SO_2 emission characteristics from co-firing of petroleum coke and coal in circulating fluidized bed

Combustion and sulfur retention experiments of mixed fuel of petroleum cokeand coal were conducted on a pilot-scale circulating fluidized bed (CFB) combustor with the thermalinput of 0. 6 MW. The effects of several parameters, such as the primary air percentage, excess aircoefficient, bed temperature, Ca/S molar ratio and mass ratio of petroleum coke to coal on SO_2emission were verified. Experimental results show that when the ratio of petroleum coke to coal inthe mixed fuel increases, the SO_2emission increases. The maximum SO_2 emission appears when purecoke burns. The SO_2 concentration in flue gas reduces with the increase in the primary airpercentage, excess air coefficient and Ca/S molar ratio for all kinds of fuel mixtures. Therangebetween 830 t and 850 t is the optimal temperature for sulfur retention during co-firing ofpetroleum coke and coal with the mass ratio R of 1 and 3 in CFB.

Improving slurryability, rheology,and stability of slurry fuel from blending petroleum coke with lignite

Petroleum coke and lignite are two important fossil fuels that have not been widely used in China. Petroleum coke-lignite slurry （PCLS）, a mixture of petro- leum coke, lignite, water, and additives, efficiently utilizes the two materials. In this study, we investigate the effects of the proportion （7） of petroleum coke on slurryability, rheo- logical behavior, stability, and increasing temperature characteristics of PCLSs. The results show that the fixed- viscosity solid concentration （COo） increases with increasing 7. The ~Oo of lignite-water slurry （LWS, ~ = 0） is 46.7 %, compared to 71.3 % for the petroleum coke-water slurry （PCWS, c~ --- i00 %）, while that of PCLS is in between the two values. The rheological behavior of PCLS perfectly fits the power-law model. The PCWS acts as a dilatant fluid. As decreases, the slurry behaves first as an approximate Newtonian fluid, and then turns into a pseudo-plastic fluid that exhibits shear-thinning behavior. With increasing ct, the rigid sedimentation and water separation ratio （WSR） increase, indicating a decrease in the stability of PCLS. When α is 60-70 %, the result is a high-quality slurry fuel for industrial applications, which has high slurryability （ω0 = 57-60 %）, good stability （WSR 〈 2 %）, and superior pseudo-plastic behavior （n = 0.9）.

Comparative Study on Combustion Performance of Petroleum Coke, Hejin Coal and Shenmu Coal

The effects of three factors on combustion performance of petroleum coke, Herin Coal and Shenmu Coal have been studied, including the ratio of primary air, excess air factor, and the swirling intensity of outer secondary air. The experiments were carried out on a one-dimensional furnace with dual channel swirling burner, in which temperature of center furnace, emission of air pollutants, and burn-out rate of fuel were measured. The results provide the optimal ratio of primary air, excess air factor and swirling intensity of outer secondary air for the fuels. The combustion performance of petroleum coke B is much better than petroleum coke A, but worse than Hejin coal and Shenmu coal. In addition, the burn-out rate of petroleum coke depends much more on the temperature in terminal stage of combustion than in the early stage of combustion.

Speciation and thermal transformation of sulfur forms in high-sulfur coal and its utilization in coal-blending coking process:A review

The utilization of high-sulfur coal is becoming more urgent due to the excessive utilization of low-sulfur,high-quality coal resources,and sulfur removal from high-sulfur coal is the most important issue.This paper reviews the speciation,forms and distribution of sulfur in coal,the sulfur removal from raw coal,the thermal transformation of sulfur during coal pyrolysis,and the sulfur regulation during coal-blending coking of high organic-sulfur coals.It was suggested that the proper characterization of sulfur in coal cannot be obtained only by either chemical method or instrumental characterization,which raises the need of a combination of current or newly adopted characterization methods.Different from the removal of inorganic sulfur from coal,the organic sulfur can only be partly removed by chemical technologies;and the coal structure and property,particularly high-sulfur coking coals which have caking ability,may be altered and affected by the pretreatment processes.Based on the interactions among the sulfur radicals,sulfur-containing and hydrogen-containing fragments during coal pyrolysis and the reactions with minerals or nascent char,regulating the sulfur transformation behavior in the process of thermal conversion is the most effective way to utilize high organic-sulfur coals in the coke-making industry.An in-situ regulation approach of sulfur transformation during coal-blending coking has been suggested.That is,the high volatile coals with an appropriate releasing temperature range of CH4 overlapping well with that of H2 S from high organic-sulfur coals is blended with high organic-sulfur coals,and the C–S/C–C bonds in some sulfur forms are catalytically broken and immediately hydrogenated by the hydrogencontaining radicals generated from high volatile coals.Wherein,the effect of mass transfer on sulfur regulation during the coking process should be considered for the larger-scale coking tests through optimizing the ratios of different coals in the coal blend.

COMPARING STUDY OF BLENDING PREHEATING MODIFIED COAL COKING AND STAMPING COKING FOR DONGSHEN COAL

The compaison of the properties of coke of three coking methods is introduced. The mechanical properties and high temperature reactivity of coke bleding preheating modified Dongshen coal are improved obviously than those of normal coke, and achieve or exceed that of stamping coke. This method shows more ability of expending coking coal resources.

Quality of Some Nigerian Coals as Blending Stock in Metallurgical Coke Production

Two Nigerian coals, Lafia-Obi and Chikila were blended in the mass ratio of 70:30 with imported American and Polish coking coals. Proximate analysis, free swelling index, Ruhr dilatometer and Gieseler plastometer were used in assessing the coking qualities of both the single coals and the blends. The results show that the blends are lower in moisture and ash contents;higher in volatile matter and fixed carbon than the single Nigerian coals. The rheological parameters revealed superiority in thermo-plastic properties of the blends over the unblended local coals. Lafia-Obi/Foreign coals blends possess lower ash and better rheological properties compared to Chikila/Foreign coal composites which have high ash and poor rheological properties. These together suggest that amongst the two Nigerian coals, Lafia-Obi is superior for blending with the foreign ones in metallurgical coke production.

Effect of coke properties and its blending recipe on performances of carbon anode for aluminium electrolysis

The properties and blending recipe of petroleum cokes used to make high quality carbon anodes for aluminium electrolysis were studied. Three kinds of green cokes were selected for bench scale study to illustrate the effects of cokes properties and its blending recipe on anode performances. The results show that impurities derived mainly fi＇om cokes remarkably affect the CO2 reactivity and air reactivity of carbon anodes. Ca, Na and V can increase CO2 reactivity of calcined cokes but S has the contrary effect, and the cokes of high V level generally present high air reactivity. The anodes with good quality can be made by properly selecting and scientifically blending of cokes, some poor quality cokes can also be used to produce high quality anodes with a reasonable blending recipe. Na contaminated anodes have high CO2 reactivity and air reactivity, so the recycled anode butts should be well cleaned to reduce Na content before being introduced into anode production, which is especially important to the low S cokes.

高炉喷吹用烟煤配煤炼焦试验研究

为了扩大炼焦煤资源,优化配煤结构,结合烟煤配煤炼焦理论,通过高炉喷吹用烟煤的工业铁桶试验研究,分析了配加烟煤后配合煤的性能变化和所炼焦炭的质量。结果表明:适当增加1/3焦煤、减少气煤配比,烟煤配加质量分数控制在2%~3%,可以有效优化配煤结构,使配合煤的灰分、硫分及挥发分保持在稳定状态,改善焦炭的机械强度、热强度,提高焦炭的块度,同时还可以降低配煤成本,当烟煤配加质量分数为2%时,配煤成本可降低15.60元/t。

气化渣基脱硫活性焦制备工艺与性能评价

煤气化过程中产生的气化渣的处置问题日趋严重。气化渣中的残余炭具有较发达的孔隙结构和较大的比表面积,具有制备活性炭和其他高附加值碳材料的潜质。通过水介重力分选方法得到高品质气化渣分离炭后,采用配煤法制备脱硫活性焦,可实现气化渣的高附加值利用。通过单因素试验法及正交试验法考察在气化渣分离炭高掺比条件下配煤种类、比例及炭化、活化工艺条件对脱硫活性焦结构和性能影响。研究表明,气化渣分离炭在掺入比例为50%时,活性焦的最佳配煤组成为:焦煤29%、长焰煤8%、煤沥青13%;最佳炭化条件为:升温速率5℃/min、炭化温度700℃、炭化时间30 min;最佳活化条件为:活化温度900℃、升温速率8℃/min、活化时间120 min、活化水量1.0 mL/(g·h)。利用固定床反应装置对气化渣基脱硫活性焦进行脱硫和再生性能评价,在最佳配方和工艺条件下,公斤级试验制备的脱硫活性焦耐磨强度为97.26%,耐压强度为696.3 N(实测值),灰分为11.66%,碘吸附值为378.78 mg/g,脱硫值为28.5 mg/g,满足脱硫用煤质颗粒活性炭指标A型优级品的技术指标且再生性能良好。以气化渣分离炭作为碳源制备脱硫活性焦在大幅降低活性焦生产成本的同时,也为气化渣的高值化利用提供了一条可行途径,对气化渣的减量化、资源化、高值化利用具有重要意义。

智能配煤技术在炼焦配煤中的应用进展

综述了传统经验配煤、煤岩学理论配煤以及人工智能配煤三种炼焦配煤技术,分析了计算机辅助配煤算法在炼焦配煤中的应用。在此基础上,提出了炼焦配煤技术后续的发展趋势。在通过大数据训练配煤模型的同时,还需要综合考虑炼焦煤性质、炼焦工艺等对焦炭质量的影响。基于以上内容,结合钢铁生产实际,可以建立焦炭质量与配合煤性质之间的关系,提出了关联数据分析、煤质指标、降本增效等指标的整体思路。

选煤厂产品结构多元化发展的研究与探索

介绍了晋能控股煤业集团煤炭洗选基本现状及煤炭资源优势,针对企业产品结构单一、产品开发与利用率较低的问题,以同忻选煤厂为试点,通过工艺优化、系统改造,调整产品结构,生产炼焦配煤,以点带面,逐步形成集团气精煤及弱粘煤产品规模竞争优势,不断增强企业的盈利能力、抗风险能力和核心竞争力。

基于BP神经网络和遗传算法的智能配煤系统开发与应用

针对炼焦煤品种繁多,同一矿点来煤的煤质波动较大,混煤现象严重的问题,宁波钢铁有限公司通过搭建煤焦数据库,开发智能配煤系统,实现全流程监测煤焦数据变化。智能配煤系统结合历史生产数据分析提取影响焦炭质量的关键指标,采用多元线性回归和BP神经网络的建模方法,建立焦炭质量关键指标预测模型。同时,智能配煤系统结合焦炭质量预测模型、配煤专家系统和炼焦单种煤库存信息,采用优化后的遗传算法进行配煤模型的构建,从而实现快速实时调整配比、合理利用炼焦煤资源、稳定焦炭质量并且有效降低炼焦成本的目的。智能配煤系统运行稳定,实现了对炼焦煤资源的合理利用和降本增效的目的。

基于瘦煤煤质特性的炼焦配煤方案优化试验研究

在炼焦配煤中合理利用瘦煤并提升其占比,可实现焦化企业降本增效和保护优质炼焦煤资源。为探究焦化厂配煤方案中瘦煤比例添加及方案优化调整对焦炭质量的影响,选取贫瘦煤(MC)和瘦煤(LC1和LC2)及采用工业分析、岩相分析等了解单种煤的基本煤质特性,利用红外光谱、热重分析确定煤样的结构特征和挥发分释放行为,并基于瘦煤的煤质特性,采用40 kg焦炉试验对不同瘦煤比例的配合煤进行焦炭质量评价,探究焦炭质量差异原因。结果表明:基于基础配煤方案,将LC1和LC2的占比增加至35%时,焦炭反应性(CRI)降低,反应后强度(CSR)升高,焦炭质量依然优于基础方案所制备的焦炭质量;在基础方案中,MC能对LC1和LC2进行替换,且替换后的CRI降低及CSR升高,焦炭光学组织中的细粒和中粒镶嵌结构增加,焦炭质量未发生劣化;MC占比增加至11%时,CRI升高以及CSR降低,焦炭质量发生明显劣化。基于瘦煤的煤质特性,配煤中的瘦煤比例可达到较高的配比,为后续工业配煤方案中利用高阶煤提供理论依据。

超级电容器用活性炭的研究进展

简述了超级电容器的工作原理和超级电容炭的市场情况,分析了植物类、石油焦类、树脂类不同原料制备电容炭(无定型粉末炭)的性能特点及制备工艺,介绍了煤焦油沥青基球形活性炭和煤液化沥青球形活性炭的研究进展,对比了无定型粉末活性炭与球形活性炭的性能优劣,最后对煤液化沥青球形活性炭用于超级电容器的优势及推广应用进行了展望。

俄罗斯炼焦煤的煤质特性研究

在我国优质炼焦煤短缺和环保问题日益突出的背景下,我国焦化企业对优质炼焦煤的需求不断增长,因此进口俄罗斯优质炼焦煤可作为我国炼焦煤的有益补充,从而缓解炼焦煤供需紧张的状况。通过对3种俄罗斯炼焦煤的煤岩、煤质、煤灰化学成分、黏结性指标和单种煤炼焦的焦炭质量分析,以期探明俄罗斯煤在配煤中存在的问题以及为后期大规模利用俄罗斯炼焦煤提供技术支撑。结果显示:俄罗斯炼焦煤的灰分低、硫分低、有害微量元素含量低,能够满足我国进口炼焦煤的要求;煤中镜质组含量均在80%以上,以均质镜质组为主;碱性金属的含量较高,矿物催化指数较高;俄罗斯煤具有黏结性强、胶质层厚度大、流动性好、膨胀度好的特点,可较好地应用于配煤炼焦生产中。3种俄罗斯煤制备的焦炭的反应性(CRI)均在40%以上,而反应后强度(CSR)大多在30%以下。因此,针对俄罗斯炼焦煤应开展煤灰化学调控和活惰比调控的研究,设计出科学合理的配煤方案,以期缓解国内焦化企业优质炼焦煤紧缺的状况。

高挥发分气煤在配煤炼焦中的应用探究

为扩展炼焦用煤资源范围,合理高效利用不同类型煤炭资源,开发新的可用于炼焦生产的煤炭资源,以山西焦化股份有限公司炼焦生产配煤方案为基础,选取一种高黏结性、高流动度、高挥发分的气煤,分析其与基础配煤中气煤、中黏煤的煤质特性差异,通过40 kg焦炉炼焦试验,考察了高挥发分气煤对配煤焦炭质量的影响。结果表明:高挥发分气煤以适宜比例替代配煤中部分气煤或中黏煤,配煤焦炭质量明显高于基础焦炭,且配煤成本降低。

基于煤质特性的京唐高炉喷吹煤结构优化

为优化首钢京唐高炉喷吹煤结构和降低冶炼成本,对京唐高炉喷吹煤粉的煤质特性进行了分析,用煤焦置换比理论公式计算了单种煤的理论置换比,并计算了京唐高炉喷吹煤的煤粉利用率。认为,随着高炉煤比的提高,煤焦置换比逐步降低;通过对配煤结构及高炉操作参数进行优化,京唐三座高炉的煤粉利用率得到进一步提升。1号高炉煤粉利用率达到了97.64%,2号高炉达到了97.58%,3号高炉达到了98.14%,较2022年6月分别提高了3%左右。

炼焦配煤动态评价体系的开发与应用

以炼焦煤的性质和化产循环再生系统为评价基础,以新煤源性价比及适配性研究为指导,开发炼焦煤适配性动态评价体系,建立炼焦煤适配性数据库,为低成本炼焦生产提供保障。

中高灰炼焦煤生产高品质83焦的应用实践

为了降低配煤成本,云煤能源安宁分公司使用低价格的中高灰炼焦煤。由于配量过大,导致焦炭CSR严重下降,在总结经验和小焦炉试验的基础上,采用合适的配煤比,消化了库存的中高灰炼焦煤,焦炭CSR达到≥66.0%的要求。

焦化除尘灰配煤炼焦的研究与应用

为解决邯钢西区焦化厂生产过程中产生的大量焦油渣、生物污泥等危险废弃物和除尘灰等固体废弃物,经过调研及试验研究,可将焦油渣、生物污泥、各工序除尘灰等,按不同配比混合均匀后压制成冷压块(除尘灰约占85%),然后配入配合煤炼焦使用。在应用过程中,实现了焦化废弃物的综合利用,符合当前的环保形势和要求,同时拓宽了炼焦配煤资源,将带来巨大的经济和社会效益,在焦化行业有很好的推广前景。