实验室条件下微生物降解原油的地球化学特征

利用选育出的高效降解菌种对辽河油样进行了微生物降解实验,通过对原油样品微生物作用前后的族组分进行色谱质谱分析,分析了微生物降解对原油中饱和烃、芳烃及胶质和沥青质各组分在原油中相对含量和内部组成的影响.结果表明,辽河油样经微生物降解,120天后正构烷烃和无环类异戊二烯烃完全消失,芳烃中烷基萘也部分降解.以此探讨原油中各组分的地球化学特征,对石油的质量、加工及勘探都有指导作用.     

云南保山盆地生物气源岩生物标志化合物特征

通过对保山盆地气源岩有机质饱和烃色谱、三环萜烷、四环萜烷、五环三萜烷及甾烷分布特征的研究,发现气源岩有机质碳数分布存在比较明显的奇碳优势,结合R.数据,认为该区气源岩成熟度很低;可溶有机质生物标志化合物中的三环萜烷、四环萜烷含量低,五环三萜烷中有含量十分丰富的生物藿烷,表明源岩成熟度低;还检测出与细菌作用有关的C<,30>-藿烯,并通过C<,30>-藿烯的含量初步确定研究区1.2 km左右深度为细菌活动的死亡深度;C<,27>、C<,28>、C<,39>规则甾烷具有C<,29>＞C<,27>＞C<,28>的分布特征,为不对称"V"字形与反"L"字形,表现了陆源有机质输入为主的特征;甾/萜比值小,表明细菌对有机质的改造比较强烈.     

准噶尔盆地西北缘车排子凸起上、下层系原油的地球化学特征差异及其意义

根据原油物性、化学组成、生物标志化合物以及稳定碳同位素等特征,将准噶尔盆地车排子地区各层系的原油划分为2组:一组是储集在侏罗系及以下层系的原油(下层系原油),另一组是储集在白垩系及以上层系的原油(上层系原油).同一组原油的物理和化学特征相似,而不同组的原油则相差较大.下层系原油为同一来源,来自二叠系烃源岩;上层系原油亦为同一来源,主要来自侏罗系.利用含氮化合物分布特征对该区进行油源划分和对比的结果与用密度、粘度、原油族组成和生物标志化合物等参数所得到的结果完全吻合,可见含氮化合物也可以用于原油类型划分和油源对比方面的研究.最后建立了车排子凸起的油气成藏模式:车排子凸起紧邻凹陷,油源条件充足;构造位置有利,是油气运移的优势指向区;该区发育的众多断层和不整合面,为油气的运移提供了良好的通道.油气沿断裂垂向运移时遇到不整合面则发生侧向运移,从而在空间上构成"Z"字形或呈阶梯状的运移路线,最终形成油藏类型多、含油层系多的成藏面貌.     

气相色谱-质谱联用研究聚乙烯在氩气中的裂变行为

模拟电弧炉的燃烧环境,利用气相色谱-质谱联用法研究了聚乙烯在氩气气氛中不同温度、不同氩气流量下的裂变行为。结果表明:聚乙烯在氩气气氛中,在温度低于700℃时主要裂变形成链烃;在温度达到900℃时开始形成多环芳烃,温度越高,所形成的多环芳烃的种类越多,烷基化程度越高,相对浓度越大。氩气流量的变化明显影响了聚乙烯的裂变产物,实验结果验证了烯烃、二烯烃(炔烃)是多环芳烃前体化合物的假设,高温下多环芳烃生成数量和相对浓度比低温下高的主要原因是高温下聚乙烯的裂解程度增大,使得更多量烯烃、二烯烃(炔烃)形成。因此,控     

集输管道CO2/油/水环境中X65钢的腐蚀特征

通过高温高压动态反应釜实验模拟油田集输管道腐蚀环境,采用腐蚀失重、X射线衍射、扫描电镜和电化学分析等方法,研究了CO₂/油/水环境中X65钢的腐蚀行为. 结果表明:不同原油含水率条件下,X65钢CO₂腐蚀形态发生改变. 含水率较低(40%~50%)时,原油的浸润作用使X65钢表面发生均匀腐蚀,局部由于原油吸附不均匀出现点蚀特征;含水率在70%~80%之间时,原油对钢表面屏障作用减弱,生成的产物膜厚而疏松、局部脱落引发台地腐蚀;含水率为90%时,台地腐蚀破坏区域扩大,腐蚀加重. 原油可以明显改变腐蚀产物晶体颗粒大小、堆垛方式、产物膜结构以及化学成分. 在原油的缓蚀作用下,X65钢CO₂腐蚀过程的温度敏感点向低温段移动,出现在50℃左右,腐蚀速率降低区间变宽,X65钢耐蚀性增强.      

钛氟酸钾-木屑法制备Al-Ti-C母合金机制与显微组织研究

采用X射线衍射(XRD)、扫描电子显微镜(SEM)、能谱仪(EDS)等研究了氟盐-木屑法制备的Al-Ti-C母合金的组织性能。结果表明:由氟盐-木屑与铝液反应制备的Al-Ti-C母合金的合成过程包含以下几个阶段。(1)铝与钛氟酸钾反应置换出的钛与铝反应生成钛铝化合物;(2)木屑在高温条件下发生脱水、碳化反应,裂解产物二氧化碳、碳与铝反应生成碳铝金属化合物,与钛反应生成钛碳化合物;(3)钛铝、碳铝、钛碳化合物组成具有细化作用的Al-Ti-C母合金。合金的物相为α(Al)、铝钛化合物与碳铝化合物组成的共晶组织,其中α(Al)相的平均晶粒尺寸为10～60μm。铝钛化合物为棒状、骨骼状共晶组织并沿晶界分布,晶内可见针片状Al_3Ti,颗粒状TiC相聚合成团块状分布。木屑裂解产物水、二氧化碳与铝反应生成氧化铝和氢以渣-气共生的形式聚集于晶界。     

近临界特性的地层水及其对烃源岩生排烃过程的影响

研究利用特制的地层孔隙热压模拟实验装置,开展了模拟地层孔隙空间高压液态水热体系烃源岩生排烃模拟实验.模拟实验施加的流体压力为38±2 MPa,温度为290～390℃.模拟实验结果显示了有关高压液态水及其与之相联系的流体压力和孔隙空间等因素对烃源岩生排烃影响作用的一些重要现象,实验发现高压液态水介质条件有利于液态油的生成和保存,不利于液态油向气态烃的转化,而且干酪根的生烃潜力和排油效率有一定的提高.这些新的实验现象可能主要与近临界特性的高压液态地层水的作用有关,进一步推断近临界特性的高压液态水参与干酪根向油气的转化反应,增加了水对油气的溶解能力.在地下实际烃源岩生排烃的温压(100～200℃,30～120 MPa)条件下,岩行孔隙中的地层水是一种相对低温高压压缩液态水,这种地层水可能具有近临界特性,对烃源岩生排烃过程有重要影响.但目前对这种现象的机理和石油地质意义还知之较少.因此,加强高压地层水近临界条件下烃源岩生排烃热压模拟实验研究,对进一步深入理解地层条件下的近临界水介质、流体压力、孔隙空间因素对生排烃过程的影响,深化烃源岩生排烃机理的探讨,建立地质尺度上的烃源岩生排烃动力学模型,都具有重要的理论和实际意义.     

长期低温模拟实验下松柏萜类化合物的早期演化特征

为了研究萜类化合物的早期演化特征,对松柏类有机质样品进行了长期(超过5年)的低温(80℃)模拟实验研究.使用色谱和色潜一质谱联用技术,测定了样品模拟早期(1年)和模拟后期(5年半)的饱和烃组成特征,实验结果表明萜类化合物和直链烷烃在沉积后发生了明显的早期演化.利用质谱鉴定出了地质体中较少报道的两种杜松四烯,一种松香四烯和三种降松香四烯等中间演化产物.据此给出了相对完整的杜松类倍半萜和松香类三环二萜的早期演化途径,发现该过程主要生成了萜类的各种芳构化衍生物,细菌等微生物应起到了重要的生物化学促进作用.     

高磷赤铁矿气化脱磷热力学研究

采用Fact Sage6.4热力学分析软件研究不同条件对高磷赤铁矿中磷平衡组成的影响,并结合试验进行验证。结果表明:不同温度下气态磷的存在形式不同,升高温度有利于气化脱磷;适量的Si O2含量能降低碳热还原氟磷酸钙的开始反应温度,Si O2含量较高时,气化脱磷率受反应生成的硅酸盐熔融物制约;当C含量较低时,磷仍以氟磷酸钙形式存在,当C含量较高时,磷被还原成Fe P形式;Cl2可以和被还原出来的P2反应生成PCl3,温度较低时,脱磷产物为PCl3,温度较高时,脱磷产物先为P2,改变脱磷产物生成PCl3需要更高的Cl2含量。采用综合热分析仪进行试验验证,其结果与热力学分析结果相符。     

生物质焦油催化裂解过程中二次焦油成分

以秸秆热解产生的焦油为原料,在固定床反应器实验台上进行了催化裂解实验,研究了反应温度和催化剂种类对生物质焦油的裂解反应产物——二次焦油成分的影响规律.在高铝砖作为催化剂作用下,随着温度的升高,二次焦油构成有芳香化的趋势,多环芳烃的种类和含量都在增加.反应温度的提高有利于焦油的深度转化,二次焦油产率降低;但是高温下生成的二次焦油芳化程度更高,更容易引起催化剂积炭失活.当反应温度为900℃时,碱性催化剂白云石和石灰岩作用下二次焦油成分相似,以复杂的大分子环烃为主,而且焦油成分种类减少到10种左右;酸性催化剂高铝砖作用下焦油成分仍然很复杂,有将近30种,除了含有大分子环烃外,还含有部分石蜡烃,芳香族种类很多,多以双环、三环以及四环的形式存在.      

油液对油底壳模态的影响分析

针对柴油机湿式油底壳的振动特性问题,以4120s型柴油机为例,采用有限元法对不同充液量的油底壳模态频率和振型特征进行分析,并对存在油液时的油壳系统进行增加加强板的结构改进.结果表明:随着机油量的增加,油底壳模态频率逐渐降低,模态振型也发生了显著变化;形貌优化后的油底壳,固有频率有较大提高,刚度大幅度增加,有利于减振降噪.     

冷轧轧制油抗杂油性能研究

杂油是影响冷轧轧制油乳化液性能的主要污染物之一,含杂油过多的乳化液将直接影响轧制生产润滑及轧后产品表面质量,因此测试轧制油的抗杂油性能十分重要。就冷轧不同种类及不同含量的杂油对乳化液的理化性能、稳定性、润滑性能以及热挥发性能的影响进行了分析测试。试验结果表明,液压油、油膜轴承油对乳化液的理化性能、润滑性能的影响基本一致,而液压油比油膜轴承油对乳化液的稳定性以及热挥发性能的影响更大。总体而言,杂油含量控制在20%以内是比较安全的,最大不能超过30%。     

海外大型油田油水井钢管的腐蚀机理

针对卡拉姆卡斯油田油井管、套管的实际腐蚀情况,选取腐蚀失效的油水井井管进行了失效分析,研究了造成井管腐蚀失效的主要原因,并开展了模拟高温高压环境下的静态及动态试验。结果表明:腐蚀速率随温度的升高而增大;高压环境中的腐蚀速率大于低压环境中的腐蚀速率;在CO2腐蚀环境中,碳钢试样表面生成的腐蚀产物主要为有一定保护性的FeCO3膜,导致均匀腐蚀减弱,局部腐蚀加剧;流动介质会破坏附着在金属表面的腐蚀产物膜。在相似的环境条件下,动态条件下的腐蚀速率大于静态条件。     

Melaleuca oil poisoning

A 23-month-old boy became confused and was unable to walk thirty minutes after ingesting less than 10 mL of T36-C7, a commercial product containing 100% melaleuca oil. The child was referred to a nearby hospital. His condition improved and he was asymptomatic within 5 hours of ingestion. He was discharged to home the following day. Melaleuca oil, extracted from the Melaleuca alternifolia, contains 50-60% terpenes and related alcohols. Clinical experience with products containing melaleuca oil is limited. This case report suggests that ingestion of a modest amount of a concentrated form of this oil may produce signs of toxicity.     

Comparative hypocholesterolemic effects of capybara (Hydrochoerus hydrochaeris dabbenei) oil, horse oil, and sardine oil in cholesterol-fed rats

A clinical trial was undertaken to assess the value of incorporating fluoride released from a commercially available bonding adhesive (Rely-a-Bond) to determine the extent of any protection provided against enamel decalcification. Fifty patients undergoing fixed appliance therapy were included in the trial. Contralateral quadrants were used as controls where no fluoride was present in the adhesive. Enamel decalcification after treatment and bond failure rates during treatment were investigated. A total of 366 experimental and 371 control teeth were included in the study. The results showed that 50 per cent of patients and 13.5 per cent of teeth exhibited post-treatment decalcification. The addition of fluoride to the adhesive did not significantly reduce the incidence of enamel decalcification. Bond failure rates were satisfactory for both experimental and control teeth (all under 5 per cent).     

Effect of high fat corn oil, olive oil and fish oil on phospholipid fatty acid composition in male F344 rats

Venous stasis associated with prolonged bed rest can enhance the risk of deep venous thrombosis (DVT). Pneumatic compression of the lower extremities can reduce this risk by preventing venous stasis. When selecting a method of leg compression for their patients, physicians must chose between two distinctly different types of compression devices. One device applies pressure with a single-chambered sleeve to the below knee region while the other applies pressure in a sequential gradient fashion from the ankle to the thigh. The current prospective study was designed to evaluated the ability of two such devices to increase blood flow in the profunda femoral vein. Venous blood flow velocity, compression time, and vein diameter were measured in nine normal experimental subjects using an Accuson duplex-Doppler before, during and after leg compression. Compression with the single-chambered device produced a significant rise in venous blood flow velocity; however, this could not be maintained and our results indicate a higher average velocity was achieved with the sequential gradient device. The sequential gradient device also moved a greater volume of blood and achieved a higher average blood flow rate. The time between deflation of the sleeve and return of a phasic respiratory signal was greater after compression with the sequential gradient device. These results suggest that sequential gradient compression produces the type of hemodynamic alterations needed to reduce the risk of DVT by achieving a sustained increase in venous blood flow and more completely emptying of the veins in the leg.     

A comparison of fish oil or corn oil supplements in hyperlipidemic subjects with NIDDM

OBJECTIVE: To examine the effects on blood lipids and glycemic control of fish oil and corn oil supplementation at two levels in subjects with hyperlipidemia and non-insulin-dependent diabetes mellitus (NIDDM). RESEARCH DESIGN AND METHODS: Forty subjects (18 men and 22 women; aged 53.9 +/- 7.0 years) with NIDDM and hyperlipidemia were randomly assigned to one of four treatment groups: 9 g of fish oil, 18 g of fish oil, 9 g of corn oil, or 18 g of corn oil daily supplementation for 12 weeks. RESULTS: The level of oil supplements (9 g compared with 18 g) did not have a significant effect within each oil group on glycemic control and lipids. Significant differences (P < 0.05) in lipids were found when the 9-g and 18-g groups were combined. In subjects consuming fish oil, plasma very-low-density lipoprotein (VLDL) cholesterol (P = 0.0001), plasma triglyceride (TG) (P = 0.0001), and plasma VLDL TGs (P = 0.02 at 6 weeks and P = 0.0001 at 12 weeks) were significantly lowered compared with subjects consuming corn oil. Plasma VLDL cholesterol increased across time in the corn oil group (P = 0.04). Plasma low-density lipoprotein (LDL) cholesterol was temporarily increased (P = 0.008) in the fish oil group at 6 weeks, but the effect was no longer present at 12 weeks. No significant differences between fish oil- or corn oil-supplemented diets were found in total plasma cholesterol, high-density lipoprotein cholesterol, fasting plasma glucose, glycosylated HbA1c, weight, and blood pressure. CONCLUSIONS: In this study, fish oil supplementation improved plasma VLDL cholesterol, VLDL TGs, and total TGs while having a transient deterioration in LDL cholesterol in subjects with NIDDM. Furthermore, fish oil supplementation had no significant deleterious effect on glycemic control.     

Regulating the use of degraded oil/fat in deep-fat/oil food frying

During frying, the degradation of oil produces harmful compounds. Improper monitoring of oil-discard times in restaurants either risks the public health or causes financial losses to industries. Measuring the oil quality is a complex problem and an online sensor is needed. The process of frying reviewed includes moisture, heat and fat/oil transfer, crust formation and various structural, textural and chemical changes in the product, and degradation of frying medium. Some of the European nations and the U.S. have specific regulations against the use of deteriorated frying oils. Due to the absence of a suitable online frying oil quality sensor for restaurant situations, it is difficult to implement any regulation against the use of deteriorated frying oil. Based on various regulations, a model regulation to increase the safety and quality of fried foods is discussed. Background and requirements for developing an online sensor to measure frying oil quality are discussed. Other related areas reviewed in this article are factors affecting oil penetration and absorption by the food, surfactant theory of frying, analytical indices, quick tests and acceptability of frying oil.