湿氧化法测定硅酸盐岩石中的全硫

测定岩石中全硫常用的方法是把样品与Na₂CO₃及NaNO₃的混合物一起进行氧化熔融,冷却之熔融物水提过滤,滤波酸化,而此时以硫酸盐形式存在之硫,在借酸之凝聚移去硅酸之后使成BaSO₄沉淀析出。该法费时,而空白值又较高;我们还发现它对有机物含量高的物质不适合,因为在熔融时侵蚀铂容器。故对湿氧化的快速决进行了探讨。      

我国高含硫化氢气的成因

根据我国发育高含硫化氢气所在地层组合类型和特点等,可把其成因归纳为以下几种:1.还原型:H₂S是由于硫酸盐在烃类或有机质参与下的高温化学还原作用产物,其形成可用以下反应式概括之:2C+CaSO₄+H₂O→CaCO₃+H₂S+CO₂ (1) ∑CH+CaSO₄→CaCO₃+H₂S+H₂O (2) (1)式中C为生油岩中有机化合物的碳;(2)式中∑CH为烃气(C_nH_2n+2),或为石油(LHC),或者两者皆有。     

辽河油田杜84块H2S成因探讨

辽河油田杜84块超稠油由蒸汽吞吐转为蒸汽辅助重力泄油（SAGD）开发后,产生了较高浓度的H₂S,导致脱硫设施投入和油气处理成本增加。通过原油、伴生气、地层水和储层矿物地球化学测试分析,H₂S产量与原油含硫量、地层水SO₄2-浓度无明显相关性,而与储层中黄铁矿含量一致性强,黄铁矿中的硫属于生物来源,同位素范围与原油基本一致,起源于原油稠化阶段,大量形成于稠油热采阶段。高温高压热模拟实验表明,注蒸汽热力采油过程中,除含硫有机质热裂解（TDS）和硫酸盐热化学还原反应（TSR）外,黄铁矿氧化分解也是H₂S形成途径之一,当注入低矿化度蒸汽对地层水稀释后,SO₄2-浓度下降,黄铁矿分解是H₂S的主要生成途径,H₂S的生成和分布受控于油藏地质条件、开发方式、开发时间和受热温度。      

石油伴生H2S的成因分析——以鄂尔多斯盆地彭阳油田为例

彭阳油田是鄂尔多斯盆地新探明的低H₂S含量的油田,其主力产层为侏罗系延安组,原油伴生H₂S含量最高为0.115%,明确H₂S成因机制对于油田合理开发及安全生产具有重要意义。基于储层硫化物及油田水硫同位素的系统分析,预测了侏罗系延安组原油伴生H₂S的成因。延安组主要发育集块状、斑点状、斑块状、星点状等黄铁矿类型,其δ³⁴S值为-1.9 ‰~10.1 ‰,其中,斑块状、集块状黄铁矿为沉积早期快速结晶成因,斑点状、星点状黄铁矿为硫酸盐还原菌还原作用成因。石膏的δ³⁴S值在16.8 ‰~17.7 ‰,为后期成岩阶段的产物,其并非H₂S的硫元素来源。油田水的δ³⁴S值较高,平均为37.9 ‰,这主要是由于硫酸盐还原菌还原作用消耗地层水中的³²S,使水体相对富集³⁴S。黄铁矿后期溶解和硫酸盐还原菌还原有机硫化物均可释放SO₄^2-,使侏罗系油田水具有较高的SO₄^2-浓度,为H₂S的生成提供了充足的物质基础。侏罗系地层水的矿化度、pH值及地层温度等物理化学条件均利于硫酸盐还原菌的生存,为硫酸盐还原菌还原作用提供了适宜的反应场所。综合分析认为,彭阳油田侏罗系原油伴生H₂S为硫酸盐还原菌还原成因。     

油气藏中烃类微渗漏与特态矿物形成

油气藏中烃类组分,尤其是轻烃(C₁—C₅)和非烃组分 H₂S、CO₂、H₂、CO 等,沿沉积地层中孔缝系统向地表方向微渗漏,引起油气藏上方岩石中孔缝系统化学环境改变,微渗漏的烃类组分与孔缝系统周围的岩石组分相互作用,形成特态矿物。目前,已发现具实际应用价值的特态矿物是黄铁矿、磁铁矿、磁黄铁矿和褐铁矿,其形成的物质是来源于油气藏的 H₂S 和沉积地层中的二价铁。特态矿物主要分布于油气藏上方沉积地层中,因此可用于油气勘探中。特态矿物法的最大特点是,可以对钻井尚未钻到的下伏地层中是否有油气层存在作出判断,对含低阻油气层的老探井进行含油气性重新评价。     

CO2与砂岩相互作用机理与形成的自生矿物组合

当CO₂以天然方式或人工方式注入到含水砂岩时,成岩流体将转变成弱酸性流体,引起宿主砂岩中不稳定矿物(如碳酸盐、长石)的分解和新矿物的沉淀,进而使砂岩的孔隙度、渗透率和地层水地球化学特征发生改变。CO₂注入砂岩后,仅有少量CO₂溶解于水中以气体形式存在,大部分CO₂以次生矿物形式(如方解石、白云石、菱铁矿等)被“固化”在宿主砂岩中,形成的典型自生矿物组合为:片钠铝石±含铁碳酸盐矿物±其它碳酸盐矿物组合和铁白云石+高岭石+自生石英组合。其中,前一种矿物组合是示踪CO₂运移、聚集的典型自生矿物组合。CO₂与砂岩相互作用机理及形成的自生矿物组合研究不仅拓宽了沉积盆地中流体-岩石相互作用研究领域,揭示了深部流体与浅部储集层之间、浅部烃源岩或其它岩石与附近储集层之间的物质转移,而且为储集砂岩品质评价、CO₂气藏(田)预测、CO₂地下储存等研究提供了基础地质信息。     

矿物/金属元素在煤成烃过程中的作用——以黔西滇东上二叠统大河边煤矿煤样为例

通过对原煤及添加过渡金属元素Mo(钼)和黄铁矿的原煤进行不同升温速率条件下煤层气生成热模拟实验,论述黄铁矿和Mo对于原煤热解生烃过程的影响。结果表明：矿物/过渡金属元素使原煤有机质具有更大的生烃潜力。黄铁矿对CH₄具有显著的正催化作用;同时加入黄铁矿和Mo时,生成的气体中会含有更多数量的重烃气,并有利于烯烃的产出;Mo对C₇-C₁₄具有显著的催化作用,但当同时有黄铁矿的参与时则会使C₇-C₁₄产率降低;黄铁矿/Mo的加入,则会影响到芳烃的产率高峰;较高的过渡金属单质含量对煤中本身含有的硫元素转化为H₂S气体有抑制作用。在中-高温度范围内,催化剂对有机质生烃具有催化作用,升温条件能明显影响黄铁矿对芳烃、饱和烃和沥青质的催化作用,反映古地温场条件是催化生烃的一个重要影响因素。      

Fe/Cu有机湿法氧化脱硫体系的H2S脱除性能

为提高湿法氧化脱除H₂S的效率,在酸性N-甲基吡咯烷酮溶剂中加入FeCl₃和CuCl₂,配制成双金属有机脱硫剂体系,测定其黏度、密度、化学结构、热稳定性等性质,考察了金属盐浓度、温度、再生时间等因素对脱硫与再生效果的影响,并对其脱硫反应机理进行了分析。结果表明：含Fe/Cu双金属盐的有机湿法氧化脱硫体系具有高效的脱硫能力,常压下该脱硫体系静态实际硫容为1.65 g/L;脱硫产物为纯度较高的硫磺,无硫代硫酸盐、硫酸盐等副产物,而且不存在脱硫污水排放问题;与传统水相湿法氧化脱硫剂相比,Fe/Cu双金属盐有机脱硫体系具有更好的经济性和环境友好性。     

一种聚集体溶垢剂对硫酸钡的溶解性能研究

以乙二胺四乙酸钠四水合物(Na₄EDTA·4H₂O)为单体与1,3-二氯丙烷反应合成了两个聚集体溶垢剂(二聚体QG1和四聚体QG2)。使用红外光谱对QG1和QG2的分子结构进行了表征，评价了溶垢剂对硫酸钡(BaSO₄)的溶解性能，并对溶垢机理进行了分析。溶垢性能评价结果表明，与Na₄EDTA·4H₂O相比，QG1与QG2聚集体溶垢剂对BaSO₄具有更好的溶解能力，且溶垢率随分子结构中聚集体数目的增加而增加。溶垢机理分析结果表明，两种聚集体溶垢剂对BaSO₄具有优异溶解性能的原因在于聚集体结构增加了溶垢剂分子与钡离子的络合稳定常数，且随着分子结构中聚集体数目的增多，络合稳定常数越大。QG1与QG2对Ba²⁺的络合稳定常数分别达到了12.51和18.54,而Na₄EDTA·4H₂O对Ba²⁺的络合稳定常数仅为8.54。     

钴铁尖晶石在CO2加氢中的结构演变与催化特性

利用原位X射线衍射(XRD)分析结合密度泛函理论(DFT)计算,揭示了采用溶胶-凝胶法合成的结构明确的钴铁尖晶石(CoFe₂O₄)在催化CO₂加氢转化中的结构演变与催化特性。原位XRD分析结果表明,CoFe₂O₄在预还原过程中形成Co₃Fe₇合金,Co₃Fe₇合金在反应中保持稳定,且其催化加氢能力较强,转化产物主要为甲烷与C₂～C₄烷烃(C₂⁰～C₄⁰)。K-CoFe₂O₄(将CoFe₂O₄用K₂CO₃助剂改性)的预还原过程中出现富钴合金(K-Co₁Fe₁)向富铁合金(K-Co_3...     

含铁矿物对高成熟有机质有水体系热解生气的影响

为了探讨含铁矿物对水—有机质生气的影响，基于黄金管热模拟装置，选用了高熟干酪根样品开展了3组有水体系（干酪根+水、干酪根+黄铁矿+水、干酪根+磁铁矿+水）的恒温热解实验。气体产物的定量分析结果表明，黄铁矿和磁铁矿的加入均导致干酪根在有水体系下气态烃产率一定程度的降低。比如，水—黄铁矿体系和水—磁铁矿体系在Easy%R_O=3.08%时CH₄产率相比单独有水体系分别降低8.5 mL/g_TOC和13.3 mL/g_TOC。水—黄铁矿体系CO₂产率及碳稳定同位素值明显高于单独有水体系和水—磁铁矿体系，含铁矿物（尤其是磁铁矿）加入的热解体系的H₂S产率明显低于单独有水体系。气体组成分析结果表明，含铁矿物的加入明显提高了烃类气体的干燥系数，同时导致异构烷烃相对含量的降低。水—磁铁矿体系气体产物氢同位素值相对低于单独有水体系，表明磁铁矿的加入促进了早期H₂的生成而与有机质之间发生了加氢作用。这些结果表明，含铁矿物的加入可能抑制了碳正离子的反应，水—有机质的加氢生气可能主要是自由基反应。     

MICROBIAL DESULFURIZATION OF COAL

The sulfur found in coal is generally divided into three forms: pyritic, sulfate, and organic sulfur. Originating from irt-situ oxidation of metal sulfides, sulfates axe present in coal at low concentrations. Being soluble in water, they are relatively easy to be leached from the coal. Similarly, microbial depyritization promotes the oxidative conversion of inorganic sulfur compounds to water-soluble products. The pyrite removal results from the combined effects of direct bacterial attack and indirect chemical solubilization. In the former, pyrite (FeS₂) is oxidized by bacteria into Fe₂(SO4) ₃; in the latter, ferric iron is the actual oxidizing agent and microorganisms serve to regenerate the ferric iron from ferrous iron.

Organic sulfur is chemically bound to the carbon skeleton of coal. It is believed to be present mainly in the forms of organic sulfides, disulfides, thiols and thiophenes. Two pathways have been proposed for microbial desulfurization of heterocycles. One emphasized the oxidation of carbon ring structures to polar teachable derivatives. The other stressed the sulfur-specific metabolism without degradation of the carbon skeleton. Both pathways have been demonstrated with model organosulfur compounds, especially dibenzothiophene (DBT). Reports on organic sulfur removal from coal and water-soluble coal-derived products by microorganisms are also available. Unfortunately, due to the difficulty in accurate analysis.of organic sulfur content, the technical feasibility of microbial organic sulfur removal from coal is still in dispute.

The costs of independent microbial depyritization and organic:sulfur removal were estimated to be $10-14 and $14 per ton of coal, respectively. A cost analysis for a tow-step process, which was designed to achieve complete removal of inorganic sulfur and a 40% reduction of organic sulfur, yieded $11 per ton of coal. These are lower than the costs of other techniques, e.g. $20-40 per ton of coal for flue-gas desulfurization.     

Prevention of Spontaneous Combustion of Sulfur-Containing Oil Tanks

Hydrogen sulfide in oil tanks can react with the corrosion products from inner walls (Fe₂ O₃, Fe₃ O₄, and Fe(OH)₃) to form ferrous sulfide. When the reaction is exothermic, it results in spontaneous combustion of ferrous sulfide and fires in oil tanks. In this paper, the effects of air flow rate; existence of water, oil, and monocrystal sulfur; and particle sizes of ferrous sulfide on the spontaneous combustion of ferrous sulfide are discussed and the measures to prevent the spontaneous combustion of ferrous sulfide are brought forward.     

DEEP DESULPHURISATION OF A DIESEL BLEND IN A PILOT PLANT TRICKLE BED REACTOR

A pilot plant investigation was conducted to study the influence of hydrotreating conditions on conversion and characteristics of diesel blend and to determine the severity of operating conditions required to meet the proposed product specifications for diesel fuel in India. A typical diesel blend derived from various refinery streams with sulphur content of 2·06 wt% was hydrodesulphurised over a commercial NiO-MoO₃/Al₂O₃ catalyst in a pilot plant trickle bed reactor. The experiments were conducted at 300-370°C, 30-50 kg/cm², 2·0 3·0 hr^-1 liquid hourly space velocity and constant H₂/oil ratio of 185 m³/m³. The data showed that the diesel blend could be hydrotreated to meet revised product specifications of 0·25 wt% sulphur, 46 cetane number by increasing the severity of operation. The cetane number and aromatic saturation were limited by thermodynamic equilibrium at temperatures above 360°C. The influence of temperature was found to be more pronounced than that of pressure in the range of operating conditions studied.     

MILD HYDROCRACKING OF VACUUM GAS OILS TO IMPROVE FCC PERFORMANCE AND MAXIMIZE DISTILLATE YIELDS

A pilot plant study was conducted on mild hydrocracking of heavy vacuum gas oils derived from two different crude sources over a commercially available catalyst to determine the possibility of utilizing mild hydrocracker bottoms as fluidized catalytic cracking feedstock along with improved middle distillate yields. The mild hydrocracking experiments were conducted at 390°C, 60 kg/cm², 1.0/h liquid hourly space velocity and H₂/oil ratio of 390 l/l in a pilot plant trickle bed reactor using two catalyst beds for pretreatment and mild hydrocracking reactions. The experimental results showed that mild hydrocracking would result in valuable middle distillates with low sulphur and nitrogen content. With research octane number of 78, the naphtha obtained from mild hydrocracking was found to be a good blending stock for gasoline pool. The middle distillate fraction (140-370°C) obtained from mild hydrocracking product was found to have cetane number in the range of 48-54. The bottom product from mild hydrocracking of heavy vacuum gas oils was found to be a good feedstock for fluidized catalytic cracking unit because of its low sulphur, nitrogen and aromatic contents. The data obtained from pilot plant studies showed that the processing of mild cracker bottom in FCC unit would result in better quality fuels.     

柴达木盆地英西地区古近系下干柴沟组上段TSR与储层改造

硫酸盐热化学还原反应(TSR)作为溶蚀作用的一种重要机制在储层研究中具有重要意义.通过岩心观察、薄片鉴定、扫描电镜、测井等资料的分析,研究了柴达木盆地英西地区下干柴沟组上段TSR特征及其对储层的改造作用.研究结果表明:①TSR反应物主要为烃类与硫酸盐岩,生成物为高含量的H2S,CO2及蚀变烃类、方解石、单质硫、黄铁矿、...     

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     

渤海湾盆地渤中坳陷沙一段与沙三段古湖泊水体分层新证据

前人对渤海湾盆地渤中坳陷湖相烃源岩有机质保存条件，尤其是对水体分层的研究，主要提出的是生物标志物证据，缺乏无机地球化学方面的证据。基于U、V元素在沉积水体中的富集原理，以及草莓状黄铁矿的形成机理，尝试探讨渤中坳陷沙一段与沙三段古湖泊水体分层的证据。结果显示，沙一段与沙三段V/（V+Ni）值分别介于0.20~0.93与0.62~0.78之间，指示古湖泊水体为缺氧环境。沙一段与沙三段U/Th值介于0.14~0.43之间，但是沙一段与沙三段U元素与TOC值具有明显正相关性，说明U元素富集于缺氧水体中。同时，沙一段与沙三段V元素与TOC值也具有明显正相关性，进一步说明沙一段与沙三段烃源岩沉积期，古湖泊边部水体均为缺氧环境，但非停滞缺氧环境。对沙一段与沙三段草莓状黄铁矿的平均粒径统计显示，沙一段与沙三段草莓状黄铁矿平均粒径仅略大于停滞缺氧环境的粒径上限5.0 μm，说明沙一段与沙三段沉积期，古湖泊边部浅水区水体存在一个氧化还原界面，该界面位于湖底沉积物向下几厘米深处。据此可推断，向古湖泊沉积中心方向，水体逐渐加深，水体中的氧化还原界面必然会逐渐上升至水体中部，此界面即为沙一段与沙三段水体的分层界面。     

Pt-Pd/SiO2-Al2O3催化剂芳烃加氢饱和性能研究

以SiO2质量分数40%的无定形硅铝和氢氧化铝干胶为主要原料,制备不同SiO₂含量的SiO₂-Al₂O₃载体,以氯铂酸和氯化钯为Pt和Pd的前躯物配制浸渍液,并用等体积浸渍法制备Pt-Pd/SiO₂-Al₂O₃催化剂。采用N₂吸附-脱附、X射线衍射、程序升温脱附、金相显微镜、透射电子显微镜等手段对所制备催化剂进行表征,在10 mL固定床加氢装置上,以2%（w）四氢萘+10%（w）十氢萘+88%（w）异辛烷混合物为原料对催化剂进行芳烃加氢活性评价。结果表明：在SiO₂质量分数为20%~40%范围内,随着SiO₂含量的增加,催化剂的比表面积增大,晶相组成不变,中强酸酸量增加,L酸酸量减少,B酸酸量增加;Pt-Pd在SiO₂-Al₂O₃载体上的分散由蛋壳型转变为均匀型,分散度增加;其催化四氢萘加氢的活性提高。随着浸渍液中盐酸浓度增加,催化剂上活性组分的分散度先增大后减小,盐酸浓度为0.1 mol/L时Pt-Pd/SiO₂-Al₂O₃活性组分的分散度最好,催化剂的四氢萘加氢活性最高。     

硫酸亚铁、硫酸高铁分离法及干酪根与黄铁矿结合形式的研究

对于干酪根样品的制备,目前方法较多,制备的纯度各不相同,甚至差异很大,直接影响了各项参数的测定。我们在制备干酪根过程中主要采用如下步骤:①有机溶剂除去可溶性有机质;②盐酸处理碳酸盐;③氢氟酸处理硅酸盐;④稀盐酸处理不溶性硅氟化物;⑤氯仿抽提进一步除净可溶性有机质;③溴化锌重液超声离心除去黄铁矿及其他杂质。