摘要
以碳酸钾为催化剂,通过高温热台原位研究气化阶段神府/合肥煤焦与催化剂的交互作用,采用热重分析仪,考察气化温度（750-950℃）、催化剂负载量（钾离子负载量2.2%、4.4%、6.6%（质量分数））对煤焦气化反应性的影响。结果表明,K2CO3有利于促进神府/合肥煤热解过程孔隙结构的发展。气化温度低于碳酸钾熔点时,大部分煤焦颗粒与CO2的反应以颗粒收缩形式进行,当气化温度高于碳酸钾熔点时,对于神府煤焦,随着碳骨架快速消耗,在反应后期可观察到明显的熔融态钾催化剂扩散现象;而对于合肥煤焦,其碳骨架稳定消耗缓慢,大部分熔融态钾催化剂存在于煤焦表面。神府/合肥煤焦气化反应活性随碳酸钾负载量的增加而提高。钾催化剂对神府煤焦的催化作用随气化温度的升高先增强后减弱,转折温度点接近碳酸钾熔点,原因为熔融态钾催化剂流动性好,造成部分孔隙结构堵塞,导致钾催化剂催化作用减弱。
Interactions of catalyst（ K2CO3） with Shenfu（ SF） /Zunyi（ ZY） char during gasification were observed by in-situ heating stage microscope. The effects of gasification temperature（ 750 - 950 ℃） and catalyst loading amount（ 2. 2%,4. 4%,6. 6%） were investigated in a thermogravimetric analyzer. The results show that loading K2CO3 on SF /ZY stimulates development of pore structure in pyrolysis process. The in-situ heating stage experiments indicates that most of the char particles react with CO2 in shrinking core mode below the melting point of K2CO3. Above this temperature,for SF char,obvious molten potassium catalyst diffusion can be observed in the later reaction stage with rapid consumption of carbon skeleton; but for ZY char,most of the molten potassium exists on the surface of coal char with slower consumption of stable carbon skeleton.Gasification reactivity of SF /ZY char increases with increasing loading amount of K2CO3. Catalytic efficiency of potassium catalyst on SF char initially increases and then decreases with gasification temperature,the turning point of gasification temperature is close to the melting point of K2CO3. This may be due to blocking of a fraction of pore structure resulted from the good fluidity of molten potassium catalyst.
出处
《燃料化学学报》
EI
CAS
CSCD
北大核心
2015年第11期1311-1319,共9页
Journal of Fuel Chemistry and Technology
基金
国家自然科学基金(21376081)
国家高技术研究发展计划(863计划
2012AA053101)资助项目~~
关键词
原位高温热台
碳酸钾
熔融
催化气化
in-situ heating stage
K2CO3
fusion
catalytic gasification
