轻石脑油中C_6烷烃在5A分子筛上的吸附/脱附等温线研究

测定了轻石脑油中正、异构C6烷烃在5A-1分子筛上的低温(25～80℃)及高温(150～300℃)吸附/脱附等温线,分析了吸附温度、吸附压力、脱附压力对5A-1分子筛吸附/脱附性能的影响。结果表明:正己烷在5A-1分子筛上低温(25～80℃)及高温(150～300℃)下的吸附等温线均为I型吸附等温线,且随着吸附温度的升高,等温线优惠程度逐渐降低。吸附温度25℃、平衡压力7.5kPa时,异构C6烷烃在5A-1分子筛上的吸附量较小,对正己烷平衡吸附量影响不大。对于轻石脑油中的C_6烷烃来说,较适宜的吸附温度优选200～250℃,在该温度范围内,正己烷平衡吸附量为5.68～9.03g/(100g);脱附压力为1.4 kPa时,正己烷脱附量为0.69～2.35g/(100g),能够满足变压吸附的操作要求。

Study on isotherm of C6 alkanes in light naphtha adsorption and desorption on the 5A molecular sieve

The isotherm of C6 n-and i- alkanes in light naphtha adsorption and desorption on the 5A molecular sieve under low temperature （25- 80℃ ） and high temperature （150 -300 ℃ ） is determined. The influence of adsorption temperature, adsorption pressure and desorption pressure on the adsorption and desorption performance of 5A molecular sieve is analyzed. The results show that the adsorption isotherm of n-hexane on the 5A molecular sieve under low temperature （25 - 80℃ ） and high temperature （ 150 - 300℃ ） is I type one, and the isotherm preferential degree gradually reduces with the increasing of adsorption temperature. The adsorption capacity of i-hexane on the 5 A molecular sieve under 25℃ and 7.5 kPa is small, which has slightly effect on the equilibrium adsorption capacity of n-hexane. The optimum adsorption temperature is 200 - 250 ℃to C6 alkanes in light naphtha. Within the above temperature limits, the equilibrium adsorption capacity of n-hexane is 5.68 - 9. 03 g/（ 100 g）, and the desorption capacity of n-hexane is 0. 69 - 2. 35 g/（ 100 g） under desorption pressure of 1.4 kPa,whieh can meet the operation demand of pressure swing adsorption.