摘要
为确定甲烷在活性炭上的等量吸附热和预测过剩吸附量的吸附模型,在温度区间268～338K、压力范围0～12.8MPa测试甲烷在Ajax活性炭上的吸附等温线。引用Ono-Kondo方程分析吸附数据,并由等量吸附线标绘和Henry定律常数确定等量吸附热。结果表明,标定参数后的Ono-Kondo方程预测甲烷过剩吸附等温线的相对误差小于2.5%;温度变化影响等量吸附热的数值,甲烷在Ajax活性炭上的等量吸附热和平均极限吸附热分别为17.25kJ·mol-1～21.5kJ·mol-1和22.5kJ·mol-1。应根据吸附天然气(ANG)系统在典型充放气过程中温度变化极值时的等量吸附热来设置吸附热管理措施。
The isosterie heat and the adsorption model of methane on activated carbon were determined for the further study on the adsorbed natural gas （ANG） storage system. Activated carbon Ajax was selected as an adsorbent, six adsorption isotherms of high purity methane were measured at temperature from 268 K to 338 K and pressure up to 12.8 MPa. Isosteric heats of adsorption at nine excess adsorption amounts and those at zero surface coverage were respectively plotted by adsorption isosteres and the temperature dependent of Henry law＇s constants. Ono-Kondo model was parameterized by adsorption data to predict the excess adsorption amount. Results show that the parameterized model can predict the isotherms with a relative error smaller than 2.5 %, and the isosteric heat of adsorption is about 17.25kJ.mol1 ～21.5kJ·mol^-1 with a mean valueat zero surface coverage. Results also reveal that adsorption isosteres of adsorption data at different temperature regions bring about a different isosteric heat of adsorption due to the variation in contributions from thermal motion of adsorbate molecules. Conclusions are drawn that adsorption isosteres on the adsorp- tion data in correspondence with the lowest and highest temperatures of the ANG system during the typical charge or discharge process should be carried out to determine the isosteric heat of adsorption for effectively managing the thermal effect.
出处
《天然气化工—C1化学与化工》
CAS
CSCD
北大核心
2009年第1期41-45,共5页
Natural Gas Chemical Industry
基金
福建省高等学校新世纪优秀人才计划支持计划资助
福建省教育厅资助项目(JA08148)
福建省青年人才创新项目(2006F3092)
集美大学科研基金项目(F05008)
关键词
甲烷
活性炭
吸附模型
吸附热
methane
activated carbon
adsorption model
adsorption heat
