|
Ⅹ.Analysis
and Test Methods
-
TEMPERATURE-PROGRAMMED
TECHNIQUES AND THEIR APPLICATIONS
Zhang
Xiwen Ling Fengxiang Sun Wanfu
Abstract
This
paper elucidates the characteristics of
temperature-programmed techniques, including automated
chemisorpmetry (AUTOCHEM), differential thermal
analysis (DTA), differential scanning calorimetry
(DSC), thermogravimetry (TG), differential
thermogravimetry (DTG), programmed-temperature gas
chromatography (PTGC), microreactor and
high-temperature X-Ray difframetry (HTXRD). It also
introduces the applications of temperature-programmed
desorption（TPD）,temperature-programmed
reduction (TPR）,
temperature-programmed oxidation (TPO),
temperature-programmed sulfidation（TPS）and
temperature-programmed reaction in determining
properties of samples .
-
STUDY
ON STRUCTURAL CHARACTERISTICS OF RESIN AND ASPHALTENE
IN SHENGLI RESIDUE WITH U.V. ABSORPTION SPECTROMETRY
Qi
Bangfeng Zhang Huicheng
Abstract
Based on the relevant theory, the U.V. absorption
spectrometry and second derivative spectra of resins
and asphaltenes in Shengli residue were analyzed and
compared with those of model compounds to characterize
their chemical structures. The results indicated that
the unit with polycyclic aromatics is the basic
structure in resins and asphaltenes. The structure and
the coloring groups in resins and asphaltenes are
similar. The unit mainly has three or four rings, and
the arrangement of conjugated aromatic rings are
mainly linear, namely linear-condensed structure.
There is still structural difference between
asphaltene and resin, t he unit in asphaltenes
contains some conjugated aromatics with over five
rings , but it does not in resins. And he unit in
asphaltenes partly are arranged as a “plane”,
namely peri-condensed structure. Approximate
structural model of resins and asphaltenes was derived
from experimental results.
-
STUDY
OF MULTI-DIMENSIONAL GC METHOD FOR DETERMINATION OF
OXYGEN-CONTAINING COMPOUNDS IN CLEAN GASOLINES
Wang
Lijun Cheng Zhongqian Yu Yaqin
Abstract
A
study of multi-dimensional GC (gas chromatography)
technique for determining oxygen-containing compounds
was carried out. The split ratio, displacement time of
valve and other influential factors were investigated
and the optimal conditions were determined. Besides,
The accuracy and precision of the method were
verified. By means of this method, the content of
oxygen-containing compounds in gasolines can be
determined rapidly and accurately.
-
METHOD
FOR SIMULTANEOUS DETERMINATION OF VARIOUS METALLIC
ELEMENTS IN CRUDES AND HEAVY CRUDES
Zhao
Ronglin Xu Zhaoming
Abstract
Method
for simultaneous determination of 14 metallic
elements, such as Fe, Ni, Cu, V, Pb, Al, Na, K, Ca,
Mg, Mn, Mo, Co and Zn in crude oils and heavy crudes,
by using ICP-AES technique has been studied. The total
recovery of the elements was 97%-107% after the
samples pretreated by dry-ashing method. The relative
standard deviation was less than 10% when the method
was used to determine the samples with a content of
the elements over 1mg/l.
-
DETERMINATION
OF BENZENE AND TOLUENE IN FOOD-GRADE ICROCRYSTALLINE
WAX WITH HEADSPACE GAS CHROMATOGRAPHY
Qi
Bangfeng Zhang Huicheng
Abstract
The
headspace gas chromatography was used to
quantitatively analyze the remainder benzene and
toluene in microcrystalline waxes by using the
external standard method. The food-grade white oil was
selected as blank solution for preparing a series of
standard samples. The standard curve was designed
according to peak area as X-coordinate and remainder
benzene and toluene as Y-coordinate under the selected
conditions. The curve represents the content of
remainder benzene and toluene in the range of 10～2000μg/kg
has a linear correlation with the peak area. The
detection limit is 5μg/kg.
-
FACTORS
INFLUENCING ON THE DETERMINATION OF GASOLINE
COMPONENTS BY FLUORESCENT INDICATOR ADSORPTION
Zhao
Bin Qi Bangfeng Cai Xiudang
Abstract
Effect
of silica gel, adsorption column, fluorescent
indicator, oxygen-containing compound, sample
depentanization and the other factors on the
determination of gasoline components was studied. Main
influence factors were found with the standard sample
to improve precision and practicability of the method.
The experimental results showed that the pore volume
of silica gel and the depentanization of samples are
the main factors which influence the determination of
gasoline components. The test results for saturated
hydrocarbons decrease and that for olefins increase as
the pore volume of silica gel increases. Gasoline with
high content of C2～C5
should be depentanized by using SH/T 0062 test method.
-
STUDY
OF SULFUR-CONTAINING COMPOUNDS
IN
DIESEL OILS BY GC/AED
Wang
Shaojun Ling Fengxiang Wu Hongxin
Abstract
The
production of clean diesels by hydrotreating and deep
hydrodesulfurization (HDS) has attracted an increasing
attention recently due to the introduction of new
environmental regulations regarding fuel
specifications. A well-understanding of
sulfur-containing compounds existing in diesels is
useful to clarify the reaction mechanism under
conditions of deep HDS, to get information about
catalyst development, and to optimize the process of
HDS. In the paper, capillary gas chromatography
coupled with an atomic emission detector (GC/AED) was
used for the qualitative and quantitative analyses of
sulfur-containing compounds in middle distillates. The
changes of sulfur-containing compounds present in
various diesels before and after HDS were
investigated. The distribution and relative
concentrations of sulfur-containing compounds were
different for both diesels from Kechangsan and Jinshan
oils. So it is necessary to use different catalysts
and/or technologies to treat them. The removal
efficiencies of different sulfur-containing compounds
depended on number，size
and location of the substituting groups, and the
removal of steric hindered sulfur-containing molecules
was observed to be a key issue for deep HDS. Knowledge
of the individual sulfur types is both important for
developing new catalysts and optimizing processes.
|
