Xie Xinlei, Wu Wei, Fu Jiali, Di Linwen, Bu Changsheng, Xu Guiling, Meng Junguang, Piao Guilin, Wang Xinye
Jiangsu Provincial Key Laboratory of Materials Cycling and Pollution Control, School of Energy and Mechanical Engineering, Nanjing Normal University Nanjing 210023 China.
Nanjing Environment Group Co., Ltd Nanjing 210026 China.
RSC Adv. 2023 Aug 21;13(35):24854-24864. doi: 10.1039/d3ra04615j. eCollection 2023 Aug 11.
The preparation of refuse-derived fuel (RDF) is an effective and simple means of rural municipal solid waste utilization. The release of chlorine during RDF combustion is important as it causes high-temperature corrosion and pollutants emission such as HCl, dioxins, In this paper, constant-temperature and increasing-temperature combustion experiments were carried out using an electrically heating furnace to analyse the effects of granulation (pressure and additives) on the release of chlorine in particles. During the constant-temperature combustion below 800 °C, only organic chlorine was released from the RDF. The increase of granulation pressure from 1 MPa to 10 MPa did not affect the total amount of chlorine release, but delayed the organic chlorine release by increasing the gas diffusion resistance. During the constant-temperature combustion above 900 °C, inorganic chlorine was released as well. The increase of granulation pressure enhanced the inorganic chlorine release significantly by promoting the reactants contact. During the increasing-temperature combustion, the increase of granulation pressure delayed the organic chlorine release as well but inhibited the inorganic chlorine release. This was mainly attributed to the slow temperature rise to 900 °C, during which the inherent calcium in the RDF reacted with silicon and aluminium, resulting in less reactants for an inorganic chlorine release reaction. Three calcium-based additives were used to inhibit chlorine release. CaCO showed no dechlorination effect, and CaO showed better dechlorination effect than Ca(OH). For the constant-temperature combustion at 900 °C, the addition of CaO with a Ca/Cl ratio of 2 achieved a dechlorination efficiency of over 90%, with little influence from the granulation pressure. For the increasing-temperature combustion, the granulation pressure had a significant influence on CaO dechlorination effectiveness. Only at a granulation pressure as high as 10 MPa, did the addition of CaO with the Ca/Cl ratio of 2.5 achieve a dechlorination efficiency of 95%.
制备垃圾衍生燃料（RDF）是农村城市固体废物利用的一种有效且简便的方法。RDF燃烧过程中氯的释放很重要，因为它会导致高温腐蚀以及HCl、二噁英等污染物排放。本文利用电加热炉进行了恒温燃烧和升温燃烧实验，以分析造粒（压力和添加剂）对颗粒中氯释放的影响。在800℃以下的恒温燃烧过程中，RDF仅释放有机氯。造粒压力从1MPa增加到10MPa，不影响氯的总释放量，但通过增加气体扩散阻力延迟了有机氯的释放。在900℃以上的恒温燃烧过程中，也会释放无机氯。造粒压力的增加通过促进反应物接触显著提高了无机氯的释放。在升温燃烧过程中，造粒压力的增加同样延迟了有机氯的释放，但抑制了无机氯的释放。这主要归因于升温至900℃的速度较慢，在此期间RDF中固有的钙与硅和铝发生反应，导致无机氯释放反应的反应物减少。使用了三种钙基添加剂来抑制氯的释放。CaCO₃没有脱氯效果，CaO的脱氯效果比Ca(OH)₂好。对于900℃的恒温燃烧，添加Ca/Cl比为2的CaO实现了超过90%的脱氯效率，造粒压力的影响很小。对于升温燃烧，造粒压力对CaO的脱氯效果有显著影响。仅在高达10MPa的造粒压力下，添加Ca/Cl比为2.5的CaO才能实现95%的脱氯效率。
