| Due to the volatilization of solvents,a large amount of carbon disulfide containing hydrogen sulfide gas will be generated in the production process of viscose fibers,which will harm human health and damage the atmospheric environment.At present,the main process of treatment is "alkali absorption-activated carbon adsorption".The waste gas of viscose fiber is first absorbed by multistage alkali solution to remove the hydrogen sulfide gas,and then it is directly discharged into the atmosphere after being adsorbed by activated carbon.However,the widely used activated carbon has the disadvantages of low mechanical strength,easy crushing,and easy moisture absorption.And hydrogen sulfide in the gas oxidizes into sulfur in the catalytic action of activated carbon,blocking the pore channel of the activated carbon,and seriously affecting the adsorption capacity.Due to its high mechanical strength,easy control of pore structure,easy regeneration after adsorption saturation,hydrophobic surface and no catalysis,hypercrosslinked adsorption resin has attracted many scholars' attention.Therefore,in this paper,a series of high-specific surface area and high-microporous hypercrosslinked adsorption resins were synthesized.Using carbon disulfide as adsorbate,the adsorption and desorption properties of carbon disulfide on commercial activated carbon and hypercrosslinked adsorbent resin were comparative studied.The main research contents and conclusions are as follows:(1)Using styrene as a monomer,divinylbenzene as a cross-linking agent,and chloromethyl methyl ether as a chloromethylating agent,a series of high-specific surface area and rich-microporous hypercorsslinked adsorption resin were synthesized by suspension polymerization,which the dosage of crosslinking agent and the pore-forming agent(toluene or liquid paraffin)were changed.Column breakthrough adsorption experiments showed that the adsorption capacity of CS2 by M series W resins was related to the pore volume betwewn 0.4nm and 1 nm,and there is no obvious correlation with the surface area.Among them,W-8 resin has the largest pore volume(0.141cm3/g)between 0.4nm and 1nm,and the highest breakthough adsorption capacity(up to 67.0mg/g).While the M-6 resin has the largest specific area 1579.7m2/g,but the breakthrough adsorption capacity is only 53.4mg/g.In addition,temperature programmed thermal desorption experiments showed that both M and W series of synthetic adsorption resins could be desorbed completely.(2)Adsorption isotherms of carbon disulfide on commercial activated carbon GAC and hypercrosslinked adsorption resin W-8 at different temperatures were measured using the static headspace method.The results showed that the equilibrium adsorption capacity of CS2 on GAC was higher than that of W-8,and the equilibrium adsorption capacity decreased with the increase of temperature.The static adsorption experimental data on two adsorbents were simulated using Langmuir,Freundlich and DR equations,respectively.According to the analysis,the three equations all have good fitting results,among which the DR equation has the best fitting effect,and the correlation coefficient R2 is greater than 0.996.(3)The adsorption breakthrough characteristics of carbon disulfide on GAC and W-8 were studied by dynamic column breakthrough adsorption method.The study found that the penetration amount of CS2 on GAC was higher than that of W-8,which was about 67.5%higher.And the increasing of concentration and the shortening of residence time would lead to the advance of CS2 breakthrough time to some extent.The constant temperature desorption experiments showed that the complete regeneration time of W-8 was lower than that of GAC,which was about 53.4%shorter.When the regeneration temperature was 150?,the GAC complete regeneration time was 31.7 minutes,while W-8 was only 14.8 minutes.The surface characteristics of GAC and W-8 were studied by reversed-phase gas chromatography.The non-polar surface energies of GAC and W-8 were 184.7mJ/m2 and 131.7mJ/m2,respectively.Although the specific surface area and micropore pore volume of GAC and W-8 were relatively approximate,GAC has a stronger force on CS2,which makes GAC have higher adsorption capacity and longer desorption time.(4)The effects of water vapor and H2S on the adsorption of CS2 by GAC and W-8 were studied by column adsorption method.And it was found that both co-adsorption and pre-adsorption of water vapor have an adverse effect on the adsorption of CS2.When the water vapor content increased from 0%to 90%at 30?,the adsorption of GAC and W-8 decreased by 30.54%and 26.7%,respectively.And pre-adsorption experiments showed that as the pre-adsorption humidity increases,the mass transfer zone on GAC increases and the adsorption rate decreases,while W-8 is hardly affected.This is related to the higher oxygen-containing functional groups on the AC,resulting in a stronger adsorption of polar water molecules and affecting the adsorption of CS2 by GAC.The experimental results of pre-adsorption of H2S showed that H2S has a more significant effect on the adsorption of CS2 by GAC,but it has almost no effect on W-8.The adsorption capacity of GAC decreased from 107.6mg/g to 43.7mg/g after pre-adsorption of H2S,decreasing 59.4%,while that of W-8 was stable at about 70.0mg/g.By N2-physical adsorption desorption and XPS characterization,it was found that CS2 reacts on AC surface to form S and S-containing oxides,occuping the adsorption site and blocking pore channel,which leads to the decrease of adsorption capacity. |
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