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MATHEMATICAL OPTIMIZATION OF NON-COKING COAL INCLUSION IN COKING BLEND FORMULATIONS  [PDF]
A. A. Adeleke,P. Onumanyi,S.A. Ibitoye
Petroleum and Coal , 2011,
Abstract: Blend formulation to maximize the inclusion of non-coking coals with the scarce and expensivecoking coals is an essential practice in the steel industry. This study demonstrated the use ofMicrosoft Excel based on a blending model to obtain probable cokeable blends between sampleprime coking coals and non-coking Nigerian Lafia-Obi and Okaba coals; having high ash/sulphurand high volatile, respectively. The results obtained showed that optimal binary, ternary andquaternary probable cokeable blends are possible. A cokeable binary blend of 64.51% low volatile,high vitrinite reflecting Western Canada prime coking coal and 35.49% Okaba coal with a costreduction per ton of $61.56 was obtained. Also, a ternary blend of 74.04% medium volatile primecoking UK Ogmore coal produced an optimal cokeable blend including 19.22 and 6.74 percents ofLafiia-Obi concentrate and Okaba (as-received); respectively with a saving in cost per ton of$39.05. Furthermore, a quaternary blend comprising 40.35, 23.17, 23.17 and 13.30 percents oflow volatile Canada, medium volatile Ogmore, Lafiia-Obi concentrate and Okaba (as-received);respectively with a saving in cost per ton of $56.06 was realized. The results obtained showed thatvitrinite reflectance, coal beneficiation to reduce ash and sulphur contents and the use of a highvolatile coal as a blend component are critical factors in obtaining probable cokeable blends. If thelowest cost binary blend proves cokeable in confirmatory tests, the significant cost reduction ofabout 29.31% achievable will make cokemaking more economical and sustainable.
Enzymatic transesterification of palm stearin and olein blends to produce zero-trans margarine fat  [cached]
Sellami Mohamed,Ghamgui Hanen,Frikha Fakher,Gargouri Youssef
BMC Biotechnology , 2012, DOI: 10.1186/1472-6750-12-48
Abstract: Background Food industries aim to replace trans fat in their products by formulations having equivalent functionality and economic viability. Enzymatic transesterification can be a technological option to produce trans free fats targeting commercial applications. Results Palm stearin and palm olein blends in different ratios were enzymatically transesterified in a solvent free system using a Rhizopus oryzae lipase immobilised onto CaCO3 to produce a suitable fat for margarine formulation. Slip melting points and triacylglycerols profiles were evaluated upon transesterification. Results indicated that all transesterified blends had lower slip melting points than their non transesterified counterparts. Furthermore, the triacylglycerols profile showed a decrease in the concentration of the high melting point triacylglycerols. The rheological analysis showed that margarine prepared with the transesterified blend showed a better spreadability than that of a control margarine prepared with non transesterified fat. Adding powder of dry bark orange to margarine preparation improved its colour and fairly affected its spreadability and rheological behaviour. The margarine prepared with transesterified fat displayed a rheological behaviour that was comparable to that of commercial sample. Conclusions This study is an ecofriendly approach to the utilization of relatively low value bioresources like palm stearin and palm olein for making margarine free of trans fatty acids that are now implicated as risk factor for heart diseases.
Characterization of Ajaokuta Coke for Blast Furnace Ironmaking  [PDF]
A.O. Adeleke, R.S. Makan, S.A. Ibitoye
Journal of Minerals and Materials Characterization and Engineering (JMMCE) , 2006, DOI: 10.4236/jmmce.2006.52011
Abstract: The 300kg coke sample received from Ajaokuta Steel Plant was subjected to proximate analysis and pilot scale size distribution test. The proximate analysis showed that the coke contains 0.38%, 13.45%, 2.72% and 0.14% of moisture, ash, volatile matter and sulphur respectively; while size distribution test gave micum 10 and micum 40 of 3.62% and 89.67% respectively. Therefore, the coke satisfies the blast furnace requirements for moisture, sulphur and micum strength. However, its ash and volatile contents exceed the specified limits except for Indian standard practice.
Experimental study on the pyrolysis characteristic of coal blends using TGA-FTIR
用热重红外光谱联用技术研究混煤热解特性

ZHOU Jun-hu,PING Chuan-juan,YANG Wei-juan,LIU Jian-zhong,CHENG Jun,CEN Ke-fa,
周俊虎
,平传娟,杨卫娟,刘建忠,程军,岑可法

燃料化学学报 , 2004,
Abstract: The pyrolysis characteristics of the coals and their blends in an inertia atmosphere were investigated using a thermo-gravimetric apparatus with a on-line infrared-spectrum analyzer. The influence of coal rank, blend ratio and heating rate on the pyrolysis of coal blends was examined. The experimental results show that the pyrolysis characteristics of coal blends are similar to that of single coal, but the yield of gas is not the simple addition of single coal's. Due to the interaction of different coals of the blends, there is a difference in the gas yield between coals and the blends. By investigating the infrared spectrogram, it is discovered that the low rank coal has an important role in the pyrolysis of the blends. The beginning pyrolysis temperature decreases and the yield of gas increases with increasing the proportion of low rank coal.
The Effects of Blends of Enugu Coal and Anthracite on Tin Smelting Using Nigerian Dogo Na Hauwa Cassiterite  [PDF]
Fatai Afolabi Ayeni, OladunniOyelola Alabi, Rose Okara
Journal of Minerals and Materials Characterization and Engineering (JMMCE) , 2013, DOI: 10.4236/jmmce.2013.16052
Abstract: The effects of blending Enugu coal and anthracite on tin smelting using Nigerian Dogo Na Hauwa cassiterite have been studied. The work utilized various blends ranging from 100% to 0% anthracite. The content of the Enugu coal in the blend varied from 5% to 100%. The various tin metal recovery percentage for each batch of smelting using various blends was noted. Anthracite alone had the highest recovery of 71.90% followed by 5% blend of Enugu with anthracite. The result, however, showed that as the Enugu Coal was increased in the blend, the recovery was also decreasing. This equally affected the quality of tin metal recovered by increasing the grade. The work recommended that since the cost of production is the critical issue, 5% - 15% range of Enugu Coal should be used in preparing blends to bring down the cost of imported anthracite which is put at $906.69 per ton. The use of 15% Enugu coal will result in lowering the cost of imported anthracite by $136.0.
Thermal Behavior of Coal and Biomass Blends in Inert and Oxidizing Gaseous Environments  [PDF]
Ping Wang, Sheila W. Hedges, Kent Casleton, Chris Guenther
International Journal of Clean Coal and Energy (IJCCE) , 2012, DOI: 10.4236/ijcce.2012.13004
Abstract: Oxy-fuel combustion and gasification (pre-combustion) may have potential for capturing carbon dioxide at lower costs for power generation. Oxy-co-firing and co-gasifying coal with biomass could further reduce effective CO2 emissions and utilize renewable energy resources. A key feature of these two approaches is that they process fuel in concentrated CO2 or O2/CO2 instead of N2 or O2/N2. Accurate predictive models of these processes using blends of coal and biomass can be used in process simulation and could aid in the development and implementation of these technologies. To develop these accurate predictive models, it is important to understand the conversion routes and thermal behavior of these fuels in appropriate gas environments. The objectives of this study are to investigate the impact of inert and oxidative gaseous environments on thermal behavior and reactivity of coal and biomass blends and to study the effect of biomass percentage on coal/biomass blend co-utilization. Fuel samples included a Powder River Basin (PRB) sub-bituminous coal, yellow pine wood sawdust pellets, and mixtures of 10 and 20 weight percent wood in coal. The samples were tested under N2, CO2, and 10% O2 in CO2 by volume using a non-isothermal thermogravimetric method for temperatures up to 1000℃. Fuel weight losses of both coal and wood are essentially the same in CO2 as in N2 in the low temperature range, but higher in 10% O2 in CO2 compared to N2 and CO2. However, total weight losses at 1000℃ under CO2 and 10% O2 in CO2 are similar and higher than in N2 due to char gasification by the CO2 and combustion by O2. The char combustion in 10% O2 in CO2 takes place at lower temperature than char gasification in CO2. Coal and wood blends have higher reactivity compared to coal alone in the lower temperature range due to the high volatile matter content of wood. Interactions of wood and coal in these gas environments and blend percentage are discussed.
Study on the Reliability of Coke Research Establishment Micum 40 Formula to Predict Coke Micum 40 Strength at The Ajaokuta Steel Plant, Nigeria  [PDF]
A.O. Adeleke, A.O. Olulana, A.B. Adahama, R.S Makan, S.A. Ibitoye
Journal of Minerals and Materials Characterization and Engineering (JMMCE) , 2007, DOI: 10.4236/jmmce.2007.62011
Abstract: G-values of 0.97, 0.93, 0.94 and 1.01 were determined for Polish Bellview blend 1 (BV1), Polish Bellview blend 2 (BV2), Australian Agro-Allied blend (AA) and American Carbon Energy blend (CE), respectively. The coking duration of 18 hours, 17 hours, 16 hours and 22.5 hours, respectively were used to carbonize the coals each having volatiles 31.8%, 31.3%, 30.22%, and 21.90%, respectively. The Coke Research Establishment (CRE) formula predicted M40 micum strength of 77.98%, 77.12%, 77.55% and 92.05% for BV1, BV2, AA and CE blends, respectively. These predicted values were found to deviate from the experimentally determined M40 indices of 77.80%, 70.80%, 78.20% and 64.16% determined for BV1, BV2, AA and CE respectively by 0.18 units, 6.32 units, -0.65 units, and 27.89 units respectively. Thus, the best M40 index predicted was determined for BV1 blend with 0.97 G-value and 18 hours coking time with only a small allowable deviation of 0.18 units. The CRE formula has therefore been shown to be valid to predict M40 index of coke produced from coal blends with G-value of about 0.97 and carbonized at a moderate coking time of 18 hours. It has also been shown that the coking conditions that produce the best M40 index also produced the best M10 index.
Computations in DEA
Dulá, José H.;
Pesquisa Operacional , 2002, DOI: 10.1590/S0101-74382002000200005
Abstract: dea is a well-established, widely used, and powerful analytical resource in the toolbox of the or/ms analyst. it is used to assess relative efficiency of many, functionally similar, entities. it has applications in diverse areas including finance and banking, education, and healthcare. dea is computationally intensive and, as the scale of applications grows, this intensity rapidly becomes one of the limiting factors in its utility. in this paper, we explore computations in dea. we investigate the theory behind schemes, procedures and algorithms used in performing a dea study and we report on current practices ranging from the basic and standard to the advanced and sophisticated. our objective is to give researchers and practitioners an appreciation for the computational aspects of dea that will permit them to understand the performance, problems, complications, limitations, as well as the potential of this technique.
Computations in DEA  [cached]
Dulá José H.
Pesquisa Operacional , 2002,
Abstract: DEA is a well-established, widely used, and powerful analytical resource in the toolbox of the OR/MS analyst. It is used to assess relative efficiency of many, functionally similar, entities. It has applications in diverse areas including finance and banking, education, and healthcare. DEA is computationally intensive and, as the scale of applications grows, this intensity rapidly becomes one of the limiting factors in its utility. In this paper, we explore computations in DEA. We investigate the theory behind schemes, procedures and algorithms used in performing a DEA study and we report on current practices ranging from the basic and standard to the advanced and sophisticated. Our objective is to give researchers and practitioners an appreciation for the computational aspects of DEA that will permit them to understand the performance, problems, complications, limitations, as well as the potential of this technique.
CHARACTERIZATION OF EXTERNAL INDUCED CORROSION DEGRADATION OF AJAOKUTA-ABUJA GAS PIPELINE SYSTEM, NIGERIA  [PDF]
ADEDIPE OYEWOLE
International Journal of Engineering Science and Technology , 2011,
Abstract: Characterization of External Induced corrosion degradation of Ajaokuta- Abuja gas pipeline system was successfully carried out. The objective of this work is to analyze the mechanism of corrosion, analyze the effect of the corrosion on oil and gas pipeline and to evaluate the corrosion potential of a pipeline route. These were achieved by carrying out resistivity experiment on every one kilometer on the right of way (ROW) of the pipeline. Soil and water aggressiveness test was also carried out on soil and water sample of the pipeline route respectively. The resistivity result was considerably high, chemical analysis revealed that the soil and wateracidity is between the pH of 6.7 and 8.2 respectively, which is moderately alkaline in nature, which makes the soil environment not conducive for pipelines due to potential for corrosion attack. The chloride content of the soil and water were also high. Based on the experimental results, it was proposed that the pipe should be laid on2-5m below the ground and that the galvanic anode for cathodic protection be located 1m below the ground, in order to avoid corrosion. It is therefore necessary to note that characterization of external corrosion is quite different from internal pipeline corrosion characterization.
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