Total man-made CO2 emissions in the world today amount to approximately 30 gigatons per year, with fossil fuel based power stations contribute in excess of 30% total.
Carbon capture is energy intensive. Sulzer’s specialized technology allows the operator to minimize expenditures and power output losses that can result from poor designs.
High-efficiency mass transfer products reduce capital costs
Generally, only structured packing can meet the low pressure drop requirements for the design of a direct contact cooler and the CO2 absorber. Compared with random packing or trays, structured packing has a significantly lower pressure drop and better mass transfer efficiency which makes it ideal for these services. The resulting lower column diameters and packed bed heights translate into lower capital expenditure and lower operating costs.
Sulzer’s new MellapakCCTM structured packing absorbs CO2 more efficiently than conventional packings, particularly for post-combustion capture. Compared with MellapakTM 2X structured packing, MellapakCC provides a 20% higher efficiency and a 20% lower pressure drop. When compared with conventional Mellapak 250.Y structured packing, MellapakCC provides the same efficiency but up to 60% lower pressure drop.
Specialized structured packing excels at low liquid rates
In post-combustion capture, solvent emissions into the atmosphere from the top of the CO2 Absorber must be controlled in order to meet environmental regulations. The make-up water required to reduce the solvent emissions substantially (from ppm down to ppb range) is very low due to the low vapor pressure of most amine solvents. Low water rates result in specific liquid loads of less than 100 liters/m2 hr operating conditions where conventional structured packing shows significantly reduced efficiency. Sulzer has developed a new structured packing, AYPlus™ DC, which shows extraordinary wetting characteristics with aqueous systems. To handle such low liquid rates, a special liquid distributor (VEPK), was also developed. This combination of AYPlus DC structured packing and VEPK liquid distributor dramatically increases the separation performance, thus making it possible to realize “close to zero” solvent emissions at the top of the CO2 absorber.
Unique technical challenges require experienced designers
Carbon capture column diameters can reach 20 meters or more. Poor structural design or internals that cannot properly distribute gas or liquid across an extremely large cross-sectional area can create major increases in initial capital cost or serious operating problems. The installation of the vessel internals must be carefully considered to minimize the time and cost of field work. To effectively address the unique challenges related to these mega-size columns, an experienced mass transfer engineering company, like Sulzer Chemtech and Sulzer’s Field Services Group, is required.