利用脱碳气化渣矿化封存CO_(2)制备碳酸钙的影响研究  

Study on the impact of using decarbonized gasification slag for CO_(2)mineralization and storage to prepare calcium carbonate

作　　者：李翔宇 李旭 樊盼盼 鲍卫仁 常丽萍[1,2] 王建成 LI Xiangyu;LI Xu;FAN Panpan;BAO Weiren;CHANG Liping;WANG Jiancheng(State Key Laboratory of Clean and Efficient Coal Utilization,Taiyuan University of Technology,Taiyuan 030024,China;College of Chemical Engineering and Technology,Taiyuan University of Technology,Taiyuan 030024,China;College of Environmental Science and Engineering,Taiyuan University of Technology,Taiyuan 030024,China)

机构地区：[1]省部共建煤基能源清洁高效利用国家重点实验室,山西太原030024 [2]太原理工大学化学工程与技术学院,山西太原030024 [3]太原理工大学环境科学与工程学院,山西太原030024

出　　处：《燃料化学学报（中英文）》2024年第8期1193-1202,共10页Journal of Fuel Chemistry and Technology

基　　金：国家自然科学基金青年项目(22308247);山西省基础研究计划青年项目(202203021212199);国家自然科学基金区域创新发展联合基金重点项目(U23A20131)资助。

摘　　要：本实验研究了浸出剂种类、浓度、反应时间、温度和液固比等对脱碳气化渣中钙浸出率的影响,并讨论了CO_(2)流量、温度、碳酸化时间对碳酸化效率和生成的沉淀碳酸钙(PCC)晶型结构的影响规律。结果表明,在2 mol/L盐酸、液固比为20 mL/g、反应温度为50℃、反应时间为90 min的浸出条件下,钙浸出率最高,为98.79%。在碳酸化阶段,CO_(2)流量主要影响碳酸化效率,通过优化碳酸化反应条件,CO_(2)流量300 mL/min,反应温度60℃,反应120 min时,最高碳酸化效率可达99.59%。而反应温度和时间则会对碳酸钙晶型和形貌产生显著影响,降低反应温度和缩短反应时间更有利于球霰石型碳酸钙的生成。The gasification slag after carbon separation is difficult to realize effective utilization because of its high content of water and the presence of a small amount of residual carbon.To address these problems,a mineralization based on indirect carbonation to sequester CO_(2)and recycle calcium extraction to prepare nano-calcium carbonate process is proposed.The gasification slag after carbon separation mainly consists of CaO,Al_(2)O_(3),Fe2O3,MgO,as well as some non-metallic components such as SiO_(2).Most of the metal components exist in amorphous form.After preliminary screening of acidic leaching agents,it was found that hydrochloric acid can effectively destroy the structure of gasification slag and dissolve the metal components in gasification slag.In this paper,the effects of leaching agent type,concentration,reaction time,temperature and liquid-solid ratio on the leaching rate of calcium from decarbonized gasification slag were investigated in detail.The results showed that the highest calcium leaching rate of 98.79%was achieved under the leaching conditions of 2 mol/L HCl,liquid-to-solid ratio of 20 mL/g,reaction temperature of 50℃and reaction time of 90 min.Meanwhile,the effects of CO_(2)flow,temperature and time on the carbonation efficiency and precipitated calcium carbonate(PCC)crystal structure were investigated.In the carbonation stage,the main factor affecting carbonation efficiency is CO_(2)flow.This is because excessive CO_(2)will cause carbonic acid to form in the solution and partially dissolve the precipitated CaCO3,resulting in a sharp decrease in carbonation efficiency.And the carbonation efficiency gradually increases with the increase of reaction temperature.Generally speaking,increasing the temperature is beneficial for chemical reactions.However,owing to the exothermic nature of the carbonation reaction,the positive promotion effect of high temperature on the reaction process is weakened,and the solubility of CO_(2)in water is reduced,resulting in a slow decrease in carbonation efficie

关 键 词：煤气化灰渣 间接碳化 二氧化碳减排 沉淀碳酸钙 晶型调控 

分 类 号：TQ536.4[化学工程—煤化学工程]