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Xiangpeng Gao - One of the best experts on this subject based on the ideXlab platform.
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particulate matter emission from bio oil incomplete combustion under conditions relevant to stationary applications
Fuel, 2016Co-Authors: Chao Feng, Xiangpeng GaoAbstract:A raw bio-oil from biomass fast pyrolysis and a filtrated bio-oil, which was prepared from the raw bio-oil via syringe filtration to remove fine char particles, were atomized via an air-assist nozzle set and then combusted in a laboratory-scale drop-tube furnace (DTF) at 1400 °C under incomplete combustion conditions. Both air and oxygen (O2) atmospheres were considered to produce PM with aerodynamic diameter of <10 μm (PM10). Regardless of experimental conditions, it was found that the particle size Distributions (PSDs) of PM10 follow a bimodal Distribution. Under such incomplete combustion conditions, the PM10 samples apparently contain substantial amounts of carbonaceous material. Whereas the PSDs of Na, K, Cl and S (in the form of View the MathML sourceSO42-) exhibit a Unimodal Distribution, those of Mg and Ca in PM10 are dependent on combustion atmosphere, i.e. a Unimodal Distribution for air combustion and a bimodal Distribution for O2 combustion. The results show that under incomplete combustion conditions, the fine char particles in the raw bio-oil play significant roles in the emission of PM10 as well as Mg and Ca in PM10. The removal of the fine char particles in the raw bio-oil leads to considerable reductions in the mass of PM with aerodynamic diameters of 0.1–10 μm as well as that of Mg and Ca in the PM with a size range of 0.372–10 μm from the filtrated bio-oil combustion, compared to those from the raw bio-oil combustion. Combustion atmospheres also have significant effects on the emission and chemical composition of PM10 due to incomplete combustion. Switching combustion atmosphere from air to O2 increases the PM1 yield by ∼74.2% due to the increased yields of Na, K, Mg, Ca, View the MathML sourceSO42- and View the MathML sourcePO43- in PM1, but decreases the PM1–10 yield by ∼27.2%, apparently as a result of improved burnout and thereby decreased amounts of unburned carbonaceous material in PM1–10.
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Biochar as a Fuel: 4. Emission Behavior and Characteristics of PM1 and PM10 from the Combustion of Pulverized Biochar in a Drop-Tube Furnace
Energy & Fuels, 2011Co-Authors: Xiangpeng GaoAbstract:Six biochar samples were produced from both slow and fast pyrolysis of mallee bark at 400–550 °C, respectively; such temperatures are typically used for biochar and/or bio-oil production in practice. Under the pyrolysis conditions, the biochar yields range from 26.7 to 37.0% and the majority (78.5–100.0%) of alkali and alkaline earth metallic (AAEM) species (mainly Na, K, Mg, and Ca) in biomass are retained in the biochars, while the retention of Cl in biochars is only 2.0–33.4%. The raw biomass and its derived biochar samples were then combusted in a laboratory-scale drop-tube furnace (DTF) at 1300 °C to investigate the emission behavior and characteristics of sub-micrometer particulate matter (PM1) and PM with an aerodynamic diameter less than 10.0 μm (PM10). The particle size Distribution (PSD) of PM10 from raw biomass combustion has a bimodal size Distribution, while the PSDs of PM10 from biochar combustion generally show a Unimodal Distribution. Although most inorganic species are retained in the bio...
Changya Deng - One of the best experts on this subject based on the ideXlab platform.
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mechanistic insights into effect of feeding rate on soot formation during rapid pyrolysis of biomass model components in a drop tube furnace at high temperature
Proceedings of the Combustion Institute, 2020Co-Authors: Changya DengAbstract:Abstract This paper reports the significant effect of feeding rate on soot formation during rapid pyrolysis of water-washed cellulose and acid-washed lignin (denoted as W-cellulose and A-lignin, respectively) in a drop-tube furnace at 1300 °C and a residence time of ∼0.75 s in argon. Soot produced during W-cellulose pyrolysis has a Unimodal Distribution, with only a fine mode that its modal diameter increases from 0.043 to 0.246 µm as the feeding rate increases from 40 to 280 mg/min. However, at feeding rates of 12–200 mg/min, soot produced from A-lignin pyrolysis has a bimodal Distribution with two fine modes located at 0.077 µm and 0.246 µm, respectively. As the A-lignin feeding rate further increases from 200 to 280 mg/min, the fine mode at 0.077 µm disappears and the particle size Distribution of soot becomes Unimodal with only a fine mode with diameter of 0.246 µm. Increasing feeding rate increases the yield and particle size of total soot but decreases the yield of non-mature soot for W-cellulose at feeding rates
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a novel two stage alumina reactor system for burning volatiles generated in situ from biosolid effect of pyrolysis temperature and combustion conditions on pm1 emission
Energy & Fuels, 2018Co-Authors: Sui Boon Liaw, Changya DengAbstract:A novel two-stage alumina reactor system is developed for studying particulate matter (PM) emission from in situ volatiles combustion. It enables the generation of in situ volatiles at different pyrolysis temperatures (up to 1300 °C) and the subsequent combustion of in situ volatiles in air and oxyfuel at 1300 °C. It is found that the PM emitted from volatiles combustion contains only PM with aerodynamic diameter <1 μm (PM1) and has a Unimodal Distribution. An increase in pyrolysis temperature from 1100 to 1300 °C results in a substantial increase in PM1 yield and a shift of fine mode diameter from 0.043 to 0.108 μm. The PM1 emitted from the volatiles generated at 1100 °C mainly consists of Na, K, S, and P. For PM1 emitted from the volatiles generated at 1300 °C, there are substantial increases in the yield of Na, K, and P; in addition, Mg and Si are present in PM1 because of the release of these inorganic species from biosolid into the volatiles. For trace elements, increasing pyrolysis temperature from ...
Chao Feng - One of the best experts on this subject based on the ideXlab platform.
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particulate matter emission from bio oil incomplete combustion under conditions relevant to stationary applications
Fuel, 2016Co-Authors: Chao Feng, Xiangpeng GaoAbstract:A raw bio-oil from biomass fast pyrolysis and a filtrated bio-oil, which was prepared from the raw bio-oil via syringe filtration to remove fine char particles, were atomized via an air-assist nozzle set and then combusted in a laboratory-scale drop-tube furnace (DTF) at 1400 °C under incomplete combustion conditions. Both air and oxygen (O2) atmospheres were considered to produce PM with aerodynamic diameter of <10 μm (PM10). Regardless of experimental conditions, it was found that the particle size Distributions (PSDs) of PM10 follow a bimodal Distribution. Under such incomplete combustion conditions, the PM10 samples apparently contain substantial amounts of carbonaceous material. Whereas the PSDs of Na, K, Cl and S (in the form of View the MathML sourceSO42-) exhibit a Unimodal Distribution, those of Mg and Ca in PM10 are dependent on combustion atmosphere, i.e. a Unimodal Distribution for air combustion and a bimodal Distribution for O2 combustion. The results show that under incomplete combustion conditions, the fine char particles in the raw bio-oil play significant roles in the emission of PM10 as well as Mg and Ca in PM10. The removal of the fine char particles in the raw bio-oil leads to considerable reductions in the mass of PM with aerodynamic diameters of 0.1–10 μm as well as that of Mg and Ca in the PM with a size range of 0.372–10 μm from the filtrated bio-oil combustion, compared to those from the raw bio-oil combustion. Combustion atmospheres also have significant effects on the emission and chemical composition of PM10 due to incomplete combustion. Switching combustion atmosphere from air to O2 increases the PM1 yield by ∼74.2% due to the increased yields of Na, K, Mg, Ca, View the MathML sourceSO42- and View the MathML sourcePO43- in PM1, but decreases the PM1–10 yield by ∼27.2%, apparently as a result of improved burnout and thereby decreased amounts of unburned carbonaceous material in PM1–10.
Domínguez-petit R. - One of the best experts on this subject based on the ideXlab platform.
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First approach to the growth and age corroboration of Northeast Atlantic chub mackerel (Scomber colias) in northern Iberian Waters
'Elsevier BV', 2021Co-Authors: Navarro, M.r. Rosario), Landa J., Villamor B., Domínguez-petit R.Abstract:The growth pattern and parameters of Atlantic chub mackerel in Northern Iberian waters were analysed for the first time in this study, using otolith analyses (direct age estimation-DAE, back-calculation-BC and otolith marginal analyses) and length frequency analyses (Bhattacharya, SLCA and PROJMAT methods), on a time series of data from 2011 to 2017. Two main different growth patterns were obtained, one slower (DAE, BC and PROJMAT) and other faster (Bhattacharya and SLCA). Otolith marginal analyses showed an annual periodicity in the formation of one hyaline and one opaque edge, with a prevalence of the opaque edge from June to December, what in addition to the Unimodal Distribution of the annuli radii and the obtained back-calculated mean lengths, similar to those obtained by DAE, support the age estimation criteria used here. The growth parameters obtained from DAE (L∞: 45.34, k: 0.28, t0: -1.18) are proposed for the upcoming stock assessment process.Postprin
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Growth, age estimation and corroboration of northeast Atlantic chub mackerel (Scomber colias) in northern Iberian waters: a first attempt.
Centro Oceanográfico de Santander, 2021Co-Authors: Navarro, M.r. Rosario), Landa J., Villamor B., Domínguez-petit R.Abstract:Updated information on growth of Atlantic chub mackerel in several areas of its Distribution is required for the first stock assessment. Its growth pattern in Northern Iberian waters (2011-2017) is here analyzed with different approaches: those based on otoliths analyses (direct age estimation-DAE, back-calculation-BC and otolith marginal analyses) and those based on length frequency analyses (Bhattacharya, SLCA and PROJMAT methods). Two main different growth patterns are obtained, a "slow" one based on DAE, BC and LFDA from surveys; and a "fast" one based on Bhattacharya and LFDA from commercial landings. The divergence between both patterns begins to be evident at age 3 and older. Otolith marginal analyses that show an annual periodicity in the formation of the hyaline and opaque edge, the Unimodal Distribution of the annuli radius and the similarity of the back-calculated mean lengths to those obtained by DAE, support the age estimation criteria used in our analysis. The VBGF growth parameters (L∞=45.34, k=0.28, t0=1.18) obtained by otolith age estimation are available for the upcoming stock assessment process
Gilles Pagès - One of the best experts on this subject based on the ideXlab platform.
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optimal dual quantizers of 1d log concave Distributions uniqueness and lloyd like algorithm
Journal of Approximation Theory, 2021Co-Authors: Benjamin Jourdain, Gilles PagèsAbstract:Abstract We establish for dual quantization the counterpart of Kieffer’s uniqueness result for compactly supported one dimensional probability Distributions having a log -concave density (also called strongly Unimodal): for such Distributions, L r -optimal dual quantizers are unique at each level N , the optimal grid being the unique critical point of the quantization error. An example of non-strongly Unimodal Distribution for which uniqueness of critical points fails is exhibited. In the quadratic r = 2 case, we propose an algorithm to compute the unique optimal dual quantizer. It provides a counterpart of Lloyd’s method I algorithm in a Voronoi framework (see Lloyd (1957) and McQueen (1967)). Finally semi-closed forms of L r -optimal dual quantizers are established for power Distributions on compacts intervals and truncated exponential Distributions.
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Optimal dual quantizers of 1D log-concave Distributions: uniqueness and Lloyd like algorithm
2020Co-Authors: Benjamin Jourdain, Gilles PagèsAbstract:We establish for dual quantization the counterpart of Kieffer's uniqueness result for compactly supported one dimensional probability Distributions having a $\log$-concave density (also called strongly Unimodal): for such Distributions, $L^r$-optimal dual quantizers are unique at each level $N$, the optimal grid being the unique critical point of the quantization error. An example of non-strongly Unimodal Distribution for which uniqueness of critical points fails is exhibited. In the quadratic $r=2$ case, we propose an algorithm to compute the unique optimal dual quantizer. It provides a counterpart of Lloyd's method~I algorithm in a Voronoi framework. Finally semi-closed forms of $L^r$-optimal dual quantizers are established for power Distributions on compacts intervals and truncated exponential Distributions.
