Energy Penalty For CO2 Capture Research Articles

Reducing the energy penalty of CO2 capture and compression using pinch analysis

Integration of CO2 capture and storage (CCS) into coal-fired power stations is seen as a way of significantly reducing the carbon emissions from stationary sources. A large proportion of the estimated cost of CCS is because of the additional energy expended to capture the CO2 and compress it for transport and storage, reducing the energy efficiency of the power plant. This study uses pinch analysis and heat integration to reduce the overall energy penalty and, therefore, the cost of implementing CCS for power plants where the additional heat and power for the CCS plant will be provided by the existing power plant. A combined pinch analysis and linear programming optimisation are applied to determine targets for the energy penalty of existing power plants. Two existing pulverised brown coal power plants with new CCS plants using solvent absorption are used as the basis for the study that show the energy penalty can be reduced by up to 50% by including effective heat integration. The energy penalty can be further reduced by pre-drying the coal.

Effect of Pressure on the Behavior of Copper-, Iron-, and Nickel-Based Oxygen Carriers for Chemical-Looping Combustion

The combustion process integrated by coal gasification and chemical-looping combustion (CLC) could be used in power plants with a low energy penalty for CO2 capture. This work analyzes the main characteristics related to the CLC process necessary to use the syngas obtained in an integrated gasification combined cycle (IGCC) power plant. The kinetics of reduction with H2 and CO and oxidation with O2 of three high-reactivity oxygen carriers used in the CLC system have been determined in a thermogravimetric analyzer at atmospheric pressure. The iron- and nickel-based oxygen carriers were prepared by freeze-granulation, and the copper-based oxygen carrier was prepared by impregnation. The changing grain size model (CGSM) was used for the kinetic determination, assuming spherical grains for the freeze-granulated particles containing iron and nickel and a platelike geometry for the reacting surface of the copper-based impregnated particles. The dependence of the reaction rates on temperature was low, with the activation energy values varying from 14 to 33 kJ mol-1 for the reduction and 7 to 15 kJ mol-1 for the oxidation. The reaction order depended on the reacting gas and oxygen carrier, with values ranging from 0.25 to 1. However, an increase in the operating pressure for the IGCC + CLC system increases the thermal efficiency of the process, and the CO2 is recovered as a high pressure gas, decreasing the energy demand for further compression. The effect of pressure on the behavior of the oxygen carriers has been analyzed in a pressurized thermogravimetric analyzer at 1073 K and pressures up to 30 atm. It has been found that an increase in total pressure has a negative effect on the reaction rates of all the oxygen carriers. Moreover, the use of the CGSM with the kinetic parameters obtained at atmospheric pressure predicted higher reaction rates than those experimentally obtained at higher pressures, and therefore, the kinetic parameters necessary to design pressurized CLC plants must be determined at the operating pressure.

Molecular dynamics studies of lattice vibrations of proton-ordered ice XI

We have developed a slurry of basic immobilized amine sorbent (BIAS) and polydimethylsiloxane (PDMS) oil for a CO2 adsorption/desorption process aided by the Microwave-Accelerated Regeneration of a Slurry (MARS). Selective microwave heating of CO2-adsorbed BIAS can accelerate the CO2 desorption flux by 10 times and consume much less energy for sorbent regeneration, compared to thermal heating. Furthermore, the microwave regeneration temperatures of the slurry can be lowered to 65–85 °C. These results indicate that the microwave-accelerated swing method is highly energy-efficient, which can substantially decrease the energy penalty for CO2 capture and downscale the capture process, especially the regeneration equipment. The microwave-assisted non-aqueous capture technology without water and steam use can decrease the cooling duty by 18–48%, compared to the aqueous amine-based capture technology and promote decarbonization in a more sustainable manner.