This is the 2nd installment in our In Transition series where we explore the role and benefits of fuel cells and hydrogen energy for sectors in transition to a more economically and environmentally sustainable future.
As governments and companies look for ways to decrease their environmental footprint, carbon capture and sequestration (CCS) is gaining attention as a solution to reduce carbon emissions into the atmosphere. Fuel cell technologies are making significant strides to enable CCS commercialization.
Carbon capture separates carbon dioxide (CO2) from the flue gas stream exiting a power plant after combustion. After preventing the CO2 from reaching the atmosphere, it is prepared for transport to a storage site or industrial site to be used as a feedstock. Geologic sequestration, i.e. underground storage, involves injecting the CO2 into appropriate geologic formations where it can be trapped for millions of years.
Research and development continue for best practices to carry out CCS. However, a fundamental challenge is that every stage -capture, transport, and sequestration- consumes energy. The conventional CCS process uses 20-30% of a power plant’s output itself. This reduces the efficiency of power plants that are already plagued by inefficiency and significantly raises the cost of electricity for consumers. However, fuel cells offer a carbon capture strategy that produces energy rather than consuming it, enough to power every stage of the process and increase the efficiency of power plants.
To power carbon capture applications, molten carbonate fuel cells (MCFC) can use internally reformed hydrogen from a fuel source (natural gas, biogas, etc.) and carbon dioxide from flue gas to produce electricity, heat, and water. The flue gas depleted of most of its CO2 passes through the system. The captured CO2 joins the depleted fuel exiting the fuel cell, where it can easily be separated due to its high concentration and transported to an appropriate storage or industrial site.
FCHEA member FuelCell Energy is testing their MCFC technology with ExxonMobil at Southern Company’s James M. Barry Electric Generating Plant in Bucks, Alabama. Starting in early 2019, FuelCell Energy’s MCFC will go through six months of testing using flue gas from Barry’s coal-fired generators, supported by funding from the United States Department of Energy. The project will use a modified 2.8-MW SureSource 3000 fuel cell system to capture 54 metric tons of carbon dioxide per day.
Following this initial trial, the MCFCs will be tested on the flue gas emitted from natural gas generators at the Barry plant. While the coal-fired generators only contribute a small portion of Barry’s daily emissions, the scalability of the fuel cells will allow them to meet the carbon capture needs of a variety of CO2 sources. Power plants, steel mills, cement plants, and other carbon-intensive facilities can utilize fuel cell-enabled CCS technologies to reduce their CO2 output.
Electric utilities are investing significant resources in CCS technologies to help reduce their CO2 output, and are paying close attention to fuel cell-enabled CCS tests as a potential energy- efficient solution. Through CCS, fuel cells can play a role in not only producing clean energy, but also reducing the greenhouse gas emissions of current fossil fuel technologies as we continue to transition to a more environmentally sustainable future.