VARIATION IN THE CHEMICAL NATURE OF ASPHALTENES WITH THE PROCESS,THE COAL AND THE REACTION CONDITIONS

ABSTRACT

Average structure data for twelve asphaltenes are reported, based on ¹³C- and H- n.m.r. spectroscopy combined with elemental, molecular weight and functional group analyses. The asphaltenes were from supercritical gas extraction, flash pyrolysis and hydrogenation of a brown and a bituminous coal. The effect of the reaction temperature and, for hydrogenation, the catalyst and solvent on the nature of the asphaltene produced was studied. The asphaltene obtained from supercritical gas extraction of the brown coal at 350°C was the least aromatic (f_a = 0.44) with the highest H/C atomic ratio (1.16) and probably consists mainly of single ring aromatlcs with about half of the aromatic sites substituted. A significant proportion of the carbon in this asphaltene is in long alkyl chains and the hydroxyl content is high. Whereas, the asphaltenes produced by hydrogenatlon of the bituminous coal at 450°C were far more aromatic with more highly condensed but less substituted aromatic ring systems and few, if any, long alkyl chains, together with a lower hydroxyl content. The asphaltenes obtained from the brown coal are less aromatic with less condensed aromatic ring systems but a higher degree of aromatic substitution than those produced from the bituminous coal under the same conditions. The asphaltenes formed at 450°C had lower H/C atomic ratios, molecular weights and degree of aromatic substitution, but higher aromaticities Ohan those produced at 35O°C or 400°C under like processing conditions. The asphaltene produced in the presence of both stannous chloride catalyst and tetralin was less aromatic than when either of these species was absent.     

催化裂化汽油中芳烃含量随反应条件及催化剂的变化规律

首先将气相色谱法测定汽油馏分的芳烃含量和行业标准方法SH/T0693分析结果进行关联。在实验室小型固定流化床装置上，考察了裂化产物汽油馏分中芳烃含量随反应条件及催化剂的变化规律。结果表明，通过调节剂油比提高转化率时，苯含量增加较小；反应温度提高，汽油馏分中的苯含量显著提高；在催化剂中添加丙烯助剂时，在增产丙烯的同时，汽油中苯含量显著增加。     

EXTRACTION ENHANCEMENT OF COAL THROUGH CHEMICAL REACTIONS WITH CETENE AND CETANOL IN THE ANTHRACENE OIL UNDER ATMOSPHERIC PRESSURE CONDITIONS

ABSTRACT

Assam coal has been reacted with cetene or cetanol in anthracene oil. These reactions were attempted to alkylate the coal in the absence of a catalyst under the conditions of extractive disintegration of coal. Coal derived chemicals were used in the reactions as far as possible. The reactions resulted in enhancing the extractability of coal in quinoline by more than 70–90%. These reactions resulted in the alkylation of coal and increase of carbon contents in coal along with the addition of nitrogenous bases from anthracene oil to coal.     

EXTRACTION ENHANCEMENT OF COAL THROUGH CHEMICAL REACTIONS WITH CETENE AND CETANOL IN THE ANTHRACENE OIL UNDER ATMOSPHERIC PRESSURE CONDITIONS

Assam coal has been reacted with cetene or cetanol in anthracene oil. These reactions were attempted to alkylate the coal in the absence of a catalyst under the conditions of extractive disintegration of coal. Coal derived chemicals were used in the reactions as far as possible. The reactions resulted in enhancing the extractability of coal in quinoline by more than 70-90%. These reactions resulted in the alkylation of coal and increase of carbon contents in coal along with the addition of nitrogenous bases from anthracene oil to coal.     

Knoevenagel法合成肉桂酸及其工艺优化

以苯甲醛和丙二酸为原料,吡啶为催化剂,利用Knoevenagel反应合成肉桂酸,从而降低了反应温度,提高了收率和产物纯度,简化了合成工艺。同时通过正交实验探讨了不同工艺参数如反应物配比、反应时间、催化剂种类和用量等对肉桂酸收率的影响,确定的最佳工艺条件为:以吡啶为催化剂,n(苯甲醛):n(丙二酸)= 1:3,催化剂用量0．02mol,反应时间为90min,肉桂酸收率可达90%。     

THE VARIATION OF SULFUR FORMS IN SUPERCRITICAL DESULFURIZATION OF COAL WITH ETHANOL

Using Mossbauer and X-ray Photoelectron Spectroscopy ( XPS) techniques the sulfur forms in solid products obtained at different reaction were analyzed. The results show that: during supercritical desulfurization the pyritic sulfur is removed as following process: FeS₂ -FeS+ Fe_1-x S, the transformation amounts and the value of x are dependent on reaction conditions, especially on temperature. The conversion of pyrite is very little at 275° C. Pyrrhotite ( Fe_1-xS) is Fes_1.101 at 275° C and Fe_1.085 at 450° C. Among the organic sulfur groups PhSH. Ph₂ S and thiolane are easily removed; Ph ₂ SO is more difficult to be removed, its removal may be realized by increasing temperature and adding some water into ethanol; thiophene is most difficult to be removed, its removal needs high reaction temperature     

THE VARIATION OF SULFUR FORMS IN SUPERCRITICAL DESULFURIZATION OF COAL WITH ETHANOL

ABSTRACT

Using Mossbauer and X-ray Photoelectron Spectroscopy ( XPS) techniques the sulfur forms in solid products obtained at different reaction were analyzed. The results show that: during supercritical desulfurization the pyritic sulfur is removed as following process: FeS₂ -FeS+ Fe_1-x S, the transformation amounts and the value of x are dependent on reaction conditions, especially on temperature. The conversion of pyrite is very little at 275° C. Pyrrhotite ( Fe_1-xS) is Fes_1.101 at 275° C and Fe_1.085 at 450° C. Among the organic sulfur groups PhSH. Ph₂ S and thiolane are easily removed; Ph ₂ SO is more difficult to be removed, its removal may be realized by increasing temperature and adding some water into ethanol; thiophene is most difficult to be removed, its removal needs high reaction temperature     

EFFECT OF EXPERIMENTAL CONDITIONS AND SOLVENTS ON THE PRECIPITATION AND COMPOSITION OF ASPHALTENES

The ASTM D 3279 test method for “n-Heptane Insolubles” is being currently used to determine the asphaltene content of fuel oils as defined by insolubility in normal (n) heptane solvent. Precipitation of n-heptane insolubles can produce sediments which vary in color, morphology and composition. The SEM analysis of n-heptane insolubles indicated that the sediments were heterogeneous containing some large particles >300 μ and the majority of particles to be small, <10 μ, “chained” together forming agglomerates. Significant fractions of n-heptane insolubles were found insoluble in toluene indicating their non-asphaltenic nature (“solids”). FTIR and XRF analyses of “solids” indicated the presence of multiring aromatics, Ni and carboxylate and sulfate salts. FTIR analysis of toluene soluble asphaltenes showed the presence of multiring aromatics. GC/MS analysis of toluene soluble asphaltenes indicated desorption of alkylbenzenes and O-containing molecules but no desorption of N- and S-containing molecules was observed. The tendency for N- and S-containing molecules to remain in the nonvolatile residue during the GC/MS analysis indicates that the N- and S-containing compounds have higher stability. The XRF analysis of the toluene soluble asphaltenes indicated that the molecules are similar to asphaltenes found in crude oils in terms of C, H, N and S contents, however, no presence of V- and Ni-containing molecules was found.     

PYROLYSIS AND LIQUEFACTION OF BRAZILIAN COAL AND COAL-DERIVED ASPHALTENES

ABSTRACT

The present work describes a study of the liquefaction and pyrolysis of a Southern Brazilian mineral coal and its derived asphaltenes, using conversion systems developed in our laboratory.

The results show that significant quantities of the intermediate polarity fraction named resins is obtained through the pyrolysis of coal, while after the liquefaction process higher quantities of the higher fractions was found. A model is proposed to explain the liquefaction and pyrolysis processes of both coal and coal-derived asphaltenes.     

催化裂化汽油加氢脱硫及芳构化工艺反应条件的研究

在100 mL固定床反应器试验装置上,针对中国石化集团洛阳石油化工工程公司工程研究院开发的催化裂化汽油加氢脱硫及芳构化技术(Hydro-GAP),考察了反应温度,氢分压、进料空速、氢油体积比等工艺条件对加氢脱硫及芳构化反应的影响.结果表明:随着反应温度、氢分压的升高和空速的减小,加氢脱硫性能提高;芳构化性能随反应温度的升高、氢分压的降低而增加.氢油体积比对加氢脱硫及芳构化性能影响不大.     

减压渣油中胶状沥青状物质的化学结构研究

利用对芳香碳有高选择性转化能力的钌离子催化氧化法研究了减压渣油中轻、中、重胶质和戊烷沥青质的化学结构,定量了与芳香环相连的正构烷基侧链和桥链的分布,并了芳香环系的缩合型式,结果表明,这些石油重质组分中均存在碳数为Ｃ１￣Ｃ３０的与芳香 相连的正构烷基侧链,其摩尔浓度随链长的增加而下降,也存在由正构烷基桥连接的至少具有两个芳香环系的芳香性分子,在芳香结构中存在着渺位缩合,迫位缩合以联苯型结构,其中联苯     

PYROLYSIS AND LIQUEFACTION OF BRAZILIAN COAL AND COAL-DERIVED ASPHALTENES

The present work describes a study of the liquefaction and pyrolysis of a Southern Brazilian mineral coal and its derived asphaltenes, using conversion systems developed in our laboratory.

The results show that significant quantities of the intermediate polarity fraction named resins is obtained through the pyrolysis of coal, while after the liquefaction process higher quantities of the higher fractions was found. A model is proposed to explain the liquefaction and pyrolysis processes of both coal and coal-derived asphaltenes.     

CORRELATION OF COAL AND OVERBURDEN MINERALOGY WITH INORGANIC CONSTITUENTS IN UCG PROCESS EFFLUENTS

Inorganic constituents present in UCG process effluents can be strongly correlated with changes in coal and overburden mineralogy. An analysis of the Hanna, Wyoming, UCG site provides insight on how inorganic constituents enter the system. A comparison of preburn versus postburn mineralogy indicates that carbonates, clay minerals, micas, and sulfurous minerals break down structurally because of high temperatures. This decomposition releases calcium, magnesium, silica, and aluminum for rebonding in high-temperature stable silicate and al um1 nosi1icate minerals. It also releases constituents such as iron, sodium, sulfur, and boron into the UCG process effluent. Other constituents such as calcium, copper, magnesium, manganese, potassium, and sodium are predominantly introduced into the groundwater by leaching. Groundwater quality data and analyses of other process effluents support these interpretations. Complete chemical and mineralogical characterization of the coal, coal ash, and immediate overburden is an important tool in determining inorganic constituents that affect groundwater quality at UCG sites. Early planning offers substantial economic incentives by allowing treatment while the constituents are confined to the cavity before migration affects much larger areas.     

CORRELATION OF COAL AND OVERBURDEN MINERALOGY WITH INORGANIC CONSTITUENTS IN UCG PROCESS EFFLUENTS

ABSTRACT

Inorganic constituents present in UCG process effluents can be strongly correlated with changes in coal and overburden mineralogy. An analysis of the Hanna, Wyoming, UCG site provides insight on how inorganic constituents enter the system. A comparison of preburn versus postburn mineralogy indicates that carbonates, clay minerals, micas, and sulfurous minerals break down structurally because of high temperatures. This decomposition releases calcium, magnesium, silica, and aluminum for rebonding in high-temperature stable silicate and al um1 nosi1icate minerals. It also releases constituents such as iron, sodium, sulfur, and boron into the UCG process effluent. Other constituents such as calcium, copper, magnesium, manganese, potassium, and sodium are predominantly introduced into the groundwater by leaching. Groundwater quality data and analyses of other process effluents support these interpretations. Complete chemical and mineralogical characterization of the coal, coal ash, and immediate overburden is an important tool in determining inorganic constituents that affect groundwater quality at UCG sites. Early planning offers substantial economic incentives by allowing treatment while the constituents are confined to the cavity before migration affects much larger areas.     

PHYSICAL AND CHEMICAL CHARACTERIZATIONS OF ASPHALTENES FROM DIFFERENT SOURCES

ABSTRACT

Asphaltenes and resins are two of the several, but important, heavy organics present in petroleum fluids. Asphaltenes are operationally defined as the non-colatile and polar fraction of petroleum that is insoluble in n-alkanes (i.e., n-pentane). Conversely resins are defined as the non-colatile and polar fraction of petroleum that is soluble in n-alkanes (i.e., n-pentane), and aromatic solvents (i.e., toluene), and insoluble in ethyl acetate. A commonly accepted view in the petroleum chemistry is that crude oil asphaltenes form micelles which are stabilized by adsorbed resins kept in solution by aromatics. Two key parameters that control the stability of asphaltene micelles in a crude oil are the ratio of aromatics to saturates and that of resins to asphaltenes. When these ratios decrease, asphaltene micelles will coalesce and form larger aggregates. The precipitation of asphaltene aggregates can cause problems such as reservoir plugging and wettability reversal.     

煤层气的封存与富集条件

在水文地质条件简单的地区,煤层气的封存主要取决于煤层气富集区的构造及盖层岩性。通常情况下,压性断层可使煤层甲烷增多,张性断层使其降低。但在远离张性断层面的两侧,一般形成两个对称的平行条带状构造应力高压区,使得煤层甲烷含量相对升高,成为阻止煤层甲烷进一步向断层运移的天然屏障。背斜构造的中和面以上及向斜构造的中和面以下常会出现煤层甲烷的富集。依据煤层气盖层的排驱压力、渗透率等值,盖层可分为屏蔽层、半屏蔽层和透气层,它们在不同的构造发育区,其封盖性能不同,由此可划分出9类不同的构造封盖层岩性组合类型。平顶山矿区的实例分析表明:Ⅰ类组合煤层气含气性最好,其次为Ⅱ类、Ⅳ类、Ⅴ类,其它类型含气性最差。     

T-STAR工艺的发展及其在煤液化工艺中的应用

对T-STAR工艺的产生、工艺特点及其发展应用进行综述,重点介绍该工艺在国内（神华煤制油化工有限公司鄂尔多斯煤制油分公司）煤直接液化项目上的首次应用情况及其工艺过程。通过对反应原料、产品和反应器内温度分布等方面的考察,阐述T-STAR装置与煤直接液化装置配套应用的优点,展望T-STAR工艺的应用前景。     

PHYSICAL AND CHEMICAL CHARACTERIZATIONS OF ASPHALTENES FROM DIFFERENT SOURCES

Asphaltenes and resins are two of the several, but important, heavy organics present in petroleum fluids. Asphaltenes are operationally defined as the non-colatile and polar fraction of petroleum that is insoluble in n-alkanes (i.e., n-pentane). Conversely resins are defined as the non-colatile and polar fraction of petroleum that is soluble in n-alkanes (i.e., n-pentane), and aromatic solvents (i.e., toluene), and insoluble in ethyl acetate. A commonly accepted view in the petroleum chemistry is that crude oil asphaltenes form micelles which are stabilized by adsorbed resins kept in solution by aromatics. Two key parameters that control the stability of asphaltene micelles in a crude oil are the ratio of aromatics to saturates and that of resins to asphaltenes. When these ratios decrease, asphaltene micelles will coalesce and form larger aggregates. The precipitation of asphaltene aggregates can cause problems such as reservoir plugging and wettability reversal.     

中压加氢裂化装置催化剂再生及其反应性能评价

中海炼化惠州炼化分公司3.6 Mt/a煤柴油加氢裂化装置采用中国石化石油化工科学研究院开发的中压加氢改质MHUG技术及其配套的RN-10B精制剂和RT-5裂化剂,加工环烷基直馏煤柴油和催化裂化柴油的混合油,主要生产高芳烃潜含量石脑油、3号喷气燃料和满足国V排放标准的清洁柴油产品。在该装置第一周期连续稳定运转了5年6个月后停工检修,对催化剂进行器外再生,再生后催化剂的运转结果表明：经过长周期运转和再生后,RN-10B再生剂与新鲜剂的脱硫、脱氮活性相当;RT-5再生剂的活性和提高十六烷值能力与新鲜剂相当;RN-10B和RT-5催化剂活性稳定性良好,再生剂活性损失小,产品分布和产品性质达到或优于设计值,可满足长周期稳定生产需要。     

IMPREGNATION AND RECOVERABILITY OF ELEMENTAL SULFUR IN COAL USING THE PERCHLOROETHYLENE DESULFURIZATION PROCESS

ABSTRACT

During the perchloroethylene extraction process, C-S bond cleavage reactions occur, which liberate labile sulfur from the organic matrix of coal into the solvent medium i.e., perchloroethylene, where it is dissolved and extracted. In this paper, the effect of impregnation of elemental sulfur in raw coal on its forms of sulfur analyses has been investigated. The effect of the same sulfur-impregnated coal on its organosulfur extractability has also been explored. Studies were conducted to observe whether the impregnated elemental sulfur was fully recoverable by the perchloroethylene extraction process. It was observed that sulfur can be very easily impregnated into the microstructure of coal. On the basis of tests on raw and impregnated coals, based on ASTM D-2492 standard, the impregnated sulfur reflects mostly in the form of organic sulfur. The impregnated sulfur which appears in the form of organic sulfur is fully recoverable via the perchloroethylene extraction