Reaction intermediates and products characterisation of NH_(3) in desulphurisation with activated coke  

作　　者：Wei-li Zhang Meng Wang Wen-zhe Si Jun-hua Li 

机构地区：[1]School of Environment,Tsinghua University,Beijing,100084,China [2]State Key Laboratory of Chemical Resource Engineering,Beijing University of Chemical Technology,Beijing,100029,China

出　　处：《Journal of Iron and Steel Research International》2024年第11期2664-2674,共11页钢铁研究学报（英文版）

基　　金：support of China Petrochemical Corporation Funding(Sinopec Group,No.321094).

摘　　要：The sulphate is an important factor restricting the efficient and stable operation of the activated coke (AC) flue gas purification system. The simulation experiments and in situ infrared tests of AC taken from desorption tower of the AC flue gas purification system were carried out to first calibrate the thermal desorption characteristics of adsorbed NH_(3) and sulphate and explore the reaction behaviour of NH_(3) with SO_(2) and H_(2)SO_(4). On this basis, some advice for optimising the sulphate generation was put forward to improve the purification efficiency of the AC system. The results show that the temperatures of the desorption of adsorbed NH_(3), the decomposition of (NH_(4))_(2)SO_(4) and NH_(4)HSO_(4) are 224, 276 and 319 ℃, respectively, which lays the foundation for the quantitative analysis of sulphate on AC. Regardless of the NH_(3) amount, only a small portion of H_(2)SO_(4) is converted to sulphate, as the H_(2)SO_(4) deposited in AC pores or agglomerated together could not come into contact with NH_(3). The final reaction product of NH_(3) and SO_(2) is mainly (NH_(4))_(2)SO_(4) which is continuously generated because the newly generated H_(2)SO_(4) is continually exposed to NH_(3), if NH_(3) is enough. The reaction of NH_(3) with H_(2)SO_(4) takes precedence over with NH_(4)HSO_(4). In the initial stages in which H_(2)SO_(4) is exposed to NH_(3), the product is essentially all NH_(4)HSO_(4) as intermediate. Then, it is further converted to (NH_(4))_(2)SO_(4) whose amount reaches equilibrium when the accessible H_(2)SO_(4) is exhausted. All the NH_(3) adsorbed on AC entering the desulphurisation tower generates NH_(4)HSO_(4), but the amount is limited. The remaining SO_(2) entering the denitrification tower mainly generates (NH_(4))_(2)SO_(4);thus, limiting the remaining SO_(2) amount is necessary to guarantee denitrification efficiency. When the NH_(3) injection is changed to the desulphurisation tower, the initial NH_(3) injection rate can be increased to complete the conversion of accessibl

关 键 词：Sulphate generation Activated coke Sintering flue gas treatment NH_(4)HSO_(4) (NH_(4))_(2)SO_(4) 

分 类 号：O64[理学—物理化学]