Spirax Sarco has delivered a comprehensive steam-driven heat exchange package for a ground-breaking carbon capture project at Ferrybridge coal-fired power station in Yorkshire. The Spirax Sarco system is a key element in the success of this cuttingedge project to develop large-scale technology to mitigate the environmental damage from burning fossil fuels.
Carbon Capture and Storage (CCS) technology aims to capture carbon dioxide from the flue gas of major emitters such as power stations and store it out of harm’s way, possibly by burying it in exhausted oil and gas reservoirs or saline aquifers.
The Ferrybridge project demonstrates the “capture” part of the process at a much larger scale than previous pilot schemes, using an amine-based solvent to absorb up to 100 tonnes of carbon dioxide per day. Spirax Sarco’s steam system is used to re-boil and regenerate the carbon dioxide saturated solvent for reuse by stripping the carbon dioxide out under carefully controlled high-temperature conditions.
The temperature and pressure in the clean-up column, or stripper, has to be controlled precisely. If the temperature is too high, the amine solvent breaks down. If it’s too low, the pressure in the column drops, which means it subsequently takes more energy to compress the carbon dioxide ready for transport and storage.
Steam is the ideal heating medium, because it helps provide very precise temperature control.
And according to project partner Doosan Power Systems, Spirax Sarco was the right choice to provide the steam system, because the company’s all-round steam expertise and project management capability meant that Spirax Sarco could deliver a skid mounted package and free Doosan’s team to work on other areas of this complex process design.
“Spirax Sarco has an excellent reputation in dealing with steam and condensate management,” says Scott Hume, Process Engineer at Doosan. “They supplied everything as a package, from the steam interface back to the condensate return line, including the heat exchanger. That simplified the scope of work for our team and it really helped.”
Spirax Sarco supplied everything needed to make the steam system run smoothly, including safety valves, pressure reducing valves, steam traps, heat exchanger, condensate receiving vessel and condensate return system.
The team was working under tight time constraints, but got the entire package designed, checked and built within 12 weeks. “We’ve absolutely no complaints about the performance of the Spirax Sarco package,” he adds. This is in spite of the fact that the system has been working extra hard, since the pilot plant has been using a standard amine solvent, which requires the steam heat exchanger to deliver a higher duty than the proprietary solvent that is still being developed.
“It’s doing a higher duty than it will when we move over to the new proprietary solvent and it’s still performing to the required specifications,” he says. Ferrybridge power station is operated by SSE plc, which has worked with partners Doosan Power Systems and Vattenfall R&D to build the carbon capture pilot plant.