Evaluation of the Permeation of Syngas and Its Components through a Synthesized Matrimid Asymmetric Hollow-Fiber Membrane

Bioconversionof syngas (H-2-CO-CO2) to organicsis an excellent means of carbon recycling. Membrane-basedgas-delivery systems can overcome the challenge of syngas'slow solubility in water. However, to maintain syngas conversion stoichiometry,it is crucial to have a membrane that delivers gases at high rateswithout selectivity toward any component. We synthesized an asymmetric,high-flux, low-selectivity hollow-fiber membrane, small-defect-engineered,to prevent bubble formation in future bioreactors. We created sixsets of Matrimid membranes and screened their He/N-2 selectivityand permeances. We compared the pressure-normalized flux of the setwith the highest He/N-2 permeance against a commercial symmetricmembrane for a syngas mixture and its individual purified components.Under equal pressure, the asymmetric membrane exhibited 300-fold higherH(2)-flux, 80-fold higher CO-flux, and 100-fold higher CO2-flux than the symmetric membrane for pure gases. For themixture, the asymmetric membrane had a 45-fold greater H-2-flux, 100-fold greater CO-flux, and 400-fold greater CO2-flux than those of the symmetric membrane. Although the asymmetricmembrane's selectivity (H-2:CO:CO2, 1:5.2:12)exceeded that of the commercial membranes (1:3:1.7), the asymmetricmembrane possesses highly desirable traits for bioconversion of syngas,as its gas fluxes greatly exceed those of commercial membranes.

Automated summary

Bioconversion of syngas to organics is achieved using a high-flux, low-selectivity hollow-fiber membrane. This asymmetric membrane demonstrates significantly higher gas fluxes compared to commercial membranes, making it highly desirable for syngas bioconversion. Despite its higher selectivity, the membrane delivers gases at high rates without selectivity toward any component, ensuring syngas conversion stoichiometry is maintained.