检索结果-南通市图书馆

Particuology 2024年第8期91卷 235-248页

作者： Min Cai Shuangzhu Kong Mengxi Liu Chunxi Lu state key laboratory of heavy oil processing China University of PetroleumBeijing102249China

Oxidative coupling of methane(OCM)is characterized by high temperature and strong heat released.A riser reactor is designed for the OCM process to improve gas-solid contacting and heat *** work illustrates the effect of hydrodynamic conditions and feed gas composition on the performance of an OCM riser *** findings suggest that oxidative reactions predominantly occur within the acceleration zone and developed flow ***,at the low superficial gas velocity accompanied by a high solid circulating rate,the C_(2)yield initially increases in the acceleration zone,followed by a decrease in the developed flow zone and deceleration *** optimal operating conditions are a specific region corresponding to the solids holdup ranges from 0.015 to ***,the C_(2)yield can be elevated using an appropriate feed mixture.

关键词： Oxidative coupling of methane Riser Hydrodynamics Solids holdup

Acoustic characterization of hydrate formation and decomposition in clay-bearing sediments

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

petroleum Science 2024年第4期21卷 2830-2838页

作者： Yi-Jian Zhu Xiao-Mei Yang Xing Huang Hao Li Xiao-Hui Wang Yi-Fei Sun Peng Xiao Chang-Yu Sun Guang-Jin Chen state key laboratory of heavy oil processing College of Chemical Engineering and Environment China University of Petroleum

Understanding the acoustic characteristics of hydrates in various sediments is crucial for hydrate resource detection and safe and efficient exploitation, as hydrate occurrence patterns vary greatly in different sediments. In this work, sediments with different bentonite contents, water saturations, and types were prepared to investigate the characteristics of P-wave velocity(reflecting the magnitude of hydrate saturation in the sediment) and amplitude(reflecting the degree of hydrate-sediment cementation) during hydrate formation and depressurization. During hydrate formation, the P-wave velocity and amplitude have similar trends. As clay content increases, the P-wave velocity increase rates quickened. On the other hand, the increased rate of P-wave velocity slows down with the increase of water saturation in the clay-bearing sediments. Comparing various types of sediment shows that the water absorption and swelling of bentonite reduce the pore space, speeding up the cementation of the hydrate with the sediment and increasing P-wave velocity at a faster rate. Correspondence between P-wave velocity and hydrate saturation is strongly related to sediment type, clay content, and water *** rapidly decreasing amplitude in the early stage of hydrate depressurization indicates that hydrate in clay-bearing sediments is weakly cemented to the sediments, which is prone to stratigraphic *** findings of this study offer guidance for hydrate resource assessments in clay-bearing sediments as well as geologic risk estimations during hydrate mining.

关键词： Gas hydrate Bentonite Illite P-wave velocity Amplitude

Fabrication of highly effective electrodes for iron chromium redox flow battery

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2024年第5期17卷 3988-3996页

作者： Yingchun Niu Chao Guo Yinping Liu Guangfu Wu Tianhang Zhou Fangang Qu Ziji Yang Ali Heydari Chunming Xu Quan Xu state key laboratory of heavy oil processing China University of Petroleum(Beijing)Beijing 102249China

Iron-chromium redox flow batteries(ICRFBs)have emerged as promising energy storage devices due to their safety,environmental protection,and reliable *** carbon cloth(CC),often used in ICRFBs as the electrode,provides a suitable platform for electrochemical processes owing to its high surface area and interconnected porous ***,the CC electrodes have issues,such as,insufficient electron transfer performance,which limits their industrial ***,we employed silicic acid etching to carve dense nano-porous structures on the surface of CC electrodes based on the favorable design of ICRFBs and the fundamental principles of electrode polarization *** a result,we developed a multifunctional carbon cloth electrode with abundant vacancies,notably enhancing the performance of the *** fabricated electrode showcased a wealth of defect sites and superior electronic transport properties,offering an extensive and effective reaction area for rapidly flowing *** an electrode compression ratio of 40%and the highest current density in ICRFBs so far(140 mA·cm^(-2)),the battery achieved the average energy efficiency of 81.3%,11.24%enhancement over the previously published ***,throughout 100 charge-discharge cycles,the average energy efficiency degradation was negligible(~0.04%),which has the potential to become the most promising candidate for large-scale and long-term electrochemical energy storage applications.

关键词： iron chromium redox flow battery electron carbon cloth defect site density functional theory(DFT)calculation

A multiscale adaptive framework based on convolutional neural network: Application to fluid catalytic cracking product yield prediction

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

petroleum Science 2024年第4期21卷 2849-2869页

作者： Nan Liu Chun-Meng Zhu Meng-Xuan Zhang Xing-Ying Lan state key laboratory of heavy oil processing China University of Petroleum (Beijing) College of Artificial Intelligence China University of Petroleum (Beijing)

Since chemical processes are highly non-linear and multiscale, it is vital to deeply mine the multiscale coupling relationships embedded in the massive process data for the prediction and anomaly tracing of crucial process parameters and production indicators. While the integrated method of adaptive signal decomposition combined with time series models could effectively predict process variables, it does have limitations in capturing the high-frequency detail of the operation state when applied to complex chemical processes. In light of this, a novel Multiscale Multi-radius Multi-step Convolutional Neural Network(Msrt Net) is proposed for mining spatiotemporal multiscale information. First, the industrial data from the Fluid Catalytic Cracking(FCC) process decomposition using Complete Ensemble Empirical Mode Decomposition with Adaptive Noise(CEEMDAN) extract the multi-energy scale information of the feature subset. Then, convolution kernels with varying stride and padding structures are established to decouple the long-period operation process information encapsulated within the multi-energy scale data. Finally, a reconciliation network is trained to reconstruct the multiscale prediction results and obtain the final output. Msrt Net is initially assessed for its capability to untangle the spatiotemporal multiscale relationships among variables in the Tennessee Eastman Process(TEP). Subsequently, the performance of Msrt Net is evaluated in predicting product yield for a 2.80 × 10～6 t/a FCC unit, taking diesel and gasoline yield as examples. In conclusion, Msrt Net can decouple and effectively extract spatiotemporal multiscale information from chemical process data and achieve a approximately reduction of 30% in prediction error compared to other time-series models. Furthermore, its robustness and transferability underscore its promising potential for broader applications.

关键词： Fluid catalytic cracking Product yield Data-driven modeling Multiscale prediction Data decomposition Convolution neural network

Low-concentration and multi-component NMHCs capture from oil field exhaust using porous ZIF-8/iso-hexadecane slurry

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Green Chemical Engineering 2024年第2期5卷 245-256页

作者： Kun Li Han Tang Jin Cai Chun Deng Bei Liu Yunlei Peng Changyu Sun Guangjin Chen state key laboratory of heavy oil processing China University of PetroleumBeijing102249China

Non-methane hydrocarbons(NMHCs)are a common type of volatile organic compounds(VOCs)pollutant in the petrochemical industry and have attracted widespread attention because of their adverse health effects and environmental *** this paper,we report a new porous slurry formed with zeolitic imidazolate framework-8(ZIF-8)and iso-hexadecane to capture the low-concentration and multi-component NMHCs(mainly ethane(C_(2)H_(6)),propane(C_(3)H_(8)),and n-butane(n-C_(4)H_(10)))from the oil field *** sorption capacity of C_(2)H_(6)in the slurry is significantly higher than that of nitrogen(N_(2))and methane(CH_(4)).Moreover,the slurry demonstrated a clear advantage for C_(2)H_(6)over N_(2)and CH_(4)in competitive adsorption through the pressure-drop *** the NMHCs capture experiments,the C_(3)H_(8)and n-C_(4)H_(10)concentrations after purification can be reduced to below 100 ppm,while the C_(2)H_(6)concentration can reach approximately 180 *** encouragingly,in the breakthrough tests,the slurry exhibits a perfect kinetic separation selectivity for multi-component ***,to avoid structural collapse of ZIF-8 material during long-term use in acidic and wet environments,a certain amount of 2-methylimidazole was retained in the slurry as a protective agent in the material synthesis *** this way,the ZIF-8 materials in the slurry can retain the stable characteristic structure in an aqueous and acidic environment and keep the capture capacity for NMHCs without *** believe the porous ZIF-8/iso-hexadecane slurry is a promising capture agent for low-concentration and multi-component NMHCs with strong purification capacity and stability.

关键词： VOCs capture NMHCs capture MOFs ZIF-8 Porous slurry

Mixing effects of high-speed jets in gas-solid riser and downer reactors

在线全文

学校读者我要写书评

暂无评论

Particuology 2024年第9期92卷 196-209页

作者： Zihan Yan Dongdong Wang Lining Wu Chunxi Lu College of Chemical Engineering and Environment State Key Laboratory of Heavy Oil ProcessingChina University of Petroleum-BeijingBeijing102249China

For the high-temperature and short-contact time gas-solid reaction process,riser and downer are considered appropriate *** realize an intensive and complete mixing of reactants with catalysts,the feed raw is always introduced in the form of high-speed *** this study,in order to investigate the mixing effects of different types of high-speed jets in riser and downer,traceable ozone is injected with the high-speed feed jets to react with catalyst *** detecting the decomposition of ozone,the gas-solid mixing and reaction in riser and downer under the influence of both co-current and counter-current injections are *** relative ozone concentration is used to reflect the location reaction extent and its radial nonuniformity index is proposed to compare the results in riser and *** is found that the jet influence zone in downer provides a relatively better environment for the mixing of feed jets with *** the riser,introduction of counter-current injections could improve the uniformity of gas-solid mixing in the initial contact region of feed with catalysts.

关键词： Riser Downer Gas-solid two-phase flow Jet

Ce-and La-doped polymetallic layered double hydroxides for enhanced oxygen evolution reaction performance at high current density

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第8期67卷 2586-2598页

作者： Rinel R.Kimaka P. Ping Wang Miao He Senyao Meng Jiasai Yao Huawei Li Cheng Yang Zhenxing Li state key laboratory of heavy oil processing College of New Energy and MaterialsChina University of Petroleum(Beijing)Beijing 102249China

Polymetallic layered double hydroxides are promising cost-effective catalysts for the oxygen evolution reaction(OER) due to their versatile anionic and cationic tunability. Nevertheless, several challenges persist, notably, issues related to low electrical conductivity, poor catalytic activity, and stability, especially at high current density. Herein, we report the design of Ce-and Ladoped Co Ni Fe-layered double hydroxide(Ce La Co Ni Fe-LDH) nanosheets through a facile and scalable in situ self-assembly strategy that displays enhanced OER activity. Experimental and theoretical investigations provide insights into the impact of Ceand La-doping by comparing Ce Co Ni Fe-LDH, La Co Ni Fe-LDH, and pristine Co Ni Fe-LDH, all synthesized using the same methodology. These results reveal that doping Ce^(3+)and La^(3+)into Co Ni Fe-LDH substantially improves its electronic structure,resulting in enhanced conductivity, more oxygen vacancies(Vo), electron interaction, and active site formation. Consequently,significantly reduced overpotentials of 175, 314, and 424 m V at 10, 100, and 500 m A cm^(-2), respectively, and a highly stable current density of 120 h in 1 M KOH were achieved. Notably, these performance metrics surpass those of unmodified LDHs and are competitive with many lanthanide-doped transition metal-based LDH electrocatalysts, as well as noble metal catalysts like ruthenium catalysts. This work represents a pioneering effort in doping Ce^(3+)and La^(3+)ions into a functional Co Ni Fe-based electrocatalyst, offering inspiring OER performance and scalability potential.

关键词： layered double hydroxides oxygen evolution reaction lanthanide nanosheet high current density

Rate-limiting factors in hydrate decomposition through depressurization across various scales:A mini-review

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2024年第3期67卷 206-219页

作者： Xian Sun Peng Xiao Qinfeng Shi Lingban Wang Zhenbin Xu Yuhao Bu Xiaohui Wang Yifei Sun Changyu Sun Guangjin Chen state key laboratory of heavy oil processing China University of Petroleum(Beijing)Beijing 102249China Jining university Jining 273115China

Natural gas hydrate is an energy resource for methane that has a carbon quantity twice more than all traditional fossil fuels ***,their practical application in the field has been limited due to the challenges of long-term preparation,high costs and associated *** studies,on the other hand,offer a safe and cost-effective means of exploring the mechanisms of hydrate dissociation and optimizing exploitation *** hydrate decomposition is a complicated process along with intrinsic kinetics,mass transfer and heat transfer,which are the influencing factors for hydrate decomposition *** identification of the rate-limiting factor for hydrate dissociation during depressurization varies with the scale of the reservoir,making it challenging to extrapolate findings from laboratory experiments to the actual *** review aims to summarize current knowledge of investigations on hydrate decomposition on the subject of the research scale(core scale,middle scale,large scale and field tests)and to analyze determining factors for decomposition rate,considering the various research scales and their associated influencing factors.

关键词： Gas hydrate Rate-limiting factors Research scale Depressurization Decomposition

Ca and Sr co-doping induced oxygen vacancies in 3DOM La_(2-x)Sr_(x)Ce_(2-y)CayO_(7-δ)catalysts for boosting low-temperature oxidative coupling of methane

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2024年第4期91卷 331-344页

作者： Tongtong Wu Yuechang Wei Jing Xiong Yitao Yang Zhenpeng Wang Dawei Han Zhen Zhao Jian Liu state key laboratory of heavy oil processing China University of PetroleumBeijing 102249China key laboratory of Optical Detection Technology for oil and Gas China University of PetroleumBeijing 102249China

It is urgent to develop catalysts with application potential for oxidative coupling of methane(OCM)at relatively lower ***,three-dimensional ordered macro porous(3 DOM)La_(2-x)Sr_(x)Ce_(2-y)CayO_(7-δ)(A_(2)B_(2)O_(7)-type)catalysts with disordered defective cubic fluorite phased structure were successfully prepared by a colloidal crystal template method.3DOM structure promotes the accessibility of the gaseous reactants(O2and CH4)to the active *** co-doping of Ca and Sr ions in La_(2-x)Sr_(x)Ce_(2-y)CayO_(7-δ)catalysts improved the formation of oxygen vacancies,thereby leading to increased density of surface-active oxygen species(O_(2)^(-))for the activation of CH4and the formation of C2products(C2H6and C2H4).3DOM La_(2-x)Sr_(x)Ce_(2-y)CayO_(7-δ)catalysts exhibit high catalytic activity for OCM at low temperature.3DOM La1.7Sr0.3Ce1.7Ca0.3O7-δcatalyst with the highest density of O_(2)^(-)species exhibited the highest catalytic activity for low-temperature OCM,i.e.,its CH4conversion,selectivity and yield of C2products at 650℃are 32.2%,66.1%and 21.3%,*** mechanism was proposed that the increase in surface oxygen vacancies induced by the co-doping of Ca and Sr ions boosts the key step of C-H bond breaking and C-C bond coupling in catalyzing low-temperature *** is meaningful for the development of the low-temperature and high-efficient catalysts for OCM reaction in practical application.

关键词： 3DOM catalysts Ca ions Sr ions Low-temperature oxidative couplingof methane Oxygen vacancies O_(2)^(-) species

Preparation of N-B doped composite electrode for iron-chromium redox flow battery

在线全文

学校读者我要写书评

暂无评论

Green Energy and Intelligent Transportation 2024年第3期3卷 1-10页

作者： Yingchun Niu Senwei Zeng Guangfu Wu Qingtan Gao Ruichen Zhou Chuanyuan Li Yang Zhou Quan Xu state key laboratory of heavy oil processing China University of Petroleum Beijing102249BeijingChina

Iron-chromium redox flow battery(ICRFB)is an electrochemical energy storage technology that plays a vital role in dealing with the problems of discontinuity and instability of massive new energy generation and improving the acceptance capacity of the power *** cloth electrode(CC)is the main site where the electrochemical reaction occurs,which always suffers from the disadvantages of poor electrochemical reactivity.A new N-B codoped co-regulation Ti composite CC electrode(T-B-CC)is firstly generated and applied to ICRFB,where the REDOX reaction can be promoted significantly owing to the plentiful active sites generated on the modified *** contrasted with ICRFB with normal CC electrode,after 50 battery charge/discharge cycles,the discharge capacity(1,990.3 mAh vs 1,155.8 mAh)and electrolyte utilization(61.88%vs 35.94%)of ICRFB with CC electrode(T-B-CC)are significantly ***,the energy efficiency(EE)is maintained at about 82.7%under 50 cycles,which is 9.3%higher than that of the pristine electrically assembled *** comodulation of heteroatom doping and the introduction of Ti catalysts is a simple and easy method to improve the dynamics of the Cr^(3+)/Cr^(2+)and Fe^(3+)/Fe^(2+)reactions,enhancing the performance of ICRFBs.

关键词： Iron-chromium redox flow battery N-B co-doped co-regulation REDOX reaction rate Performance