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In this work, the thermodynamics and kinetics of hydrate formation in 9.01 wt% tetra butyl ammonium bromide (TBAB) mixed with water-soluble hydroxylated multi-wall carbon nanotube (MWCNTol) systems were characterized by measuring hydrate formation conditions, induction time, and final gas consumption. The results showed that MWCNTols had little effect on the phase equilibrium of CO2 hydrate formation. Nanoparticles (graphene nanoribbons (GNs) and MWCNTols) could significantly shorten the induction time. When the concentration was ≤0.06 wt%, MWCNTols had a better effect on the induction time than the GN system, and the maximum reduction in induction time reached 44.22%. The large surface area of MWCNTols could provide sites for heterogeneous nucleation, thus shortening the induction time of hydrate formation. Furthermore, adding different concentrations of nanoparticles to the 9.01 wt% TBAB solution effectively increased the final gas consumption, and the maximum increase was 10.44% of the 9.01 wt% TBAB + 0.08 wt% GN system. Meanwhile, the suitable initial pressure and experimental temperature could also promote the hydrate formation and increase the motivation in hydrate formation. The 9.01 wt% TBAB + 0.02 wt% MWCNTol system had the best effect at 3.5 MPa and 277.15 K. The induction time was reduced by 66.67% and the final gas consumption was increased by 284.11% compared to those of the same system but at a different initial pressure and experimental temperature. This work helps to promote the industrial application of hydrate technology in CO2 capture and storage. [ABSTRACT FROM AUTHOR]

Multiple upwelling systems develop in the Indian Ocean during the summer monsoon. The Sri Lanka dome (SLD), which occurs in the open ocean off the east coast of Sri Lanka from June to September, is distinct from those near the coast. The SLD is characterized by uplifted thermocline and increased chlorophyll concentration. Mechanisms of the upwelling and its biogeochemical response are not well understood. Here, we explored the dynamics of the chlorophyll and sea-to-air CO2 flux in the SLD using ocean color and altimetry remote sensing data, together with other reanalysis products. We found that the occurrence of high chlorophyll concentration and sea-to-air CO2 flux happens along the pathway of the southwest monsoon current (SMC). The annual cycle of chlorophyll in the SLD has a one-month lag relative to that in the southern coast of Sri Lanka. The positive wind stress curl that forms in the SLD during the summer does not fully explain the seasonal chlorophyll maximum. Transport of the SMC, eddy activity, and associated frontal processes also play an important role in regulating the variability in chlorophyll. In the SLD, upwelled subsurface water has excess dissolved inorganic carbon (DIC) relative to the conventional Redfield ratio between DIC and nutrients; thus, upwelling and sub-mesoscale processes determine this region to be a net carbon source to the atmosphere. [ABSTRACT FROM AUTHOR]

• The RELAP5/MOD3.3 is modified with the implementation of the PbLi and CO 2 as working fluids and verified. • The modified RELAP5/MOD3.3 is applied to the COOL blanket outboard segment for preliminary accident analyses. • Thermal hydraulic requirements can be satisfied according to steady state and plasma pulse operation simulation of the COOL blanket. • The COOL blanket can endure 20% of plasma heat flux excursion during MARFE event. • Safety requirements of COOL blanket can be generally fulfilled during LOFA with different assumptions and then mitigation measures are suggested accordingly. The supercritical CO 2 cOoled Lithium-Lead (COOL) blanket is an advanced blanket candidate for the Chinese Fusion Engineering Testing Reactor (CFETR). The COOL blanket has dual coolant. Supercritical CO 2 (S-CO 2) is used to cool the structural components, while lithium-lead (PbLi) is self-cooling in the breeding zones. To verify the reliability of the COOL blanket, it is essential to conduct the accident analysis. The system code RELAP5/MOD3.3 is developed with implementation of the two working fluids of the COOL blanket, namely PbLi and CO 2. The outboard blanket segment of the COOL blanket is modeled using the modified RELAP5. The plasma pulse operation and fusion power excursion transient caused by Multifaceted Asymmetric Radiation From the Edge (MARFE) are simulated to study the thermal dynamic behavior of the COOL blanket. Furthermore, sensitivity analysis of Loss of Flow Accident (LOFA) is carried out. The results show that the outlet temperature of PbLi under steady-state operation meets its design requirements, and the temperature of the structural material does not exceed its temperature limit. The thermal hydraulic parameters have pulsed characteristics under plasma pulse operation. The MARFE event can cause sharp temperature rise of the First Wall (FW) but the material remains below its temperature limit. In case of LOFA of the CO 2 system, it is suggested to restore CO 2 mass flow rate in time to prevent the FW from overheating when the outlet temperature of PbLi is 973 K. The results of the preliminary accident analysis can provide the basis for the design and optimization of the blanket structure and system. [ABSTRACT FROM AUTHOR]

• Hydrate phase equilibrium in the presence of THT and different gas systems were measured. • Dissociation enthalpies for THT and different gas systems were determined. • THT's molar fractions were proved cannot affect the hydrate formation conditions. The phase equilibrium data of hydrate formation in tetrahydrothiophene (THT) and different gasses including CH 4 , H 2 , CO 2, and IGCC syngas(40 mol% CO 2 /60 mol% H 2) were measured in this work. The results show that the addition of THT remarkably reduces the CH 4 , H 2 , CO 2, and IGCC syngas hydrate formation conditions. Besides, for H 2 , CO 2 , and IGCC syngas, THT's effect in reducing hydrate formation conditions is slightly less than that in the system containing CP or 5.6 mol% THF. However, for the CH 4 gas, the hydrate formation conditions curve obtained from the system containing THT, 5.6 mol% THF and CP are almost similar. In addition, since THT is a water-insoluble promoter, the results proved that its molar fractions can not affect the hydrate formation conditions. Based on the phase equilibrium data we obtained, the dissociation enthalpies of hydrate formation in these systems were also determined via the Clausius-Clapeyron equation and its modified style. The hydrate dissociation enthalpies for THT + CH 4 , THT + H 2 , THT + CO 2, and THT + IGCC syngas are within 102.2 - 115.26 kJ•mol−1, 312.01 - 315.94 kJ•mol−1, 149.93–213.40 kJ•mol−1 and 160.19 - 181.02 kJ•mol−1, respectively. [ABSTRACT FROM AUTHOR]

• A conceptual design of the supercritical CO 2 cooled Lithium-Lead blanket has been proposed for CFETR. • Structural designs are carried out and analyses of neutronics and thermo-hydraulics are conducted. • Tritium Breeding Ratio of 1.183 and a PbLi outlet temperature of 600–700°C can be achieved. • Gross thermal efficiency is estimated to be 39%–46% by using the supercritical CO 2 recompressing cycle. A conceptual design of the supercritical CO 2 cOoled Lithium-Lead (COOL) blanket has been proposed as one advanced blanket candidate for the Chinese Fusion Engineering Testing Reactor (CFETR). At present, the COOL blanket is designed to fulfill the requirement of operating under the fusion power of 1.5 GW of CFETR while realizing the tritium self-sufficiency. Structural designs are carried out for outboard and inboard blanket segments and analyses with regard to neutronics and thermo-hydraulics are conducted to evaluate the blanket performance. Results indicate that a comparatively high Tritium Breeding Ratio (TBR) of 1.183 and a PbLi outlet temperature of 600 – 700°C can be achieved for this blanket concept. Besides, a Power Conversion System (PCS) based on the supercritical CO 2 recompressing cycle is preliminarily designed for the blanket and the gross thermal efficiency is estimated to be 39% – 46% when assuming the turbine inlet temperature ranges between 550°C and 650°C. [ABSTRACT FROM AUTHOR]