化工学报 ›› 2020, Vol. 71 ›› Issue (5): 2088-2098.DOI: 10.11949/0438-1157.20191357

• 分离工程 • 上一篇    下一篇

CH4-N2在自支撑颗粒型Silicalite-1上的吸附分离及PSA模拟

尚华1(),白洪灏1,刘佳奇1,杨江峰1,2(),李晋平1,2   

  1. 1.太原理工大学化学化工学院精细化工研究所,山西 太原 030024
    2.气体能源高效清洁利用山西省重点实验室,山西 太原 030024
  • 收稿日期:2019-11-11 修回日期:2020-02-22 出版日期:2020-05-05 发布日期:2020-05-05
  • 通讯作者: 杨江峰
  • 作者简介:尚华(1992—),男,博士研究生,1332993003@qq.com
  • 基金资助:
    国家自然科学基金项目(21676175);山西省煤层气联合基金项目(2016012005)

PSA simulation and adsorption separation of CH4-N2 by self-supporting pellets Silicalite-1

Hua SHANG1(),Honghao BAI1,Jiaqi LIU1,Jiangfeng YANG1,2(),Jinping LI1,2   

  1. 1.Research Institute of Special Chemicals, Taiyuan University of Technology, Taiyuan 030024, Shanxi, China
    2.Shanxi Key Laboratory of Gas Energy Efficient and Clean Utilization, Taiyuan 030024, Shanxi, China
  • Received:2019-11-11 Revised:2020-02-22 Online:2020-05-05 Published:2020-05-05
  • Contact: Jiangfeng YANG

摘要:

纯硅分子筛Silicalite-1原粉(Si/Al>470)在6 MPa压力下制成自支撑颗粒状吸附剂,经XRD和77 K氮气吸脱附表征表明自支撑颗粒型的Silicalite-1保留了原粉的晶体结构和比表面。静态重量法测试了273/298/313 K下CH4和N2在其上的吸附等温线,利用理想吸附溶液理论(IAST)法计算了吸附剂对CH4/N2的选择性。动态气体穿透实验测试了颗粒型Silicalite-1吸附剂对不同浓度CH4/N2混合气的分离效果,结果表明该吸附剂更适合于低浓度甲烷(20%/80% CH4/N2)的富集脱氮。通过总传质模型利用数值模拟预测了颗粒型Silicalite-1吸附剂的变压吸附分离(PSA)富集低浓度煤层气中甲烷的效果。模拟结果显示20%/80%的CH4/N2混合气经一次提浓,CH4浓度可以提升至37%~41%,回收率达到60%~92%;30%/70%的CH4/N2混合气经一次提浓,CH4浓度可以提升至50%~53%,回收率达到58%~92%。

关键词: 甲烷, 氮气, 变压吸附, 纯硅分子筛

Abstract:

Pure-silica zeolite Silicalite-1 powder was pressed at 6 MPa pressure to form self-supporting pellets. By characterization of powder X-ray diffraction and 77 K nitrogen adsorption-desorption, there was no change in crystalline and specific surface area after pelletization. Single component adsorption equilibrium isotherm of CH4 and N2 on the self-supporting pellets Silicalite-1 at 273/298/313 K were measured by static gravimetric method. Selectivity of CH4/N2 mixtures on the adsorbent were calculated from Ideal Adsorbed Solution Theory (IAST). Separation effects of CH4/N2 mixtures on the adsorbent were investigated by dynamic mixtures breakthrough experiments, which show it is more suitable for enrichment and nitrogen removal from low concentration coal-bed methane. Separation and enrichment of methane from low concentration coal-bed methane by pressure swing adsorption (PSA) on the particle-shaped Silicalite-1 were predicted using total mass-transfer model by numerical simulation based on abovementioned data. The simulation results show that once the 20% / 80% CH4 / N2 mixture is concentrated, the CH4 concentration can be increased to 37%—41%, and the recovery rate can be 60%—92%; 30%/70% CH4/N2 mixture is once concentration, CH4 concentration can be increased to 50%—53%, and the recovery rate is 58%—92%.

Key words: methane, nitrogen, pressure swing adsorption, Silicalite-1

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