FUEL
·
2024
·
IF 6.7
Xiaofang Lv,Chang Li,Yang Liu,Mingguo Peng,Chuanshuo Wang,Qianli Ma,Shidong Zhou,Xiaoyan Li,Bohui Shi,Shangfei Song
Understanding the transportability of silica-sand-containing hydrate slurries is crucial for production safety of non-consolidated natural gas hydrate reservoirs, especially when solid-state fluidization technology is utilized. Despite some research on silica sand and marine sediments’ influence on hydrate formation kinetics, rheological studies are scarce for systems with silica sands. The formation process of cyclopentane hydrates under the coexistence of hydrophilic silica particles and surfactants were observed. The effects of the concentration and particle size of silica sands as well as the water cut and surfactant concentration of emulsion on the rheological properties of hydrate slurries were investigated using a rheometer. The results indicated: (1) Hydrophilic sand aggregates were entrapped in water droplets, indirectly affecting the oil–water contact area due to the increase in water droplet volume, which was conducive to the combination of alkanes and water molecules to form a hydrate shell; silica particles provided nucleation sites at the oil–water interface to promote the adsorption and aggregation of cyclopentane molecules. (2) The synergistic effect of silica sand and surfactants significantly shortened the induction time of hydrates and increased the viscosity of the slurry. As the concentration of silica sand (1 wt%, 5 wt%, 10 wt%) increased, the induction time of hydrate formation decreased by 44.8 min. Within the concentration range below 5 wt%, the viscosity of the slurry increased as the concentration increased, with an amplitude of 13830.7 mPa·s. The induction time of hydrate formation decreased with increasing silica sand particle size (2 μm, 6.5 μm, 12 μm), but the size of silica sand particles had no significant effect on the viscosity of the slurry. (3) Hydrate slurries in all systems exhibited shear-thinning behavior. There was no obvious relationship between the yield stress of slurry under different silica sand concentrations. However, the yield stress of the slurry was inversely proportional to the size of silica sand particles. The yield stress decreased by 141.13 Pa when the size of silica sand particles increased from 2 μm to 12 μm. Overall, this study highlighted the influence of silica sand presence on flow safety assurance in solid-state fluidization technology.
研究领域:
石油工程
·
流体力学
✓ 已验证
产品关联
DOI
高影响因子
CONSTRUCTION AND BUILDING MATERIALS
·
2025
·
IF 8
Ming Zhang,Pengfei Hu,Shangyu Sun,Jie Yao,Yubo Sun,Jing Zhong
The global surge in construction has intensified demand for natural silica sand (SS), causing shortages due to unsustainable extraction. This study explores the potential of using desert sand (DS) as an alternative to SS in producing ultra-high-performance alkali-activated concrete (UHPAAC), emphasizing the interactions between aggregates and the binding matrix. DS demonstrated a smoother surface morphology, finer particles, and a narrower gradation compared to SS. Substituting SS with DS at varying volume ratios improved the concentration of several elements in the pore solution of fresh mixtures. Samples with 10 vol% DS achieved the highest compressive strength, about 20 % higher than the SS reference mix. However, higher DS content reduced mechanical performance. Investigations of reaction products and microstructural characteristics revealed changes in the binder phase, including a lower Ca/Si ratio and improved local elastic modulus when DS was incorporated. Additionally, the smaller grain sizes of DS created numerous interfaces with the binding matrix, resulting in a more porous microstructure and declined micromechanical properties in the interfacial transition zone (ITZ) compared to SS. Nevertheless, the strategic incorporation of DS as a partial replacement for SS enhances both compressive and flexural strength while simultaneously reducing the environmental impact of UHPAAC production.
研究领域:
土木工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2019
·
IF 5.128
Mucong Zi,Daoyi Chen,Jiang Wang,Peng Hu,Guozhong Wu
Gas hydrate blockage in the emulsifying crude oil poses security risks to the subsea multiphase flow transportation. The kinetic and rheological properties of methane gas hydrate in the water-in-oil emulsion were in situ characterized by experiments in a high-pressure rheometer with particular focus on the effects of emulsion composition and silica sands. Results demonstrated that the methane hydrate growth rate and yield stress increased with the surfactant concentration and water fraction, while the hydrate formation in the emulsion of pure light alkanes was faster than that in the mineral oil emulsion. Moreover, the presence of silica sands shortened the hydrate nucleation time, eliminated the stochasticity of nucleation, and induced the occurrence of hysteresis by affecting the transient and steady state viscosity of hydrate-in-oil slurry. Overall, this study was of added knowledge to the hydrate formation mechanisms in the water-in-oil emulsion, which highlighted the fact that the high emulsification degree, high water fraction, and the high concentration and large particle size of silica sands in the multiphase flow would increase the risks of hydrate blockage in the oil-gas transportation pipelines.
研究领域:
化学工程
·
石油工程
✓ 已验证
产品关联
DOI
高影响因子
STUDIES IN CONSERVATION
·
2020
·
IF 0.623
Lina Xie,Bingjian Zhang
Sandstone is a common sedimentary rock that is easily carved due to its weakly cemented fine grains and relatively low strength. Therefore, numerous large-scale grottoes in China are made of sandstone. However, these sandstone cultural heritage structures are often seriously damaged due to temperature and humidity changes, air pollution, biodeterioration, and repeated dissolution and crystallization of soluble salts. In general, it is imperative that a consolidant capable of providing cohesion by infilling pores between the stone grains is synthesized. In recent years, it has been reported that using organic consolidation materials for sandstone protection comes with various negative effects, such as a short lifetime, poor compatibility, and preservation damage. Using inorganic consolidation materials to protect sandstone seems to be one of the research trends for the future. Herein, this paper introduces a permeable, inorganic magnesium-based material (MMH solution) for silica sand consolidation. To assess this consolidant, the paper investigates the influence of varying molar ratios of MgO:MgCl2·6H2O:H2O on properties such as penetration depth, consolidation weight, colour variation, and compressive strength. The results demonstrate that the molar ratios of MgO:MgCl2·6H2O:H2O can significantly affect the consolidation performance. Additionally, it is believed that the MMH solution of MgO:MgCl2·6H2O:H2O = 5:1:16 can be successfully used for the consolidation of silica sand, as the cubic specimens’ surface micrographs show good compatibility between the consolidation product and sand grains. Experiments (i.e. weight loss rate and mineralogical compositions analysis) are performed to evaluate the cubic specimens’ water resistance properties after being immersed in water. Furthermore, the consolidation material’s failure mechanism as a self-sacrificing material is preliminarily analyzed. Results indicate that MMH solution is a promising conservation material that shows great potential for consolidating severely weathered sandstone.
研究领域:
文物保护
·
材料科学
·
地质学
✓ 已验证
DOI
高影响因子
CONSTRUCTION AND BUILDING MATERIALS
·
2024
·
IF 7.4
Yanchen Oinam,Kebede Alemayehu Moges,Prabhat Vashistha,Sukhoon Pyo
This study investigates the impact of incorporating lime mud (LM) as a filler material to develop sustainable, cementless ultra-high performance concrete (UHPC) by replacing silica powder (SP) and silica sand (SS) at varying percentages. Flowability analysis reveals that LM, with its distinctive particle size, influences flow characteristics differently at different replacement levels. Compressive strength was improved by 5.4% with 30% SP replacement, showcasing the role of LM in nucleation, as well as its particle size advantage. The heat of hydration analysis indicates that LM likely influences the early curing stages, enhancing reactivity and nucleation. TGA analysis also confirms that LM plays a role in hydration reaction , influencing weight loss and hydration peaks. The mercury intrusion porosimeter results show the impact of LM on pore distribution, with 30% for SP and 50% for SS replacements, favoring denser matrices. Life cycle assessment (LCA) demonstrates reduced CO 2 emissions and favorable environmental performance, highlighting the sustainability potential of LM replacements. Overall, the incorporation of LM in UHPC shows promise in terms of enhancing its mechanical properties and environmental sustainability.
研究领域:
土木工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）