A review of potential routes to zero and negative emission technologies via the integration of renewable energies with CO2 capture processes

The global concentration of CO 2 in the atmosphere is increasing rapidly. CO 2 emissions have an impact on global climate change. Carbon dioxide capture technologies have been proposed as a promising alternative to reducing CO 2 emissions from fossil fuel power plants with post-combustion capture. Amine-based chemical absorption is considered the most industrially developed technology for this kind of process. In this work, a strategy for defining the relationships between design and the operational policies in CO 2 capture technologies is addressed. The solution to the problem consists in maximizing the percentage of the CO 2 removal, while the stripper reboiler duty is minimized. Since both objective functions in conflict, a multi-objective optimization approach is proposed to achieve a trade-off. Moreover, due to the highly non-ideal behavior in the heat and mass transfer phase, a fully rigorous model was used to capture this strongly non-linear behavior. In addition, an economic evaluation of the heating and cooling utilities in the stripper according to the operation process is carried out. The results show the importance of considering the significance between the influence of operating variables (i.e., temperature, liquid solvent flow rate, and operating pressure) on the amount of CO 2 removed and the associated reboiler duty. It shows that both optimal operating policies can be traded-off. Finally, with 30 wt% of MEA solvent, the compromise solution presents a 77% CO 2 capture with an energy consumption of 4.98 GJ/t of CO 2 for the reboiler service, a cost of heat utilities per year of $3971 capturing 142.29 kg/h of CO 2 . • Optimal design of absorption-based CO 2 capture process with amines is addressed. • Multi-objective analysis considering energetic, economic, and environmental aspects. • CO 2 capture maximization and amine regeneration reboiler duty minimization analysis. • Utopia tracking approach is used for reaching a trade-off solution. • The operating cost of the process is evaluated in terms of energy requirements. 

Multi Objective Optimization of the amines- CO2 Capture Absorption-Desorption Process by a Non-Equilibrium Rate Model

The foremost purpose of this review study is to summarize the potential of solar thermal energy in coal-fired power plants retrofitted with post-combustion carbon-capturing (PCC) system to mitigate carbon dioxide gas. The integration of the PCC system in coal-fired power plants required thermal energy for solvent regeneration in the reboiler . This thermal energy is supplied by the steam bleeding from the turbine and it causes a reduction in the thermal efficiency of the power plant as well as electricity production, which is termed as energy penalty. Thus, the integration of solar thermal energy in PCC retrofitted coal-fired plants is utilized to eliminate the energy penalty by offsetting the thermal energy requirement of the reboiler. Also, it seems to be a suitable method of introducing renewable energy to existing power plants. This review paper discusses different post-combustion techniques, their integration with solar thermal energy along with integration types, economic and environmental impacts, benefits and challenges. • Identify the need for carbon capturing Technologies in coal fired power plants . • Solar-assisted post combustion carbon-capture system is discussed in details. • Economic and Environmental aspects of the carbon-capturing system are highlighted. • Summarized the existing Solar-assisted post combustion carbon-capture system. 

Solar-assisted post-combustion carbon-capturing system retrofitted with coal-fired power plant towards net-zero future: A review

Numerical study on stratification performance of cascaded three-layered packed-bed in the thermal storage process

One of the concerned aspects in the design of molten salt packed-bed thermal energy storage (TES) tank with encapsulated phase change materials (EPCMs) is to evaluate the creep damage because of molten salt tanks have to withstand elevated temperature and stress level in charging and discharging processes. This paper aims at estimating the creep damage and investigating the effects of EPCM particle properties on creep damage performance of EPCM-TES tank. First, a commercial scale molten salt EPCM-TES tank applied in 50MWe tower plant is designed. Second, a method to evaluate the creep damage of packed-bed tank in service life is developed based on the integration model coupling FVM and FEM. Then, the effects of particle diameter and melting temperature of EPCMs on creep damage are discussed. Finally, a novel diameter-changed and melting temperature-changed two-layered EPCMs packed-bed structure with lower creep damage is proposed. The results are concluded as follows. (1) The creep damage of bottom wallboard is more significant than that of other wallboards in operation. (2) The EPCMs with smaller particle diameter or higher melting temperature is helpful to reduce the creep damage of tank. When particle diameter decreases from 42 mm to 20 mm or melting point rise from 365 °C to 395 °C, the creep damage of bottom wallboard can be reduced by 4.8 times and 58 %, respectively. (3) The creep damage of novel two-layered EPCM-TES configuration with lower creep damage time and stress is weaker than single-layered form. Compared with single-layered form filling with higher particle diameter and melting temperature of EPCMs, the creep damage of bottom wallboard in two-layered structure can be reduced by 53 %. This work can provide insights on the optimization design of the EPCM packed-bed TES configuration for lower creep damage in service life. 

Effects of EPCM particle properties on creep damage of the molten salt packed-bed thermal energy storage system

Solar-powered PCC: An upfront levy for sustainable carbon capture

Heat transfer enhancement and optimization are found to be essential for the PCM (phase change material) thermal energy storage design. In this work, the performance advantage of the packed bed PCM storage unit design is analyzed in comparison, and the impacts of key geometric parameters of a packed bed unit were numerically investigated. The optimized shell-and-tube design, based on the hexagonal circle configuration, serves as the benchmark for the comparison. The thresholds of the bed and PCM-capsule diameter ratio,D/d, is found, above which the effective energy storage capacity of the packed bed would be higher than that of an optimal shell-and-tube unit. The threshold of D/d can be quantitatively correlated to the superficial velocity of the heat transfer fluid, providing a pathway for the tailored design of a packed bed PCM thermal storage system. In conclusion, it was found that packed bed units are advantageous due to their larger surface-to-volume ratio, in particular in large-scale applications. This work proposes a numerical analysis based framework to design packed bed PCM storage units in comparison with shell-and-tube units so that a proper type of PCM thermal storage design can be selected under a specific geometric and operational condition. 

Ali Abbas

Papers

Solar-powered PCC: An upfront levy for sustainable carbon capture

Phase change material thermal energy storage design of packed bed units