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Alleviation of the plastic deformation of gel ink under strong stress through an esterification of xanthan gum reinforcing its double helix structure

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Chinese Journal of Chemical Engineering 2024年第3期67卷 49-57页

作者： Xiaokun Li Mingyi Wang Zilu Liu Song Yang Na Xu Wei Zhao Gan Luo Shoujun Liu College of Chemical Engineering and Technology Taiyuan University of TechnologyTaiyuan 030024China Shanxi Engineering Center of Civil clean Fuel Taiyuan University of TechnologyTaiyuan 030024China Shanxi Coking Coal in Yuncheng Salt Refco group Ltd. Yuncheng 044000China

As a natural organic polymer,xanthan gum(XG)can alleviate the plastic deformation of gel ink under strong stress and realize the reasonable regulation of the rheological properties of gel ink.However,as the double-helix structure connected by hydrogen bonds cannot resist the mechanical environment of strong stress,XG shows poor shear resistance.In this study,a polymer gel with interpenetrating polymer network structure was prepared by esterifying XG,taking polystyrene maleic anhydride(SMA)as the modifier.In addition to retaining the excellent rheological properties of XG,the generated polymer gel also exhibited high shear resistance.The optimal addition amount of the esterification reaction modifier was determined as mXG:mSMA=5:3 according to the gel ink standard.With this amount,the viscosity of the modified xanthan gum(SXG)gel increased to 1578.8 mPa·s and 100.7 mPa·s at shear rates of 4 s1 and 383 s1,respectively,and the shear resistance increased more than 2 times compared to the unmodified one.It is because of the ester bond formed by esterification that the reaction strengthens the interaction between molecular segments,enabling the new gel to resist to strong mechanical stress.The new polymer gel studied in this paper and the proposed mechanism of action provide new insights for the development of high-end gel ink and also provide theoretical support for the study of rheological properties of non-Newtonian fluids.

关键词： Gel ink Xanthan gum Esterification Simulation Shear resistance Gels

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Optimizing the Diameter of Plugging Balls in Deep Shale gas Wells

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Fluid Dynamics & Materials Processing 2024年第3期20卷 609-624页

作者： Yi Song Zheyu Hu Cheng Shen Lan Ren Xingwu Guo Ran Lin Kun Wang Zhiyong Zhao Shale gas Research Institute PetroChina Southwest Oil&Gasfield CompanyChengdu610056China State Key Laboratory of Oil&gas Reservoir Geology and Exploitation Southwest Petroleum UniversityChengdu610500China National Pipe Network group Sichuan East Natural gas Transmission Pipeline Co. Ltd.Wuhan430205China Fracturing Acidizing Company Downhole Operation Company of Chuanqing Drilling Engineering Co.Ltd.Chengdu610213China

Deep shale gas reserves that have been fractured typically have many relatively close perforation holes. Due to theproximity of each fracture during the formation of the fracture network, there is significant stress interference,which results in uneven fracture propagation. It is common practice to use “balls” to temporarily plug fractureopenings in order to lessen liquid intake and achieve uniform propagation in each cluster. In this study, a diameteroptimization model is introduced for these plugging balls based on a multi-cluster fracture propagationmodel and a perforation dynamic abrasion model. This approach relies on proper consideration of the multiphasenature of the considered problem and the interaction force between the involved fluid and solid phases. Accordingly,it can take into account the behavior of the gradually changing hole diameter due to proppant continuousperforation erosion. Moreover, it can provide useful information about the fluid-dynamic behavior of the consideredsystem before and after plugging. It is shown that when the diameter of the temporary plugging ball is1.2 times that of the perforation hole, the perforation holes of each cluster can be effectively blocked.

关键词： Deep shale gas fracture propagation fluid mechanics fluid-solid coupling perforation hole abrasion

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Performance of gas-Steam Combined Cycle Cogeneration Units Influenced by Heating Network Terminal Steam Parameters

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Energy Engineering 2024年第6期121卷 1495-1519页

作者： Guanglu Xie Zhimin Xue Bo Xiong Yaowen Huang Chaoming Chen Qing Liao Cheng Yang Xiaoqian Ma Zhongshan Jiaming Electric Power Co. Ltd.CNOOC Gas&Power GroupZhongshan528403China School of Electric Power South China University of TechnologyGuangzhou510640China

The determination of source-side extracted heating parameters is of great significance to the economic operation of cogeneration systems.This paper investigated the coupling performance of a cogeneration heating and power system multidimensionally based on the operating characteristics of the cogeneration units,the hydraulic and thermodynamic characteristics of the heating network,and the energy loads.Taking a steam network supported by a gas-steam combined cycle cogeneration system as the research case,the interaction effect among the source-side prime movers,the heating networks,and the terminal demand thermal parameters were investigated based on the designed values,the plant testing data,and the validated simulation.The operating maps of the gas-steam combined cycle cogeneration units were obtained using THERMOFLEX,and the minimum source-side steam parameters of the steam network were solved using an inverse solution procedure based on the hydro-thermodynamic coupling model.The cogeneration operating maps indicate that the available operating domain considerably narrows with the rise of the extraction steam pressure and flow rate.The heating network inverse solution demonstrates that the source-side steam pressure and temperature can be optimized from the originally designed 1.11 MPa and 238.8°C to 1.074 MPa and 191.15°C,respectively.Under the operating strategy with the minimum source-side heating parameters,the power peak regulation depth remarkably increases to 18.30%whereas the comprehensive thermal efficiency decreases.The operation under the minimum source-side heating steam parameters can be superior to the originally designed one in the economy at a higher price of the heating steam.At a fuel price of$0.38/kg and the power to fuel price of 0.18 kg/(kW·h),the critical price ratio of heating steam to fuel is 119.1 kg/t.The influence of the power-fuel price ratio on the economic deviation appears relatively weak.

关键词： gas-steam combined cycle cogeneration of heating and power steam network inverse problem operating performance

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Late Ordovician Mass Extinction: Earth, fire and ice

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National Science Review 2024年第1期11卷 51-65页

作者： David A.T.Harper Palaeoecosystems group Department of Earth SciencesDurham University

The Late Ordovician Mass Extinction was the earliest of the ‘big’ five extinction events and the earliest to affect the trajectory of metazoan life. Two phases have been identified near the start of the Hirnantian period and in the middle. It was a massive taxonomic extinction, a weak phylogenetic extinction and a relatively benign ecological extinction. A rapid cooling, triggering a major ice age that reduced the temperature of surface waters, prompted a drop in sea level of some 100 m and introduced toxic bottom waters onto the shelves. These symptoms of more fundamental planetary processes have been associated with a range of factors with an underlying driver identified as volcanicity. Volcanic eruptions, and other products, may have extended back in time to at least the Sandbian and early Katian, suggesting the extinctions were more protracted and influential than hitherto documented.

关键词： Ordovician LOME paleoecology palaeobiogeography biotas

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Inter-layer interference for multi-layered tight gas reservoir in the absence and presence of movable water

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Petroleum Science 2024年第3期21卷 1751-1764页

作者： Tao Zhang Bin-Rui Wang Yu-Long Zhao Lie-Hui Zhang Xiang-Yang Qiao Lei Zhang Jing-Jing Guo Hung Vo Thanh National Key Laboratory of Oil and gas Reservoir Geology and Exploitation Southwest Petroleum University Shaanxi Yanchang Petroleum (group) Corp.Ltd. Waseda Research Institute for Science and Engineering Waseda University

Due to the dissimilarity among different producing layers, the influences of inter-layer interference on the production performance of a multi-layer gas reservoir are possible. However, systematic studies of inter-layer interference for tight gas reservoirs are really limited, especially for those reservoirs in the presence of water. In this work, five types of possible inter-layer interferences, including both absence and presence of water, are identified for commingled production of tight gas reservoirs. Subsequently, a series of reservoir-scale and pore-scale numerical simulations are conducted to quantify the degree of influence of each type of interference. Consistent field evidence from the Yan'an tight gas reservoir(Ordos Basin, China) is found to support the simulation results. Additionally, suggestions are proposed to mitigate the potential inter-layer interferences. The results indicate that, in the absence of water, commingled production is favorable in two situations: when there is a difference in physical properties and when there is a difference in the pressure system of each layer. For reservoirs with a multi-pressure system, the backflow phenomenon, which significantly influences the production performance, only occurs under extreme conditions(such as very low production rates or well shut-in periods). When water is introduced into the multi-layer system, inter-layer interference becomes nearly inevitable.Perforating both the gas-rich layer and water-rich layer for commingled production is not desirable, as it can trigger water invasion from the water-rich layer into the gas-rich layer. The gas-rich layer might also be interfered with by water from the neighboring unperforated water-rich layer, where the water might break the barrier(eg weak joint surface, cement in fractures) between the two layers and migrate into the gas-rich layer. Additionally, the gas-rich layer could possibly be interfered with by water that accumulates at the bottom of the wellbore due to gravitational differentiation duri

关键词： Tight gas Comingled production Interference Two-phase flow Water blocking

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SAPO-34 facilitates the formation of benzene,toluene and xylenes in direct syngas conversion over MnCrO_(x)-SAPO-34-ZSM-5

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Science China Chemistry 2024年第2期67卷 732-740页

作者： Shuchi Zhang Dengyun Miao Yi Ding Mengyuan Li Shujing Guo Yujuan Zhang Xiulian Pan Xinhe Bao State Key Laboratory of Catalysis Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian116023China University of Chinese Academy of Sciences Beijing100049China Shaanxi Yanchang Petroleum(group)Co. Ltd.&Dalian Institute of Chemical Physics Xi’an Clean Energy(Chemical Industry)Research InstituteXi’an710000China

Direct conversion of syngas to aromatics over metal oxide and zeolite(OXZEO) composite catalysts is promising.However,the selectivity of more valuable products such as benzene,toluene and xylenes(BTX) is limited due to undesired secondary methylation of BTX.Herein,we report that the introduction of SAPO-34 into MnCrO_(x)-ZSM-5 catalyst enhances significantly the formation of BTX without sacrificing the aromatics selectivity.Under optimized conditions,the fraction of BTX in aromatics reaches 64.7% versus 28.9% over the catalyst without SAPO-34.A number of model reaction tests and characterizations reveal that SAPO-34 consumes partially the intermediates such as ketene,by converting them to light olefins.Thus,the methylation of BTX by ketene to heavy aromatics is inhibited over the external acid sites of ZSM-5,leading to an enhanced BTX selectivity in the products.This hybrid catalyst provides an efficient method for highly selective synthesis of BTX from syngas.

关键词： selective syngas conversion OXZEO aromatics BTX multi-functional catalysts

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Isotopic insights on quantitative assessments of interaction of eco-hydrological processes in multi-scale karst watersheds

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International Soil and Water Conservation Research 2024年第1期12卷 156-170页

作者： Zhuo Hao Yang Gao Qingwen Zhang Wen Wen Agricultural clean Watershed Research group Institute of Environment and Sustainable Development in AgricultureCAASBeijing100081China Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources ResearchCASBeijing100101China School of Humanities and Social Sciences Beijing Institute of TechnologyBeijing100081China

The dynamics of hydrological processes and the storage mechanisms of karst water resources are the most important issues in karst hydrology.The impact of environmental changes on water quantity,and the evaluation and quantification of eco-hydrological processes remain poorly addressed.In this study,high-frequency continuous monitoring in multi-scale karst watersheds in Southwest China combined the approaches of water isotopes and the hybrid single-particle lagrangian integrated trajectory(HYSPLIT)model to identify the recharge mechanisms between atmospheric vapor,rainfall,surface water,and groundwater,and to reveal the interaction of eco-hydrological processes.The dominant moisture sources in Puding(PD)County were the Indian Ocean(43-69%)and local moisture(24-33%).Theδ^(18)O and deuterium excess(d-excess)values showed a positive correlation indicating that secondary or sub-cloud evaporation was prominent in the wet seasons.Karst water line-conditioned excess(lc-excess)indicated that karst water interacted with recent precipitation,groundwater,and evaporation across seasons.Owing to its specific hydrogeological structure,surface water and rainwater have a higher contribution rate to groundwater replenishment.The Chenqi stream replenished the Houzhai River mainly in the form of groundwater,with percentages ranging from 38.1 to 93.5%in the wet season,and 47.8-80.1%in the dry season.In the Houzhai outlet,surface water and groundwater interconverted frequently with a percentage of 45.6-49.1%.We believe this is the first systematic study to quantify the supply relationship between water vapor transport,rainfall,surface water and groundwater in the Chinese karst zone,making a significant move forward in the field of karst hydrological processes and improving the efficiency of water resource evaluation and management.

关键词： Stable isotope Moisture sources Water cycle Karst watersheds

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Migration and transformation of Pb,Cu,and Zn during co-combustion of high-chlorine-alkaline coal and Si/Al dominated coal

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Journal of Environmental Sciences 2024年第7期141卷 26-39页

作者： Jiangze Luo Qiwei Yang Jianqiao Wang Boxiong Shen Zhuozhi Wang Qiqi Shi Zhong Zhao Chao Huang Jie Xu Tianjin Key Laboratory of clean Energy and Pollution Control School of Energy and Environmental EngineeringHebei University of TechnologyTianjin 300103China School of Chemical Engineering Hebei University of TechnologyTianjin 300103China

Shaerhu(SEH)coal is abundant in Xinjiang,China.The utilization of SEH suffers from severe ash deposition,slagging,and fouling problems due to its high-chlorine-alkaline characteristics.The co-combustion of high-alkaline coal and other type coals containing high Si/Al oxides has been proven to be a simple and effective method that will alleviate ash-related problems,but the risk of heavy metals(HMs)contamination in this process is nonnegligible.Hence,the volatilization rates and chemical speciation of Pb,Cu,and Zn in co-combusting SEH and a high Si/Al oxides coal,i.e.,Yuanbaoshan(YBS)coal were investigated in this study.The results showed that the addition of SEH increased the volatilization rates of Pb,Cu,and Zn during the co-combustion at 800℃from 23.70%,23.97%,and 34.98%to 82.31%,30.01%,and 44.03%,respectively,and promoted the extractable state of Cu and Zn.In addition,the interaction between SEH and YBS inhibited the formation of the Pb residue state.SEM-EDS mapping results showed that compared to Zn and Cu,the signal intensity of Pb was extremely weak in regions where some of the Si and Al signal distributions overlap.The DFT results indicated that the O atoms of the metakaolin(Al_(2)O_(3)·2SiO_(2))(001)surface were better bound to the Zn and Cu than Pb atoms after adsorption of the chlorinated HMs.These results contribute to a better understanding of the effects of high-alkaline coal blending combustion on Pb,Cu,and Zn migration and transformation.

关键词： Heavy metals High-chlorine-alkaline coal Coal blending combustion Density functional theory

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Sludge composition and characteristics shaped microbial community and further determined process performance: A study on full-scale thermal hydrolysis-anaerobic digestion processes

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Journal of Environmental Sciences 2024年第3期137卷 96-107页

作者： Wei Liu Chenxiang Sun Wei Li Tianle Li Zhan Chen Jiawei Wang Zhengran Ren Xianghua Wen School of Environment Tsinghua UniversityBeijing 100084China Jinneng Holding group DatongShanxi 037000China Research and Development Center Beijing Drainage Group Co.Ltd.Beijing 100124China Beijing Dabeinong Science and Technology group Co. Ltd.Beijing 100080China

Anaerobic digestion (AD) with thermal hydrolysis (TH) pretreatment is a promising process for excess sludge treatment,while there lacks of the knowledge from full-scale process about the impact of sludge composition and characteristics on microbial community and performance.The sludge physiochemical indices,microbial community and performance data of four full-scale TH-AD plants were characterized,and their relationships was elucidated.The four plants were operated under almost similar total organic loading rate (OLR)but their methanogenesis performance differentiate into two groups,namely superior group(SupG) and the inferior group (Inf G).In both groups,TH effectively solubilized particulate organic compounds,meanwhile raised the ammonia nitrogen (NH_(4)^(+)-N) and volatile fatty acid (VFA) concentration.Compared with the Sup G,thermal hydrolyzed sludge of Inf G had higher level of VFAs,NH_(4)^(+)-N and total chemical oxygen demand (t COD),which showed higher inhibition effect on microbes,leading to a community with lower diversity,lower abundance of carbohydrate degrading functional guild,higher protein degrading one,and methanogens that adapted to limited substrates,and further declined the methane production rate.Thus,it was recommended that OLR alone was not sufficient for controlling the system in design and operation,the concentration of VFAs,NH_(4)^(+)-N and t COD should be equally considered.Their higher concentration,together with the higher abundance of Defluviitoga and Proteiniphilum were recommended as indicators for inferior running condition.Our results proposed that microbial communities played a role of bridge between environmental factors and performance,provided implications for engineering ecology and operational regulation for full-scale sludge TH-AD process.

关键词： Thermal hydrolysis Anaerobic digestion Microbial community Full-scale

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Geological conditions and reservoir characteristics of various shales in major shalehosted regions of China

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China Geology 2024年第1期7卷 138-149页

作者： Shu-jing Bao Tian-xu Guo Jin-tao Yin Wei-bin Liu Sheng-jian Wang Hao-han Li Zhi Zhou Shi-zhen Li Xiang-lin Chen The Key Laboratory of Unconventional Petroleum Geology China Geological SurveyMinistry of Natural Resources100083 BeijingChina Oil and gas Survey China Geological Survey100083 BeijingChina Research Institute of Yanchang Petroleum(group)CO.LTD 710076 Xi’anChina

China is home to shales of three facies:Marine shale,continental shale,and marine-continental transitional shale.Different types of shale gas are associated with significantly different formation conditions and major controlling factors.This study compared the geological characteristics of various shales and analyzed the influences of different parameters on the formation and accumulation of shale gas.In general,shales in China’s several regions exhibit high total organic carbon(TOC)contents,which lays a sound material basis for shale gas generation.Marine strata generally show high degrees of thermal evolution.In contrast,continental shales manifest low degrees of thermal evolution,necessitating focusing on areas with relatively high degrees of thermal evolution in the process of shale gas surveys for these shales.The shales of the Wufeng and Silurian formations constitute the most favorable shale gas reservoirs since they exhibit the highest porosity among the three types of shales.These shales are followed by those in the Niutitang and Longtan formations.In contrast,the shales of the Doushantuo,Yanchang,and Qingshankou formations manifest low porosities.Furthermore,the shales of the Wufeng and Longmaxi formations exhibit high brittle mineral contents.Despite a low siliceous mineral content,the shales of the Doushantuo Formation feature a high carbonate mineral content,which can increase the shales’brittleness to some extent.For marine-continental transitional shales,where thin interbeds of tight sandstone with unequal thicknesses are generally found,it is recommended that fracturing combined with drainage of multiple sets of lithologic strata should be employed to enhance their shale gas production.

关键词： Shale gas Marine shale Continental shale Marine-continental transitional shale Neoproterozoic-Cretaceous strata Geological conditions Reservoir characteristics Petroleum geological survey engineering

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