Thermodynamics of NaHCO3 decomposition during Na2CO3-based CO2 capture

Amine-basedcarbon-capture technologies have been shown to be energetically expensive and to cause significant environmental and epidemiological impacts due to their volatility.Bicarbonate formation from carbon dioxide's reaction with water has been suggested as an effective alternative for capturing CO_2;however,the thermodynamics of this reaction are not well understood.This study experimentally determined the equilibrium constant of sodium bicarbonate(Na HCO_3)decomposition to sodium,water,and carbon dioxide;the study also compared the equilibrium constant to theoretical calculations.Using a combination of experimentation and thermodynamic relationships,the unitless equilibrium constants of the forward and reverse reactions were calculated accurately(error±9%and±4%,respectively).Equilibrium data were calculated using enthalpy and entropy values of each component of Na HCO_3decomposition at temperatures ranging from 25 to 155°C respectively.These results offer more data essential to optimizing Na HCO_3use in environmentally friendly nextgeneration CO_2-capture technologies.     

Chip-scale calorimeters: Potential uses in chemical engineering

This work illustrates the potential use of chip-scale calorimeters in typical applications found in chemical engineering including thermal hazard screening, material characterization, and mixing compatibility screening. Experimental results were obtained from two liquid nanocalorimeters and one thermal conductivity sensor designed and commercialized by Xensor Integration, and from two microfabricated calorimeter prototypes developed at Texas A&M University and University of Louisiana at Lafayette.     

Effects of ocean acidification, temperature and nutrient regimes on the appendicularian Oikopleura dioica: a mesocosm study

Increasing pCO₂ is hypothesized to induce shifts in plankton communities toward smaller cells, reduced carbon export rates and increased roles of gelatinous zooplankton. Appendicularians, among the most numerous pan-global “gelatinous” zooplankton, continuously produce filter-feeding houses, shortcutting marine food webs by ingesting submicron particles, and their discarded houses contribute significantly to carbon fluxes. We present a first mesocosm-scale study on the effects of temperature, pCO₂ and bloom structures on the appendicularian, Oikopleura dioica. There were effects of temperature and nutrients on phytoplankton communities. No shifts in functional phytoplankton groups, nor changes in particle sizes/morphotypes, known to impact appendicularian feeding, were observed under manipulated pCO₂ conditions. However, appendicularian abundance was positively correlated with increased pCO₂, temperature and nutrient levels, consistent with hypotheses concerning gelatinous zooplankton in future oceans. This suggests appendicularians will play more important roles in marine pelagic communities and vertical carbon transport under projected ocean acidification and elevated temperature scenarios.     

Do voluntary pollution reduction programs (VPRs) spur or deter environmental innovation? Evidence from 33/50

We study whether a government-sponsored voluntary pollution reduction program (VPR) promotes or deters the development of new environmental technologies that yield future emission reduction benefits. Using a panel of 127 U.S. manufacturing industries defined by 3-digit SIC classifications over the 1989–2004 period, we estimate impacts of industry-level participation in the 33/50 program, a VPR initiated by government regulators in 1991, on industry-level rates of environmental patenting. We find that higher rates of 33/50 program participation are associated with significant reductions in the number of successful environmental patent applications five to nine years after the program ended.     

Open and closed seascapes: where does habitat patchiness create populations with high fractions of self-recruitment?

Which populations are replenished primarily by immigrants (open) and which by local production (closed) remains an important question for management with implications for response to exploitation, protection, and disturbance. However, we lack methods for predicting population openness. Here, we develop a model for openness and show that considering habitat isolation explains the existence of surprisingly closed populations in high-dispersal species, including many marine organisms. Relatively closed populations are expected when patch spacing is more than twice the standard deviation of a species'. dispersal kernel. In addition, natural scales of habitat patchiness on coral reefs are sufficient to create both largely open and largely closed populations. Contrary to some previous interpretations, largely closed marine populations do not require mean dispersal distances that are unusually short, even for species with relatively long pelagic larval durations. We predict that habitat patchiness has strong control over population openness for many marine and terrestrial species with a highly dispersive life stage and relatively sedentary adults. This information can be used to make initial predictions about where populations will be more or less resilient to local exploitation and disturbance.