Preparation of Hierarchically Trimodal-Porous ZSM-5 Composites through Steam-assisted Conversion of Macroporous Aluminosilica Gel with Two Different Quaternary Ammonium Hydroxides

This article presents a detailed structural study of a new spherical Mg Cl2-supported Ti Cl4 Ziegler-Natta catalyst for isotactic propylene polymerization, and researches on the relationship between catalyst structure and polymer properties. The spherical support with the chemical composition of CH3CH2 OMg OCH(CH2Cl)2 has been synthesized from a new dispersion system and is used as the supporting material to prepare Ziegler-Natta catalyst. The XRD analysis indicates that the catalyst is fully activated with δ-Mg Cl2 in the active catalyst. The far-IR spectrometric results confirm again the presence of δ-Mg Cl2 in the active catalyst. Textural property of the active catalyst exhibits high surface area coupled with high porosity. The high activity in propylene polymerization is mainly ascribed to the full activation and the porous structure of the catalyst. Scanning electron microscopy/energy dispersive spectrometer mapping results indicate a uniform titanium distribution throughout the catalyst particles. Particle size analysis shows that the catalyst has a narrow particle size distribution. The perfect spherical shape, uniform titanium distribution and narrow particle size distribution of the catalyst confirm the advantage of polymer particles production with less fines. The solid state 13 C NMR and mid-IR spectroscopic analyses indicate that there exists strong complexation between diisobutyl phthalate and Mg Cl2, which leads to the high isotacticity of polypropylene.

Models of steam-assisted gravity drainage(SAGD) steam chamber expanding velocity in double horizontal wells and its application

The development of steam chamber can be used to evaluate steam-assisted gravity drainage(SAGD) performance. The velocity of steam chamber expanding is the key parameter for evaluating the development of steam chamber. Based on SAGD technology theory and heat transfer theory, two calculation model methods, observation well temperature method and steam chamber edge method for estimating the horizontal expanding velocity of steam chamber, were presented. Through analyzing the monitoring data and numerical simulation results of a typical super heavy oil block developed by SAGD in Fengcheng oilfield in Xinjiang, NW China, the development patterns of steam chamber and temperature variation law in the observation well at different stages are determined. The observed temperature data was used to calculate steam chamber expanding velocity. The calculated chamber velocity at different time was applied to predict the temperature distribution of oil drainage zone at the edge of steam chamber and SAGD oil rate. The results indicate that temperature function of high temperature zone in the observation well temperature curve has a linear relationship with measuring depth.The characteristic section can be used to calculate key parameters such as the angle of the drainage interface, expanding edge and velocity of steam chamber. The field production data verify that the results of the two proposed methods of steam chamber growth are reliable and practical, which can provide theoretical support for the efficient development of SAGD.

Sustainable Synthesis of Hierarchically Porous Silicalite-1 Zeolite by Steam-assisted Crystallization of Solid Raw Materials Without Secondary Templates

Hierarchical silicalite-1 zeolites were obtained from the direct conversion of a mixture of ground solid raw materials via a steam-assisted crystallization（SAC） method without involvement of any mesoscale template. Only a trace amount of water was necessary during the crystallization, implying that the amount of water can be dramatically reduced, which still offers easy separation and high yields. The simple procedure involved only grinding and heating, which not only saves resources and energy, but also significantly reduces the discharge of eco-friendly synthesis of zeolites for practical applications. Compared to conventional bulk silicalite-1, the nanosized hierarchical zeolites with MFI structure show enhanced removal capabilities for methylene blue owing to their hierarchical porosity.

Hierarchically Structured Monolithic ZSM-5 through Macroporous Silica Gel Zeolitization

The hierarchically structured ZSM-5 monolith was prepared through transforming the skeletons of the macroporous silica gel into ZSM-5 by the steam-assisted conversion method. The morphology and monolithic shapes of macroporous silica gel were well preserved. The hierarchically structured ZSM-5 monolith exhibited the hierarchical porosity, with mesopores and macropores existing inside the macroporous silica gel, and micropores formed by the ZSM-5. The products have been characterized properly by using the XRD, SEM and N2 adsorption–desorption methods.

SAGD Optimization for Heterogeneous Reservoir

This paper demonstrates the use of a commercial simulator as a tool with which to optimize the SAGD （steam-assisted gravity drainage） start-up phase process. The factors affecting the start-up phase are the prime targets. Among the key investigated factors are wellbore geometry effects, reservoir heterogeneity and circulation phase length. Each of the parameters was investigated via steam chamber development observation along the well pair length and the cross sections in the mid, toe and heel areas. In addition, the cumulative recovery in given time, steam-to-oil ratio and CDOR （calendar day oil rate） production data are used to backup the observations produced in the simulated model. Furthermore, an additional component developed during the research is a statistical modification of a layer cake model with which to create a heterogeneous reservoir to represent real reservoir conditions, based on Monte Carlo＇s simulation.

Controllable synthesis of a large TS-1 catalyst for clean epoxidation of a C=C double bond under mild conditions

Development of a titanium silicalite-1(TS-1)catalyst with good crystallinity and a four-coordinate Ti framework is critical for efficient catalytic oxidation reaction under mild conditions.Herein,a size-controlled TS-1 zeolite(TS-10.1ACh(acetylcholine))was synthesized via steam-assisted crystallization by introducing acetylcholine as a crystal growth modifier in the preparation process,and TS-10.1ACh was also employed in epoxidations of different substrates containing C=C double bonds.The crystalline sizes of the as-synthesized TS-10.1ACh catalysts were controlled with the acetylcholine content,and characterization results showed that the particle sizes of highly crystalline TS-10.1ACh zeolite reached 3.0μm with a good Ti framework.Throughout the synthetic process,the growth rate of the crystals was accelerated by electrostatic interactions between the connected hydroxyl groups of the acetylcholine modifier and the negatively charged skeleton of the pre-zeolites.Furthermore,the TS-10.1ACh catalyst demonstrated maximum catalytic activity,good selectivity and high stability during epoxidation of allyl chloride.Importantly,the TS-10.1ACh catalyst was also highly versatile and effective with different unsaturated substrates.These findings may provide novel,easily separable and large TS-1 catalysts for efficient and clean industrial epoxidations of C=C double bonds.

Pad-scale control improves SAGD performance

Steam Assisted Gravity Drainage(SAGD)is widely used in the Athabasca oil sands deposit to recover bitumen.Since the viscosity of bitumen is high at original reservoir conditions,heat is required to lower its viscosity to the point it becomes mobile enough to be recovered under gravity drainage.To heat the reservoir,steam is injected into the formation and thus SAGD is energy intense.Given that the fuel used to generate steam is the largest operating cost,the steam-to-oil ratio is one of the key parameter for evaluating the economics of any SAGD project.Here,the use of dynamic distributed steam injection within a pad of SAGD wellpairs is explored.The results demonstrate that feedback control leads to improvements of the SOR over that of constant pressure.The results show that the controller is able to detect the“sweet spots”(oil zones with better geological properties)in the reservoir and dynamically deliver more steam to that region.Meanwhile,it reduces the steam injection towards relatively worse quality zones to lower the local SOR.

Direct synthesis of ordered mesoporous ZSM-5 zeolites from in situ crystallization of carbonaceous SBA-15

Two types of ordered mesoporous ZSM-5 zeolites with different mesopores were synthesized by a two-step method. First, carbonaceous SBA- 15 was produced by in situ carbonization of SBA- 15/P 123 composite. Then the obtained SBA- 15/C composite was transformed into crystallized mesoporous ZSM-5 by impregnation TPAOH followed by steam-assisted crystallization. The final calcined samples synthesized with typical SBA-15/P 123 precursor showed a wormlike morphology with the mean mesopore size of 4.6 nm, while samples synthesized with the addition of trimethylbenzene as swelling agent in the precursor exhibited the morphology of microsphere with the mesopore size of about 9.5 nm. Both two types of mesoporous ZSM-5 zeolites exhibited large surface area and mesopore structure. The steam-assisted crystallization （SAC） was performed with lower consumption of solvents. This two-step method may also be suitable for synthesizing other ordered mesoporous zeolites used as catalysts in some catatytic processes.