Photoautotrophs, such as microalgae and cyanobacteria, use sunlight to convert inorganic carbon, especially dissolved CO2 and bicarbonates, to organic materials, commonly biofuels or biofuel precursors. For large-scale biofuel production, the CO2 abundance in ambient air is not sufficient and CO2 must be delivered in a concentrated form, ideally captured from anthropogenic sources such as flue gas streams from power plants. Carbon dioxide capture and delivery to the photoautotrophic culture can add significantly to the cost of biofuels. Much of that cost can be attributed to the regeneration of the CO2 sorbent, a generally energy intensive process. Herein, a liquid-based CO2 delivery methodology is described and demonstrated. The system involves a conventional CO2 sorption system (exemplified by an amine-functionalized sorbent), and a carbonate stripping solution that produces a bicarbonate-rich solution after contacting the absorber. The latter solution serves as the feed stream for a CO2 selective membrane with the permeate side of the membrane being swept by a seawater solution, designed as a model for a photoautotrophic culture medium. Changes in pH and carbon content of the solutions, as well as the lack of any ionic transport across the membrane, are consistent with molecular transport of CO2. The CO2 flux is shown to be consistent with the chemical potential differential provided by the carbon-rich stripping solution and the carbon-depleted seawater solution. In application to biofuel production, the driving force would be sustained by carbon consumption in the photosynthetic process. Thus, photosynthesis provides much of the energy for the CO2 sorbent regeneration in the form of the regenerated carbonate stripping solution. The overall liquid-based CO2 delivery process described here provides the potential for a more cost-effective biofuel production process.