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Estimation of solids circulation rate and char transfer rate from gasifier to combustor in a dual fluidized-bed pilot plant for biomass steam gasification

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Particuology 2019年第5期17卷 22-29页

作者： M. Hafizur rahman Lius Daniel Ujash shah Xiaotao Bi John r. Grace C.Jim Lim Fluidization research Centre Department of Chemical & Biological Engineering University of British Columbia 2360 East Mall Vancouver British Columbia V6T1Z3 Canada

Operation of a dual fluidized bed, consisting of a riser as combustor and bubbling bed as gasifier, for synthesis gas production from a solid fuel requires determination of the solids circulation rate and char transfer rate. The performance relies on supplying sufficient heat from the combustor to the gasifier by circulation of solids between these two reactors. The flow rate of char is required to track the heat generated in the combustor, which supports endothermic reactions in the gasifier. Direct measurement of these two critical parameters is difficult, with the number of reported techniques capable of working at high temperatures extremely small. An indirect method was developed, using mass and energy balances over the entire system and individual reactors, to estimate the solids circulation rate and char transfer rate. There was general agreement between heat losses estimated from energy-balance calculations and from direct measurement of the outer reactor surface temperature. Under typical gasification conditions, the solids circulation fluxes were estimated to be 45.2 and 55.6 kg/(m^2 s) in two independent tests, which were in good agreement with values obtained using a thermal tracer;char transfer rates were calculated to be 1.2 and 0.6 kg/h, which were in reasonable agreement with average biomass feed rates. This method can be applied to dual gasification systems at any temperature or flow rate.

关键词： solids circulation rate char transfer rate Pilot-plant gasifier Dual fluidized bed Mass and energy balance

Intraday Lead-Lag relationship between Index Futures and stock Index Markets:Evidence from Malaysia

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Journal of Modern Accounting and Auditing 2018年第10期14卷 561-569页

作者： Jude W. Taunson Mohd. Fahmi Bin Ghazali Minah Japang Abd. Kamal Bin char Universiti Malaysia sabah SabahMalaysia

This paper investigates the lead-lag relationship between the stock index futures(known as FKLI)and its underlying index,the Kuala Lumpur Composite Index(KLCI)in the emerging Malaysian *** 15-second interval data,cross-correlation,and the partial adjustment model,we find a bi-directional asymmetric lead-lag relationship and that the KLCI’s lead over FKLI is much *** evidence also suggests that the KLCI returns over-react to information,more so once thin trading effects are ***,the evidences suggest that traders prefer to exploit stock specific information in the underlying market despite the advantages of trading the index futures.

关键词： lead-lag relations index futures emerging market

characteristics of Chemical Modified Activated Carbons from Bamboo scaffolding

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Chinese Journal of Chemical Engineering 2012年第3期20卷 515-523页

作者： W.H.Cheung s.s.Y.Lau s.Y.Leung A.W.M.Ip G.McKay Department of Chemical and Biomolecular Engineering the Hong Kong University of Science and TechnologyHong KongChina scott Wilson Ltd 38th Floor MetroPlaza Tower 1Kwai FongHong KongChina

In this study, bamboo scaffolding was used to produce activated carbon by carbonization at 600 ℃ and 900 ℃with the purge of nitrogen. The 600 ℃ char was then further modified chemically by acids and alkalis by reflux for 6 hours. The produced chars were then characterized by nitrogen adsorption isotherm, He pyncometry, pH, elemental analysis and Boehm titration. For most of the chemically modified carbons, the micropore surface areas and volumes have increased compared with the 600 ~C char, while the mesopore surface areas and volumes slightly decreased, which may have been due to the dissolving of some of the permeated inorganic matter and oxidizing deposited carbon that blocks the pore openings. For the acidic modified carbons, larger amounts of acidic groups were present in the carbons after being activated by phosphoric acid, phosphoric acid furth, er treated with 2 mol-L-1nitric-acid, and calcium hydroxide. Although carbon treated with 2 mol.L-1 and 5 mol·L-1 nitric acid also produced high acidity, the surface areas and pore volumes were relatively low, due to the destruction of pores by nitric acid oxidation. The reduction of porosity may impair the adsorption capacity.

关键词： activated carbon bamboo surface area chemical activation porosity surface functional group

Genetic basis of heterosis and inbreeding depression in rice （Oryza sativa L.）

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Journal of Zhejiang University science 2004年第4期5卷 406-411页

作者： ALAMM.F. KHANM.r. NUrUZZAMANM. PArVEZs. sWArAZA.M. ALAMI. AHsANN PlantBiotechnologyLab DepartmentofBotanyUniversityofRajshahiRajshahi-6205Bangladesh

The genetic basis of heterosis was studied through mid-parent, standard variety and better parent for 11 quantitative traits in 17 parental lines and their 10 selected hybrids in rice (Oryza sativa L.).The characters were plant height,days to flag leaf initiation, days to first panicle initiation, days to 100% flowering, panicle length,flag leaf length, days to maturity, number of fertile spikelet/panicle, number of effective tillers/hill, grain yield/10-hill, and 1000-grain *** general the hybrids performed significantly better than the respective *** heterosis was observed for most of the studied characters. Among the 10 hybrids, four hybrids viz., 17A×45r,25A×37r,27A×39r,31A×47r,and 35A×47r showed highest heterosis in 10-hill grain yield/10-hill. Inbreeding depression of F2 progeny was also studied for 11 characters of 10 *** positive and negative inbreeding depression were found in many crosses for the studied characters,but none was found significant. selection of good parents was found to be the most important for developing high yielding hybrid rice varieties.

关键词： Heterosis Inbreeding depression rice

In-chamber thermocatalytic tar cracking and syngas reforming using char-supported NiO catalyst in an updraft biomass gasifier

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International Journal of Agricultural and Biological Engineering 2014年第6期7卷 91-97页

作者： Arthur M.James r Wenqiao Yuan Michael D.Boyette Donghai Wang Ajay Kumar Department of Biological and Agricultural Engineering North Carolina State UniversityRaleighNC 27695-7625USA Department of Biological and Agricultural Engineering Kansas State UniversityManhattanKS 66506-2906USA Department of Biosystems and Agricultural Engineering Oklahoma State UniversityStillwaterOK74078-6016USA

The objective of this study was to evaluate the performance of an in-chamber tar cracking and syngas reforming *** unit was composed of a two-stage tubular reactor placed within the combustion zone of an updraft biomass *** generated in the exothermic combustion reactions of biomass gasification drove tar cracking and syngas reforming in the tubes,eliminating the need of external *** performance of the unit was evaluated using char-supported NiO catalysts and was found to be very effective in tar removal and syngas composition enhancement.A tar removal rate of 95% was achieved at 0.3 s residence time and 10%nickel *** condition also gave syngas high-heating value increment of 36%(to 7.3 MJ/m^(3)).The effect of gas residence time and Ni loading on tar removal and syngas composition of the unit was also *** residence of 0.2-0.3 s and Ni loading of 5%-10% were found appropriate to produce clean syngas with tar content appropriate for industrial applications(raft biomass gasifier without external heating.

关键词： biomass gasification tar cracking syngas reforming nickel catalyst char catalyst

Conversion of residue straws Using Intermediate Pyrolysis for Decentralised Off-Grid Electricity Generation in India

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Conversion of Residue Straws Using Intermediate Pyrolysis fo...

Effects of Halloysite Nanotube reinforcement in Expandable Graphite Based Intumescent Fire retardant Coatings Developed Using Hybrid Epoxy Binder system

The 20th European Biomass Conference and Exhibition

作者： sagi,s. Patel,A.r. Apfelbacher,A. Tyagi,H. singh,H. Hornung,A.

Intermediate pyrolysis for biomass conversion is an existing alternative to off?grid electricity production from fossil fuel resources, which helps and supports local farmers, reduces the dependency on imports and creates by this way a long term sustainable and economical way of rural energy conversion. Use of agricultural residues, like wheat or rice straw for energy conversion, is the most effective measure in terms of costs and availability. The straw obtained from the field is milled and pelletized prior to the pyrolysis process. Pyrolysis tests are carried on a lab scale Pyroformer with wheat straw at a feed rate of 20 kg/h. The products of the process are the vapour and the char. The vapours are quenched using biodiesel as direct contact medium without any hot gas filtration. The process temperature was at 360 °C and the yields for the product fractions char, pyrolysis oil, and non?condensable gas fractions were, 33 %, 33 %, and 34 % respectively. The pyrolysis oil was condensed in a quenching unit using bio?diesel. The blend produced was 30 % pyrolysis liquid and 70 % bio?diesel. The blended oil has a heating value of 36 MJ/kg, and acidity of 4.8, no separate water fraction appeared.

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Chinese Journal of Polymer science 2018年第11期36卷 1286-1296页

作者： Qandeel Fatima Gillan Faiz Ahmad M.I.Abdul Mutalib Puteri s.M.Megat-Yusoff sami Ullah Mechanical Engineering Department Universiti Teknologi PETRONAS31750 TronohPerakMalaysia Chemical Engineering Department Universiti Teknologi PETRONAS31750 TronohPerakMalaysiac Department of Mechanical Engineering University of Gujrat50700 GujratPakistan

In this study, the effects of halloysite nanotubes （HNTs） reinforcement in expandable graphite based intumescent fire retardant coatings （IFrCs） developed using a polydimethylsiloxane （PDMs）/phenol BA epoxy system were investigated. Intumescent coating formulations were developed by incorporating different weight percentages of HNTs and PDMs in basic intumescent ingredients （ammonium polyphosphate/melamine/boric acid/expandable graphite, APP/MEL/BA/EG）. The performance of intumescent formulations was investigated by furnace fire test, Bunsen burner fire test, field emission electron microscopy （FEsEM）, thermogravimetric analysis （TGA）, transmission electron microscopy （TEM）, and Fourier transform infrared analysis （FTIr）. The Bunsen burner fire test results indicated that the fire performance of HNTs and PDMs reinforced intumescent formulation has improved due to the development of silicate network over the char residue. Improved expansion in char residue was also noticed in the formulation, sH（3）, due to the minimum decomposition of char carbon. FEsEM and TEM results validated the development of silicate network over char layer of coating formulations. A considerable mass loss difference was noticed during thermal gravimetric analysis （TGA） of intumescent coating formulations. reference formulation, sH（0） with no filler, degraded at 300 ~C and lost 50% of its total mass but sH（3）, due to synergistic effects between PDMs and HNTs, degraded above 400 ~C and showed the maximum thermal stability. XrD analysis showed the development of thermally stable compound mulltie, due to the synergism of HNTs and siloxane during intumescent reactions, which enhanced fire performance. FTIr analysis showed the presence of incorporated siloxane and silicates bonds in char residue, which endorsed the toughness of intumescent char layer produced. Moreover, the synergistic effect ofHNTs, PDMs, and other basic intumescent ingredients enhanced the polymer cross-linking in binder system an

关键词： Polydimethylsiloxane (PDMs) Halloysite nanotubes (HNTs) Intumescent fire retardant coatings (IFrC) Thermogravimetric analysis (TGA) Transmission electron microscopy (TEM)

Variation Trend and characteristics of Anthropogenic CO Column Content in the Atmosphere over Beijing and Moscow

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Atmospheric and Oceanic science Letters 2014年第3期7卷 243-247页

作者： WANG Pu-Cai Georgy s.GOLITsYN WANG Geng-Chen Evgeny I.GrECHKO Vadim s.rAKITIN Ekaterina V.FOKEEVA Anatoly V.DZHOLA Institute of Atmospheric Physics Chinese Academy of Sciences А.М.Оbukhov Institute of Atmospheric Physics Russian Academy of Sciences

The anthropogenic CO column content in the atmosphere is derived from measurements with infrared grating spectrometers in Beijing,China,and Moscow,russia,during 1992–*** specific variation characteristics and long-term variation trends of the CO column content in the atmosphere in these regions are *** evident variation trend of anthropogenic CO in the atmosphere for the Beijing region is not observed during 1992–2012,while for the Moscow region,it decreases yearly by about 1.4% for the same *** CO concentrations appear quite frequently in Beijing,but much less frequently in Moscow,except during the natural fire events in summer *** back trajectory analysis,the high CO concentration observed in Beijing can be attributed to the intensive CO emission sources in its surrounding areas.

关键词： anthropogenic CO column contentinfrared grating spectrometerair pollution

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环境友好型棉织物阻燃剂

国际纺织导报 2014年第4期42卷 39-40,43页

作者： s.Dasarwar C.r.Meena N.Khurana r.V.Adivarekar 何文卿化学技术研究院(印度)

随着含卤阻燃剂的缺点越来越为人所知,开发环境友好型阻燃剂已成为必然趋势。为此,近来科学家日益重视使用锡酸钠。将锡酸钠用作阻燃剂,研究其对LOI、炭化长度、燃烧时间和续燃时间的影响,同时研究阻燃剂配方中磷酸氢二铵及尿素对阻燃... 详细信息

随着含卤阻燃剂的缺点越来越为人所知,开发环境友好型阻燃剂已成为必然趋势。为此,近来科学家日益重视使用锡酸钠。将锡酸钠用作阻燃剂,研究其对LOI、炭化长度、燃烧时间和续燃时间的影响,同时研究阻燃剂配方中磷酸氢二铵及尿素对阻燃性能的影响。结果表明:经处理织物具有高阻燃性,LOI值为33%,同时对织物的物理性能影响小。

关键词：锡酸钠阻燃剂棉织物易燃性耐洗性