13 research outputs found

    Solvent Degradation and Emissions from a 0.7MWe Pilot CO\u3csub\u3e2\u3c/sub\u3e Capture System with Two-Stage Stripping

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    The UKy-CAER team successfully tested an advanced 0.7 MWe post-combustion CO2 capture system on a coal-fired power plant using a heat integration process combined with two-stage stripping to enhance the CO2 absorber performance. One of the unique feature of the UKy-CAER integrated process is a two-stage stripping unit for solvent regeneration. The secondary stripper is empowered by the heat rejection from a conventional steam-heated (primary) stripper. The secondary stripper outlet stream at the commercial scale can be used as boiler secondary combustion air, consequently enriching the flue gas with CO2, resulting in less energy penalty required by the CO2 capture system. The primary goal of this study was to form an initial assessment of the impact on the amine solvent from coal combustion flue gas contaminants and the potential higher oxygen content in the solvent due to incorporation of the secondary air stripper into the conventional amine scrubber/stripper system. The overall oxidative degradation was comparable to previous reports with 30 wt% MEA solvent at similar flue gas run hours. This suggests that the addition of the secondary air stripper appears to be negligible with regards to solvent oxidation

    Impact of Flue Gas Contaminants on Monoethanolamine Thermal Degradation

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    The buildup of flue gas contaminants in amine-based postcombustion CO2 capture processes is an important concern due to its potential impact on solvent degradation and reclaiming. In this research, in order to explore the impact of flue gas contaminants on solvent thermal degradation, sodium nitrite, fly ash, sodium sulfate, and sodium thiosulfate were each added into carbon-loaded 5.0 M monoethanolamine (MEA) solution and the solutions were exposed to high-temperature degradation conditions. MEA degrades significantly more in the presence of nitrite (5000 ppm) than MEA alone at the same amine mole concentration. The MEA degradation activation energy of MEA–nitrite solution is calculated and found to be approximately one-seventh of that of MEA solution without nitrite. Addition of nitrite not only enhanced generation of several MEA thermal degradation products but also induced formation of diethanolamine (DEA) and N-(2-hydroxyethyl)piperazin-3-one (HEPO), which have been known to form during MEA oxidative degradation. Interestingly, fly ash was observed to inhibit nitrite-induced MEA degradation and greatly increase the MEA degradation activation energy of MEA–nitrite solution. This led to a reduction in accumulation of several degradation products. Fly ash, sodium sulfate, and sodium thiosulfate by themselves were not shown to impact MEA thermal degradation rate

    Data from: Multiscale factors affecting human attitudes toward snow leopards and wolves

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    The threat posed by large carnivores to livestock and humans makes peaceful coexistence between them difficult. Effective implementation of conservation laws and policies depends on the attitudes of local residents toward the target species. There are many known correlates of human attitudes toward carnivores, but they have only been assessed at the scale of the individual. Because human societies are organized hierarchically, attitudes are presumably influenced by different factors at different scales of social organization, but this scale dependence has not been examined. We used structured interview surveys to quantitatively assess the attitudes of a Buddhist pastoral community toward snow leopards (Panthera uncia) and wolves (Canis lupus). We interviewed 381 individuals from 24 villages within 6 study sites across the high-elevation Spiti Valley in the Indian Trans-Himalaya. We gathered information on key explanatory variables that together captured variation in individual and village-level socioeconomic factors. We used hierarchical linear models to examine how the effect of these factors on human attitudes changed with the scale of analysis from the individual to the community. Factors significant at the individual level were gender, education, and age of the respondent (for wolves and snow leopards), number of income sources in the family (wolves), agricultural production, and large-bodied livestock holdings (snow leopards). At the community level, the significant factors included the number of smaller-bodied herded livestock killed by wolves and mean agricultural production (wolves) and village size and large livestock holdings (snow leopards). Our results show that scaling up from the individual to higher levels of social organization can highlight important factors that influence attitudes of people toward wildlife and toward formal conservation efforts in general. Such scale-specific information can help managers apply conservation measures at appropriate scales. Our results reiterate the need for conflict management programs to be multipronged

    Thermal Degradation of Amino Acid Salts in CO2 Capture

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    The resistance of amine-based CO2 capture solutions to thermal degradation is a critical characteristic that helps to determine their potential for use as a post-combustion CO2 capture solvent. In this research, sodium salts of glycine, sarcosine, alanine and β-alanine were thermally degraded at 125 °C, 135 °C and 145 °C, respectively, to discover the structural reasons for their thermal stability. These four amino acids have enhanced thermal degradation rates compared to reference monoethanolamine (MEA) solvent. The stability order for amino acid salts tested to date is: sarcosinate \u3e alaninate \u3e β-alaninate. Steric hindrance at the amine group plays a positive role in protecting the amino acid against degradation. Calculated activation energies for the degradation processes are lower than that of MEA. β-Alaninate (β-Ala) thermal degradation generates β-Ala dimer (major degradation product), β-Ala dimer carbamate and tetrahydro-1,3-oxazin-6-one. The relative yields of these three β-alanine degradation routes are discussed

    Multiscale factors affecting human attitudes toward snow leopards and wolves-Dataset

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    Sheet 1: Contains the meta data describing all the column heads of sheet 2. Sheet 2 contains the raw data. Column heads describe the values contained within them. Rows are individual observations (interviews)

    Algal nanobionics to enhance value added products – A review

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    Microalgae nanobionics is a new field of study that combines nanotechnology and plant biology. Microalgae are single celled, photosynthetic organisms that live in saltwater or freshwater and convert solar energy to chemical energy through the process of photosynthesis. The site of photosynthesis in plants is the chloroplast. Chloroplast traps the sunlight and converts it into the form of energy or food for algae cells. By acting as an artificial photosynthetic system to boost photosynthetic capacity, electron transport in the photosystems, pigment content, and light absorption across the UV–visible spectrum, nanobionics has been shown to benefit plants. As a result, the current study aims to review the nanobionics approach in plants and microalgae, their uptake and integration with chloroplasts, modulation in the photosynthesis process, and their effect on high value-added compounds in microalgae. Major challenges and potential opportunities related to the utilization of nanobionics are also briefly discussed

    Impact of Flue Gas Contaminants on Monoethanolamine Thermal Degradation

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    The buildup of flue gas contaminants in amine-based postcombustion CO<sub>2</sub> capture processes is an important concern due to its potential impact on solvent degradation and reclaiming. In this research, in order to explore the impact of flue gas contaminants on solvent thermal degradation, sodium nitrite, fly ash, sodium sulfate, and sodium thiosulfate were each added into carbon-loaded 5.0 M monoethanolamine (MEA) solution and the solutions were exposed to high-temperature degradation conditions. MEA degrades significantly more in the presence of nitrite (5000 ppm) than MEA alone at the same amine mole concentration. The MEA degradation activation energy of MEA–nitrite solution is calculated and found to be approximately one-seventh of that of MEA solution without nitrite. Addition of nitrite not only enhanced generation of several MEA thermal degradation products but also induced formation of diethanolamine (DEA) and <i>N</i>-(2-hydroxyethyl)­piperazin-3-one (HEPO), which have been known to form during MEA oxidative degradation. Interestingly, fly ash was observed to inhibit nitrite-induced MEA degradation and greatly increase the MEA degradation activation energy of MEA–nitrite solution. This led to a reduction in accumulation of several degradation products. Fly ash, sodium sulfate, and sodium thiosulfate by themselves were not shown to impact MEA thermal degradation rate

    ABCD2 is abundant in adipose tissue and opposes the accumulation of dietary erucic acid (C22:1) in fat[S]

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    The ATP binding cassette transporter, ABCD2 (D2), is a peroxisomal protein whose mRNA has been detected in the adrenal, brain, liver, and fat. Although the role of this transporter in neural tissues has been studied, its function in adipose tissue remains unexplored. The level of immunoreactive D2 in epididymal fat is >50-fold of that found in brain or adrenal. D2 is highly enriched in adipocytes and is upregulated during adipogenesis but is not essential for adipocyte differentiation or lipid accumulation in day 13.5 mouse embryonic fibroblasts isolated from D2-deficient (D2−/−) mice. Although no differences were appreciated in differentiation percentage, total lipid accumulation was greater in D2−/− adipocytes compared with the wild type. These results were consistent with in vivo observations in which no significant differences in adiposity or adipocyte diameter between wild-type and D2−/− mice were observed. D2−/− adipose tissue showed an increase in the abundance of 20:1 and 22:1 fatty acids. When mice were challenged with a diet enriched in erucic acid (22:1), this lipid accumulated in the adipose tissue in a gene-dosage-dependent manner. In conclusion, D2 is a sterol regulatory element binding protein target gene that is highly abundant in fat and opposes the accumulation of dietary lipids generally absent from the triglyceride storage pool within adipose tissue
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