Demonstrating CO2 capture efficiencies from 98% to 99.95% in continuous operation for an AMP/PZ-based solvent
article
Since the economic optimum of amine-based CO2 capture processes is generally achieved at CO2 capture effi ciencies between 85 and 95%, it is sometimes misbelieved that general technical limits exist to elevate the capture efficiency. At the CO2 capture pilot plant at Niederaussem the key performance data of CO2 capture with capture efficiencies from 98 to 99.95% have been assessed in four testing campaigns (24/7) with a total testing time of 7200 h using the CESAR1 solvent, an aqueous solution of 3.0 M 2-amino-2-methylpropan-1-ol (AMP) and 1.5 M piperazine (PZ). 47 different tests of parameter settings and process configurations have been carried out with aged and fresh CESAR1 to validate process models based on the ProTreat® process simulator software for highest capture efficiencies with regard to the effect of solvent flow, desorption temperature, intercooler posi tioning, and active absorber length (3 or 4 sections of structured packing). For fresh CESAR1, operation with 4 active sections (16 m) and solvent regeneration at 120 ◦C, the specific energy demand increased by ca. 50% for raising the capture efficiency from 95.0% (2951 MJ/kg CO2, CO2 concentration in the depleted flue gas 8210 ppm) to 99.95% (4440 MJ/kg CO2, 91 ppm). To control effectively the emissions of the CESAR1 solvent and minimise amine-contaminated waste streams, the combined operation of the dry bed configuration and an acid wash was demonstrated. The simulations were able to represent the pilot plant data of aged CESAR1 well. The predictions of volatile emissions were generally in good agreement with measured data. Since the emission model does not comprise aerosol-based emissions a slight underprediction occurs.
Topics
TNO Identifier
1025448
Source
Chemical Engineering Journal(529), pp. 1-16.
Pages
1-16