Hydrocarbon separation properties of a CVD-deposited ceramic membrane under single gases and binary mixed gas

In this study, we coated a commercially available porous alumina support with a gamma-Al2O3 intermediate layer and deposited a silica membrane using chemical vapor deposition (CVD) with a 3-aminopropylmethyl diethoxysilane (APMDES) precursor. The pore size of silica membrane was 0.41 using normalized Kunden-based permeance (NKP). The single-gas selectivity of CH4 at 873 K for various hydrocarbons was estimated. A membrane prepared using CVD for 60 min yielded results of 1.50 for CH4/C2H6, 2.96 for CH4/C3H8, and 10.89 for CH4/i-C4H10. After 120 min of CVD, the selectivity increased to 34.10 for CH4/C2H6, 82.63 for CH4/C3H8, and 196.00 for CH4/i-C4H10. And, the binary mixture selectivity for CH4/hydrocarbons of a membrane prepared using CVD at 873 K for 120 min was increased: 43.02 for CH4(50%)/C2H6(50%), 110.53 for CH4(50%)/C3H8(50%), and 304.11 for CH4(50%)/i-C4H10(50%).

Automated summary

In this study, a silica membrane was prepared on a commercially available porous alumina support using CVD, and its selectivity for various hydrocarbons was evaluated. By extending the deposition time, the selectivity of the membrane was significantly improved.