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Full-Text Articles in Engineering

Performance Of Desiccant Enhanced Evaporative Cooling System Based On High-Low Control, Yi Chen, Huaxia Yan, Yimo Luo Nov 2019

Performance Of Desiccant Enhanced Evaporative Cooling System Based On High-Low Control, Yi Chen, Huaxia Yan, Yimo Luo

Technological and Higher Education Institute of Hong Kong (THEi) Staff Publications

Desiccant enhanced evaporative cooling system is a sustainable air-conditioning (A/C) system which deals the latent load and sensible load separately by a dehumidifier and an evaporative cooler. A LDD-RIEC system consists of a liquid desiccant dehumidifier (LDD) and a regenerative indirect evaporative cooler (RIEC) were investigated. The LDD-RIEC system is characterized by low energy consumption compared with conventional mechanical cooling system, but the main shortcoming is the high dependency on ambient air conditions. To maintain stable indoor temperature, a control scheme is essential. However, very limited research work regarding control strategy can be found in open literatures. In this ...


Outside The Site Boundary, Timothy Kwan Fai Chan Jan 2019

Outside The Site Boundary, Timothy Kwan Fai Chan

Technological and Higher Education Institute of Hong Kong (THEi) Staff Publications

No abstract provided.


Fuel Consumption And Emissions Performance Under Real Driving: Comparison Between Hybrid And Conventional Vehicles., Yuhan Huang, Surawski C. Nic, Organ Bruce, John L. Zhou, Oscar H.H Tang, Edward F.C. Chan Jan 2019

Fuel Consumption And Emissions Performance Under Real Driving: Comparison Between Hybrid And Conventional Vehicles., Yuhan Huang, Surawski C. Nic, Organ Bruce, John L. Zhou, Oscar H.H Tang, Edward F.C. Chan

Technological and Higher Education Institute of Hong Kong (THEi) Staff Publications

Hybrid electric vehicles (HEVs) are perceived to be more energy efficient and less polluting than conventional internal combustion engine (ICE) vehicles. However, increasing evidence has shown that real-driving emissions (RDE) could be much higher than laboratory type approval limits and the advantages of HEVs over their conventional ICE counterparts under real-driving conditions have not been studied extensively. Therefore, this study was conducted to evaluate the real-driving fuel consumption and pollutant emissions performance of HEVs against their conventional ICE counterparts. Two pairs of hybrid and conventional gasoline vehicles of the same model were tested simultaneously in a novel convoy mode using ...


Lignin Valorizations With Ni Catalysts For Renewable Chemicals And Fuels Productions, Xiao Chen, Weixiang Guan, Chi-Wing Tsang, Haoquan Hu, Changhai Liang Jan 2019

Lignin Valorizations With Ni Catalysts For Renewable Chemicals And Fuels Productions, Xiao Chen, Weixiang Guan, Chi-Wing Tsang, Haoquan Hu, Changhai Liang

Technological and Higher Education Institute of Hong Kong (THEi) Staff Publications

Energy and fuels derived from biomass pose lesser impact on the environmental carbon footprint than those derived from fossil fuels. In order for the biomass-to-energy and biomass-to-chemicals processes to play their important role in the loop of the circular economy, highly active, selective, and stable catalysts and the related efficient chemical processes are urgently needed. Lignin is the most thermal stable fraction of biomass and a particularly important resource for the production of chemicals and fuels. This mini review mainly focuses on lignin valorizations for renewable chemicals and fuels production and summarizes the recent interest in the lignin valorization over ...


Study Of Synthesis Of Biodegradable Plastics From Alkaline Fermented Excessive Activated Sludge, Yaohui Liu, Chua Hong Jan 2019

Study Of Synthesis Of Biodegradable Plastics From Alkaline Fermented Excessive Activated Sludge, Yaohui Liu, Chua Hong

Technological and Higher Education Institute of Hong Kong (THEi) Staff Publications

The environmental problems associated with plastics have become increasingly severe in recent years. Technologically and economically feasible solutions are in urgent need in order to ensure sustainable development in the plastic industry. Polyhydroxyalkanoates (PHAs) are a family of specialized polyesters of hydroxyalkanoates (HAs) and can be completely degraded in natural environment. They can be synthesized naturally or under artificially controlled processes. The barrier of limiting the application of PHAs is the high production cost. From years of study, PHAs are proofed to be able to be accumulated within the bacterial cells in activated sludge and the production yield had been ...


Recent Advancement In Lignin Biorefinery: With Special Focus On Enzymatic Degradation And Valorization, Chong Li, Chao Chen, Xiaofen Wu, Chi-Wing Tsang, Jinhua Mou, Yun Liu, Carol Sze Ki Lin Jan 2019

Recent Advancement In Lignin Biorefinery: With Special Focus On Enzymatic Degradation And Valorization, Chong Li, Chao Chen, Xiaofen Wu, Chi-Wing Tsang, Jinhua Mou, Yun Liu, Carol Sze Ki Lin

Technological and Higher Education Institute of Hong Kong (THEi) Staff Publications

With the intensive development of lignocellulosic biorefineries to produce fuels and chemicals from biomass-derived carbohydrates, lignin was generated at a large quantity every year. Therefore, lignin has received increasing attention as an abundant aromatics resource in terms of research and development efforts for value-added chemicals production. In this review, studies about lignin degradation especially the crucial enzymes involved and the reaction mechanism were substantially discussed, which provided the molecular basis of lignin biodegradation. Then, the latest improvements in lignin valorization by biological methods were summarized and case studies about value-added compounds from lignin were introduced. Afterwards, challenges, opportunities and prospects ...


Nimoal Catalysts Derived From Heptamolybdate-Intercalated Layered Double Hydroxides For Hydrodeoxygenation Of Anisole, Chuang Li, Xingzhao Zhang, Xiao Chen, Zhijian Peng, Chi-Wing Tsang, Changhai Liang Jan 2019

Nimoal Catalysts Derived From Heptamolybdate-Intercalated Layered Double Hydroxides For Hydrodeoxygenation Of Anisole, Chuang Li, Xingzhao Zhang, Xiao Chen, Zhijian Peng, Chi-Wing Tsang, Changhai Liang

Technological and Higher Education Institute of Hong Kong (THEi) Staff Publications

The catalytic performance of NiMoAl catalysts derived from layered double hydroxide (LDH) precursors with molybdenum species incorporated into the interlayers was investigated for the hydrodeoxygenation (HDO) of anisole as a model compound of the lignin. The results showed that high dispersion of small Ni nanoparticles with 2–5 nm due to the pinning effect of Mo from Mo7O246− intercalated the LDHs. Due to presence of the oxygen vacancy sites on the molybdenum oxide, the NiMoAl catalysts exhibit higher conversion of anisole than the corresponding NiAl catalyst. The activity for hydrodeoxygenation was enhanced with the increased content of molybdenum species, which ...


Atmospheric Pressure Plasma‐Induced Decolorisation Of Cotton Knitted Fabric Dyed With Reactive Dye, Yaohui Liu, Chester Kin-Man To, Mei‐Ki Ngai, Chi-Wai Kan, Chua Hong Jan 2019

Atmospheric Pressure Plasma‐Induced Decolorisation Of Cotton Knitted Fabric Dyed With Reactive Dye, Yaohui Liu, Chester Kin-Man To, Mei‐Ki Ngai, Chi-Wai Kan, Chua Hong

Technological and Higher Education Institute of Hong Kong (THEi) Staff Publications

The aim of this study was to investigate the decolorisation effect of atmospheric pressure plasma treatment on knitted fabrics dyed with reactive dyes under different processing parameters, ie, air concentration, treatment duration and water content. The fabrics were dyed with reactive dye of a blue colour, and the colour depths were 0.5%, 1.5% and 3.0% on weight of fabric. The colour properties of untreated and plasma‐treated fabric samples were evaluated by means of reflectance, K/S and relative unlevelness index. The colour properties were evaluated instrumentally and quantitatively in order to study the decolorisation effect induced ...


A Review On High Catalytic Efficiency Of Solid Acid Catalysts For Lignin Valorization, Weixiang Guan, Chi-Wing Tsang, Carol Sze Ki Lin, Christophe Len, Haoquan Hu, Changhai Liang Jan 2019

A Review On High Catalytic Efficiency Of Solid Acid Catalysts For Lignin Valorization, Weixiang Guan, Chi-Wing Tsang, Carol Sze Ki Lin, Christophe Len, Haoquan Hu, Changhai Liang

Technological and Higher Education Institute of Hong Kong (THEi) Staff Publications

It is imminent to develop renewable resources to replace fossil-derived energies as fossil resources are on the brink of exhaustion. Lignin is one of the major components of lignocellulosic biomass, which is a natural amorphous three-dimensional polymer with abundant C-O bonds and aromatic structure. Hence, valorization of lignin into high value-added liquid fuels and chemicals is regarded as a promising strategy to mitigate fossil resource shortages. Solid acid catalysts are extensively studied due to environmentally friendly in terms of the ease of separation, recovery and reduced amount of wastes. Hence, this review focuses on summarizing the recent progress of catalytic ...


Nb(Ta)-Based Solid Acid Modified Pt/Cnts Catalysts For Hydrodeoxygenation Of Lignin-Derived Compounds, Weixiang Guan, Xiao Chen, Chuang Li, Jie Zhang, Chi-Wing Tsang, Haoquan Hu, Shaojie Li, Changhai Liang Jan 2019

Nb(Ta)-Based Solid Acid Modified Pt/Cnts Catalysts For Hydrodeoxygenation Of Lignin-Derived Compounds, Weixiang Guan, Xiao Chen, Chuang Li, Jie Zhang, Chi-Wing Tsang, Haoquan Hu, Shaojie Li, Changhai Liang

Technological and Higher Education Institute of Hong Kong (THEi) Staff Publications

Efficient upgrading of lignin bio-oils into oxygen-free liquid alkane fuels is a challenging task owing to the incompatibility of the phenolic feedstock with conventional fuels and the availability of effective hydrotreating catalysts based on the current refinery infrastructure. In this work, a series of solid acid nanosheets (HNbWO6, HNbMoO6, HTaWO6) modified Pt/CNTs bifunctional catalysts were evaluated in hydrodeoxygenation (HDO) of lignin-derived compounds. The effects of types of nanosheets and the synergistic effect between metal sites and acid sites were discussed via HDO of diphenyl ether. Pt/HNbWO6/CNTs catalyst exhibited the most efficient performance for the HDO of diphenyl ...


Synthesis Of Sea Urchin-Like Nico2o4 Via Charge-Driven Self-Assembly Strategy For High Performance Lithium-Ion Batteries, Bin Wang, Chi-Wing Tsang, Ka Ho Li, Yuanyuan Tang, Yanping Mao, Xiao-Ying Lu Jan 2019

Synthesis Of Sea Urchin-Like Nico2o4 Via Charge-Driven Self-Assembly Strategy For High Performance Lithium-Ion Batteries, Bin Wang, Chi-Wing Tsang, Ka Ho Li, Yuanyuan Tang, Yanping Mao, Xiao-Ying Lu

Technological and Higher Education Institute of Hong Kong (THEi) Staff Publications

In this study, hydrothermal synthesis of sea urchin-like NiCo2O4 was successfully demonstrated by a versatile charge-driven self-assembly strategy using positively charged poly(diallydimethylammonium chloride) (PDDA) molecules. Physical characterizations implied that sea urchin-like microspheres of ~ 2.5 μm in size were formed by self-assembly of numerous nanoneedles with a typical dimension of ~ 100 nm in diameter. Electrochemical performance study confirmed that sea urchin-like NiCo2O4 exhibited high reversible capacity of 663 mAh g−1 after 100 cycles at current density of 100 mA g−1. Rate capability indicated that average capacities of 1085, 1048, 926, 642, 261, and 86 mAh g−1 ...


Study On The Performance Of Distributed Energy Systems Based On Historical Loads Considering Parameter Uncertainties For Decision Making., Chong Zhang, Xue Xue, Qianzhou Du, Yimo Luo, Wenjie Gang Jan 2019

Study On The Performance Of Distributed Energy Systems Based On Historical Loads Considering Parameter Uncertainties For Decision Making., Chong Zhang, Xue Xue, Qianzhou Du, Yimo Luo, Wenjie Gang

Technological and Higher Education Institute of Hong Kong (THEi) Staff Publications

Distributed energy systems (DESs) are becoming increasingly popular because of their high-energy efficiency and low pollution emissions. Accurate performance evaluation of such systems is critical for processes at the early design stages. However, there are considerable uncertainties in terms of the parameters used for performance evaluation and design optimization, including component efficiencies, customer demands, and energy markets. These uncertainties can significantly influence the performance of DESs. Without consideration of these uncertainties, the performance of DESs can be overestimated or underestimated, which leads to inaccurate decision-making. Therefore, this paper presents a comprehensive evaluation of the performance of DESs by considering uncertainties ...


An Orthogonal Study Of Industrial Scale Colour Fading Process Of Cotton Fabric, Yaohui Liu, Chester Kin-Man To, Hiu-Yan Cheung, Chi-Wai Kan, Chua Hong Jan 2019

An Orthogonal Study Of Industrial Scale Colour Fading Process Of Cotton Fabric, Yaohui Liu, Chester Kin-Man To, Hiu-Yan Cheung, Chi-Wai Kan, Chua Hong

Technological and Higher Education Institute of Hong Kong (THEi) Staff Publications

Colour fading is now a popular process used for imparting a vintage look to textile and fashion products, which enhances market value because of the current fashion trends. This study examined a non-aqueous colour fading process with the use of oxygen plasma-induced ozone treatment. An industrial scale machine and commercially available red sulpur-dyed cotton fabric (with 0.5 %, 1.5 % and 2.5 % colour depths) were used in this study. Since the colour fading process factors are inter-related to each other, a specific experiment approach, i.e. orthogonal method, was used for obtaining the optimum conditions in an industrial scale ...


Effect Of Limited Tension Stiffening On Behavior Of Reinforced Concrete Panels In Shear., Xueying Wang, Jun Shang Kuang Jan 2019

Effect Of Limited Tension Stiffening On Behavior Of Reinforced Concrete Panels In Shear., Xueying Wang, Jun Shang Kuang

Technological and Higher Education Institute of Hong Kong (THEi) Staff Publications

The principal tensile strength of cracked concrete is not well defined in existing models for predicting the shear response of reinforced concrete (RC) membrane elements; hence, the shear strength of RC elements is generally overestimated due to the unrealistic decreasing slope of tensile stress as the crack accumulates. In this paper, the effect of limited tension-stiffening behavior of cracked RC panels under pure shear stresses is investigated by proposing an analytical model named as the tension-stiffening fixed-angle truss model (TFTM). The proposed model includes the limited tension-stiffening effect of post-cracking reinforced concrete and adopts the fixed-angle theory. In the analysis ...


Effect Of Limited Tension Stiffening In Rc Elements Under Cyclic Loads., Xueying Wang, Jun Shang Kuang Jan 2019

Effect Of Limited Tension Stiffening In Rc Elements Under Cyclic Loads., Xueying Wang, Jun Shang Kuang

Technological and Higher Education Institute of Hong Kong (THEi) Staff Publications

The tension capacity in cracked concrete is not well defined in existing shear models for reinforced concrete (RC) membrane elements under cyclic reversed loading, and the shear strength of RC elements is consequently overestimated due to the deviated decreasing branch of envelope of cyclic tensile stress-strain relationship. In this paper, the cyclic effect of limited tension stiffening of cracked RC elements is evaluated by proposing an analytical model named as the cyclic tension-stiffening fixed-angle truss model (CTFTM). The proposed model, based on fixed-angle theory, integrates unloading and reloading rules and accumulated damage into the limited tension-stiffening effect under cyclic loading ...


Effects Of Eccentricity On Seismic Behavior Of Non-Seismically Designed Reinforced Concrete Beam-Column Joint, Ho-Fai Wong, Ying Liu, Sung-Hei Luk, Pok-Man Lee, Wing-Hei Kwong Jan 2019

Effects Of Eccentricity On Seismic Behavior Of Non-Seismically Designed Reinforced Concrete Beam-Column Joint, Ho-Fai Wong, Ying Liu, Sung-Hei Luk, Pok-Man Lee, Wing-Hei Kwong

Technological and Higher Education Institute of Hong Kong (THEi) Staff Publications

The staggering numbers of eccentric reinforced concrete beam-column joints without seismic design details were used in existing RC frame building due to geometrical constraints, which implied high susceptibility of the building structures to anticipated seismic risk. Three exterior RC beam-column joints were fabricated and tested, which were applied reversed cyclic loads to simulate seismic action. In this study, the effects of stirrup ratio in joints and the eccentricity which is defined as the distance between the axis of the beam and column on seismic performance are investigated. The test results provide a further understanding of the failure mode and shear ...


Effects Of Beam-Column Depth Ratio On Seismic Behaviour Of Non-Seismic Detailed Reinforced Concrete Beam-Column Joints, Ying Liu, Ho-Fai Wong, Sung-Hei Luk, Ching-Kit Tong, Hei Lam Jan 2019

Effects Of Beam-Column Depth Ratio On Seismic Behaviour Of Non-Seismic Detailed Reinforced Concrete Beam-Column Joints, Ying Liu, Ho-Fai Wong, Sung-Hei Luk, Ching-Kit Tong, Hei Lam

Technological and Higher Education Institute of Hong Kong (THEi) Staff Publications

Four reinforced concrete exterior beam-column joints with open anchorage beam reinforcement, which are manufactured to simulate those in existing reinforced concrete framed buildings, are tested under reversed cyclic loads simulating earthquake excitation. The particular emphasis of this project is given to the effects of the beam-column depth ratio and the stirrup ratio in joints on the shear strength and seismic behaviour of the exterior joints without seismically designed details. The experimental results indicate that the stirrup placed in the beam-column joint cores can effectively improve the shear strength of the joint and enhance the seismic performance, and the shear strength ...


Study Of Behavior Of Plastic Modified Bitumen By Incorporating Carbon Black, Ho-Fai Wong, Hao-Jue Hong, Lai-Ming Leung, Tsz-Chun Fong, Yi-Fei Shen, Tsz-Hin Lo Jan 2019

Study Of Behavior Of Plastic Modified Bitumen By Incorporating Carbon Black, Ho-Fai Wong, Hao-Jue Hong, Lai-Ming Leung, Tsz-Chun Fong, Yi-Fei Shen, Tsz-Hin Lo

Technological and Higher Education Institute of Hong Kong (THEi) Staff Publications

In recent years, the performance of polymer modified bitumen has been widely studied. This study reports a research carried out to investigate the properties of polymer modified bitumen (PMB) by using polypropylene as modifier, carbon black as additives, to examine the optimum ratio of polypropylene to carbon black. With this objective, sample preparation using wet mixing method combining high shear mix was firstly performed. Subsequently, 18 samples were developed for the study, of which the polypropylene (PP) contents 10%, 12%, 14%, 16%, 18% and 20% with 2%, 3%, 4% of carbon black content. Afterwards, samples were characterized by standard tests ...


Fragility Curves For Buildings In Hong Kong, Sung-Hei Luk, Ho-Fai Wong Jan 2019

Fragility Curves For Buildings In Hong Kong, Sung-Hei Luk, Ho-Fai Wong

Technological and Higher Education Institute of Hong Kong (THEi) Staff Publications

Fragility curves are the tools for evaluating the damage of structural or nonstructural components under different levels of ground excitation. It is also the necessary information for calculating the life-cycle cost of buildings during their design period. In this paper, development of fragility curves for buildings designed based on HK standard is presented. Two prototype models, which include three-storey and tenstorey reinforced concrete rigid frames, were considered. Incremental dynamic analysis was conducted under nine sets of past earthquake records with scaled peak ground accelerations. Maximum inter-storey drift ratio was selected as the damage indices and three performance levels were considered ...


Characterisation Of Diesel Vehicle Emissions And Determination Of Remote Sensing Cutpoints For Diesel High-Emitters., Yuhan Huang, Organ Bruce, John L. Zhou, Surawski C. Nic, Yat-Shing Yam, Edward F.C. Chan Jan 2019

Characterisation Of Diesel Vehicle Emissions And Determination Of Remote Sensing Cutpoints For Diesel High-Emitters., Yuhan Huang, Organ Bruce, John L. Zhou, Surawski C. Nic, Yat-Shing Yam, Edward F.C. Chan

Technological and Higher Education Institute of Hong Kong (THEi) Staff Publications

Diesel vehicles are a major source of air pollutants in cities and have caused significant health risks to the public globally. This study used both on-road remote sensing and transient chassis dynamometer to characterise emissions of diesel light goods vehicles. A large sample size of 183 diesel vans were tested on a transient chassis dynamometer to evaluate the emission levels of in-service diesel vehicles and to determine a set of remote sensing cutpoints for diesel high-emitters. The results showed that 79% and 19% of the Euro 4 and Euro 5 diesel vehicles failed the transient cycle test, respectively. Most of ...


Impact Of Potential Engine Malfunctions On Fuel Consumption And Gaseous Emissions Of A Euro Vi Diesel Truck., Yuhan Huang, Elvin C.Y. Ng, Yat-Shing Yam, Casey K.C. Lee, Surawski C. Nic, Wai-Chuen Mok, Organ Bruce, John L. Zhou, Edward F.C. Chan Jan 2019

Impact Of Potential Engine Malfunctions On Fuel Consumption And Gaseous Emissions Of A Euro Vi Diesel Truck., Yuhan Huang, Elvin C.Y. Ng, Yat-Shing Yam, Casey K.C. Lee, Surawski C. Nic, Wai-Chuen Mok, Organ Bruce, John L. Zhou, Edward F.C. Chan

Technological and Higher Education Institute of Hong Kong (THEi) Staff Publications

Although new vehicles are designed to comply with specific emission regulations, their in-service performance would not necessarily achieve them due to wear-and-tear and improper maintenance, as well as tampering or failure of engine control and exhaust after-treatment systems. In addition, there is a lack of knowledge on how significantly these potential malfunctions affect vehicle performance. This study was therefore conducted to simulate the effect of various engine malfunctions on the fuel consumption and gaseous emissions of a 16-tonne Euro VI diesel truck using transient chassis dynamometer testing. The simulated malfunctions included those that would commonly occur in the intake, fuel ...


Recycling Licoo2 With Methanesulfonic Acid For Regeneration Of Lithium-Ion Battery Electrode Materials., Bin Wang, Xin-Ye Lin, Yuanyuan Tang, Qiang Wang, Michael K.H. Leung, Xiao-Ying Lu Jan 2019

Recycling Licoo2 With Methanesulfonic Acid For Regeneration Of Lithium-Ion Battery Electrode Materials., Bin Wang, Xin-Ye Lin, Yuanyuan Tang, Qiang Wang, Michael K.H. Leung, Xiao-Ying Lu

Technological and Higher Education Institute of Hong Kong (THEi) Staff Publications

With the massive consumption of lithium-ion batteries in portable consumer electronics and electric vehicles, proper disposal of spent batteries is of paramount importance for sustainable development. In this study, biodegradable organic methanesulfonic acid (MSA) is investigated for the first time to leach valuable metals from waste LiCoO2 powders for battery material regeneration. Under the optimal conditions, leaching efficiencies of lithium and cobalt are achieved at nearly ∼100% and ∼100%, respectively. Comparison experiment indicates that MSA can achieve better leaching performance than previously reported organic acids (e.g. citric acid, malonic acid, succinic acid, oxalic acid) under the same conditions. Besides ...


Improving The Energy Efficiency Of Petrochemical Plant Operations: A Measurement And Verification Case Study Using A Balanced Wave Optimizer, Eve Man Hin Chan, Kar-Kit Chu, Hin-Fung Chow, Chi-Wing Tsang, Danny Chi Kuen Ho, Shuk-Kei Ho Jan 2019

Improving The Energy Efficiency Of Petrochemical Plant Operations: A Measurement And Verification Case Study Using A Balanced Wave Optimizer, Eve Man Hin Chan, Kar-Kit Chu, Hin-Fung Chow, Chi-Wing Tsang, Danny Chi Kuen Ho, Shuk-Kei Ho

Technological and Higher Education Institute of Hong Kong (THEi) Staff Publications

The Chinese petrochemical industry is facing pressure to meet strict targets of energy consumption and carbon emission reductions. Water pumps are the primary equipment used in most chemical and agrochemical industries sectors since water is commonly used for cooling and heating purposes, but these pumps also consume a large amount of energy. Other uses of water pumps in these industries include producing steam for heating, preparing reaction media or absorptive reagents, rinsing products, and distilling. As for the electrical components of the water pump systems, current technologies of variable frequency drives and superconducting transmission lines are unable to increase the ...


Economic Feasibility Of A Gasoline Production Plant From Lignocellulosic Feedstocks, Weixiang Guan, Sim-Ying Chua, Chi-Wing Tsang, Xiao Chen, Carol Sze Ki Lin, Raymond Sze Wai Fu, Haoquan Hu, Changhai Liang Jan 2019

Economic Feasibility Of A Gasoline Production Plant From Lignocellulosic Feedstocks, Weixiang Guan, Sim-Ying Chua, Chi-Wing Tsang, Xiao Chen, Carol Sze Ki Lin, Raymond Sze Wai Fu, Haoquan Hu, Changhai Liang

Technological and Higher Education Institute of Hong Kong (THEi) Staff Publications

In this study, the conceptual process flowsheet was developed and the economic feasibility of woody biomass conversion to biofuel as feedstock was analysed by considering several promising experimental processes for lignin depolymerization, such as hydrodeoxygenation and hydrogenolysis, along with lignocellulosic biomass fractionation processes. The engineering simulation process toward the commercial production of bio-gasoline from lignocellulosic biomass using SuperPro Designer® was modeled. The compatibility of the end products with the current gasoline specifications was evaluated and various blending options were investigated to meet the octane number and Reid vapor pressure requirement of the product. The economic potential of the simulated engineering ...


Tuning The Acidity Of Pt/Cnts Catalysts For Hydrodeoxygenation Of Diphenyl Ether, Weixiang Guan, Chuang Li, Xiao Chen, Xiao-Ying Lu, Chi-Wing Tsang, Haoquan Hu, Hongxu Qi, Changhai Liang Jan 2019

Tuning The Acidity Of Pt/Cnts Catalysts For Hydrodeoxygenation Of Diphenyl Ether, Weixiang Guan, Chuang Li, Xiao Chen, Xiao-Ying Lu, Chi-Wing Tsang, Haoquan Hu, Hongxu Qi, Changhai Liang

Technological and Higher Education Institute of Hong Kong (THEi) Staff Publications

We herein present a method for the synthesis of HNbWO6, HNbMoO6, HTaWO6 solid acid nanosheet modified Pt/CNTs. By varying the weight of various solid acid nanosheets, a series of Pt/xHMNO6/CNTs with different solid acid compositions (x = 5, 20 wt%; M = Nb, Ta; N = Mo, W) have been prepared by carbon nanotube pretreatment, protonic exchange, solid acid exfoliation, aggregation and finally Pt particles impregnation. The Pt/xHMNO6/CNTs are characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and NH3-temperature programmed desorption. The study revealed that HNbWO6 nanosheets were attached on CNTs, with some edges of the ...


Micro/Nanostructured Mnco2o4.5 Anodes With High Reversible Capacity And Excellent Rate Capability For Next Generation Lithium-Ion Batteries, Bin Wang, Shifeng Wang, Yuanyuan Tang, Chi-Wing Tsang, Jinchuan Dai, Michael K.H. Leung, Xiao-Ying Lu Jan 2019

Micro/Nanostructured Mnco2o4.5 Anodes With High Reversible Capacity And Excellent Rate Capability For Next Generation Lithium-Ion Batteries, Bin Wang, Shifeng Wang, Yuanyuan Tang, Chi-Wing Tsang, Jinchuan Dai, Michael K.H. Leung, Xiao-Ying Lu

Technological and Higher Education Institute of Hong Kong (THEi) Staff Publications

Lithium-ion batteries have already achieved great success in consumer electronics. However, the electrochemical characteristics of the existing electrodes have constrained their widespread applications in electric vehicles, which need technical demands of high energy density and fast charging. Thus, it is highly desirable to explore high-performance electrodes with high reversible capacity and excellent rate capability. In this study, micro/nanostructured MnCo2O4.5 anodes were synthesized by hydrothermal treatment with the presence of positively charged poly(diallyldimethylammonium chloride). Physicochemical property studies suggested that the as-prepared MnCo2O4.5 of 2–5 µm in diameter was mainly composed of numerous nanoneedles, which were further ...


Year-Round-Based Optimization Of High-Low Control In The Regenerative Indirect Evaporative Cooler (Riec), Huaxia Yan, Yi Chen, Weilong Zhang Jan 2019

Year-Round-Based Optimization Of High-Low Control In The Regenerative Indirect Evaporative Cooler (Riec), Huaxia Yan, Yi Chen, Weilong Zhang

Technological and Higher Education Institute of Hong Kong (THEi) Staff Publications

The performance of the regenerative indirect evaporative cooler (RIEC) highly depends on ambient temperature and humidity. To maintain indoor thermal comfort, proper control strategy is essential. Previous research indicates that high–low (H-L) control by using multispeed technology is superior to the conventional on–off control in terms of energy consumption and thermal comfort. Under H-L control, a fan switches between a high speed and a low speed. The high speed is determined by the peak load. However, the selection of low speed involves a great sense of subjectivity. Therefore, the influence of low speed on system performance is comprehensively ...


Thermal Properties Study And Performance Investigation Of Potassium Formate Solution In A Falling Film Dehumidifier/Regenerator., Tao Wen, Meng Wang, Yi Chen, Weifeng He, Yimo Luo Jan 2019

Thermal Properties Study And Performance Investigation Of Potassium Formate Solution In A Falling Film Dehumidifier/Regenerator., Tao Wen, Meng Wang, Yi Chen, Weifeng He, Yimo Luo

Technological and Higher Education Institute of Hong Kong (THEi) Staff Publications

Compared with the extensive attention drawn by salt solutions, the promising potassium formate (KCOOH) solution which has smaller causticity and lower price receives little attention in the field of liquid desiccant cooling system (LDCS). Consequently, the present paper studied both the thermal properties and mass transfer performance of KCOOH solution for its practical engineering application. The vapor pressure and density of KCOOH solution under different concentrations and temperatures were measured and then fitted in the form of polynomials with the mean absolute relative deviation (MARD) of 0.06% and 0.551% respectively. Referring to the data in the existing literature ...


A Novel 3d Simulation Model For Investigating Liquid Desiccant Dehumidification Performance Based On Cfd Technology., Tao Wen, Yimo Luo, Lu Lin Jan 2019

A Novel 3d Simulation Model For Investigating Liquid Desiccant Dehumidification Performance Based On Cfd Technology., Tao Wen, Yimo Luo, Lu Lin

Technological and Higher Education Institute of Hong Kong (THEi) Staff Publications

Previous 2D CFD simulation models fail to elaborate the actual simultaneous flow and dehumidification process in liquid desiccant cooling system. Accordingly, the present study successfully developed a novel 3D simulation model for investigating the liquid desiccant dehumidification performance of a falling film dehumidifier. The penetration mass transfer model was implemented in the simulation to account for the interfacial dehumidification process. Experimental system was built for the model validation and the results indicated that the newly developed 3D CFD model could predict the absolute moisture removal accurately with an average deviation of 7%. Parametric study revealed that the dehumidification performance was ...


Flexible Integration Of Liquid Air Energy Storage With Liquefied Natural Gas Regasification For Power Generation Enhancement, Xiaohui She, Tongtong Zhang, Lin Cong, Xiaodong Peng, Chuan Li, Yimo Luo, Yulong Ding Jan 2019

Flexible Integration Of Liquid Air Energy Storage With Liquefied Natural Gas Regasification For Power Generation Enhancement, Xiaohui She, Tongtong Zhang, Lin Cong, Xiaodong Peng, Chuan Li, Yimo Luo, Yulong Ding

Technological and Higher Education Institute of Hong Kong (THEi) Staff Publications

Liquid Air Energy Storage (LAES) is one of the most promising energy storage technologies for achieving low carbon emissions. Our research shows that the LAES produces a considerable amount of excess heat that cannot be cost-effectively utilised in a standalone LAES system. On the other hand, the regasification of liquefied natural gas (LNG) often leads to waste of a large amount of high-grade cold energy. Therefore, this paper proposes the integration of the LAES with the LNG regasification process via a Brayton cycle (denoted as LAES-Brayton-LNG), where pressurized propane is used as both the heat transfer fluid and storage material ...