Kinetics of (TBAF + CO_2) semi-clathrate hydrate formation in the presence and absence of SDS

In this communication, the impacts of adding SDS(sodium dodecyl sulfate), TBAF(tetra-n-butylammonium fluoride) and the mixture of SDS ? TBAF on the main kinetic parameters of CO_2 hydrate formation(induction time, the quantity and rate of gas uptake, and storage capacity) were investigated. The tests were performed under stirring conditions at T = 5 ℃ and P = 3.8 MPa in a 169 cm~3 batch reactor. The results show that adding SDS with a concentration of 400 ppm, TBAF with a concentration of 1–5 wt%, and the mixture of SDS + TBAF, would increase the storage capacity of CO_2 hydrate and the quantity of gas uptake, and decrease the induction time of hydrate formation process. The addition of 5 wt% of TBAF and 400 ppm of SDS would increase the CO_2 hydrate storage capacity by 86.1% and 81.6%, respectively, compared to pure water. Investigation of the impact of SDS, TBAF and their mixture on the rate of gas uptake indicates that the mixture of SDS+TBAF does not have a significant effect on the rate of gas uptake during hydrate formation process.     

酸性聚醚离子液体中异丁烷和异丁烯的烷基化反应

The Br?nsted-acidic polyether ionic liquids (ILs) with different polymerization degrees (n value) were prepared via the reaction of tetramethylguanidine and epoxy ethane, followed by successive reactions with 1,3-propane sultone and trifluoromethanesulfonic acid (TfOH). The prepared ILs were characterized by infrared spectroscopy and 1H nuclear magnetic resonance spectroscopy, and their thermal stability was determined by thermal gravimetry. The synthesized polyether ILs coupled with TfOH were used to catalyze the alkylation reaction of isobutane and isobutene for the preparation of alkylate gasoline. The polyether ILs could improve the substrate dissolution and promote the separation of the catalyst from the products. The ideal IL (n = 94) was determined. The optimized alkylation reaction conditions covered: a VTfOH / VIL ratio of 0.35, a reaction temperature of 40 °C, a reaction time of 50 min, and a stirring speed of 800 r/min. The conversion of isobutene was 92.4% and the selectivity for the C8-product was 81.6%. Under optimal conditions, the catalyst life was determined and TfOH showed improved cyclic performance in the polyether ILs. After 8 operating cycles, the catalytic activity of the catalyst showed negligible decline.     

Mild and Highly Selective Preparation of Alkylate Gasoline Promoted by Using Polyetheramine-Based Acidic Ionic Liquid

A polyetheramine(PEA)-based Br?nsted-acidic ionic liquid(IL) was firstly prepared and used to promote the alkylation of isobutane with isobutene catalyzed by trifluoromethanesulfonic acid(TfOH). PEA-IL not only can resolve the persistent problem of poor solubility of the volatile and refractory reactants, but also can satisfactorily exhibit the separation of the catalyst from product oil for reuse. The PEA-IL/TfOH catalytic system with an adjustable acidity ensures a high alkylate selectivity. Under the conditions covering a VIL/VTfOH ratio of 10:3, a temperature of 25 °C, and a reaction time of 25 min, the C_8-product selectivity reaches 86.63%. The PEA-IL/TfOH catalyst can be reused 13 times without a decrease in the catalytic performance. After many operating cycles, the hydrophobic PEA-IL can be easily regenerated by simply adding water. This study provides a green, economic, and highly efficient method for producing high-octane alkylate gasoline.     

The assembly of a composite based on nano-sheet graphene oxide and montmorillonite

Graphene oxide(GO)nano-sheets were synthesized using a modified Hummers’method from graphite powder.The Raman spectrum of GO displayed a D-band at 1359 cm~(-1)and a G-band at 1594 cm~(-1).The I_D/I_Gvalue of GO was calculated to be 0.97,suggesting the formation of new sp~2 clusters upon reduction.A method was designed to investigate the assembly of the GO/montmorillonite(MMT)composite.After the addition of GO,the typical peaks of montmorillonite in FT-IR spectra shifted,indicating the assembly between GO and MMT.The D-band and G-band reduced sharply in the GO/MMT composite.More importantly,the D-band(1344 cm~(-1))and G-band(1574 cm~(-1))shifted significantly and the I_D/I_Gvalue of the GO/MMT composite was calculated to be 1.13,showing a change in the GO structure.In the addition of0.04 wt%GO to MMT,the value of interlayer space(d)was up to 13.0 A?measured by XRD due to the insertion of GOinto MMT.The evident increases in contents of carbon atoms(26.59%)and nitrogen atoms(3.44%)indicate that GO was successfully combined with MMT.The nano-pores and clay sheets were not observed in the SEM image of GO/clay,but obvious wrinkles,while flexible sheets were observed in the typical scanning electron microscopy images of GO.This further proves that GO was combining with clay.The TEM image shows that the GO nano-sheets were tiled on the surface of MMT sheets.This observation suggests that a stable assembly structure was formed between GO sheets and MMTsheets.The change in particle size of MMT with the addition of GO shows that interaction occurred between GO sheets and MMT sheets,which was further confirmed by the results of zeta potential.Adsorption and insertion were the main mechanisms to assemble GO and MMT.     

硅钨酸酸化的新型MIL-101（Cr）催化剂及其对正庚烷异构化反应的催化性能

0.4%Pt/xSTA-MIL-101(Cr) metal-acid bifunctional catalysts were prepared by impregnation using STA-MIL-101(Cr) as the support. The synthesized samples were verified to exhibit a typical octahedral structure of MIL-101(Cr) and the pore structure were arranged orderly. The specific surface area of the samples was extremely high and the samples were micro-mesoporous composite materials. Silicotungstic acid could retain its Keggin structure in the 0.4%Pt/xSTA-MIL-101(Cr) samples and the catalyst possessed moderately strong Br?nsted acid sites. Besides, the dispersion of Pt particles in MIL-101(Cr) was relatively high. n-Heptane isomerization was first used as a probe to test the novel 0.4%Pt/xSTA-MIL-10(Cr) catalyst. Compared with the conventional silicate catalysts, the catalytic performance of 0.4%Pt/30wt%STA-MIL-101(Cr) was significantly improved with n-heptane conversion of 58.93% and iso-heptane selectivity of 95.68%, respectively, when the reaction time was 2 h at the reaction temperature of 260 oC. The catalyst could still maintain a relatively high catalytic performance during the reaction time of 5 h. Compared with the non-noble metal catalysts, the catalytic efficiency is relatively high. The mechanism model of n-heptane isomerization over 0.4%Pt/xSTA-MIL-101(Cr) catalyst was established.     

Improvement of the prediction performance of a soft sensor model based on support vector regression for production of ultra-low sulfur diesel

A novel data-driven, soft sensor based on support vector regression(SVR) integrated with a data compression technique was developed to predict the product quality for the hydrodesulfurization(HDS) process. A wide range of experimental data was taken from a HDS setup to train and test the SVR model. Hyper-parameter tuning is one of the main challenges to improve predictive accuracy of the SVR model.Therefore, a hybrid approach using a combination of genetic algorithm(GA) and sequential quadratic programming(SQP)methods(GA–SQP) was developed. Performance of different optimization algorithms including GA–SQP, GA, pattern search(PS), and grid search(GS) indicated that the best average absolute relative error(AARE), squared correlation coefficient(R2), and computation time(CT)(AARE = 0.0745, R2= 0.997 and CT = 56 s) was accomplished by the hybrid algorithm. Moreover, to reduce the CT and improve the accuracy of the SVR model, the vector quantization(VQ) technique was used. The results also showed that the VQ technique can decrease the training time and improve prediction performance of the SVR model. The proposed method can provide a robust, soft sensor in a wide range of sulfur contents with good accuracy.     

A study of the mechanism of enhancing oil recovery using supercritical carbon dioxide microemulsions

Supercritical carbon dioxide (scCO 2) microemulsion was formed by supercritical CO 2 , H 2 O, sodium bis(2-ethylhexyl) sulfosuccinate (AOT, surfactant) and C 2 H 5 OH (co-surfactant) under pressures higher than 8 MPa at 45 oC. The fundamental characteristics of the scCO 2 microemulsion and the minimum miscibility pressure (MMP) with Daqing oil were investigated with a high-pressure falling sphere viscometer, a high-pressure interfacial tension meter, a PVT cell and a slim tube test. The mechanism of the scCO 2 microemulsion for enhancing oil recovery is discussed. The results showed that the viscosity and density of the scCO 2 microemulsion were higher than those of the scCO 2 fluid at the same pressure and temperature. The results of interfacial tension and slim tube tests indicated that the MMP of the scCO 2 microemulsion and crude oil was lower than that of the scCO 2 and crude oil at 45 oC. It is the combined action of viscosity, density and MMP which made the oil recovery efficiency of the scCO 2 microemulsion higher than that of the scCO 2 fluid.     

Optimum Operating and Regeneration Parameters of ZnI_2 Catalyst for Converting Methanol to Triptane:An Ideal Component of Unleaded Aviation Gasoline

Conversion of methanol(MeOH) to 2,2,3-trimethylbutane(triptane) over zinc iodide(ZnI_2)catalyst was investigated in a closed batch reactor.Optimum operating parameters were searched and catalyst deactivation and regeneration behaviors were discussed.The fresh,spent and regenerated catalysts were characterized by XRD,TG and XRF measurements to elucidate the related mechanism.The experimental results showed that the triptane yield reached up to 12.2% under the process conditions,including a reaction temperature of 200℃,an initial pressure of 0.35 MPa,a reaction time of 2 h,and a Me OH to ZnI_2 molar ratio of 2.The catalyst was gradually deactivated after several run cycles.A small amount of iodine was lost and a certain amount of ZnO was formed on the deactivated ZnI_2 catalyst.Deactivation of the catalyst could be attributed to the reduction of ZnI_2 amount,resulted from iodine loss and formation of Zn O.It was firstly pointed out from our work that the deactivated catalyst could be well regenerated by the hydrogen iodide(HI) and the tert-butanol compensation method,wherein the latter was added as an initiator into the reaction system.The activity recovery of the deactivated(spent) catalyst might be related to the reformation of ZnI_2 and acceleration of the initiation step of this reaction.     

Development of Light Cycle Oil(LCO) Hydrocracking Technology over a Commercial W-Ni Based Catalyst

Because of its high density and low cetane number, the light cycle oil(LCO) containing heavy aromatics(60%—80%) can hardly be transformed through the conventional hydro-upgrading technology. In this report, a novel LCO hydrocracking technology(FD2G) was proposed for the utilization of LCO to manufacture high value-added products. Through the ingenious combination of hydroprocessing catalyst and the hydrocracking process, the high octane gasoline and the ultra-low sulfur diesel(ULSD) blendstocks were produced simultaneously. The influence of catalyst type, reaction temperature, pressure, respectively, on the research octane number(RON) of produced gasoline was studied in a fixed bed hydrogenation reactor. It indicated that high reaction temperature and medium pressure would favor the production of highoctane gasoline through the conversion of bi-aromatic and tri-aromatic hydrocarbons. The typical results of FD2 G technology on commercial units showed that it could produce clean diesel with a sulfur content of less than 10 μg/g and clean gasoline with a research octane number(RON) of up to 92. It would be contributed to the achievement of the maximum profit of a refinery, the FD2 G technology could provide a higher economic efficiency than the other diesel quality upgrading technology under the current gasoline and diesel price system.     

Structure Optimization of a Horizontal Gas-Solid Rapid Separation Device

To meet the requirements for fast and efficient gas-solid separation at the outlet of a gas-solid concurrent downflow fluidized bed(downer), a new horizontal gas-solid rapid separator was designed based on the joint action of centrifugal and inertial forces. Under the same experimental conditions, a fluid catalytic cracking(FCC) catalyst was used as the material(with a particle density of 1 500 kg/m~3 and a mean particle size of 45.8 μm) to experimentally investigate the effects of the insertion length of gas outlet pipe, the bypass cylinder, the gas outlet direction, and the secondary separation structure on the separator performance. The results showed that with an inlet gas flow rate of 14.5 m/s and a gas phase solid content of 60―835 g/m~3, the downer system achieved a gas-solid separation efficiency of above 99.5%, with the separator's pressure drop within 1 846 Pa(when the separator included a bypass cylinder and a secondary separation structure with a proper insertion length of gas outlet pipe).     

进口天然气盈亏平衡定价对市场的影响——以广州市中亚天然气为例

2011年11月底土库曼斯坦天然气经过中亚—中国天然气管道和西气东输二线管道正式向位处华南的广州市供气。然而,由于中国天然气价格与国际气价脱节,天然气进口业务陷入进口越多亏损越多的尴尬境地,提高进口气入关后的价格将有助于缓解长期以来的进口气购销价格倒挂问题。为此,以广州市为例,测算了中亚天然气盈亏平衡时不同天然气用户的气价;采用天然气与可替代能源等热值直接成本对比法,按各类天然气用户实际支付可替代能源的现有价格等热值折算分析了对应的中亚天然气价格可承受能力。结果表明:从价格承受能力来看,居民用户和公共福利用户基本上是可以承受中亚天然气盈亏平衡定价;工商业用户也有一部分可以承受上述定价,但对燃料成本占总成本比重较大的用户,承受能力则较弱;天然气发电用户无法承受上述定价,中亚天然气发电只能扮演调峰角色。考虑到西气东输管道输送的既有国产气,也有进口气,为此提出:可以将国产气的出厂价与进口气的成本价加权平均,作为西气东输天然气的"出厂价"。     

稠油热采储层精细油藏描述研究进展

就稠油热采储层精细油藏描述的技术现状看:国外已经形成了完整的研究方法和技术体系,特别是在利用地震技术对油藏开发过程监测及剩余油分布规律的精细刻画等方面,具有相当高的研究水平;国内在储层单砂体的精细刻画、隔夹层研究以及储层在热采过程中的变化规律等方面,进行了大量的研究工作,取得了一定进步。稠油热采储层研究的关键问题为地层精细划分与对比、沉积微相研究、隔夹层发育规律描述、储层综合分类评价和地质建模研究等。在此基础上认为,稠油热采储层精细油藏描述研究的主要发展方向为井震结合断裂系统的精细刻画、地质体分类评价、稠油热采储层变化规律研究、剩余油分布规律的四维地震监测和隔夹层封隔能力的物理模拟与数值模拟验证等五大方面。     

阿姆河右岸酸性气田井口冲蚀及对策

中亚土库曼斯坦阿姆河右岸气田群为高含H_2S和CO_2的碳酸盐岩气藏,单井产量高,井口设备均出现了不同程度的腐蚀。初步分析认为其原因是生产过程中仅考虑酸性介质对气井井口的化学腐蚀,而没有考虑气体流速对井口的冲蚀作用,极大地影响了气田的安全生产。为此,通过对节流阀上下游阀道、法兰面均出现明显坑状腐蚀的进一步分析,明确了化学腐蚀和气体冲蚀的交互作用是井口磨损的主要影响因素,气流冲刷腐蚀坑的化学腐蚀产物会加速冲蚀损害;进而借鉴冲蚀与腐蚀运行环境下的多相管流管道的磨损计算理论,计算了该运行环境下的冲蚀极限速度,得到了不同生产工况下节流阀的抗冲蚀流量;最后,根据气田生产情况,针对性地提出了按气井配产要求来选择采气树类型、节流阀通径及类型冲蚀的技术控制策略。此举为气田安全生产提供了工程技术保障。     

微裂缝—孔隙型碳酸盐岩气藏改建地下储气库的渗流规律

微裂缝—孔隙型碳酸盐岩气藏储层非均质性强,边底水选择性水侵,渗流规律复杂,为了提高地下储气库的建库效率,需要研究储层在改建地下储气库多周期强注强采过程中的多相流体渗流规律。在获取有代表性的裂缝发育碳酸盐岩岩心较为困难的条件下,通过对天然岩心进行剪切造缝和多轮次气水互驱实验,研究了地下储气库气水过渡带在注采过程中的多相渗流规律,分析了裂缝合气空间贡献率以及储气库含气空间动用效果。结果表明:裂缝模型的相渗曲线近似于"X"形,多次气水互驱后相渗曲线基本没有变化,基质岩心模型相渗曲线经多次气水互驱后气水两相共渗区间变窄,共渗点降低;微裂缝对储层含气空间贡献率较高,微裂缝发育储层的含气空间利用率保持在较高水平,徽裂缝不发育储层的含气空间利用率逐渐降低并趋向稳定。因此,在微裂缝—孔隙型碳酸盐岩气藏改建地下储气库过程中可以在徽裂缝不发育储层布置生产井,同时通过控制边底水运移范围降低注入气损失,从而提高地下储气库的建库效率。     

山前地区深井超深井套管防磨与减磨技术研究

针对山前地区深井超深井钻井过程中套管磨损严重的问题,在分析套管磨损机理的基础上,开展了山前地区套管防磨与减磨技术研究,基于技术研究成果及应用实践,得到如下结论:1应用Power V等垂直钻井系统控制井眼轨迹,特别是上部井段的狗腿度和井斜,可明显减小侧向力和磨损量,缩短套管磨损时间;2应综合考虑套管磨损率、磨损系数以及钻杆耐磨带本身的磨损量,优选出效果最优的耐磨带;在狗腿度严重的位置,可考虑采用一定数量的橡胶钻杆卡箍来减轻对套管的磨损;3山前地区钻井液采用CX-300减磨剂能够显著降低磨损速率,减轻套管磨损程度,但在不同钻井液体系使用之前应进行优化分析以确定最佳使用量;4在迪那204井使用高密度钻井液体系,全部采用优选的高密度重晶石粉代替铁矿粉作为加重剂,整个钻进过程中未出现钻具及套管磨损,迪那204井易损件消耗量仅为邻井迪那203井的左右,防磨减磨效果非常显著。     

CNPC Maintains Strong Growth Momentum Both at Home and Worldwide

CNPC expects to raise its crude production by one million tons and natural gas output by 11.5 billion cubic meters in the year ahead. Priority must be given to the development of new oilfields as well as stabilization of the output of old ones if the crude production target is to be met, said Zhou Jiping, Vice President of CNPC. ＂The year of 2008 stands for a pivotal juncture for CNPC, during which a number of major projects will be carried out and all these strategic programs are vital to improving the production pattern and enhancing competitive strength of the company,＂ he added. In 2007,     

烷烃在ZSM-5分子筛上吸附扩散的气相色谱研究

利用气相色谱法测定了不同色谱柱温度和不同载气流速下,C1~12烷烃在ZSM-5分子筛上的保留时间,并利用相关公式对测试结果进行了线性回归分析,测得了吸附热力学参数和扩散系数;考察了色谱柱温度、烷烃碳链长度和载气流速对烷烃在ZSM-5分子筛上吸附扩散的影响。实验结果表明,回归分析的线性相关性良好,色谱柱温度越高,孔道对吸附质的吸附能力越弱;在不同载气流速下,轴向扩散系数不同;随烷烃碳链长度的增加,吸附焓变呈先增大后减小的趋势,轴向扩散系数呈线性增长;C1~12烷烃在ZSM-5分子筛上的吸附焓变在-1.264~-42.975 k J/mol之间;当载气流速为2.654~4.246 cm/s时,C1~4烷烃的轴向扩散系数在0.328 8~0.551 7 cm2/s之间;当载气流速为5.308~13.270 cm/s时,C1~4烷烃的轴向扩散系数在0.430 2~1.456 4 cm2/s之间。     

Biodiesel Projects Helpful to Ease Energy Shortage

Nearly 7,000 hectares of biodiesel forest will take shape in the northern province of Hebei in 2008, part of a national campaign to fuel the fast growing economy in a green way. In no more than five years, the Pistacia chinensis Bunge, whose seeds have an oil content of up to 40 percent, will yield five tons of fruit and contribute about two tons of high-quality biological diesel oil, according to the provincial forestry administration.     

State Energy Base Proposed in Inner Mongolia

Experts recently suggested China set up a state energy base in lnner Mongolia Autonomous Region to ease its energy thirst. The survey was co-conducted by senior researchers from the National Development and Reform Commission, Development Research Center of the State Council, Chinese Academy of Sciences and the Ministry of Finance. To plan and establish strategic energy bases at state level is in line with the principle of ＂giving priority to energy saving and diversifying energy consumption with the utility of coal at the core.＂     

基于双椭球热源模型的立管焊接残余应力研究

根据铺管时的实际工况,建立了深水钢悬链线立管的焊接有限元模型,采用双椭球热源模型模拟焊接中的移动热源,运用Fortan语言对模型进行汇编,并运用DFLUX子程序进行ABAQUS的二次开发。在仿真中运用单元生死技术来模拟焊料单元的焊接参与情况,分别选取不同的焊接参数进行焊接模拟,利用控制变量法进行立管焊接残余热应力及其影响因素研究。研究结果表明,立管焊缝处单位体积的热输入量以及单位体积的受热时间是影响残余应力场的主要因素;立管的几何参数在影响焊接残余应力场的同时也影响残余应力场应力较高区域,当其他焊接参数和焊接过程参数不变时,增大立管外径或减小壁厚均会造成更大的残余应力场和较高应力范围;焊接开始和结束位置的应力波动由材料受热不均匀造成。