Post‐combustion CO₂ capture: chemical absorption processes in coal‐fired steam power plants

Abstract

The integration of a post‐combustion CO2 capture unit in a coal‐fired steam power plant leads to a reduction in net power output, where the largest contributors to the power loss are the heat requirement for the regeneration of the chemical solvent in the desorber of the CO2 capture unit (approx. 2/3) and the auxiliary power demand of the CO2 compressor (approx. 1/4). In this review, the layout of the overall process is explained and the interaction of the three sub‐processes power plant, CO2 capture process and CO2 compressor is discussed. The optimization of process parameters of the CO2 capture unit – such as solution flow rate and reboiler temperature – is intricate due to the complex interaction of the sub‐processes. It is shown that although the heat requirement for solvent regeneration has the largest impact on the power output of the overall process, the optimal process parameters that lead to the lowest possible heat requirement of the capture unit do not necessarily coincide with the optimal process parameters that make for the most energy efficient operation of the overall process. Therefore, when optimizing process parameters of CO2 absorption processes in power plants, one should focus on the minimization of the overall power loss instead of solely reducing the heat requirement for solvent regeneration. The described coherences are illustrated by the results of process simulations based on detailed models of a post‐combustion CO2 capture unit using 7 m (30 wt.‐%) monoethanolamine (MEA), of a supercritical, hard‐coal‐fired steam power plant and of a six‐stage, intercooled CO2 compressor. © 2012 Society of Chemical Industry and John Wiley & Sons, Ltd

Carbon dioxide uptake as ammonia and amine carbamates and their efficient conversion into urea and 1,3-disubstituted ureas

“…However, the critical questions facing this technology are the high energy costs of the amine regeneration and the environmental concerns because of the amine loss by thermal and oxidative degradation [12][13][14][15][16][17]. In comparison with aqueous alkanolamines, ammonia scrubbing process provides the advantage of high CO 2 loading capacity and absorption efficiency with no absorbent degradation [18][19][20][21][22][23][24][25].…”

Modeling and Evaluation of a Coal Power Plant with Biomass Cofiring and CO2 Capture

“…The results showed that the net electrical efficiency decreases with the increase of cofiring ratio. For plants with 15,30, and 60% biomass share in the fuel mix, the net efficiency decreases by approximately 0.2, 0.4, and 1.1% points, respectively, in comparison with the reference plant without cofiring, while for the case with 100% biomass firing the efficiency penalty is significant, i.e., 2.7% points. Further, it is worth mentioning that, because of the lower overall efficiency of cofiring plants, the total CO 2 emissions, expressed in kg/MWh of power generated, are higher.…”

“…The efficiency of coal-fired as well as biomass cofiring plants can be reduced by more than 10% points as a result of CO 2 capture by means of, for example, a MEA-based chemical absorption process [6,[12][13][14]. The reduction of power output is mainly caused by the extraction of large quantities of steam from the steam cycle of the power plant for amine solvent regeneration (~65% of total energy penalty) and the auxiliary power consumption for the compression of the CO 2 product (~25%) [15]. As mentioned earlier, compared to coal-fired plants, the plants with cofiring depending on the cofiring ratio, have efficiencies up to 1% points lower.…”

Assessment of Energy Use and Elimination of Co2 Emissions in the Life Cycle of an Offshore Wind Power Plant Farm

“…energy-material-informationtime, spent in a given activity [1,3,10,[13][14][15][16][17][18]. This can be expressed in different components in different units [26,31].…”

“…Justifying the choice of a normal distribution the consideration was carried out based on Figure 1, a) density f, b) the survival function F random size X of an average a and standard deviation d. To determine the probability that X reaches a value that is equal to or greater than a given value x, the field under density is determined/counted on the right of x and the value F for x: (15) In this case, it is characteristic that the normal distribution considered is a "light tail" distribution, i.e. X is reluctant to take values far from the mean a.…”