Small and bad

Carbon emission efficiency of thermal power in different regions of China and spatial correlations

“…Yan et al (2017) measured the carbon emission efficiency of China's power sector and reported that regional heterogeneity characteristics and agglomeration effects occur simultaneously. Purohit (2018) reported that small generation power plants are the worst emitters. Sun et al (2018) reported a new allocation method of carbon emission quotas to Chinese power enterprises based on carbon efficiency.…”

TiH2 as a Dynamic Additive for Improving the De/Rehydrogenation Properties of MgH2: A Combined Experimental and Theoretical Mechanistic Investigation

“…4 Thus far, no solid-state hydride system is known that can meet the US DOE target for hydrogen storage (5.50 wt % and 40 g/L on a system basis with reversible hydrogen storage). 1,3 MgH 2 is an attractive option as a solid-state hydrogen-storage material owing to its high hydrogen-storage capacity (gravimetric capacity of 7.60 wt % and volumetric capacity of 110 g/L) and reversibility in terms of reaction with H 2 . 6−9 Other attractive factors are high abundance of Mg in the earth's crust and its light weight.…”

“…The negative impacts of increasing levels of CO 2 in the atmosphere due to burning of fossil fuels have motivated a need to change the way we generate and store energy. Hydrogen is a promising nonpolluting energy carrier − and if generated from renewable or nuclear energy sources could lead to a decrease in CO 2 emissions.…”

“…However, hydrogen storage, especially for mobile applications such as fuel cell vehicles, is one of the most difficult challenges facing the hydrogen economy. − Out of all storage modes, solid-state hydrogen storage has the potential to provide twice as high volumetric hydrogen densities as in the liquid state and reversible gravimetric storage capacities up to ∼6 wt % H 2 . Thus far, no solid-state hydride system is known that can meet the US DOE target for hydrogen storage (5.50 wt % and 40 g/L on a system basis with reversible hydrogen storage). , MgH 2 is an attractive option as a solid-state hydrogen-storage material owing to its high hydrogen-storage capacity (gravimetric capacity of 7.60 wt % and volumetric capacity of 110 g/L) and reversibility in terms of reaction with H 2 . − Other attractive factors are high abundance of Mg in the earth’s crust and its light weight. − However, undoped MgH 2 has a high operating temperature for desorption, ≥400 °C, and slow hydrogen ab/desorption kinetics (1 wt % H 2 /min, at 300 °C) . Various approaches have been proposed to overcome these thermodynamic and kinetic difficulties, such as Mg-rich alloys, − MgH 2 -complex hydride composites, , and the use of effective additives/catalysts with MgH 2 . , …”