The ability to easily and cheaply transport CO₂ from point-sources, such as power plants, to multiple, potentially distant, utilization sites of widely varying scales will enable wider utilization of carbon capture (CC) from flue gas. In the case of algal biomass cultivation, the use of carbonate sorbents for CC, transport, and delivery to algae has the potential to 1) eliminate the requirement for co-location of algal production facilities with power plants or costly, low-volume pipelines, 2) develop a means of inorganic carbon transport, storage, and delivery tuned directly to seasonal and daily algal productivity levels, and 3) reduce CC costs. Directly delivering CO₂ from the sorbent to algae avoids the need for a desorber and compressor in the CO₂ capture system, thus eliminating up to 90% of the energy use and ~60% of the capital cost of a typical capture system.

Lawrence Livermore National Laboratory has developed advanced manufactured composite sorbent materials that captures CO₂ as sodium bicarbonate, encapsulated within a CO₂-permeable polymer to increase the surface area and improve carbon capture rates by an order-of-magnitude compared with carbonate solution. In collaboration with Sandia National Laboratories, we have demonstrated the biocompatibility and ability of these composite sorbents to deliver CO₂ and control the media pH in algal cultures up to 100L. In collaboration with University of Arizona and Southwest Technologies LLC, we are now scaling up the composite sorbent material synthesis and integrating our CC system with a natural gas flue gas stream, coupled with a delivery system to 1000 L algal pond to perform 30-day continuous tests (Figure 1).

This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. (LLNL-ABS-854252)