Oxygen absorption and desorption properties of YBaCo4O7+δ monolithic oxygen carrier in the fixed-bed reactor

Limin Hou,Chaoyue Qiao,Qingbo Yu,Wenfei Wu 한국화학공학회 2022 Korean Journal of Chemical Engineering Vol.39 No.3

The technology of chemical looping air separation, with the characteristics of simple operation, low cost, and low energy consumption, separates oxygen from air with the oxygen carrier. In this work, reaction properties of monolithic oxygen carriers were investigated in a fixed-bed apparatus, with the consideration of the reactor temperature, oxygen concentration, and reaction gas flow. The XRD results showed that active phase, Al2O3, and cordierite cannot react with each other in calcination processing. The SEM results showed that the micromorphology of oxygen carrier was loaded on cordierite honeycomb uniformly with sphere or sphere-like particles. Oxygen carriers show a faster oxygen release rate and a slower oxygen intake rate. With increasing of absorption temperature, oxygen concentration of inlet gas, and desorption temperature, the reaction rate per unit mass increases. With increasing of gas flow rate, the reaction rate per unit mass decreases. The maximum value of the reaction rate per unit mass was obtained by Y0.95Ti0.05BaCo4O7+δ monolith sample. Samples substituted with Dy element showed fine performance of stability, as Dy substitution causes more serious local lattice distortions.

Presidential Invited Talk Ⅱ : Presidential Invited Speakers

( Limin Hou ) 한국유아교육학회 2021 정기학술대회 논문집 Vol.2021 No.1

Kinetics of perovskite-like oxygen carriers for chemical looping air separation

Limin Hou,Qingbo Yu,Tuo Wang,Kun Wang,Qin Qin,Zhenfei Qi 한국화학공학회 2018 Korean Journal of Chemical Engineering Vol.35 No.3

Chemical looping air separation gives an energy-efficient choice for oxygen production. We performed kinetic analysis of YBaCo4O7+δ, Y0.95Ti0.05BaCo4O7+δ, Y0.2Ti0.05Dy0.75BaCo4O7+δ, and Y0.15Zr0.1Dy0.75BaCo4O7+δ oxygen carriers in a CLAS process. TG experiments were conducted with heating rates of 0.5, 1, and 2 oC/min in a thermogravimetric analyzer. Further exploration is required to develop an appropriate oxygen carrier. So, we used the model-free approach, Starink method, to evaluate the apparent activation energy. And, masterplots method was applied to determine the most probable mechanism function. The results show that the distributed activation energies of oxidation/ reduction process are 189.42/286.22 kJ/mol, 197.70/324.87 kJ/mol, 195.41/310.4 kJ/mol, and 192.20/293.53 kJ/mol for YBaCo4O7+δ, Y0.95Ti0.05BaCo4O7+δ, Y0.2Ti0.05Dy0.75BaCo4O7+δ, and Y0.15Zr0.1Dy0.75BaCo4O7+δ oxygen carriers, respectively. Random nucleation and nuclei growth A model is the most suitable for oxidation process. The A model and D are the most suitable for the reduction process. Regarding YBaCo4O7+δ, Y0.95Ti0.05BaCo4O7+δ, Y0.2Ti0.05Dy0.75BaCo4O7+δ, and Y0.15Zr0.1Dy0.75BaCo4O7+δ kinetic, oxygen transfer materials are rate-determined by nucleation and nuclei growth. For reduction kinetic, the gas diffusion stage could also become a dominant step.

Sensitivity analysis of key factors in controlling absorption and desorption of oxygen to oxygen carriers

Limin Hou,Qingbo Yu,Kun Wang,Shuo Zhang,Qin Qin,Fan Yang 한국화학공학회 2019 Korean Journal of Chemical Engineering Vol.36 No.1

Chemical looping air separation gives an oxygen resource for the oxy-fuel combustion system. To investigate the sensitivity of operation parameters and optimal operation parameters, with the consideration of the reactor temperature, we used the oxygen concentration, and reaction gas flow, an orthogonal experiment and multi-objective comprehensive evaluation method to analyze the results obtained by fixed-bed apparatus with the YBaCo4O7+, Y0.95Ti0.05BaCo4O7+, Y0.5Dy0.5BaCo4O7+, and Y0.2Ti0.05Dy0.75BaCo4O7+ oxygen carriers. The results showed that the effects of operating conditions on oxygen absorption/desorption properties varieds in the order: oxygen concentration>gas flow rate>absorption temperature=desorption temperature. Analysis of max-min difference showed that the optimum operating conditions such as absorption temperature, 350 oC, desorption temperature, 430 oC, gas flow rate, 200 ml/min, and oxygen concentration, 21% were confirmed

Mate recognition and antennal morphology of Octodonta nipae (Coleoptera: Chrysomelidae) adults

Lingfei Peng,Limin Chen,Jinlei Li,Youming Hou,Yigen Chen 한국응용곤충학회 2018 Journal of Asia-Pacific Entomology Vol.21 No.1

The nipa palm hispid beetle, Octodonta nipae (Maulik) has been killing palm trees since its introduction intoHainan province, China, from Malaysia in 2001. It continues to spread within Hainan province, northeast toFujian province, and northwest to Yunnan province within China. Knowledge on signals involved in mate locationand recognition could help develop effective integrated pest management programs. In the present study,we first experimentally proved that antennae were essential in success of O. nipae mating. We then excisedvarious segments/flagellomeres of adult male and female antennae and observed their mating behavior. Resultsrevealed that the 5th to 9th flagellomeres, especially those of males, were important for the mating success. Finally, in an attempt to elucidate the types of antennal sensilla accountable for the mating success, morphologyof O. nipae antennae was studied in detail with scanning electron microscopy. Six types of sensilla were distinguished:aporous sensilla trichodea (T1), multiporous sensilla trichodea (T2), aporous sensilla chaetica (Ch1),uniporous sensilla chaetica (Ch2), multiporous sensilla basiconica (B), and Böhm sensilla (Bm). Aporous sensillatrichodea is the most abundant; multiporous sensilla trichodea and sensilla basiconica are considered as olfactoryreceptors, and uniporous sensilla chaetica as gustatory receptor. Importance of flagellomeres 5–9 in matingsuccess seemed to correspond to the abundance of sensilla on these segments.

Bayesian Networks Application to Reliability Evaluation of Distribution Systems Containing Micro-Grids or Looped Network

Gao Liai,Zhou Yongjie,Su Kun,Hou Chenwei,Huo Limin 보안공학연구지원센터 2016 International Journal of Grid and Distributed Comp Vol.9 No.10

It is one of the effective methods to improve the reliability of the distribution system by using looped network power supply. With the development of new energy technology, distributed generation has been more widely used. But a small power system named micro-grid which is assembled by the device such as distributed generation, energy storage device and controllable load in a certain operating rules catches the attention of people. It can operate in islanded mode with the power grid failure, which can greatly improve the reliability of the system. Traditional analytical method and Monte Carlo method are difficult to evaluate its reliability accurately. In this paper, a new artificial intelligence method based on Bayesian networks is used for the system reliability analysis and evaluation. The corresponding Bayesian networks are established for the reliability test bus 2 which containing looped network and the improve reliability test bus 6 which containing micro-grids separately. With the help of causal reasoning and diagnostic reasoning, the supply influence of different types of DG output intermittent, operation mode on loads are detected, the key factors which have an impact on important load power supply reliability are found out, which is the theoretical foundation for practical engineering decision, so as to improve system reliability, identify failures and make maintenance scheduling.

Framework Design of Emergency Management Information System for Cloud Computing in Chemical Park

Jinfeng Zhang,Xin Zhao,Xin Liu,Limin Hou 보안공학연구지원센터 2014 International Journal of Future Generation Communi Vol.7 No.5

Comparative kinetic study of coal gasification with steam and CO2 in molten blast furnace slags

Fan Yang,Qingbo Yu,Huaqing Xie,Zongliang Zuo,Limin Hou,Qin Qin 한국화학공학회 2018 Korean Journal of Chemical Engineering Vol.35 No.8

To make a comparison between coal gasification in molten blast furnace slag (MBFS) in different ambience and choose an appropriate agent to recover BF slag’s waste heat entirely, coal gasification with steam and CO2 in molten blast furnace slags was studied by isothermal thermo-gravimetric analysis. The effects of temperature and addition of MBFS were studied. Carbon conversion and reaction rate increased with increasing temperature and MBFS. Volumetric model (VM), shrinking core model (SCM), and diffusion model (DM) were applied to describe the coal gasification behavior of FX coal. The most appropriate model describing the coal gasification was SCM in steam ambience and VM in CO2 ambience, respectively. The reaction rate constant k(T) in CO2 ambience is greater than that in steam ambience, which means the gasification reactivity of coal in CO2 ambience is better than that in steam ambience. BF slag can effectively reduce the activation energy EA of coal gasification reaction in different ambiences. But, the difference of activation energies is not large in different ambiences. Based on the results of kinetic analysis including k(T) and EA calculated by the established model, CO2 was chosen to be the most appropriate agent.

Power control of CiADS core with the intensity of the proton beam

Kai Yin,Wenjing Ma,Wenjuan Cui,Zhiyong He,Xinxin Li,Shiwu Dang,Feng Yang,Yuhui Guo,Limin Duan,Meng Li,Yikai Hou 한국원자력학회 2022 Nuclear Engineering and Technology Vol.54 No.4

This paper reports the control method for the core power of the China initiative Accelerator DrivenSystem (CiADS) facility. In the CiADS facility, an intense external neutron source provided by a protonaccelerator coupled to a spallation target is used to drive a sub-critical reactor. Without any control rodinside the sub-critical reactor, the core power is controlled by adjusting the proton beam intensity. Inorder to continuously change the beam intensity, an adjustable aperture is considered to be used at theLow Energy Beam Transport (LEBT) line of the accelerator. The aperture size is adjusted based on theProportional Integral Derivative (PID) controllers, by comparing either the setting beam intensity or thesetting core power with the measured value. To evaluate the proposed control method, a CiADS coremodel is built based on the point reactor kinetics model with six delayed neutron groups. The simulations based on the CiADS core model have indicated that the core power can be controlled stably byadjusting the aperture size. The response time in the adjustment of the core power depends mainly onthe adjustment time of the beam intensity