混合方式对CaO/煤焦水蒸气气化反应的影响

采用某内蒙烟煤,基于加压固定床反应器,通过气体产物分析研究了CaO/煤焦混合方式以及反应条件对煤焦水蒸气气化反应的影响。研究表明,在相同反应气氛下,添加CaO能够显著提高煤焦水蒸气气化反应速度,且其提高程度与CaO/煤焦的混合方式有关,与不添加CaO时相比,CaO/煤焦混合物共热解制得的煤焦/CaO水蒸气气化反应速度可提高182.34%,而煤单独热解制得煤焦与CaO机械混合的煤焦/CaO水蒸气气化反应速度仅提高21.13%,钙离子在煤焦中的分散程度是影响CaO/煤焦水蒸气气化反应的主要因素。CaO/煤焦水蒸气气化反应速率随Ca/C摩尔比增加先升高后降低,在Ca/C摩尔比约为1.0时反应最快。当温度由650℃升高至750℃,CaO/煤焦水蒸气气化反应速度提高了594.67%;水蒸气分压力由0.35 MPa提高至0.50,0.65 MPa,气化反应速度分别提高了95.86%和204.14%。

Influences of mixing methods on CaO/char steam gasification

The reaction rates of a bituminous coal (Inner Mongolia) steam gasification with CaO additive had been studied with a pressurized fix-bed reactor through gas products analysis.The results show that CaO additive has a sufficient effect on char steam gasification rate，and the promotion effect of CaO on char steam gasification has a positive correlation with the mixing extent between CaO and char.Compared with non-CaO gasification，the steam gasification rate of char/CaO mixture which is the product of coal/CaO co-pyrolysis increases by 182.34%.In addition，the steam gasification rate of the mixture of CaO and char that made of coal individual pyrolysis increases by 21.13%.The degree of Ca2+ dispersion is the main factor which impacts char steam gasification rate.Furthermore，the reaction rate of char steam gasification with CaO additive has a positive correlation with Ca/C under the condition of Ca/C≤1.0，while there would be a decrease in char/CaO steam gasification rate when Ca/C increases to 1.2，compared with the condition of Ca/C=1.0.Temperature plays a sufficient role on char/CaO steam gasification rate.When temperature increases from 650 ℃ to 750 ℃，the reaction rate of char/CaO steam gasification increases by 594.67%.When steam partial pressure increases from 0.35 MPa to 0.50 MPa and 0.65 MPa，the char/CaO steam gasification rates increases by 95.86% and 204.14%，respectively.