摘要
本文分别在间歇和连续反应釜中研究KOH、Na2CO3、K2CO3、Li2CO3、NaOH及NH4OH,(NH4)2CO3和氨作为催化剂时,气-水溶液体系水煤气变换催化反应体系的催化性能.研究表明,这些化合物作为催化剂,都能提高水煤气变换反应的速度,其中以NaOH、Na2CO3、KOH和K2CO3性能较好,综合考虑,其中Na2CO3是最具潜力的催化剂.对比实验表明,其中对加速反应速度起决定性作用是其中的阴离子,而不是阳离子.对于Na2CO3催化剂系统研究表明,温度对反应体系的性能也是至关重要的因素,只有在250℃以上时催化活性才能明显提高.催化剂的浓度对于变换反应的活性影响最大,虽然少量的催化剂就能促进反应活性,但只有当催化剂的浓度达到一定值,反应速度才能明显提高.压力对反应系统的催化性能有显著影响,提高系统的压力明显加速反应速度.实验后残余液体中甲酸根(HCO-2)和甲醛(HCOH)的存在,可以推测反应过程是通过甲酸根(HCO-2)和甲醛(HCOH)作为中间物种进行的.
A batch reactor working at 10.0 MPa is used to study the performance of gas-aqueous catalytic systems for water-gas shift reaction,with KOH,Na_2CO_3,K_2CO_3,Li_2CO_3,NaOH,NH_4OH,(NH_4)_2CO_3 and ammonia used as catalysts.Results show that,in aqueous catalytic systems,all these compounds can increase the rate of water-gas shift reaction,of which compound Na_2CO_3 possesses the greatest potential.Ions in compounds are crucial to the catalytic performance.Metal cations do not constitute a necessary factor for the catalytic performance.In the Na_2CO_3-aqueous catalytic system,the initial activity temperature is higher than 100 ℃,and only when the temperature rises up to higher than 250 ℃,will the increase of water-gas shift reaction rate become obvious.The concentration of Na_2CO_3 has great effect on the catalytic performance and only when the concentration reaches a certain amount,can the rate of water-gas shift reaction be increased significantly.A continuous flow reactor is used to study the performance of gas-aqueous catalytic systems for water-gas shift reaction,which NaOH,Na_2CO_3,KOH and K_2CO_3 used as catalysts.Results show that all these four compounds can increase the rate of water-gas shift reaction,of which compounds KOH and Na_2CO_3 possess the greatest potential.Catalytic reaction rates increase with the increase of the catalytic concentration,reaction pressure and temperature.Only when the temperature rises up to higher than 250 ℃,will the increase of water-gas shift reaction become obvious.Intermediate species formate (HCO_2) and formaldehyde (HCOH) are found in the recovered solution product.By inference,the reaction mechanism is brought into action through the two intermediates.
出处
《内蒙古工业大学学报(自然科学版)》
2004年第1期17-23,共7页
Journal of Inner Mongolia University of Technology:Natural Science Edition
基金
内蒙古自然科学基金(990304-2)
内蒙古教育厅重点领域(ZL9904)
国家自然科学基金(20066002)联合资助项目
关键词
变换反应
气-水溶液催化反应
间歇反应器
连续体系
water-gas shift reaction
gas-aqueous catalytic reaction
batch reactor
continuous system