Oil shale semicoke, formed in retort furnaces, is a source of severe environmental pollution and is classified as a dangerous
solid waste. For the industrial application of oil shale semicoke in combustion, this present work focused on the thermal
analysis of its combustion characteristics. The pyrolysis and combustion experiments of semicoke were conducted in a Pyris
thermogravimetric analyzer. From the comparison of pyrolysis curves with combustion curves, the ignition mechanism of semicoke
samples prepared at different carbonization temperatures was deduced, and was found to be homogeneous for semicoke samples
obtained at lower carbonization temperature, shifting to heterogeneous with an increase in the carbonization temperature.
The effect of carbonization temperatures and heating rates on the combustion process was studied as well. At last, combustion
kinetic parameters of semicoke were calculated with the binary linear regression method, showing that activation energy will
increase with increasing the heating rate.
An analysis developed in previous work has been further refined in order to study the effect of heat transfer on the heat
capacity and phase angle measurements by TMDSC. In the present model, a temperature gradient within the sample has been taken
into account by allowing for heat transfer by thermal conduction within the sample. The influence of the properties of the
sensors, the heat transfer conditions between the sensor and sample,and the properties of the sample have been investigated
by varying each parameter in turn. The results show that heat capacity measurements are reliable only within a restricted
frequency range, for which the experimental conditions are such that the heat transfer phase angle depends linearly on the
The dehydration process of Co(II), Cu(II)
and Zn(II) methanesulfonates was studied by thermogravimetry/derivative thermogravimetry
(TG/DTG) and differential scanning calorimetry (DSC) techniques in dynamic
N2 atmosphere. The TG/DTG curves show that all of them
contain four crystallization water molecules, which are lost in two steps.
The peak temperature and dehydration enthalpies ΔH
were measured from DSC curves for each compound. The effect of procedural
variables on the TG and DSC curves was investigated. In this work, the procedural
variables included heating rate, Al pan state (unsealed and sealed) and sample
In this paper, pyrolysis characteristics of oil shale obtained from
Huadian, China, are investigated by thermogravimetry method. The effect of
operating conditions, such as particle size, heating rate on the pyrolysis
process is analyzed, and kinetic parameters of pyrolysis at different heating
rates are calculated using a two-stage Arrhenius model that is solved by the
On the basis of these experimental results
and theoretical analysis, a mathematical model, fully suitable for the pyrolysis
characteristics of oil shale, is developed: mass loss rate is described by
a two-stage intrinsic kinetics equation for reducing the calculation error;
pyrolytic heat value of volatile is contained in energy equation, and density
equation is considered as well, due to the release of a large amount of volatiles
in pyrolysis process. Thermogravimetric experimental data are used to validate
the described models.
Combustion and pyrolysis experiments of Huadian oil
shale have been conducted using a STA409 thermogravimetric analyzer. The effect
of various factors on combustion of oil shale is studied. Particle size has
little effect on combustion process of oil shale; starting temperature of
combustion mass loss and ignition temperature of oil shale decrease with increasing
O2 concentration of ambient gas; increase of heating
rate can result in ignition temperature, burn-out temperature and maximum
rate of combustion mass loss increasing. Homogeneous ignition mechanism of
oil shale is ascertained using a hot state microscope.
energy was determined using Arrhenius model that is solved by Freeman–Carroll
method. Calculation results show activation energy will increase with heating
The thermal decompositions of dehydrated or anhydrous bivalent transition metal (Mn, Fe, Co, Ni, Cu, Zn, Cd) and alkali rare
metal (Mg, Ca, Sr, Ba) methanesulfonates were studied by TG/DTG, IR and XRD techniques in dynamic Air at 250–850 °C. The initial
decomposition temperatures were calculated from TG curves for each compound, which show the onsets of mass loss of methanesulfonates
were above 400 °C. For transition metal methanesulfonates, the pyrolysis products at 850 °C were metal oxides. For alkali
rare metal methanesulfonates, the pyrolysis products at 850 °C of Sr and Ba methanesulfonates were sulphates, while those
of Mg and Ca methanesulfonate were mixtures of sulphate and oxide.
Hydrated methanesulfonates Ln(CH3SO3)3nH2O (Ln=La, Ce, Pr, Nd and Yb) and Zn(CH3SO3)2nH2O were synthesized. The effect of atmosphere on thermal decomposition products of these methanesulfonates was investigated.
Thermal decomposition products in air atmosphere of these compounds were characterized by infrared spectrometry, the content
of metallic ion in thermal decomposition products were determined by complexometric titration. The results show that the thermal
decomposition atmosphere has evident effect on decomposition products of hydrated La(III), Pr(III) and Nd(III) methanesulfonates,
and no effect on that of hydrated Ce(III), Yb(III) and Zn(II) methanesulfonates.
Co-combustion experiments of mixture of Huadian
oil shale and Heshan coal with high sulphur content have been conducted using
a thermogravimetric analyzer. The effects of five different Ca/S mol ratios
on the combustion characteristics of mixture fuel are analyzed using TG and
DTG curves. The results show that the initial temperature of combustion of
mixture fuel is decreased with an increase in the oil shale content of mixture
fuel. The combustion characteristic of mixture fuel is superior to that of
Heshan coal. Adding about 20 mass% Huadian oil shale into Heshan coal is feasible
for desulfurization of mixture fuel during combustion.
Authors:Q. Xu, H. Fan, Z. Jiang, Z. Zhou, L. Yang, F. Mei and L. Qu
This research was aimed to study the cell wall degradation and the dynamic changes of Ca2+ and related enzymes in developing aerenchyma of wheat root under waterlogging. An examination of morphological development by light and electron microscope revealed that the structure of cell wall in middle cortical cells remained intact after 12 h of waterlogging and turned thinner after waterlogging for 24 h. At 48 h, the aerenchyma has been formed. The cellulase activity gradually increased in middle cortical cells within 24 h of waterlogging, and decreased with the formation of aerenchyma. Fluorescence detection and subcellular localization of Ca2+ showed the dynamic changing of Ca2+ at the cellular and subcellular levels during the development of aerenchyma. The activity of Ca2+-ATPase enhanced markedly in intercellular space, plasma membrane and tonoplast of some middle cortical cells after 8 h of waterlogging and remained high after 24 h, but it decreased after 48 h of waterlogging. All these suggests that cellulase, Ca2+ and Ca2+-ATPase show a dynamic distribution during the aerenchyma development which associated with the cell wall degradation of middle cortical cells. Moreover, there is a feedback regulation between Ca2+ and Ca2+-ATPase.
Authors:M. Jiang, Z.Q. Xaio, S.L. Fu and Z.X. Tang
Fluorescence in situ hybridization (FISH) can reveal minor structural differences of chromosomes. The karyotype of common wheat (Triticum aestivum L.) based on FISH pattern is seldom reported. In this study, non-denaturing FISH (ND-FISH) using Oligo-pSc119.2-1, Oligo-pTa535-1 and (AAG)6 as probes was used to investigate the chromosomal structure of 85 common wheat including 83 wheat-rye 1RS.1BL translocation cultivars/lines, a wheatrye 1RS.1AL translocation cultivar Amigo and Chinese Spring (CS). Two, three, two, three, six, three and four structural types respectively for 1A, 2A, 3A, 4A, 5A, 6A and 7A chromosomes were observed. Two, eight, two, two, four and six types of chromosome for 2B, 3B, 4B, 5B, 6B and 7B were respectively detected. The structure of 1B chromosomes in Amigo and CS is different. Five, two, two and two types of chromosomal structure respectively for 1D, 2D, 3D and 5D were distinguished. Polymorphisms of 1RS.1BL, 4D, 6D and 7D chromosomes were not detected. Chromosomes 1AI, 2AI, 3AI, 4AI, 5AIII, 6AI, 7AIII, 2BI, 3BV, 4BI, 5BII, 6BIII, 7BI, 1DIV, 2DI, 3DI and 5DII appeared in these 85 wheat cultivars/lines at high frequency. Each of the 85 wheat cultivars/lines has a unique karyotype. Amigo is a complex translocation cultivar. The FISH karyotype of wheat chromosomes built in this study provide a reference for the future analyzing wheat genetic stocks and help to learn structural variations of wheat chromosomes. In addition, the results in this study indicate that oligonucleotide probes and ND-FISH technology can be used to identify individual wheat cultivar.