Abstract Booklet 2006 - Swanson School of Engineering - University ...

commercial-scale gasifier was shutdown for routine maintenance of which the
Mössbauer spectroscopy technique will be described here. Representative samples
from the gasifier were extracted after sufficient cooling was done to allow the safe
turn-out of the gasifier. In the coal samples that entered the gasifier, pyrite was the
abundant Fe-containing mineral, whilst the pyrite changed gradually to form, in
conjunction with the SiO 2 and Al 2 O 3 present in the coal, a Fe-containing glass and
hematite at the bottom, or ash grate of the gasifier.
50-4
Uneven Distribution of Sulfurs and Their Transformation during Coal Pyrolysis
Baoqing Li, Fenrong Liu, Wen Li, Haokan Chen, Chinese Academy of Sciences, P.R.
CHINA
Two Chinese coals, Liuzhi high pyrite coal with high ash content (LZ) and Zunyi high
organic sulfur coal (ZY), were pyrolyzed in a fixed-bed reactor under nitrogen and
hydrogen at temperature ranging from 400 to 700ºC. The effects of heat rate,
temperature and gas atmosphere on sulfur transformation and sulfur uneven
distribution were examined by XPS combined with traditional sulfur analysis method.
The ratio of surface S to bulk S is used to describe the uneven distribution of sulfurs. It
is found that oxygen is rich on the surface, while S in the bulk. The increasing ratio of
surface S to bulk S with increasing temperature clearly indicates the sulfur transfer
from the bulk to the char surface during pyrolysis. The ratios are higher at all
temperatures studied for ZY coal than for LZ coal, which may be related to the higher
ash content in LZ coal. The ratio of surface S to bulk S increases with increasing
heating rate for LZ coal, while it decreases for ZY coal. In the presence of H 2 , the S on
the surface is much lower than that under N 2 and surface S in sulphidic, thiophenic and
sulfoxide forms is totally disappeared for LZ coal at various temperatures and heating
rates, while the surface S in thiophenic and sulfoxide forms is not totally disappeared
for ZY coal, which may be related to the high rank of ZY coal. The ratio of surface S
to bulk S decreases before 600ºC with increasing temperature for both coals in the
presence of H 2 , showing that gaseous H 2 can easily react with the surface S to form
H 2 S, while above 600ºC it increases because the supply of H 2 cannot match the rate of
formation of HS· free radicals at high temperature.
50-5
Advanced Carbon Foams from Coal
Drew Spradling, Touchstone Research Laboratory, USA
Carbon foams manufactured from bituminous coal feedstocks have seen increasing
application in composites manufacturing and in naval shipbuilding, due to the unique
properties of these lightweight materials. In the unique manufacturing process,
pulverized coal is converted into a lightweight, high strength, open cell carbon foam
with highly uniform pore size distribution, and tailorable electrical and mechanical
properties. A state-of-the-art manufacturing facility is being commissioned and large
cross-sections of carbon foam are being consistently produced on a limited commercial
volume scale. Many advanced applications ranging from aerospace composites to
naval shipbuilding have been demonstrated through subscale component qualification
testing. As an example, carbon foam is being tested as a potential material for the new
Navy DDX class warship. Prototype testing in the deckhouse composite structure is
underway, with the carbon foam providing low radar cross-section, corrosionresistance,
excellent electromagnetic shielding effectiveness, and the ability to meet
fire, toxicity, and smoke requirements. The material has been demonstrated that it can
be integrated into the ship s planned composite and steel structures. In the development
of the carbon foam materials, extensive coal chemistry studies were performed, leading
to a comprehensive understanding of the controlled coking nature of the manufacturing
process. During manufacturing, the fluid and devolatilization properties of the coals
are manipulated with precise control of the heating, pressure, and atmosphere variables
necessary to produce large quantities of highly uniform foam. High pressure autoclaves
and atmosphere furnaces have been custom designed for this unique manufacturing
process. Extensive characterization of the different carbon foam grades produced,
allows for advanced material application such as those found in the aerospace and
defense industries. Mechanical, electrical, and acoustical properties of the foam were
extensively characterized, leading to the selection of appropriate application in areas
where conventional materials are inferior. A brief overview of the carbon foam
production process, as well as some of the unique applications of this advanced carbon
material will be presented.
SESSION 51
MATERIALS, INSTRUMENTATION, AND CONTROLS – 3
51-1
Studies on the Preparation of Mesophase Pitchs by Thermal
Conversion of a FCC Slurry
Xiaolong Zhou, Jing Chen, Guoxian Yu, Cheng-lie Li, East China University of
Science and Technology, P.R. CHINA
Minglin Jing, Zuo Zhang, Shanghai Institute of Technology, P.R. CHINA
Ordered mesophase pitch was prepared by thermal polymerization of a fluid catalytic
cracking (FCC) slurry stock. Thermal conversion experiments were performed on a
multi-tube well-shape crucible programmed heated furnace. Optical microscope
observation and solvent extraction separation were used to elucidate formation
behaviors of ordered mesophase. It has been indicated from our work that there are
three steps, i.e., containing the formation of the mesophase micro-crystal, the growth
of mesophase micro-crystals and the coalescence of mesophase spherules. The former
two steps are slow, whilst the last is a fast one. In addition, a novel tubular reactor
reducing in the central section was designed to guide the ordered growth of mesophase
spherules under the oriented flowing gas stream by thermal cracking. The optical
structure observation showed that anisotropic mesophase fibrous structures were first
formed radial-in-ward around the reaction tube wall. At prolonged time on stream
(TOS), such structures further developed from the wall toward the centre of the tube
and thus form a ring-shape structure.
51-2
Effect of KOH in Preparation of Activated Carbon with Low Ash Content and
High Specific Surface Area from Law Rank Bituminous Coal
Jin Lei, Qiang Xie, China University of Mining and Technology, P.R. CHINA
An experimental study on the effect of K-containing compounds in preparation of coalbased
activated carbon was conducted in this paper. KOH was used in the cocarbonization
with coal, changes in graphitic crystallites in chars derived from
carbonization of coal with and without KOH were analyzed by X-ray diffraction
(XRD) technique, activation rates of chars with different contents of K-containing
compounds were deduced, and resulting activated carbons were characterized by
nitrogen adsorption isotherms at 77 K and iodine numbers. The results showed that the
introduction of KOH into the coal feedstock before carbonization can realize the
intensive removal of inorganic matters from chars under mild conditions, especially for
the efficient removal of dispersive quartz, an extremely difficult separated mineral
component in other processes else. Apart from this, KOH demonstrates a favorable
effect in control over coal carbonization with the goal to form nongraphitizable
isotropic carbon precursor, which is a necessary prerequisite for the formation and
development of micro pores. However, the K-containing compounds such as K 2 CO 3
and K 2 O remaining in chars after carbonization catalyze the reaction between carbon
and steam, which leads to the formation of macro pores. In the end an innovative
method, in the light of which KOH is added in coal feedstock before carbonization and
K-containing compounds are removed by acid washing after carbonization, was
proposed for the synthesis of coal-based activated carbon with ash content less than
10% and specific surface area more than 1600 m 2 /g.
51-3
Effect of the Coking-Coal Property Change on Blend
Quality and Coke Microstructure
Gaifeng Xue, Peng Chen, Shangchao Liu, Wuhan Iron and Steel
Corporation, P.R. CHINA
By studying the vitrinite reflectance and its distribution, technical indexes of the single
coal and blended coal for coking in WISCO in recent years, it was discovered that the
single coal quality changed obviously, especially the metamorphism, its changes
obviously affected blended-coal qualities and coke microstructure.
51-4
Experimental Research on Coke Braise as a Cokemaking Additive
Shizhuang Shi, Wuhan University of Science and Technology, CHINA
Xueying Zhou, Wuhan Iron and Steel Corporation, P.R. CHINA
The experiment of suitability of coke braise with coking coal was carried out firstly
and then cokemaking experiment, coke braise as an additives and petroleum coke for a
comparison, was carried out in a semi-commercial scale. The influence of particle size
and its distribution, proportion of coke braise and property of coke-oven charge on
coke quality was researched. The experimental results show that there is a good
suitability between coking coal and coke braise; For high quality of coke, the particle
size of coke braise should be less than 0.45mm. The addition of 3% coke braise is
feasible under the condition of routine production in Coking plant of WISCO. The
effect of addition of 3% coke braise is superior to the effect of addition of 3%
petroleum coke.
51-5
Study of CH 4 -H 2 O In Coke-Oven Reforming to Produce
Syngas Catalyzed by Carbon Catalyst
Yongfa Zhang, Wei Zhao, Huawei Zhang, Xiling Miao, Yan Liang, Guojie Zhang,
Yaling Sun, Kechang Xie, Taiyan University of Technology, P.R. CHINA
Coke-oven gas that contains mainly 57~62% H 2 , 25~28% CH 4 , and ~6% CO is a high
quality hydrogen resource. However, coke-oven gas that contains more organic sulfur
such as COS, thiophene S, and more tar can not be converted into syngas easily by Nicatalyst
process. Based on this limitation a new kind of catalyst, carbon catalyst for
reforming CH 4 .in coke-oven gas to syngas was studied. The research of CH 4 -H 2 O (in
45