The effect of CO2 partial pressure on the regeneration energy consumption of different solvents

https://doi.org/10.3390/pr9122184

“The process simulation results shown in Figure 7 can verify the effect of CO₂ partial pressure on the regeneration energy consumption of different solvents. The solubility curve of primary amine MEA has the largest slope, which means that the change in CO₂ partial pressure has little effect on CO₂ loading. When the partial pressure is increased from 1 to 10 kPa, the CO₂ loading is almost unchanged. Therefore, it can be predicted that the increase of the CO₂ partial pressure of flue gas has no effect on the energy consumption of 40 wt.% MEA. When the partial pressure is increased from 5 to 15 kPa, the reboiler energy consumption is only reduced by about 0.1 GJ/tCO₂. The slope of the solubility curve of HEPZ and DMEA is the smallest, so the change of CO₂ partial pressure has a greater impact on CO₂ loading. The CO₂ partial pressure of flue gas was increased from 5 to 15 kPa, and the energy consumption of 30 wt.% HEPZ was reduced from 2.7 to 2.4 GJ/tCO₂, a reduction of approximately 11%. The energy consumption of 30 wt.% DMEA decreases more with the increase of the CO₂ partial pressure. When the partial pressure increases from 5 to 15 kPa, the energy consumption decreases from 3.8 to 3.05 GJ/tCO₂, a reduction of nearly 20%. For 40 wt.% 1-MPZ and 40 wt.% AMP, the slope of the solubility curve is between 40 wt.% MEA and 30 wt.% DMEA, so the reduction in energy consumption as CO₂ partial pressure increases is between 40 wt.% MEA and 30 wt.% DMEA. When the CO₂ partial pressure is increased from 5 to 10 kPa, the reboiler energy consumption of 40 wt.% 1-MPZ and 40 wt.% AMP are reduced by about 0.3 and 0.2 GJ/tCO₂, respectively. When the partial pressure is increased from 10 to 15 kPa, the energy consumption of 1-MPZ and AMP reboilers does not change significantly. The CO₂ partial pressure of flue gas mainly affects Qcon, and has almost no effect on Qabs and QT.”

“Figure 7. The effect of CO₂ partial pressure on the regeneration energy consumption of different solvents: (a) 40 wt.% MEA, (b) 30 wt.% DMEA, (c) 40 wt.% 1-MPZ, (d) 40 wt.% AMP and (e) 30 wt.% HEPZ.”