Adsorption Property of Starch-Based Microporous Carbon Materials with High Selectivity and Uptake for C1/C2/C3 Separation

Recovering light hydrocarbons from natural gas is of great significance in the petrochemical industry. In this work, starch-based microporous carbon materials (SMCs) were prepared using starch as a carbon source and characterized for their pore structure and surface chemistry. CH4, C2H6, and C3H8 isotherms of SMCs were determined using a volumetric method. The breakthrough experiments were carried out to evaluate the dynamic separation performance. A grand canonical Monte Carlo simulation was conducted to reveal the adsorption mechanism of these light hydrocarbons on the SMCs. Results showed that the resulting SMCs exhibited a high specific surface area of 1999 m(2)/g and a narrow pore size distribution within 0.5-2.0 nm. Particularly, SMCs displayed extremely high ethane and propane uptakes at 298 K and 100 kPa, reaching 5.28 mmol/g for C2H6 and 8.39 mmol/g for C3H8. Moreover, SMCs showed an ultrahigh selectivity of 27.1 for C2H6/CH4 mixtures under ambient conditions, which exceeded that of many metal-organic frameworks. Thus, SMCs have the potential for recovering light hydrocarbons from natural gas.

Automated summary

In this study, starch-based microporous carbon materials (SMCs) were prepared and showed high efficiency in adsorbing light hydrocarbons, especially ethane and propane, with exceptional selectivity. These materials demonstrate great potential for recovering light hydrocarbons from natural gas.