Development and Testing of a High Temperature PBI Hollow Fiber Membrane Technology for Pre-Combustion CO2 Capture

SRI International is responding to DE-FOA-0001830, “Transformational Pre-Combustion Carbon Capture Technologies, AOI 2 – Bench Scale”. The project involves the separation of CO2 from a syngas stream at a temperature of ~225° C and pressures up to 30 bar. The syngas stream will contain CO2, H2, CO, steam, and other trace-level gases. The technology entails the high-temperature separation of the CO2 from a syngas stream from an IGCC plant containing CO2, H2, CO, steam, and other trace-level gases. The separation process uses high-temperature stable, hydrogen-selective, PBI-polymer-based asymmetric hollow-fiber membranes. Figure 1 depicts the integration of a membrane-based system in an IGCC plant. The system will be situated downstream of the water gas shift reactors. The gas stream will be cooled to above its dew point, and the membrane module will be used to separate H2 and steam from the rest of the syngas stream. The permeate H2, acid gasses (a few percent) and steam, along with the sweep gas N2, will be sent to the turbine unit; CO2 and other trace permeate gases will be sent to a high-pressure processing unit to convert H2S to S by the Claus process, and remaining gases will be compressed to pipeline pressure. SRI tested bench-scale skid (up to 50 kW thermal) installed with PBI hollow fiber membrane (HFM) modules for separating H2 and CO2 from syngas during the G5 gasifier run at the National Carbon Capture Center (NCCC) gasifier site, Wilsonville, AL. The PBI HFM field testing at the NCCC was successfully conducted during March - April 2017. SRI proposes to update the skid and install SRI Generation -2 fibers, and demonstrate the performance at a field site. The University of Kentucky Center for Applied Energy Research (CAER) is one of the field sites identified by DOE in the referenced FOA. CAER will provide assistance in testing the SRI PBI Skid.