(200b) Polymeric-Metallic Composite Membranes for Hydrogen Purification and Carbon Capture at Elevated Temperature

Separating and
capturing carbon dioxide from mixed gas streams is a first and critical step in
carbon sequestration. To be technically and economically viable, a successful
separation method must be applicable to industrially relevant gas streams at
realistic temperatures and pressures as well as be compatible with large gas
volumes. The work being pursued by this Project Team involves the development
of polymeric-metallic composite membranes with a polybenzimidazole (PBI)-based
selective layer that can purify hydrogen and capture carbon at high
temperatures.  Our approach focuses on a pre-combustion capture approach that
integrates the high-temperature polymeric-metallic composite membranes into an
advanced Integrated Gasification Combined-Cycle (IGCC) process. The primary project
objective is the development of polymeric-metallic composite membrane
structures that achieve the critical combination of high selectivity, high
permeability, and chemical and mechanical stability at elevated temperatures
(>150 °C). Stability requirements are focused on tolerance to the primary
synthesis gas components and impurities at various locations in the process. The
project team has made significant strides towards demonstrating the technical
and economic feasibility of capturing CO₂ from large point sources,
such as power plants, via both long-term (300+ day) testing at the High
Temperature Membrane Development and Test Facility at LANL and out-of-the-laboratory
testing at a pressurized natural gas fuel processor.  We will describe the
results from the aforementioned prototype testing of separation modules
operating under industrially relevant conditions and discuss the challenges
involved in successfully developing this technology. This project supports the U.S.
DOE National Energy Technology Sequestration Program project portfolio focused
on the capture and separation of CO₂ from the power sector.