Carbonization of coals to produce anisotropic cokes. 1. Modifying activities of some additives in the co-carbonization of low-rank coals

Using low-rank coals, the modifying activities of some petroleum, coal tar and aromatic hydrocarbon additives have been examined to find procedures for their utilization in the preparation of blast furnace coke. Petroleum pitch, especially after hydrogenation, exhibited excellent modifying activity even with non-fusible coals. In contrast, the activity of coal tar was very limited with such coals. The napththenic component, revealed by n.m.r. of the additives, appears to be important in the co-carbonization by inducing fusibility and anisotropic development in such coals. Co-carbonization to recover the dehydrogenated additives was attempted. However, there was no development of the anisotropy in the resultant coke by dissolution of the coal particles although the coal particles were firmly fixed in the matrix. Acid-refluxing treatment of non-fusible coals was found to enhance their modification susceptibility, indicating that some of the acid-soluble mineral matter is important in the thermal depolymerization or fusion process of the coal.     

Bonding of solid additives in cokes from coals: a microscopy study

Cortonwood Silkstone (NCB class 401) and Betteshanger (NCB class 301 a/204) coals were co-carbonized with solid additives such as anthracite, coke breeze, green and calcined petroleum cokes. The resultant carbonization products (cokes) were examined by optical microscopy and SEM was used to investigate polished surfaces etched by chromic acid and fracture surfaces. For both coals only the anthracite and green petroleum coke become bonded to the coal cokes. This probably results from softening and interaction of interfaces of the anthracite and green coke with the fluid coal via a mechanism of hydrogenating solvolysis during the carbonization process. The coke breeze and calcined petroleum cokes were interlocked into the matrix of coal coke.     

The effect of additive chemicals on the viscosity of coal-petroleum coke-water slurry fuel for a gasification process

As a preliminary study for the gasification of an anthracite and petroleum coke mixture, viscosity was measured at various temperatures (20–50 °C), slurry concentrations (60–70 wt%) and additive amounts (0–0.8 wt%) by using an LV-II type viscometer. In addition, four types of different additives, sodium naphthalene sulfonate, poly(methyl methacrylate), polypropylene and a polypropylene glycol based additive, were applied to Korean anthracite, petroleum coke and mixtures of these materials, and the viscosity data were compared. Viscosity dependency values for coal, anthracite, bituminous and sub-bituminous coal, were compared, and it was found that a high content of moisture and particularly ash increases CWS viscosity. The four types of additives tested in this research can effectively diminish the viscosity of coal and especially petroleum coke-water slurry by more than 70% to 95%, respectively. Moreover, the sodium naphthalene sulfonate-based additive reduced the viscosity of coal and petroleum coke-water slurry best, especially at concentrations in excess of 65 wt%. Based on these results, highly loaded slurry created by mixing anthracite and petroleum coke with additives was achieved.     

煤与各种添加物共碳化的研究进展

综述了近年来世界各国钢铁公司焦化厂和实验室中煤与各种添加物如石油焦、石油沥青、煤焦油沥青、加氢残渣等共碳化炼焦技术的进展,指出煤与各种添加物的共碳化技术是有效节约炼焦煤资源、降低炼焦成本和提高焦炭质量的一种有效手段。     

Thermogravimetric study of coal and petroleum coke for co-gasification

As a preliminary study of gasification of coal and petroleum coke mixtures, thermogravimetric analyses were performed at various temperatures (1,100, 1,200, 1,300, and 1,400 °C) and the isothermal kinetics were analyzed and compared. The activation energies of coal, petroleum coke and coal/petroleum coke mixture were calculated by using both a shrinking core model and a modified volumetric model. The results showed that the activation energies for the anthracite and petroleum coke used in this study were 9.56 and 11.92 kcal/mol and reaction times were 15.8 and 27.0 min. In the case of mixed fuel, however, the activation energy (6.97 kcal/mol) and reaction time (17.0 min) were lower than the average value of the individual fuels, confirming that a synergistic effect was observed in the coprocessing of coal and petroleum coke. This work was presented at the 6 ^th Korea-China Workshop on Clean Energy Technology held at Busan, Korea, July 4–7, 2006.     

Carbonization of an anthracene oil extract of Akabira (Japan) coal

The carbonization of a non-hydrogenated extract (STC) from a low-rank coal (C, 83 wt%) of high fluidity was studied as single carbonizations and as co-carbonizations with additives, an objective being the production of needle-coke. The coke from STC had an optical texture of fine-grained mozaics; however, fractionation followed by co-carbonizations were effective in modifying carbonization properties. The lighter fraction of STC could give a coke with flow texture but in reduced yield. The addition of hydrogenated Ashland A240 pitch (HA240) in a quantity as low as 20% could effectively modify the carbonization properties of STC. A novel co-carbonization, in which an additive such as dihydroanthracene is recovered at the latter stage of the carbonization in the dehydrogenated form, was found to be effective also, although a relatively large amount of the additive was required. Among the non-hydrogenated additives, Ashland A240 pitch was the most effective in modifying the STC. The cocarbonization of fractionated STC reduced the quantity of additive required while maintaining a reasonable coke yield. Some practical aspects for the production of needle-coke from STC are discussed.     

基于配煤和表面修饰改善褐煤成浆性的研究

为改善褐煤成浆性,使其满足水煤浆气化需求,利用石油焦配煤,煤油作为表面修饰剂,研究改性方式对褐煤成浆性的影响。结果表明：（1）石油焦具有较强的疏水性,添加石油焦配煤显著提高褐煤的成浆浓度,且成浆浓度与石油焦占干基固体颗粒质量分数α（α>10.0%）正相关;（2）添加占干基固体颗粒质量β的煤油表面修饰配煤混合颗粒可以增强颗粒疏水性,进一步提高煤焦浆浓度,黏度随β先减小后增大,β最佳值与α（α>10.0%）负相关;（3）添加微量石油焦（α<1.0%）煤油悬浮液修饰时,可以提高煤油修饰效果,降低煤焦浆黏度η,α最佳值与β正相关。     

A Search for Ecofriendly Detergent/Dispersant Additives for Vegetable-Oil Based Lubricants

Carbonaceous deposits in automotive engines are the major problems associated with oil aging. Efficient detergents and dispersants have been used for several decades to solve this problem particularly in petroleum oils. But future lubricants and new engine hardware require development of new nontoxic detergent/dispersant additive technologies. Environmental concerns limit the formulation of the future lubricants. It requires not only the base oil to be ecofriendly but the additives also. In the present work, some of the potential ecofriendly chemical??s molecules were identified. Specific detergents applications along with effects of chemical modifications were evaluated by Blotters Spot and Panel Coker Tests. Among the studied compounds, the PIB (polyisobutylene) succinimides are showing promising results at lower temperature, while at higher temperature piperazine derivatives citrate and oleate have the best potential to be develop as ecofriendly detergent/dispersant additives.     

高硫石油焦气化研究进展和技术经济分析

分析我国高硫石油焦的生产现状和利用过程中存在的问题,对影响石油焦气化反应活性的因素、石油焦的催化气化和石油焦与煤或生物质共气化等方面的研究以及石油焦气化的工业应用进展进行了总结;探讨高硫石油焦配煤气化的可行性,对高硫石油焦配煤气化和干煤粉气化方案分别进行了模拟计算及技术经济分析,并与工业上掺烧高硫石油焦气化的运行结果进行了比较,与干煤粉气化相比,高硫石油焦配煤气化的比氧耗、比煤耗降低,有效合成气产量增加,具有较好的经济性;采用高硫石油焦配煤气化制取合成气既可以解决高硫石油焦的利用问题,又能拓宽煤气化的原料范围,是一条高效、清洁利用高硫石油焦的新途径。     

配入低阶煤炼焦对焦炭性能影响的研究

选用焦煤、1/3焦煤、肥煤、瘦煤、长焰煤进行配煤,堆密度为0.7g/cm3和1.0g/cm3,采用2kg焦炉炼焦,对焦炭的冷态强度和热态性能分析检测,探讨了堆密度及低阶煤加入量对焦炭性能的影响,结果表明,配入低阶煤后,焦炭的冷态强度及热态性能变差,配比小于5%时,影响较小,适当提高原料煤堆密度,焦炭的冷态强度及热态性能得到改善。     

干煤粉气化炉原料煤掺配高硫石油焦气化适应性研究

针对目前高硫石油焦利用率低的问题,选取两种典型高硫石油焦（JL、US）分别与AQ006煤掺配,考查了掺配两种焦的可磨性、灰熔融特性、黏温特性、CO2反应性,并进行了气化模拟计算。结果表明：两种石油焦具有低灰、低挥发分、高硫、高发热量等特点,且两种焦在不同掺配比例下,配煤的可磨性指数均高于80,是优质的粉煤气化配煤原料。AQ006煤分别掺配两种焦的灰熔融温度均高于1500℃,添加石灰石可有效降低掺配质量分数25%JL焦和US焦（焦∶煤=1∶3）的配煤灰熔融温度至1 400℃以下,且在石灰石质量添加量为6%时,两种掺配焦的高温灰渣黏度在2～25Pa.s的温度区间都高于200℃,满足Shell气化炉操作要求。与单独JL焦、US焦相比,配煤的CO2反应性显著提高。模拟计算结果表明掺配石油焦加助熔剂方案与中国石化安庆分公司Shell气化炉现用配煤方案相比,有效气产量增大,比氧耗和比煤耗有所下降。     

A semi-industrial scale study of petroleum coke as an additive in cokemaking

The addition of petroleum coke to a typical industrial coal blend used in the production of metallurgical coke was studied. Cokes were produced at semi-industrial scale at the INCAR coking plant, using petroleum coke of different particle size distribution as an additive. Special attention was paid to changes caused in the textural properties (porosity, pore size distribution, fissures at the interface between metallurgical coke and petroleum coke) which have been found to be responsible for variations in the metallurgical coke quality parameters (e.g., mechanical strength and reactivity towards CO₂). Variation in porosity was found to depend on particle size and the proportion of the additive. The decrease in the microporosity (i.e., pore radius<3.7 nm) of the metallurgical cokes observed when petroleum coke is added to the coal blend, is postulated to be one of the main factors responsible for the decrease in the reactivity of these cokes. The variation of the mechanical strength indices can be explained by the changes in porosity and the quality of the interfaces between petroleum coke and metallurgical coke.     

Characteristics of coal upgraded with heavy oils

We investigated the ability of an oil coating to upgrade Indonesian low-rank coal, which has a low ash content and a moisture content of approximately 30%. Proximate and ultimate analyses of the characteristics of coal samples containing different amounts of asphalt (ASP) and palm fatty acid distillate (PFAD) were studied, including the samples’ calorific values, crossing-point temperatures (CPT), specific surface areas, pore sizes, structural changes, and moisture readsorption. The results showed that the 0.5% PFAD-coated coal was the highest quality. This coal showed few physical and chemical changes, and it had a low surface area and a high CPT value.     

Rheological characteristics of coal tar and petroleum pitches with and without additives

An extensive study of rheological characteristics of coal tar and petroleum pitches with and without additives, namely, petroleum coke, natural graphite and carbon black has been made. It is found that all pitches, pure or mixed with a carbon additive are not Newtonian as reported in the literature, but behave Theologically as Bingham plastics with certain yield stress and plastic viscosity at all temperatures of measurement between 85–180°C. The yield stress and plastic viscosity both decrease with increase in temperature of the pitch. A pure petroleum pitch having the same softening point as that of a coal tar pitch is found to have a lower viscosity compared to that of the latter at all temperatures of measurement. This suggests that the criterion of softening point as a measure of suitability of a coal tar pitch binder in the manufacture of artificial carbon is not sufficient for petroleum pitches. Addition of ten parts of carbon black by weight of pitch results in a considerable decrease in viscosity change with temperature of the coal tar pitch compared to almost insignificant change in the case of the petroleum pitch of the same softening point. However, the addition of petroleum coke or natural graphite makes the pitch more viscous but does not change the temperature dependence of viscosity of either of the two types of pitches. The implications are discussed.     

不同炭质添加剂对块状活性炭强度和吸附性能的影响

为制备可净化空气的室内装饰性用块状活性炭,选择自制粉状活性炭(PAC)为吸附基体,羧甲基纤维素(CMC)为黏结剂,碳酸氢钠为发泡剂,考察生石油焦、煅后石油焦和竹炭3种炭质添加剂(CA)对块状活性炭强度和吸附性能的影响.结果表明:煅后焦替换自制粉状活性炭制备的试样机械性能提升最显著,自制粉状活性炭和煅后焦以1:1的比例作...     

Factors Affecting Quality of Dried Low-Rank Coals

The chemical and physical properties of coal are strongly affected by the upgrading process employed. For high-moisture coals, upgrading involves thermal dehydration to improve the calorific value of the coal on mass basis. This study evaluates the feasibility of upgrading a low-rank/grade coal using the oven drying method. The objective of this research work is to study the drying characteristics of low-rank coals and to understand the factors affecting the quality of dried low-rank coals. This article describes laboratory experiments conducted on the characterization of the low-rank coals before and after the drying process. The results on drying kinetics, re-absorption of coal samples, and proximate analysis of coal samples before and after drying are discussed. It was found that the upgrading process produced coal with better heating value and combustion characteristics than those of the raw coal samples.     

石油焦与煤粉燃烧性能差异的研究

石油焦作为石油工业副产品,具有低灰分质量分数、高挥发分质量分数、高发热值等特点,但对其燃烧价值的利用还很不充分。文中利用X射线衍射及扫描电镜对石油焦及烟煤和无烟煤进行微观结构的研究,同时利用热重分析方法对其燃烧性能进行系统研究发现:石油焦的芳香片层堆砌结构与无烟煤接近,但其丰富的气孔结构又有利于改善其燃烧过程。无烟煤中加入石油焦后,着火点温度从527℃降低到482.6℃;总质量分数从71.95%提高到76.82%,其燃烧效率得到提高。     

Factors Affecting Quality of Dried Low-Rank Coals

The chemical and physical properties of coal are strongly affected by the upgrading process employed. For high-moisture coals, upgrading involves thermal dehydration to improve the calorific value of the coal on mass basis. This study evaluates the feasibility of upgrading a low-rank/grade coal using the oven drying method. The objective of this research work is to study the drying characteristics of low-rank coals and to understand the factors affecting the quality of dried low-rank coals. This article describes laboratory experiments conducted on the characterization of the low-rank coals before and after the drying process. The results on drying kinetics, re-absorption of coal samples, and proximate analysis of coal samples before and after drying are discussed. It was found that the upgrading process produced coal with better heating value and combustion characteristics than those of the raw coal samples.     

石油焦配煤炼焦试验研究

通过对石油焦的特性研究及配煤炼焦试验,考察其对配煤黏结性能及焦炭质量的影响,研究结果表明,添加石油焦会引起煤的黏结指数下降,加入石油焦配煤炼焦会降低焦炭灰分,提高焦炭硫分,降低焦炭冷强度,提高焦炭热强度。     

循环流化床中石油焦与煤混合燃烧NO排放特性

在一座0．5MWt循环流化床热态试验台上进行了石油焦与煤混合燃烧试验，研究了烟气中NO的排放特性，对于石油焦与煤不同燃料配比，不同锅炉运行参数，如一次风率、过量空气系数、床温和Ca／S比等对烟气中NO排放浓度的影响规律进行了研究。试验表明对纯焦而言，其NO排放浓度较其他混合燃料要高得多，当燃料中焦煤比增大时，NO的排放浓度降低，对不同焦煤比的燃料，随一次风率增大，NO的排放量增加；随过量空气系数的增大，NO的排放浓度增大；随着运行床温的提高，NO排放浓度升高。