of recovery approximately 75%; And mercurous waste hydrochloric acid, waste lye etc. only have 20% to carry out the harmless treatment of hydrochloric acid degree of depth desorption and mercury, major part is also properly disposed.
The technology of processing at present mercurous waste hydrochloric acid is mainly " hydrochloric acid desorption technology " and " Sodium sulfhydrate is processed mercury chloride technology ".(1) in vinylchlorid gas mixture, be mixed with the hydrogen chloride gas of about 5-10%, after washing, produce a certain amount of mercurous hydrochloric acid, mercurous hydrochloric acid can pass through hydrochloric acid desorption technology, and by hydrogenchloride again reuse, the low-concentration hcl after desorption enters absorption tower and reuptakes the hydrogenchloride in vinyl chloride gas.(2) utilize the little advantage of ionic product of zunsober to process the Hg in the synthetic middle spent acid of carbide acetylene method vinylchlorid, waste water 2+the most effective means.Along with the accumulation of mercury chloride in system, after hydrochloric acid desorption, have the mercurous waste hydrochloric acid of a small amount of high density and discharge, in the waste lye producing with rear step alkaline cleaning procedure and process with Sodium sulfhydrate afterwards, the zunsober of generation carries out security landfill.Owing to processing, journey is complicated, cost is higher, and only approximately 20% manufacturing enterprise adopts this technology to carry out spent acid processing at present.
Mercury pollution is subject to the great attention of international community as a new Global Environmental Problems, become the important issue of annual board of management of United Nations Environment Programme (UNEP) (UNEP).Along with the expansion of China's generated by polyvinyl chloride by calcium carbide production capacity, mercury demand will continue to increase, and if do not taked mercury to cut down and control row measure, generated by polyvinyl chloride by calcium carbide enterprise not only faces the threat of mercury scarcity of resources, also faces the pressure of environmental constraints on industry development impact.Be necessary to research and develop novel method and process mercurous spent acid, reclaim mercury chloride simultaneously, reduce processing cost.
Summary of the invention
The object of the invention is to: for guaranteeing the sound development of China's generated by polyvinyl chloride by calcium carbide industry, increase mercury yield, reduce the emptying and impact on environment of mercury, a kind of economy, efficient, easy collection vinylchlorid is refining, mercury chloride reclaims, qualified technical hydrochloric acid is produced in the comprehensive treating process vinyl chloride synthetic gas of one method are provided, and realize
(1) crude synthesis gas, by demercuration, hydrogen chloride absorption, directly reaches mercury recovery, the production of qualified technical hydrochloric acid and the refining target of vinylchlorid;
(2) directly washing from cooling synthetic gas, absorption mercury chloride, in synthesizing chloroethylene, mercury chloride decreasing ratio is high;
(3) directly absorb the hydrogenchloride in demercuration gas mixture, produce qualified technical hydrochloric acid or desorption reuse hydrogenchloride; Eliminate the discharge of the mercurous hydrochloric acid of high density;
(4) cancel former demercuration tower demercuration operation, the treatment scheme that shortened and simplified synthetic gas is short, chemical materials and energy consumption few.
The detailed content (technical scheme) of invention
A method for comprehensive treating process vinyl chloride synthetic gas, comprise the following steps into:
1) rough synthetic gas is cooling: acetylene gas, hydrogenchloride react and generates rough vinyl chloride synthetic gas under mercuric chloride catalyst effect, and cooling, partial oxidation mercury is condensed into dust; 2) remove mercury chloride: with hydrochloric high density high-valency metal chloride soln, contact with synthetic gas, absorb gaseous state mercury chloride, and wash mercury chloride dust; 3) hydrogen chloride absorption: remove gas mixture water or dilute hydrochloric acid absorbing hydrogen chloride after mercury chloride; 4) remove the gas mixture after hydrogenchloride, then through neutralizing treatment, de-liquid, make refining vinylchlorid.Described de-liquid, removes liquid mist or drop in gas, liquid as de-in whirlwind, etc.
Described high-valency metal chloride soln is water-soluble divalence or trivalent metal muriate of energy.
Described divalent metal muriate comprises: one or more in calcium chloride, magnesium chloride, zinc chloride, cupric chloride, described trivalent metal muriate comprises one or both in iron(ic) chloride, aluminum chloride.
The concentration of described high-valency metal chloride soln is that 3.5~4.5mol/L, HCl concentration are 0.1~1.5mol/L.
Described high-valency metal muriate preferably adopts one or both in calcium chloride or magnesium chloride; The preferred 4.0mol/L of high-valency metal chloride concentration, the preferred 0.5mol/L of HCl concentration.
Described rough vinyl chloride synthetic gas is cooled to not higher than 80 ℃.
The described mercury chloride process that removes adopts the packed absorber of 2~3 grades.
Hydrochloric high density high-valency metal chloride soln independent loops in towers at different levels.
The gas of take enters three grades that level is the 1st grade and is absorbed as example, when absorbing mercury chloride, the 1st grade of hydrochloric high density high-valency metal chloride soln discharge after its content reaches 30~50g/L, after the 2nd grade of dechlorination mercury, liquid proceeds to the 1st grade, after 3rd level dechlorination mercury, liquid proceeds to the 2nd grade, and 3rd level proceeds to fresh hydrochloric high density high-valency metal chloride soln.
Hydrochloric high density high-valency metal chloride soln absorbs mercury chloride to its content and reaches after 30~50g/L, with the precipitator method or extraction process, processes and reclaims mercury chloride; The solution reclaiming after mercury chloride returns and recycles after adjusting.
The absorption process of described hydrogenchloride is also to adopt the packed absorber of 2 grades.
Vinyl chloride synthetic gas is after removing mercury chloride, and water or dilute hydrochloric acid absorbing hydrogen chloride manufacture hydrochloric acid, or produce HCl for desorb, be used further to synthesizing chloroethylene raw material.
The present invention is based on following physical and chemical principle: the existence of high-valency metal muriate in solution (divalence, trivalent villaumite), can improve significantly wherein hydrionic activity, improve sour activity.Relatively, not containing the muriatic solution of high-valency metal, containing HCl activity in the muriatic solution of high-valency metal, significantly improve, improved the gas phase (H of balance with it simultaneously 2o+HCl) fugacity (being the dividing potential drop of the HCl in balance gas phase) of HCl in.
The saturation solubility of HCl in high-valency metal chloride solution is by significantly lower than the saturation solubility in water.Research shows, especially in divalent metal aqueous chloride solution, the saturation concentration of HCl will significantly reduce, as: MCl 2during total concn 3.0~4.5mol/L, under normal temperature, HCl saturation concentration is 0.2~1.5mol/L; When temperature increases, HCl saturation concentration will be lower.So the chloride solution of low-concentration hcl can be as the filtering medium of the vinyl chloride gas of containing hydrogen chloride and mercury chloride, the condensation mercury chloride dust in washing gas mixture, absorb gaseous state mercury chloride, reach the removal of mercury purification of vinylchlorid and chlorine hydride mixed gas body.
Water absorbs HCl and obtains technical hydrochloric acid up to standard, can be directly as commodity; Hydrochloric acid is mercurous while being less than 10mg/L, as commercial hydrochloric acid, also can be used for desorb and produces HCl, is used further to synthesizing chloroethylene raw material.Refining vinyl chloride gas after de-HCl, for Production of PVC.
Vinyl chloride gas after absorbing hydrogen chloride is through whirlwind acid-mist-removing, alkali cleaning neutralization, and whirlwind, except water smoke, obtains refining vinyl chloride gas.Advantage and the positively effect of invention
The present invention has following advantage and positively effect:
(1) simplified the treating process of vinyl chloride synthetic gas, no longer adopted solid adsorbent (gac) and wash by liquid and absorb the mercury chloride in synthetic gas, technological operation is convenient, and mercury removal rate is high;
(2) owing to not adopting solid absorbent to adopt liquid-absorbent mercury chloride, mercury chloride can directly reclaim, do not exist the empty row of mercury or multithread to, do not produce mercurous hydrochloric acid or mercurous neutralizer;
(3) rough synthetic gas can be cooled to higher temperatures, save energy;
(4) hydrochloric acid that absorption demercuration hydrogenchloride produces is mercurous extremely low, is technical hydrochloric acid up to standard, can sell; Or as hydrochloric acid desorption regeneration hydrogenchloride, for the synthesis of vinylchlorid, no longer output, containing the waste hydrochloric acid of high density mercury, is economized the complicated procedures of forming such as lixiviating neutralization, sulfide precipitation mercury.
(5) substantially solved the mercury evil of acetylene method production polyvinyl chloride process, utilized expeditiously mercury chloride, save mercury resource; Be conducive to the sound development of acetylene method PVC industry.
Accompanying drawing explanation
Fig. 1 is the inventive method schematic flow sheet.
Embodiment
Below in conjunction with specific embodiment, the present invention is described further.The present invention can implement by the either type of summary of the invention.Providing of these embodiment limits the present invention anything but.
Hydrogenchloride meter 5~6%, mercury chloride meter 0.04~0.05% (weight percentage) in rough vinyl chloride synthetic gas in embodiment.Following demercuration all refers to dechlorination mercury.
Embodiment 1
Demercuration liquid is 3.5mol/L MgCl 2, the 1.5mol/L HCl aqueous solution.Adopt 3 grades of towers combination demercurations, synthetic gas enters from the 1st grade, discharges successively after 2 grades, 3 grades; The operating parameter of three grades of towers is all identical.
To go out the rough vinyl chloride synthetic gas of tower and be cooled to 75~78 ℃; Import 3 grades of tower combination demercurations; Demercuration gas mixture imports 2 grades of combination absorbing hydrogen chlorides again.In the 1st grade of demercuration liquid of demercuration, mercury chloride content reaches after 40g/L, discharges, and after the 2nd grade of tower demercuration, liquid proceeds to the 1st grade of tower, and after 3rd level tower demercuration, liquid proceeds to the 2nd grade of tower, and 3rd level tower more renews demercuration liquid.
Remove the gas mixture after hydrogenchloride, through whirlwind acid-mist-removing, alkali cleaning neutralization, whirlwind, except water smoke, obtains refining vinylchlorid.
The composition of discharging demercuration liquid is: HgCl 243.1g/L, 3.9mol/L MgCl 2, 0.8mol/L HCl;
The hydrochloric acid composition of output is: 30.2%HCl, 8.7mg/L HgCl 2
Embodiment 2
Demercuration liquid is 4.2mol/L CaCl 2, the 0.1mol/L HCl aqueous solution.Adopt 2 grades of towers combination demercurations, synthetic gas enters from the 1st grade, after 2 grades, discharges; The operating parameter of two towers is identical.
To go out the rough vinyl chloride synthetic gas of tower and be cooled to 45~50 ℃; Import 2 grades of tower combination demercurations; Demercuration gas mixture imports 2 grades of combination absorbing hydrogen chlorides again.In the 1st grade of demercuration liquid of demercuration, mercury chloride content reaches after 30g/L, discharges, and after the 2nd grade of tower demercuration, liquid proceeds to the 1st grade of tower, and the 2nd grade of tower more renews demercuration liquid.
Remove the gas mixture after hydrogenchloride, through whirlwind acid-mist-removing, alkali cleaning neutralization, whirlwind, except water smoke, obtains refining vinylchlorid.
The composition of discharging demercuration liquid is: HgCl 234.6g/L, 4.5mol/L CaCl 2, 0.3mol/L HCl;
The hydrochloric acid composition of output is: 29.1%HCl, 9.3mg/L HgCl 2
Embodiment 3
Demercuration liquid is 4.0mol/L CaCl 2, the 0.5mol/L HCl aqueous solution.Adopt 2 grades of combined column demercurations, synthetic gas enters from the 1st grade, after 2 grades, discharges; The operating parameter of two-stage tower is identical.
To go out the rough synthetic gas of tower and be cooled to 60~65 ℃; Import 2 grades of combined column demercurations; Demercuration gas mixture imports 2 grades of combined column absorbing hydrogen chlorides again.In the 1st grade of demercuration liquid of demercuration, mercury chloride content reaches after 30g/L, discharges, and after the 2nd grade of demercuration, liquid proceeds to the 1st grade of tower, and the 2nd grade more renews demercuration liquid.
Remove the gas mixture after hydrogenchloride, through whirlwind acid-mist-removing, alkali cleaning neutralization, whirlwind, except water smoke, obtains refining vinylchlorid.
The composition of discharging demercuration liquid is: HgCl 231.4g/L, 4.3mol/L CaCl 2, 0.3mol/L HCl;
The hydrochloric acid composition of output is: 29.9%HCl, 8.3mg/L HgCl 2
Embodiment 4
Demercuration liquid is 4.0mol/L MgCl 2, the 0.2mol/L HCl aqueous solution.Adopt 3 grades of combined column demercurations, synthetic gas enters from the 1st grade, after the 2nd grade, 3rd level, discharges; Three grades of tower operating parameters are identical.
To go out the rough synthetic gas of tower and be cooled to 60~65 ℃; Import 3 grades of combined column demercurations; Demercuration gas mixture imports 2 grades of combined column absorbing hydrogen chlorides again.In the 1st grade of demercuration liquid of demercuration, mercury chloride content reaches after 30g/L, discharges, and after the 2nd grade of demercuration, liquid proceeds to the 1st grade of tower, and the 2nd grade more renews demercuration liquid.
Remove the gas mixture after hydrogenchloride, through whirlwind acid-mist-removing, alkali cleaning neutralization, whirlwind, except water smoke, obtains refining vinylchlorid.
The composition of discharging demercuration liquid is: HgCl 234.7g/L, 4.3mol/L MgCl 2, 0.4mol/L HCl;
The hydrochloric acid composition of output is: 30.8%HCl, 7.6mg/L HgCl 2.

Claims (6)

1. a method for comprehensive treating process vinyl chloride synthetic gas, is characterized in that, comprise the following steps into:
1) rough synthetic gas is cooling: acetylene gas, hydrogenchloride react and generates rough vinyl chloride synthetic gas under mercuric chloride catalyst effect, and cooling, partial oxidation mercury is condensed into dust; 2) remove mercury chloride: with hydrochloric high density high-valency metal chloride soln, contact with synthetic gas, absorb gaseous state mercury chloride, and wash mercury chloride dust; 3) hydrogen chloride absorption: remove gas mixture water or dilute hydrochloric acid absorbing hydrogen chloride after mercury chloride; 4) remove the gas mixture after hydrogenchloride, then through neutralizing treatment, de-liquid, make refining vinylchlorid;
High-valency metal muriate is one or more in calcium chloride, magnesium chloride, zinc chloride, cupric chloride, or one or both in iron(ic) chloride, aluminum chloride;
The concentration of described high-valency metal chloride soln is that 3.5~4.5mol/L, HCl concentration are 0.1~1.5mol/L.
2. method according to claim 1, is characterized in that: described high-valency metal muriate adopts one or both in calcium chloride or magnesium chloride; High-valency metal chloride concentration 4.0mol/L, HCl concentration 0.5mol/L.
3. method according to claim 1, is characterized in that: described rough vinyl chloride synthetic gas is cooled to not higher than 80 ℃.
4. method according to claim 1, is characterized in that: the described process that removes mercury chloride adopts the packed absorber of 2~3 grades.
5. according to the method described in claim 1 or 4, it is characterized in that: hydrochloric high density high-valency metal chloride soln absorbs mercury chloride to its content and reaches after 30~50g/L, with the precipitator method or extraction process, process and reclaim mercury chloride; The solution reclaiming after mercury chloride returns and recycles after adjusting.
6. method according to claim 1, is characterized in that: vinyl chloride synthetic gas is after removing mercury chloride, and water or dilute hydrochloric acid absorbing hydrogen chloride manufacture hydrochloric acid, or produce HCl for desorb, be used further to synthesizing chloroethylene raw material.
CN201110400976.4A 2011-12-06 2011-12-06 Comprehensive processing method of vinyl chloride synthetic gas Active CN102516022B (en)

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CN104138706B (en) * 2013-05-07 2016-12-28 贵州省万山银河化工有限责任公司 A kind of HCl recovery mercuric chloride produces the method for tail gas
CN103408395B (en) * 2013-07-23 2016-03-16 沈阳化工大学 By the method for synthesizing high-quality vinyl containing a small amount of phosgene TDI by-product hydrogen chloride and acetylene
CN103725903B (en) * 2013-12-31 2016-01-27 新疆中泰化学股份有限公司 Mercurous HCl recovery device
CN106831320A (en) * 2016-12-14 2017-06-13 安徽华塑股份有限公司 The method of purification of vinyl chloride in a kind of generated by polyvinyl chloride by calcium carbide production
CN108855155B (en) * 2018-04-28 2021-04-06 张良儒 Preparation method and recovery method of environment-friendly low-mercury catalyst
CN109232171B (en) * 2018-10-10 2021-05-18 青岛科技大学 Method for completely removing acidic substances in crude vinyl chloride gas
CN111170276A (en) * 2020-01-16 2020-05-19 四川永祥新能源有限公司 Hydrochloric acid analysis method

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US3647359A (en) * 1968-09-21 1972-03-07 Bp Chem Int Ltd Recovery of mercury
GB1336084A (en) * 1972-01-19 1973-11-07 Bp Chem Int Ltd Removal of mercury from gas streams
CN101455974A (en) * 2008-12-29 2009-06-17 万山特区红晶汞业有限公司 Tail-gas comprehensive utilization method in mercuric chloride catalyst

Patent Citations (3)

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US3647359A (en) * 1968-09-21 1972-03-07 Bp Chem Int Ltd Recovery of mercury
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