高硫石油焦的脱硫研究

高硫石油焦深度脱硫技术研究作者：宋宁宁来源：《中国化工贸易·下旬刊》2019年第07期摘要：近年来，随着我国从中东地区进口原油量的不断增加，硫含量相对较高的原油经焦化工艺得到包括留含硫化合物的石油焦制品。

高硫石油焦最终以硫化物的形式排出，对环境造成一定的影响。

本文阐述了几种石油焦脱硫技术，并分析了脱硫技术应用优势及局限性，以期探索石油焦脱硫经济性工艺技术。

关键词：石油焦;脱硫;焦化;加工工艺石油焦是石油炼化的衍生物，由重质渣油经热解和缩聚反应生成固体碳材料，常见的石油焦生产工艺包括延迟焦化、硫化焦化、接触焦化等。

石油焦具有高碳、低挥发、低灰分和高热值等特点，广泛应用于冶金、化工、电力等领域，在我国国民生产中占有重要地位。

石油焦质量主要由灰分、挥发分、硫分和煅后真密度等因素组成，并以此作为石油焦等级评价和经济价值的评价标准。

其中，硫分作为石油焦质量优劣评价的关键指标，当石油焦含硫量较高时，将对下游生产、工艺加工造成严重影响。

因此，有必要深入研究高硫石油焦深度脱硫技术，提高石油炼化生产的经济效益和社会效益。

1 石油焦脱硫方法概况按燃烧阶段来区分，可将石油焦脱硫方法分为燃前脱硫、燃中脱硫和燃后脱硫三种类别。

就技术应用情况来看，燃后烟气脱硫技术是各大炼厂应用最为广泛、最成熟的脱硫方式。

然而，由于燃后石油焦并不适用铝电解等工艺生产，限制了石油焦的应用。

相对而言，燃前脱硫技术不仅能够有效降低石油焦中的硫分含量，而且还能够提高石油焦的适用范围，因此，研究燃前脱硫技术具有重要的研究价值。

2 高硫石油焦脱硫方法在石油焦中，硫分主要以硫醇、硫脒和噻吩类有机硫形式存在，噻吩类有机硫占硫分含量的90%左右，因此，石油焦脱硫主要是脱除此类形式的硫分、根据脱硫技术的不同，可将燃前脱硫技术分为高温煅烧脱硫、湿化学氧化脱硫、碱金属化合物脱硫、溶剂萃取脱硫等。

2.1 高温煅烧脱硫高温煅烧脱硫即通过高温煅烧的方式进行脱硫，使石油焦中的硫元素以烟气的形式逸出。

收稿日期:2009207218作者简介:周文台(1981),男,硕士研究生,主要从事CFB 锅炉的研究。

E 2mail :zwtcnn @环保技术与装备燃烧石油焦的CFB 锅炉脱硫特性的试验研究周文台1,　高胜斌1,　王恩禄2(1.上海发电设备成套设计研究院,上海200240;　2.上海交通大学热能工程研究所上海200240)摘　要:模拟燃烧石油焦的CFB 锅炉的燃烧工况,并利用智能测硫仪进行测定,研究了不同石灰石的物理化学特性对燃烧石油焦的CFB 锅炉脱硫效果的影响。

研究表明,钙硫比越大脱硫效果越好;燃烧温度(850～900℃)对脱硫效率基本没有影响;石灰石粒度与脱硫效果成反比;不同产地的石灰石脱硫效果不同。

关键词:CFB 锅炉;石油焦;脱硫特性;石灰石中图分类号:X511 文献标识码:A 文章编号:16712086X (2010)0120077204Study on Desulf urization Characteristics of CFB Boilers Burning Petroleum CokeZ HO U Wen 2tai 1,　GAO Sheng 2bin 1,　WAN G En 2lu2(1.Sha nghai Power Equip ment Research I nstitute ,Sha nghai 200240,China ;2.I nstitute of Ther mal Engineering ,Sha nghai Jiaotong U niversity ,Shanghai 200240,China )Abstract :By simulating t he combustion conditions of p et roleum coke 2fired C FB boiler and measuring t he sulf ur conte nt wit h intellige nt sulf ur a nalyzer ,t he influe nce of p hysical a nd chemical p rop erties of limest one on C FB boiler desulf urization efficiency was studied.Results show t hat larger ratio of calcium t o sulf ur p roduces higher desulf urization efficie ncy ;combustion temp erature (850～900℃)has nearly no influe nce on t he desulf urization efficie ncy ;grain size of limest one is in inverse p rop ortion t o t he desulf urization eff ect ;limest one originated f rom diff ere nt regions has a diff erent desulf urization eff ect.K eyw ords :C FB boiler ;pet roleum coke ;desulf urization characteristic ;limest one 石油焦是石化企业延迟焦化装置的副产品。

试论高硫煤炼焦过程的脱硫技术【摘要】以有机硫为主的高硫煤，洗选后精煤硫份比原煤更高。

焦煤中的硫份只有30%-50%经裂解进入煤气中，大部分硫残留在焦炭中，根据硫份在焦炭中的位置，可将脱硫技术分为入炉前脱硫，焦化过程脱硫和煤气脱硫三个阶段过程，本文主要探讨了高硫煤入焦炉前物理、化学法脱硫，焦化过程高温加氢（焦炉煤气）脱硫工艺和煤气中硫元素回收利用进行最终脱硫。

【关键词】焦煤入炉前脱硫；碳化过程加氢脱硫；回收煤气脱硫1.焦煤入焦炉前脱硫1.1无机硫的脱除无机硫脱除一般以物理法为主，它主要以硫铁矿和硫酸盐的形态存在于煤的夹层中，以地质结合为主，由于国内原煤洗选工艺一般以脱灰为主，原煤中无机硫的脱除率一般在40%左右，如将原煤洗选粒度降至一定程度，硫铁矿的脱除率可大幅提高，因此只要将部分洗煤设备和工艺加以改进，即可有效的提高无机硫的脱除效率，目前，国内外已有成熟的设备，通过优化洗选工艺，脱除原煤中的硫铁矿。

它工艺可靠，脱除效率高、投资省、运行成本低，已得到洗煤行业的高度重视，一些专业的洗煤厂商已将脱除无机硫做为设计重点，主要采用重力法、浮选法、磁选法等几种工艺。

重力法是按煤和硫铁矿比重差异进行脱硫，这是目前焦煤脱硫的主要手段，使用重介质旋流器可以实现低密度，高精度的分选，分选粒度下限可以达到0.1-0.2mm，能有效地排除未充分解离的中间密度的硫铁矿与煤的连生体，而获得较高回收率的低灰低硫精煤，高密度的硫铁矿使用重介工艺可使煤与硫铁矿进行有效的分离，且脱除率较高。

浮选法主要处理重介质分选粒度下限微未级的细微粒煤，上限可以达到0.3mm 以上，弥补了重介质分选的粒度范围，在该粒度状况下，煤与硫铁矿连生体已基本被分离，只要选用合适的浮选制，利用颗粒表面润湿差异和空气微泡有条件吸附而形成的表面张力就能有效的分离出硫铁矿和灰分，微泡浮选柱具有明显的去硫除灰能力，而且对微末级的极细粒煤效果非常好。

磁选法主要利用硫铁矿自身的磁性对其进行脱硫，它是根据煤效组份与硫铁矿的磁性差异进行脱硫。

高硫石油焦的碱催化煅烧联合超声氧化深度脱硫ZHAO Pu-jie;MA Cheng;WANG Ji-tong;QIAO Wen-ming;LING Li-cheng【摘要】采用两段脱硫方法对高硫石油焦进行深度脱硫,并对碱催化煅烧和超声辅助化学氧化阶段的工艺条件进行优化.结果表明,在Na2 CO3添加量25％、900℃恒温2 h、粒径80μm、升温速率1℃/min条件下,石油焦脱硫率达到最大值为67.2％.在氧化温度80℃、HNO3浓度65 wt％、反应12 h、粒径80μm、液固比20 mL/g的条件下,超声辅助氧化法的总脱硫率达到93.5％.在碱催化煅烧过程中,噻吩硫和亚砜的去除率分别为73.4％和59.8％,经后续的超声波辅助氧化后,噻吩硫和亚砜的总去除率分别为93.6％和93.3％.同时,通过XPS分析了高硫石油焦在碱催化煅烧和超声辅助氧化工段中的脱硫机理.【期刊名称】《新型炭材料》【年(卷),期】2018(033)006【总页数】8页(P587-594)【关键词】脱硫;碱催化;超声氧化;高硫石油焦【作者】ZHAO Pu-jie;MA Cheng;WANG Ji-tong;QIAO Wen-ming;LING Li-cheng【作者单位】;;;;【正文语种】中文【中图分类】TE62618+71 IntroductionAs an important by-product of heavy oil cracking during oil refining, petroleum coke is widely used as carbon electrode, graphite products, raw material of silicon carbide wear-resistant coating owing to its low volatility, high calorific value, low price and easy availability[1-4]. In recent years, the quality of petroleum coke has been significantly decreased because of using high sulfur petroleum, which consequently limits its use as carbon products. The sulfur contained in petroleum coke in industrial applications will eventually be discharged in the form of sulfur oxides, which will not only increase production costs but also pollute the environment[5]. In the air pollution prevention and control act in China in 2016, the sulfur content of petroleum coke is expected to be limited to lower than 3%. Therefore, it is of great value and significance to effectively reduce sulfur-containing compounds in high-sulfur petroleum coke for its utilization.The sulfur species in petroleum coke is mostly organic sulfur[6]. To break the C-S bonds in these organic groups, a few methods have been developed, including high temperature calcination[7-8], wet chemical oxidation[9-11], dielectric gas desulfurization[12] and solventextraction[13]. However, there is still a lack of a very economical way to achieve an efficient and cost-effective desulfurization for high-sulfur petroleum coke. Organic sulfur in petroleum coke has three main types of structures, namely, thiophene, benzothiophene, and dibenzothiophene[14]. It is difficult to remove thiophenic sulfur from high-sulfur petroleum coke,even when it is heated to 1 300 ℃, because of their high thermal stability. El-Kaddah and Ezz found that the desulfurization rate of high-sulfur petroleum coke reached 80% when it was calcined at a temperature of 1 400 ℃[15]. Jin Xiao carried out the oxidation treatment for high-sulfur petroleum coke through a self-made desulfurizer, and the results showed that the desulfurization rate of petroleum coke reached 50%[16]. Parmar demonstrated that the desulfurization rate of petroleum coke reached 31% in the range of 900-1 300 K under the atmosphere of steam[17]. Aly found that the desulfurization rate of petroleum coke reached 35% through soaking treatment with toluene[18]. Although sulfur-containing compounds in petroleum coke could be removed to some extent through the above mentioned methods, the damage for the quality of petroleum coke after desulfurization, the destruction of equipment and environmental pollution make it impossible to be applied in industrial applications. Therefore, these methods have certain limitations for petroleum coke desulfurization and their applications.In this paper, a two-stage desulfurization method combining Na2CO3-promoted calcination and ultrasonic-assisted chemical oxidation was attempted to efficiently remove the sulfur-containing compounds in high-sulfur petroleum coke. The effect of the processing conditions such as calcination temperature, Na2CO3 amount, holding time, particle sizes, and HNO3 concentration, oxidation temperature, liquid-solid ratio on the desulfurization rate of high-sulfur petroleum coke were studied. The physicochemical properties of petroleum coke before and afterdesulfurization were compared.2 Experimental2.1 DesulfurizationHigh-sulfur petroleum coke (Qingdao, China) with particle sizes from 80 to 1 000 μm was used in this study. The proximate and ultimate analysis results of the petroleum coke are listed in Table 1. 3 g sample and different amounts of sodium carbonate were well mixed, placed in a constant-temperature zone of a vacuum tube and heated from room temperature to different final temperatures of 600-1 000 ℃ under inert atmosphere. Then, the sample was washed thoroughly with dilute hydrochloric acid, filtered and placed in a vacuum oven at 110 ℃ for drying. The sulfur content of samples before and after the treatment were measured, and the desulfurization rates were calculated. The treated samples were placed in a beaker, to which nitric acids with different concentrations were added, which was put into an ultrasonic cleaning machine for a further desulfurization with an acid oxidation method. After desulfurization, the samples were washed thoroughly with deionized water, filtered, and then placed in a vacuum oven at 110 ℃ for drying, the sulfur contents of dry samples were measured, and the desulfurization rates were calculated. Three samples at different stages were referred to as C0 (as-received petroleum coke), C1 (obtained after Na2CO3-promoted calcination), C2 (obtained after Na2CO3-promoted calcination and ultrasonic-assisted chemical oxidation).Table 1 Proximate and ultimate analysis results of petroleumcoke.Proximate analysis wt/%AadVadFCadMadUltimate analysiswt/%CHSNO*3.829.9582.633.6086.993.407.571.230.81A: Ash; V: Volatile; FC: Fixed carbon; M: Moisture; ad: air-dried; *: by difference.The total sulfur content in samples was measured using a high-frequency infrared carbon and sulfur analyzer (HSC-500, Shanghai, China). 20-50 mg samples were put in a crucible and 1-2 min was required to complete the analysis. The desulfurization rate η (%) was calculated using Eq.1:η=(w0-w1)/w0×100(1)Where w0 represents sulfur content in petroleum coke before desulfurization and w1 represents sulfur content in petroleum after desulfurization.2.2 CharacterizationThe surface micromorphology of samples was observed under a field emission scanning electron microscope (SEM) (JEOL-7100F, JEOL, Tokyo, Japan). The microcrystalline structures of samples were obtained by X-ray diffraction patterns (XRD), which were recorded on a Rigaku D/Max2550 using the Cu (Kα) radiation (λ=0.154 06 nm) and 2θ/(°) ranging from 10° to 80°. The surface chemical compositio ns of samples were determined on the Axis Ultra DLD X-ray photo electron spectroscope (XPS). The chemical structures of samples were investigated by Fourier Transform Infrared Spectroscopy (FT-IR), using a scanning range from 4 000 to 400 cm-1 and a ratio of coke to potassium bromide of 1∶150.3 Results and discussion3.1 Optimization of Na2CO3-promoted calcinationThe Na2CO3-promoted calcination conditions were optimized by L2556 orthogonal experiment using desulfurization rate as an evaluation index. The levels and factors of orthogonal experimental are listed in Table 2, and orthogonal test results are listed in Table 3. As observed from Table 2 and Table 3, the theoretical optimal experimental condition is A4B5C2D5E1, namely, the calcination temperature of 900 ℃, Na2CO3 amount of 25 wt%, holding time for 2 h, and average particle size of 80 μm. The descending order of factors for the desulfurization rate of petroleum coke is A> B> C> D> E, and the calcination temperature exhibits the greatest influence on the desulfurization rate of petroleum coke, followed by the added amount of Na2CO3, holding time, particle size and heating rate. According to the above optimal condition, the desulfurization rate of high-sulfur petroleum coke reached 67.2% in the Na2CO3-promoted calcination process.3.2 Optimization of ultrasonic-assisted chemical oxidationThe conditions of ultrasonic oxidation were optimized by L1645 orthogonal experiment using the desulfurization rate as an evaluation index. The orthogonal experimental factors are listed in Table 4, and the results of orthogonal experiment are listed in Table 5. It can be obtained from Table 4 and Table 5 that the theoretical optimal experimental condition is A4B3C4D4E2, and the ultrasonic oxidation temperature at80 ℃, the concentration of HNO3 solution of 50 wt%, holding time for 12 h, average particle size of 80 μm, liquid-solid ratio of 20 mL/g. Thedescending order of factors for desulfurization rate of petroleum coke is D> E> B> A> C, namely, the particle size of petroleum coke has the greatest influence on the desulfurization rate of petroleum coke, followed by liquid-solid ratio, HNO3 solution concentration, ultrasonic oxidation temperature and reaction time. According to the above optimal condition, the desulfurization rate of petroleum coke reached 93.5% through Na2CO3-promoted calcination combined with ultrasonic oxidation.Table 2 Factors and levels of orthogonal experimental.LevelsFactor AFactor BFactor CFactor DFactor ECalcination temperature/℃w(Na2CO3)/wt%Holding time / hParticle size/μmHeatingrate/ ℃/min16005%1700-1 0001270010%2500-7003380015%3200-5005490020%480-20075100025%5<8010Table 3 The results of orthogonal experimental.Experiment numbersFactor and levelsABCDEDesulfurization rateη/%11111121.321222223.631333324.941444425.851555526.762123430.97 2234537.282345141.892451245.7102512350.6113135234.7123241336.913 3352450.3143413559.6153524163.8164142548.9174253151.7184314258.6 194425365.5204531452.3215154339.6225215444.7235321545.1245432150 .3255543257.4k124.535.146.040.345.8k240.438.846.844.744.0k349.144.139. 944.943.5k455.449.442.245.040.8k547.450.042.845.843.5R15.014.97.15.55.0 Table 4 Factors and levels of orthogonal experimental.LevelsFactor AFactor BFactor CFactor DFactor EOxidation temperature / ℃HNO3con centration/wt%Oxidation time /hParticle size/μmLiquid-solid/mL g-112010%3500-7001024030%6200-5002036050%980-2003048065%12<8040Table 5 The results of orthogonal experimental.ExperimentnumbersLevels and factorsABCDEDesulfurization rateη/%11111175.321222281.931333386.741444490.552123482.362214387.97 2341290.382432179.493134292.5103243182.7113312485.8123421389.613 4142386.4144231483.8154324192.9164413290.1k183.684.184.784.882.6k2 85.084.186.783.488.7k387.788.985.685.688.7k488.387.487.591.085.6R4.74.82.87.66.13.3 Characterization and analysis3.3.1 FT-IR analysis of petroleum cokeFig. 1 shows FT-IR spectra of three petroleum coke samples (C0, C1 andC2). As observed in Fig. 1, the C-H absorption peak at 3 074 cm-1 on the thiophene ring of C1 and C2 disappears, which indicates that the thiophene ring in the C1 and C2 was destroyed. The thiophene characteristic peaks of C1 and C2 at 744 cm-1 disappear, and is replaced by the stretching absorption peaks of the C-S bond at 620 cm-1, and the intensity of the C-S stretching peak of C1 is stronger than that of C2, which indicates that the thiophenic sulfur in the petroleum coke is converted to a more stable organic sulfur. But the subsequent ultrasonic oxidation treatment for the sample can effectively remove most of the more stable sulfur-containing compounds. The C-S characteristic absorption peaks of C1 and C2 at 863 cm-1 are significantly decreased, and the C-S absorption peak intensity of C2 is weaker than that of C1, which is consistent with the results of desulfurization rate of petroleum coke (67.2% for C1 and 93.5%for C1). The above mentioned facts demonstrated that Na2CO3-promoted calcination combined with ultrasonic-assisted oxidation can effectively remove most of the organic sulfur in high-sulfur petroleum coke.Fig. 1 FT-IR spectra of three petroleum coke samples.3.3.2 XRD analysis of petroleum cokeFig. 2 displays the XRD patterns of three petroleum coke samples. The crystallite parameters for three petroleum coke samples are listed in Table 6. It can be observed in Fig. 2 that the characteristic peaks of three samples are attributed to the crystal structure of graphite, demonstrating that the structure of graphite after desulfurization treatment has not been changed. The (002) peak shifts to the lower degree from C0 to C1 and C2, which illustrates that the layer spaces of graphite increase and the graphitic crystallinity decreases. The (002) peak intensity of C1 is slightly weaker than that of C0, which indicated that the crystal structure has been destroyed to some extent, the amorphous carbon content increases, grahene sheet orientation degree decreases. The intensity of the (002) peak has been weakened further through ultrasonic-assisted chemical oxidation, because the sulfur element of the petroleum coke is not only removed during the oxidation process, but also the carbon element on the carbon skeleton is removed at a small amount.Fig. 2 XRD patterns of three petroleum coke samples.Table 6 Crystallite parameters for three petroleum coke samples.Samples2θ002 /(°)d002/ nmLc/nmC025.620.347411.5C125.180.353468.8C224.660.360774.63.4 SEM images of petroleum cokeFig. 3 shows SEM images of three petroleum coke samples. As observed in Fig. 3(a), the C0 exhibits no obvious cracks and pores and its particle gives sharp edges and corners, indicating a high density. However, a small amounts of small particles is attached on the surface of the C1, and local pore structure is formed inside the C1 (SC0 =5.32 m2/g，SC1=19.4 m2/g), which is mainly due to the volatilization of light components in the petroleum coke such as sulfur-containing gas during the Na2CO3-promoted calcination. The loose particle surface, no sharp edges, and significant cracks are shown in Fig. 3(c), which is due to the fact that HNO3 possibly enters the interior of the particles through petroleum coke pores or crystal defects and reacts with the sulfur-containing compounds during the ultrasonic oxidation.Fig. 3 SEM images of three petroleum coke samples: (a) C0, (b) C1 and (c) C2.3.5 XPS analysisFig. 4 exhibits XPS spectra of three samples. Five peaks are easily recognized in Fig.4, including S 2p (l62-167 eV), S 2s (223-232 eV), C 1s (282-288 eV), N 1s (395-404 eV), and O 1s (528-537 eV). As shown in Fig.4, the peak intensities of sulfur and nitrogen decrease with proceeding of desulfurization, but the peak intensity of oxygen increases, which is mainly due to the fact that the oxygen atoms are introduced into the petroleum coke during desulfurization[18].Fig. 4 XPS spectra of petroleum coke samples: (a) C0, (b) C1, (c) C2, (d) S 2pof C0,(e) S 2p of C1 and (f) S 2p of C2.The peak fitting of XPS spectra are also shown in Fig. 4. XPSPEAK software was used to fit the peaks of sulfur element. Afterward, the sulfur species were identified from the peak positions with reference to previous literatures[19,20]. The contents of sulfur species in the three samples are displayed in Table 7.As shown in panels d, e and f of Fig. 4 and Table 7, sulfur exists in the petroleum coke in the form of thiophenes (at 164.0-164.3 eV) and sulfoxides (at 165.0-165.3 eV). It can be obtained from Table 4 that the position of the characteristic peaks of petroleum coke before and after desulfurization has no obvious change. However, there is an additional peak appearing in the calcined sample (C1), which is assigned to sulfur sulfate, and the 2p photoelectron spectroscopy intensities of the sulfur in the samples (C1, C2) after desulfurization are lower than that of pristine sample (C0), indicating that the organic sulfur in the petroleum coke is effectively removed through the above mentioned desulfurization method. Furthermore, the removal rates of thiophenic sulfur and sulfoxide were 73.4% and 59.8% after Na2CO3-promoted calcination, and the total removal rates of thiophenic sulfur and sulfoxide were 93.6% and 93.3% after a further ultrasonic assisted oxidation treatment, respectively.Table 7 Characteristic peaks and their assignments of three petroleum coke samples.Samples2p Binding energy /eVHalf width of peak /eVPeak area/eVPeak area ratio /%Conversion of sulfur content/wt%Sulfur speciesC0165.10.98644.2833.502.54Sulfoxides164.11.031278.8966.505.03Thiophenes168.50.9919.695.150.13SulfatesC1165.20.97156.9041.081.02Sulfo xides164.21.01205.3853.771.34ThiophenesC2165.20.9567.4035.050.17Sulfo xides164.20.98124.9064.950.32Thiophenes3.6 Desulfurization mechanismThe organic sulfur of petroleum coke is mainly thiophene sulfur, and it is difficult to be removed because of the stability of thiophene ring[21]. The C-S bond is the weakest one in the system of the thiophene and is preferentially broken during pyrolysis[22]. However, the destruction of C-S bonds in thiophene compounds requires higher energy because the bond energy of C-S bond is 156.64 kcal/mol. According to Attar[23], in pyrolysis, sulfur-containing compounds are cleaved to form free radicals, and these sulfur-containing radicals first abstract hydrogen atoms, and then decompose subsequently to form H2S and olefin. These hydrogen atoms come from hydrogen-containing compounds in petroleum coke (probably alkyl or hydro aromatic units), but the internal hydrogen atoms (3.40 wt%) of petroleum coke cannot meet sulfur-containing radicals. Thus, it is possible that large amounts of these radicals recombine to form more stable thiophene structures that are difficult to be removed. The addition of alkali metal compounds to petroleum coke can not only activate C-S bonds, but also react with hydrogen sulfide to avoid recombination of these free radicals to form more stable thiophenic sulfur compounds. However, the desulfurization for high-sulfur petroleum coke through adding alkali metal compounds is difficult to remove the thiophenic sulfur of complex structure. The sulfur atoms in the petroleum coke often exist innegative divalent, and these sulfur atoms contain two pairs of lonely electronic pairs, so their electronegativity is strong. The complex thiophene sulfur are partially oxidized in soluble state under the action of the oxidant, thus it could be further removed through chemical oxidation. The desulfurization mechanism of petroleum coke may be mainly carried out by (1)-(5).Where A·represents ferrite free radicals.4 ConclusionsThe desulfurization method of Na2CO3-promoted calcination combined with ultrasonic-assisted chemical oxidation was developed to deeply remove the sulfur-containing compounds in high-sulfur petroleum coke. The desulfurization rate of petroleum coke reached the maximum value of 67.2% through Na2CO3-promoted calcination under the conditions of calcination tem perature at 900 ℃, Na2CO3 amount of 25%, holding time for 2 h, average particle size of 80 μm and heating rate of 1 ℃/min. The total desulfurization rate can reach 93.5% through further ultrasonic-assisted oxidation under the conditions of oxidation temper ature at 80 ℃, HNO3 concentration of 50 wt%, holding time for 12 h, average particle size of 80 μm and liquid-solid ratio of 20 mL/g. More definitely, the removal rates of thiophenic sulfur and sulfoxide reached 73.4% and 59.8% during the Na2CO3-promoted calcination, and the total removal rates of thiophenic sulfur and sulfoxide reached 93.6% and 93.3% after subsequent ultrasonic-assisted oxidation, respectively. It demonstrates that most of theorganicsulfur in petroleum coke can be effectively removed through Na2CO3-promoted calcination combined with ultrasonic-assisted chemical oxidation as revealed by the FTIR and XPS analysis, and the physicochemical properties of petroleum coke after desulfurization are slightly reduced.References【相关文献】[1] Ibrahim H A, Al M M. The effect of increased residence time on the thermal desulphurization of Syrian petroleum coke[J]. Period Polytech Chem Eng, 2004, 48(1): 53-62.[2] Olmeda J, Snchez de Rojas M I, Frías M. Effect of petroleum (pet) coke addition on the density and thermal conductivity of cement pastes and mortars[J]. Fuel, 2013, 107:138-146.[3] Anthony E L. Fluidized bed combustion of alternative solid fuels: Status, successes and problems of the technology[J]. Prog Energy Combust Sci, 1995, 21: 239-268.[4] Wang J S, Anthony E L, Abanades J C. Clean and efficient use of petroleum coke for combustion and power generation[J]. Fuel, 2004, 83: 1341-1348.[5] Legin-Kolar M, D. Petroleum coke structure: Influence of feedstock composition[J]. Carbon, 1993, 31 (2): 383-390.[6] Al-Haj-Ibrahim H, Morsi B I. Desulfurization of petroleum coke: A review[J]. Ind Eng Chem Res 1992, 31: 1835-1840.[7] Al-Haj Ibrahim H. Thermal desulphurization of Syrian petroleum coke[J]. Journal of King Sand University-Science, 2005: 199-212.[8] Reis T. To coke, desulfurize and calcine, Part 2: Coke quality and its control[J]. Hydrocarbon Processing, 1975, 54: 97-104.[9] Edwards L C, Neyrey K J, Lossius L P. A review of coke and anode desulfurization[J]. Essential Readings in Light Metals, 2016, 4: 130-135.[10] Phillips C R, Chao K S. Desulfurization of athabasca petroleum coke by (a) chemicaloxidation and (b) solvent extraction[J]. Fuel, 1977, 56(1): 70-72.[11] George Z M, Schneider L G, Tollefson E L. Desulfurization of a fluid coke similar to the Athabasca oil sands coke[J]. Fuel, 1978, 57: 497-501.[12] Lossius L P, Neyrey K J, Edwards L C. Coke and anode desulfurization studies[J]. Light Metals, 2008, 32(1): 881-886.[13] Shelwit H, Alibrahim M. Extraction of sulfur and vanadium from petroleum coke by means of salt-roasting treatment[J]. Fuel, 2006, 85(5): 878-880.[14] Tran K N, Berkovich A J, Tomsett A, Bhatia S K. Influence of sulfur and metal micro constituents on the reactivity of carbon anodes[J]. Energy & Fuels, 2009, 23 (4): 1909-1924.[15] El-Kaddah N, Ezz S Y. Thermal desulphurization of ultra-high sulphur petroleumcoke[J]. Fuel, 1973, 52 (2): 128-129.[16] Xiao J, Yang S, Lai Y, Li J. Removal of sulfur from petroleum coke by chemical oxidation process[J]. Environmental Protection of Chemical Industry, 2010, 30(3):199-202.[17] Parmar B S, Tollefson E L. Desulfurization of oil sands coke[J]. Can J Chem Eng, 2010, 55(2): 185-191.[18] Aly I H M, Magdy Y H, Barakat N A M. Desulfurization of Egyptian petroleum coke[J]. Asia-Pacific Journal of Chemical Engineering, 2010, 11(3-4): 395-406.[19] Moulder J F, Stickle W F, Sobol P E, et al. Handbook of X-ray photoelectron spectroscopy[M]. Perkin Elmer: EdenPrairie, MN, 1992, 40.[20] Liu Q, Xu S, Niu C, et al. Distinguish cancer cells based on targeting turn-on fluorescence imaging by folate functionalized green emitting carbon dots[J]. Biosens Bioelectron, 2015, 64: 119-125.[21] Sugawara K, Enda Y, Sugawara T, et al. XANES analysis of sulphur form change during pyrolysis of coals[J]. Journal of Synchrotron Radiation, 2001, 8(2): 995-957.[22] Miura K, Mae K, Makoto Shimada A, et al. Analysis of formation rates of sulphur-containing gases during the pyrolysis of various coals[J]. 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doi：10.3969/j.issn.1007-7545.2018.10.005粒度对石油焦硫含量分布及煅烧脱硫的影响研究沈一帆，刘卫，张辉，刘云，袁明波，张念炳(贵州师范大学材料与建筑工程学院，贵阳550025)摘要：通过库伦滴定法分别测定不同粒度石油焦的硫含量及其煅烧后的硫含量。

结果表明，粒度对不同硫含量石油焦中硫含量有影响，且差异较大，硫含量 2.54%石油焦可筛分出硫含量2.25%石油焦（粒径-0.5 mm），3.35%石油焦可筛分出硫含量2.33%石油焦（粒径-0.15 mm），硫含量5.98%石油焦筛分的作用较小；粒度对石油焦脱硫具有明显差异，粒度+0.5 mm的2.54%石油焦脱硫效果较好，粒度+1 mm的3.35%石油焦脱硫效果较好，整个粒度范围内5.98%石油焦脱硫效果差异不大。

关键词：石油焦；粒度；煅烧；脱硫中图分类号：TF821;TQ522.65 文献标志码：A 文章编号：1007-7545（2018）10-0000-00 Effect of Particle Size on Sulfur Distribution and Calcining Desulfurization ofPetroleum CokeSHEN Yi-fan, LIU Wei, ZHANG Hui, LIU Yun, YUAN Ming-bo, ZHANG Nian-bing (College of Material and Civil Engineering, Guizhou Normal University, Guiyang 550025, China) Abstract：Sulfur content of petroleum coke with different size and calcined coke were determined by Kulun Titration. The results show that particle size has different influence on sulfur content of petroleum coke with different size. 2.54% sulfur petroleum coke can screen out 2.25% petroleum coke (particle size of -0.5 mm), 3.35% sulfur petroleum coke can screen out 2.33% petroleum coke (particle size of -0.15 mm), screening effect of 5.98% of petroleum coke is weak. Grain size has obvious desulfurization difference for petroleum coke with different sulfur content. 2.54% petroleum coke with grain size of +0.5 mm has good desulfurization effect. 3.35% petroleum coke with grain size of +1 mm has good desulfurization effect. For 5.98% petroleum coke, desulfurization efficiency varies little in the whole particle size range.Key words：petroleum coke; granularity; calcination; desulfurization在工业铝电解中，石油焦作为预焙炭阳极的主要原料，其质量对预焙炭阳极的性能有着重大的影响[1]。

2431 石油焦煅烧和脱硫要求1.1 石油焦煅烧的应用原理石油焦煅烧利用高温将自身体内的水分挥发，在进行除水后，石油焦能够呈现出一种高密度、高强度、导电性、抗氧化性的特征。

通过加工煅烧，成焦状的石油焦能够形成阴、阳两极的炭块，产物可以应用于工业生产中。

同时，在煅烧过程中，原石油焦内含有一定的原料硫，结合高温氧化作用，约有10%~30%的硫元素会结合化学作用形成二氧化硫随着煅烧的烟气排除。

1.2 石油焦煅烧脱硫的重要性随着我国近年来各项工业的不断发展，石化产业的石油焦也逐渐成为工业市场的重要产品。

据悉，2017年我国石油焦的产量达到了2770万吨/年，这也成为了我国一跃变成石油焦大国的标志。

作为石油焦煅烧的副产物，硫化物的产生为我国环境造成了一定的影响。

在所煅烧的石油焦中，其中含硫量大于3%的石油焦普遍超过了45%，高硫含量的烟气对我国的大气、环境都有着很大的污染。

这也引起了我国环境保护相关机构的重视。

因此，国家制定了相关排硫治理的规定，一些企业也对石油焦煅烧烟气脱硫工艺进行了探讨和实践。

2 石油焦煅烧烟气脱硫技术探究2.1 双碱法双碱法脱硫的方式借助了碳酸钠、氢氧化钠的特殊属性，在一定的环境下将二氧化硫转化特殊的酸式亚硫酸钠。

结合氢氧化钙发生化学反应后二氧化硫最终会合成为固体的硫酸钙，达到二氧化硫有效分解的目的。

因为在进行脱硫和生成固体的时候运用了氢氧化钠和氢氧化钙两种类型的碱，此方法得名双碱法，其中涉及的化学反应如下：（双碱法脱硫化学方程式-脱硫）（双碱法脱硫化学方程式-固化）结合特殊化学反应性质，双碱法在化学过程中所用的氢氧化钠仅仅起了反应催动的作用，实际上还是氢氧化钙和二氧化硫进行了反应，结合以上反应可知，本工艺原料来源广泛，成本投入较低。

脱硫效果较为明显，不过反应周期较长，因此比较适合中小脱硫工厂的使用。

2.2 氨法脱硫氨法脱硫的原理是利用氨气与石油焦中的二氧化硫发生化学反应形成硫酸铵的过程。