By Robert McIlvaine, President & Founder, The McIlvaine Company
Pump Innovations Within Power Plants
The International Energy Agency (IEA) intends to reach global net zero CO2 emissions by 2050. To achieve this, the energy industry needs to make some serious changes, namely to the kinds of technologies used within power plants.
Air, water, and combustion (AWC) product purchases for a wind or solar plants are smaller than those required for a coal plant. Since the projected capacity for wind and solar is large and the projected capacity increases for coal and nuclear plants are modest, it seems logical that the market for power plant pumps will be unattractive compared to other market opportunities – but this is not the case.
Instead, this market will become incredibly attractive. This favorable increase is due, in part, to the already extensive size of the pump market. The need for process innovation and improved technologies will however contribute significantly to higher pump expenditures within power plants. This is especially true for coal-based power plants.
Bioenergy with carbon capture and storage (BECCS) is a promising future for the power industry, specifically coal processing plants. This carbon removal technique extracts bioenergy and biomass to remove carbon dioxide and greenhouse gases from the atmosphere. This technique is not only workable and valid, but also cost-effective.
The technologies necessary to provide high-capacity factor electricity for this geo-engineering technique however, require lots of pumps. Although this is true of a number of diverse power technologies, BECCS and hydrogen require more pumps than other power generation options. This is illustrated on a comparison per kW, see Figure 2.
BECCS has twice the CO2 reduction impact of nuclear due to removal of CO2 from the air prior to burning and sequestration. Solar and wind have a smaller impact on a net CO2 reduction basis per GW due to their lower capacity factors.
Pumps for Hydrogen Power Technology
In a green hydrogen plant, pumps are required for the purification and transport of water to the electrolyzer, a system used to separate hydrogen and oxygen atoms in H2O.
ETFE-lined Ansimag pumps or HMD Kontro metallic pumps deliver Potassium Hydroxide (and other chemicals used for pH control) within electrolyzer skids. Sundyne’s magnetic drive sealless pumps even feature a compact footprint (with no seals or seal support systems), which is critical in managing skid space constraints. Sealless pumps also eliminate the danger of emissions or leaks.
If utilizing blue hydrogen, which is derived from methane in natural gas, the process involves many pumps. For example, the production of ammonia with carbon capture and sequestration requires several process-vital pumps. While external gear, progressive cavity, screw, and radial/axial piston pumps have gained some acceptance for use in the various liquidtransfer processes common in fertilizer production, plunger pumps are still often a better choice, especially when used for the injection of ammonia water in the ammonization process. For this reason, IDEX Corken’s positive displacement sliding vane pump is used in many ammonia applications.
Other companies like Yara are planning to manufacture ammonia in Australia to be used as a turbine fuel in Japan. For this process, carbon sequestration will eliminate CO2 emissions. Then, the ammonia will be transported and combusted. Each of these steps involves big pump investments.
Pumps in BECCS Power Technology
Pumps are essential to the entire BECCS bioengineering process, starting at the wood pellet plant. Pumps are used in both the processes of size reduction and pelletizing of the wood, and reducing stack emissions from the pelletizing operation using scrubbers. Once processed, the wood pellets are shipped to a power plant where they substitute for coal as the fuel.
If it is a coal-fired plant, such as Drax, in North Yorkshire, England, several types of pumps are used for energy production. This includes pumps used to manage the boiler feed pumps, water intake, and cooling.
Within BECCS power technology, pumps are also used to control air and water pollution, including in the fluegas sulfurization (FGD) systems. Additionally, carbon capture technology utilizes another set of pumps, including the amine absorber pumps, which absorbs hydrogen sulfide and carbon dioxide to convert sour gas into sweetened gas.
Once captured, the CO2 must be transported to a permanent storage site. Currently, the most economical method for transporting large volumes of CO2 is via pipeline. To make this possible, the CO2 is converted into a high-pressure, super-critical fluid called dense phase. In this phase the CO2 behaves more like a liquid than a gas, allowing it to be pumped. Flowserve offers several radially and axially split pumps for dense phase CO2 transportation.
One method of CO2 sequestration involves injection into geological reservoirs. The most economically viable of these is enhanced oil recovery (EOR), where CO2 is injected into active oil fields to increase production. The gas can also be injected into unusable saline aquifers and depleted oil and natural gas reservoirs. Regardless of the method, Flowserve offers high-pressure, axially split pumps and highly engineered, high-energy double-case pumps for injection.
The Advantages of BECCS
BECCS has a number of advantages. The most obvious is that it is carbon negative. If all the coal-fired plants in the world were converted to BECCS, global CO2 levels could be reduced. This option eliminates the tipping point worry.*
*The tipping point worry phenomena occurs when global temperatures exceed a critical threshold, causing advanced and irreversible environmental damage.
Another advantage is the cost. The only other carbon negative technology is Direct Air Capture. The cost of this option, however, is quite high. BECCS, on the other hand, can utilize existing coal plant steam generators and pollution control systems. The major capital cost is in the actual carbon capture and sequestration process.
The biggest advantage of BECCS is the potential of utilizing a staged approach, or the easy, slow implementation of BECCS processes in existing coal plants. The stages to implement BECCS are as follows:
• Co firing biomass at existing coal plants.
• Complete conversion to biomass.
• Partial carbon capture and sequestration or usage.
• Full carbon capture and sequestration or usage.
The Drax power plant in the UK is already moving from stage to stage. Though they are now at stage two, engineering and construction is underway for stage three.
This flexible approach is very desirable due to the uncertainties about CO2 impacts. The program can be accelerated if some of the more dire predictions materialize. The net zero program will result in modest growth in the market for power plant pumps over the next 30 years.