A Ni-based metal-organic framework with super-high C3H8 uptake for adsorptive separation of light alkanes

The separation of C 2 H 6 and C 3 H 8 from CH 4 is extremely important in the petrochemical industry, but the separation technology is dominated by an energy-intensive and cost-intensive process of cryogenic distillation. With lower energy consumption and cost investment, adsorptive separation technology shows great potential for the purification of natural gas. Here, we prepared a Ni-based metal-organic framework CTGU-15 and investigated its performance for the separation of light alkanes. Results show that CTGU-15 has super-high C 3 H 8 uptake (12.13 mmol/g) and relatively low CH 4 uptake (0.40 mmol/g) at 298 K and 100 kPa. The reason why CTGU-15 shows super-high C 3 H 8 uptake was studied by comparing the pore textural properties of CTGU-15 and other benchmark adsorbents. Additionally, computational simulations were used to explore the nature of the interaction of the C 3 H 8 gas within CTGU-15. The adsorption selectivities of C 3 H 8 /CH 4 and C 2 H 6 /CH 4 on CTGU-15 are 170.7 and 5.2, respectively. Breakthrough experiments show that CTGU-15 can achieve the adsorptive separation of CH 4 /C 2 H 6 /C 3 H 8 mixtures. Importantly, CTGU-15 can maintain the stability of the framework after the heat treatment at <770 K, five adsorption-desorption cycles and exposure to 58% RH for 3 days. This work indicates that CTGU-15 is a promising adsorbent for CH 4 /C 2 H 6 /C 3 H 8 separation.