This Small Business Innovation Research (SBIR) Phase I project will prove the feasibility of using a photolytic process to separate carbon dioxide (CO2) from monoethanolamine (MEA) scrubbers for carbon capture in power plants. This innovation is based on verified studies showing that photolysis reactions are faster and use significantly less energy than thermal reactions. The carbon-capture process begins when MEA is used to scrub CO2 from flue gas. The CO2-rich MEA is then sent to a chamber where it is heated to 100-120 oC to remove CO2 for sequestration. Using the current state-of-the-art thermal process to capture CO2 in a coal-fired power plant requires burning 30 % more coal to produce the same amount of electricity, increasing the cost of energy by 81 %. By proposing to use a photolytic reaction to separate CO2 from MEA, Pearlhill is not just improving the current thermal reaction process, but taking CO2 separation technology in an entirely new direction with significant cost saving potential. The broader/commercial impact of this research could drastically reduce the massive energy demand to capture CO2 from power plant flue gas. Building on the current MEA technology has dual benefits. First, for existing coal-fired power plants where MEA technology is employed, Pearlhill?s photolytic process has the potential to be retrofitted, since only the thermal unit must be replaced. Second, using a photolytic instead of the energy-intensive thermal process could reduce the energy costs for carbon capture by over 30 %, saving power plants and ultimately end-users millions of dollars.
The Phase I project has proven the feasibility of photolytic separation of carbon dioxide (CO2) from state-of-the-art monoethanolamine (MEA) scrubbers for carbon capture at power plants. MEA absorbs CO2 in the flue gas from power plants, and they are separated by heating to 100-120 oC in a different process. This is followed by recycling MEA, compression, and sequestration of CO2. Addition of CO2-capture facility results in reduced thermal efficiency of power generation, and has multiple effects on plant and power costs, such as 81 % increase in the cost of energy (COE); and burning 30 % more coal to produce the same amount of electricity. Recent improvements on the thermal process only reduced the burden from $81 to $51/t of CO2 removed. Photochemical separation technology for CO2 separation from CO2-rich MEA scrubber could further reduce the COE to about $35/t of CO2 removed. The rate of the photochemical reaction is several orders higher than the thermal desorption reaction, and use significantly less energy than comparable thermal processes. Coal is and will continue to be an important energy source for the United States and the rest of the world. According to the World Coal Institute, global use of coal is expected to rise by over 60 % from 2006 to 2030. Most of this is in the power generation sector – coal’s share in global electricity generation is set to increase from 41 % to 44 % by 2030. With this fact in mind, reducing the environmental impacts of coal, especially CO2 is vital. There are three CO2 capture concepts – post-combustion capture, oxy-combustion capture, and pre-combustion capture. Although oxy-combustion capture and pre-combustion capture may have potential in the future, both have considerable obstacles to overcome. For the foreseeable future, post-combustion capture technology is the most adoptive and cost effective CO2-capture technology. Modifying existing scrubbers has dual benefits for the dozens of coal-fired power plants throughout the world where the MEA technology is employed to capture about 90 % of 6,000-10,000 t CO2 produced every day. Pearlhill’s innovative photochemical process can be retrofitted into existing plants with amine scrubbers by replacing the thermal units with photolysis units; save power plants several million of dollars for energy generation; and potentially reduce the cost of energy to the end-user.
