The Study Of Effect Of Additives On Capability Of CMS From Surplus Sludge For Air Separation

Carbon molecular sieve(CMS)is a kind of high property carbonaceous adsorbent,which has uniform pore structures and extensive application in the fields of gas separation.A CMS for nitrogen-enriched air separation was prepared in this article.The surplus sludge of the coking plant was used as the raw materials,through pre-carbonization,crushing,adding blinder,mixing, blending,carbonization and chemical liquid deposition process to prepare the CMS.The experiments are carried out to discuss the effects of raw material ratio,adding quantity of additive,pre-carbonization technological and carbonization technological conditions on capability of CMS for air separation.The effects of dipping technology on the modification of the pore structure are also discussed in the thesis.Finally,pickling process conditions are preliminary discussed to develop pore volume,meanwhile,the structure and ash composition is analysized by ST-03 type specific surface and pore diameter,AFM,SEM and ICP.The results indicate that a CMS for nitrogen-enriched air separation,which can enrich N₂ to 96.2%and keep for 15 seconds,can be prepared at conditions that the pre-carbonization final temperature is 400℃,the pre-carbonization temperature rising rate is 7℃.min^-1,the pre-carbonization constant temperature time is 30 min, agglomerated with 30%low temperature coal tar binder,20%cellulose and 6%residue as additives,carbonized in the rotary electric 9arburization furnace,the carbonization final temperature is 700℃,the carbonization temperature rising rate is 7℃.min^-1,the carbonization constant temperature time is 30 min.The chemical liquid deposition process was adopted in order to improve capability of CMS.The concentration of anthracene oil I solution is 5%,the dipping time is 4 hours,the heat treatment temperature is 600℃.And the treated CMS can enrich N₂ to 97.2%for 8 seconds.Through second chemical liquid deposition treatment in 3%anthracene oil I solution,the nitrogen concentration was increased to 98.1%,but the constant concentration time was decreased to 5 seconds.At last,CMS was pickled in 20%hydrofluoric acid for 2 hours,to develop its pour volume.The constant concentration time was prolonged to 80 seconds and the nitrogen concentration is 96.2%.The ICP results show that its deash rate is 10.3%,in which SiO2 is 59.3%,Fe203 is 38.9%.Treated in 3% anthracene oil I solution once again,the final CMS can enrich N₂ to 97.3% and keep for 72 seconds.