摘要
为解决尿素水解制氨工艺中反应速率慢等问题,筛选了一种弱碱铵盐水解催化剂,通过提高反应液碱度来促进尿素的水解.小试和中试试验结果表明:磷酸氢二铵具有比磷酸二氢铵更高的催化效率;采用磷酸氢二铵作为催化剂时水解反应活化能由无催化剂时的73.6 kJ/mol减小到65.3 kJ/mol,水解反应速率加快,相同产氨量下反应温度降低约10℃,产氨能耗降低约3%;在相同的产氨需求和反应温度条件下,催化水解反应器的容积可减小30%以上;催化条件下的尿素水解仍然为液相慢反应,产氨速率由本征动力学控制.本研究将为尿素催化水解工艺设计提供重要参考.
In order to solve the problems such as slow reaction rate in the urea hydrolysis for ammonia,a weakly alkaline ammonium salt was selected in this research,which promoted the urea decomposition by increasing the alkalinity of the reaction solution.The lab-scale test and pilot test results indicated that,(NH4)2HPO4 has higher catalytic efficiency than NH4H2PO.The activation energy of the hydrolysis reaction is decreased from 73.6 kJ/mol without the catalyst to 65.3 kJ/mol when using the(NH4)2HPO4 as catalyst,thus the hydrolysis reaction rate is accelerated,and the reaction temperature can be reduced by about 10℃ while the energy consumption for ammonia production is reduced by about 3%.Under the same ammonia production requirement and reaction temperature,the volume of the catalytic hydrolysis reactor can be reduced by more than 30%.The urea hydrolysis with catalytic still belongs to slow liquid-phase reaction,and the ammonia production rate is controlled by the intrinsic kinetics.This research will provide an important reference for the process design of urea catalytic hydrolysis.
作者
张向宇
向小凤
郭洋洲
周广钦
ZHANG Xiangyu;XIANG Xiaofeng;GUO Yangzhou;ZHOU Guangqin(Xi’an Thermal Power Research Institute Co.Ltd&National Engineering Research Center of Clean Coal Combustion,Xi’an 710032,China)
出处
《华中科技大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2023年第8期81-87,共7页
Journal of Huazhong University of Science and Technology(Natural Science Edition)
基金
国家重点研发计划资助项目(2020YFC1910000)
中国华能集团公司科学技术资助项目(HNKJ21-H15)。
关键词
尿素水解
氨气
催化剂
动力学
热平衡
urea hydrolysis
ammonia
catalyst
kinetics
thermal equilibrium
