A kind of selective adsorption removes the method for dithiocarbonic anhydride in crude benzol
Technical field
The invention belongs to technical field of coal chemical industry, relate to the removal of impurities of the crude benzol being reclaimed by coke-oven gas, more specifically, the invention provides a kind of method that removes dithiocarbonic anhydride in crude benzol with Si-Al molecular sieve selective adsorption.
Background technology
Dithiocarbonic anhydride is as the organosulfur impurity containing in crude benzol, and massfraction is about 0.3-0.4%.It generates hydrogen sulfide owing to being slowly hydrolyzed in Chemicals production conversion process, and meeting etching apparatus, contaminate environment also can cause some commercial catalystss poisoning simultaneously, affect industrial production.In coke-oven plant's crude benzene refining technological process, first remove the dithiocarbonic anhydride in crude benzol, the organosulfur hydrotreatment ability in crude benzene refining process be can improve, and then output and the purity of crude benzene refining product improved, increase the economic benefit of factory.Therefore, remove dithiocarbonic anhydride for reducing industrial production loss, to improve quality of chemical products very important.
At present, remove dithiocarbonic anhydride and have absorption method and chemical method.Chemical method energy consumption is high, complicated operation, cost are high, and has destroyed dithiocarbonic anhydride structure, can not recycle it.Absorption method is simple, energy consumption is low, removal effect is good, is a kind of non-destructive method, can realize the recycling of dithiocarbonic anhydride simultaneously.
Publication number be CN 1846847 A Patent Application Publication a kind of activated carbon fiber adsorbing material, this material can be used for absorption and removes airborne dithiocarbonic anhydride.Publication number be CN 102295953 A Patent Application Publication a kind of method that removes dithiocarbonic anhydride, the method is converted into xanthogenate by dithiocarbonic anhydride, then by distillation or the separated xanthogenate of the method for rectifying.But the method technique is loaded down with trivial details, and energy consumption is higher, and dithiocarbonic anhydride can not be recovered utilization.
Up to the present, also report with Si-Al molecular sieve as sorbent material, thereby for the method for the dithiocarbonic anhydride of adsorbing and removing crude benzol.
Summary of the invention
For deficiency of the prior art, the object of this invention is to provide a kind of method that selective adsorption removes dithiocarbonic anhydride in crude benzol, the method adopts Si-Al molecular sieve as sorbent material.
To achieve these goals, the invention provides a kind of method that selective adsorption removes dithiocarbonic anhydride in crude benzol, the method comprises: step a) adopts Si-Al molecular sieve as sorbent material, and makes crude benzol pass through described Si-Al molecular sieve with the dithiocarbonic anhydride in adsorbing and removing crude benzol.
Wherein, the method that selective adsorption provided by the invention removes dithiocarbonic anhydride in crude benzol can further comprise: step b), after described Si-Al molecular sieve absorption is saturated, passes into N
2purge, described Si-Al molecular sieve is regenerated.
Above-mentioned steps a) and b) can loop.
Wherein, the method that selective adsorption provided by the invention removes dithiocarbonic anhydride in crude benzol also can further comprise: the N after purging step c) condensation recycling step b)
2dithiocarbonic anhydride in (this gas is the mixed gas that carries dithiocarbonic anhydride).
Wherein, Si-Al molecular sieve described in step a) can be selected from 4A type, 5A type, 13X type, 10X type, sodium Y type and calcium Y type.Above-mentioned Si-Al molecular sieve is all a kind of alkali metal aluminosilicate, the framework of molecular sieve mainly being formed by silicon oxide and aluminum oxide, and its pore distribution is even, and pore size is that between 0.4-1.0nm, specific surface area reaches 300-1000m
2/ g, has stronger adsorption function.Those skilled in the art can select the Si-Al molecular sieve of suitable types according to actual needs.
Removing described in step a) can be carried out under condition of normal pressure, and removing temperature is 10-60 ℃, and air speed is than being 0.4-2.0h
-1(crude benzol mass rate/adsorbent mass).
Described in step b), pass into N
2the condition purging is: in 2-3 hour, be warming up to after 200-400 ℃, purge 2-6 hour.
Effect of the present invention and benefit are: in adsorbing and removing crude benzol provided by the invention in the method for dithiocarbonic anhydride, adopt first Si-Al molecular sieve as sorbent material, it is large to dithiocarbonic anhydride loading capacity in crude benzol, selective adsorption decreasing ratio is high, can realize deep removal dithiocarbonic anhydride, can recycle the dithiocarbonic anhydride after adsorbing and removing simultaneously.Like this, not only reduced the required energy consumption of organosulfur hydrogenation in factory's crude benzene refining process in prior art, also improved output and the purity of crude benzene refining product, the technique that simplifies the operation, reduces maintenance cost, increases the economic benefit of factory.In addition, compare with the ordinary method that removes dithiocarbonic anhydride, method of the present invention Si-Al molecular sieve sorbent material used is conveniently easy to get, and adsorption operations mild condition is easy to operate, and cost reduces greatly.And this adsorbent reactivation is convenient, after regeneration, dithiocarbonic anhydride in benzene is still had to higher adsorption effect, the life cycle of sorbent material is long.
Embodiment
Below in conjunction with technical scheme, describe the specific embodiment of the present invention in detail.
Embodiment 1
Removing of dithiocarbonic anhydride:
Dithiocarbonic anhydride is dissolved in purified petroleum benzin and is made into simulation crude benzol, and the Carbon Disulfide that makes to simulate in crude benzol is 3000mg/kg.The 5A type Si-Al molecular sieve (Catalyst Factory, Nankai Univ) of 200g is fixed in adsorber, and under normal temperature and pressure, air speed is than being 0.7h
-1, passing into simulation crude benzol, reaction result is that dithiocarbonic anhydride adsorbing and removing rate is 100%.
The recovery of dithiocarbonic anhydride:
After the absorption of 5A type Si-Al molecular sieve sorbent material is saturated, pass into N
2purge, in 2 hours, be warming up to 300 ℃, maintain 300 ℃ of purgings and regenerate for the first time for 3 hours, the 5A type Si-Al molecular sieve after regeneration is for the first time designated as to sample I.N after purging
2after condenser condenses, the recovery that is condensed of dithiocarbonic anhydride wherein, phlegma is designated as A
1.
Use the sample I after regeneration for the first time according to the method described above crude benzol to be carried out to removing of dithiocarbonic anhydride, and according to above-mentioned renovation process processing sample I, the 5A type Si-Al molecular sieve after regeneration is for the second time designated as to sample II.5A type Si-Al molecular sieve can be recycled, and what circulate and use for 5 times is recorded in respectively in table 1 result of removal of carbon disulfide rate, and in the phlegma using for 5 times that circulates, Carbon Disulfide analytical results is recorded in table 2 respectively.
Embodiment 2
Removing of dithiocarbonic anhydride:
Dithiocarbonic anhydride is dissolved in purified petroleum benzin and is made into simulation crude benzol, and the Carbon Disulfide that makes to simulate in crude benzol is 3000mg/kg.The sodium Y type Si-Al molecular sieve (Catalyst Factory, Nankai Univ) of 200g is fixed in adsorber, and under normal temperature and pressure, air speed is than being 0.7h
-1, passing into simulation crude benzol, reaction result is that dithiocarbonic anhydride adsorbing and removing rate is 100%.
The recovery of dithiocarbonic anhydride:
After the absorption of sodium Y type Si-Al molecular sieve sorbent material is saturated, pass into N
2purge, in 2 hours, be warming up to 300 ℃, maintain 300 ℃ of purgings and regenerate for the first time for 3 hours, the sodium Y type Si-Al molecular sieve after regeneration is for the first time designated as to sample III.N after purging
2after condenser condenses, the recovery that is condensed of dithiocarbonic anhydride wherein, phlegma is designated as B
1.
Use the sample III after regeneration for the first time according to the method described above crude benzol to be carried out to removing of dithiocarbonic anhydride, and according to above-mentioned renovation process processing sample III, the sodium Y type Si-Al molecular sieve after regeneration is for the second time designated as to sample IV.Sodium Y type Si-Al molecular sieve can be recycled, and what circulate and use for 5 times is recorded in respectively in table 1 removal of carbon disulfide rate result, and in the phlegma using for 5 times that circulates, Carbon Disulfide analytical results is recorded in table 2 respectively.
Embodiment 3
Removing of dithiocarbonic anhydride:
Dithiocarbonic anhydride is dissolved in purified petroleum benzin and is made into simulation crude benzol, and the Carbon Disulfide that makes to simulate in crude benzol is 3000mg/kg.The 13X type Si-Al molecular sieve (Catalyst Factory, Nankai Univ) of 200g is fixed in adsorber, and under normal temperature and pressure, air speed is than being 0.7h
-1, passing into simulation crude benzol, reaction result is that dithiocarbonic anhydride adsorbing and removing rate is 100%.
The recovery of dithiocarbonic anhydride:
After the absorption of 13X type Si-Al molecular sieve sorbent material is saturated, pass into N
2purge, in 2 hours, be warming up to 300 ℃, maintain 300 ℃ of purgings and regenerate for the first time for 3 hours, the 13X type Si-Al molecular sieve after regeneration is for the first time designated as to sample VI.N after purging
2after condenser condenses, the recovery that is condensed of dithiocarbonic anhydride wherein, phlegma is designated as C
1.
Use the sample VI after regeneration for the first time according to the method described above crude benzol to be carried out to removing of dithiocarbonic anhydride, and according to above-mentioned renovation process processing sample VI, the 13X type Si-Al molecular sieve after regeneration is for the second time designated as to sample VII.13X type Si-Al molecular sieve can be recycled, and what circulate and use for 5 times is recorded in respectively in table 1 removal of carbon disulfide rate result, and in the phlegma using for 5 times that circulates, Carbon Disulfide analytical results is recorded in table 2 respectively.
The test-results of table 1 Different Silicon aluminum molecular screen circulation absorption
Table 2 Different Silicon aluminum molecular screen regeneration desorption N
2carbon Disulfide in phlegma after condensation
As can be seen from Table 1 and Table 2, the Si-Al molecular sieve that the present invention adopts, as sorbent material, can reach 100% to the decreasing ratio of dithiocarbonic anhydride.In addition, Si-Al molecular sieve after regeneration is still very high to the absorption property of dithiocarbonic anhydride, for example, after 3 uses that circulate, to removal of carbon disulfide rate, is more than 93%, circulate after using for 5 times and still can reach more than 82%, wherein best to the adsorptive power of dithiocarbonic anhydride with 5A type molecular sieve.