Mohammad Omar Abdullah

Performance evaluation of a hybrid system for efficient palm oil mill effluent treatment via an air-cathode, tubular upflow microbial fuel cell coupled with a granular activated carbon adsorption

An air-cathode MFC-adsorption hybrid system, made from earthen pot was designed and tested for simultaneous wastewater treatment and energy recovery. Such design had demonstrated superior characteristics of low internal resistance (29.3Ω) and favor to low-cost, efficient wastewater treatment and power generation (55mW/m(3)) with average current of 2.13±0.4mA. The performance between MFC-adsorption hybrid system was compared to the standalone adsorption system and results had demonstrated great pollutants removals of the integrated system especially for chemical oxygen demand (COD), biochemical oxygen demand (BOD3), total organic carbon (TOC), total volatile solids (TVS), ammoniacal nitrogen (NH3-N) and total nitrogen (TN) because such system combines the advantages of each individual unit. Besides the typical biological and electrochemical processes that happened in an MFC system, an additional physicochemical process from the activated carbon took place simultaneously in the MFC-adsorption hybrid system which would further improved on the wastewater quality.

Experimental Study of an Automobile Exhaust Heat-Driven Adsorption Air-Conditioning Laboratory Prototype by Using Palm Activated Carbon-Methanol

Adsorption air-cooling systems powered by waste heat or solar heat can help to reduce the use of ozone-depleting substances, such as chlorofluorocarbons (CFCs) and hydro-chlorofluorocarbons (HCFCs). In recent years, these systems have faced increasing interest in many fields because they are quiet, long lasting, inexpensive to maintain, and environmentally friendly. This paper presents a laboratory prototype of an automobile adsorption air-conditioning system powered by exhaust heat, which has been successfully built and tested in the laboratory. The working pair used is a locally produced palm-derived activated carbon with methanol. Experimental results obtained show that, by having a cycle time of 20 minutes, an average chilled-air temperature of around 73.0°XF (22.6°XC) is achieved when the cooling coil temperatures fell between 49°XF to 58°XF (9.5°XC to 14.7°XC). The coefficient of performance (COP) and specific cooling power (SCP) of this prototype are approximately 0.19 and 614 Btu/h·lb (396.6 Wkg−1), respectively.

Applied energy : an introduction

Written in clear, concise language and designed for an introductory applied energy course, Applied Energy: An Introduction discusses energy applications in small-medium enterprises, solar energy, hydro and wind energy, nuclear energy, hybrid energy, and energy sustainability issues. Focusing on renewable energy technologies, energy conversion, and conservation and the energy industry, the author lists the key aspects of applied energy and related studies, taking a question-based approach to the material that is useful for both undergraduate students and postgraduates who want a broad overview of energy conversion. The author carefully designed the text to motivate students and give them the foundation they need to place the concepts presented into a real-world context. He begins with an introduction to the basics and the definitions used throughout the book. From there, he covers the energy industry and energy applications; energy sources, supply, and demand; and energy management, policy, plans, and analysis. Building on this, the author elucidates various energy saving technologies and energy storage methods, explores the pros and cons of fossil fuels and alternative energy sources, and examines the various types of applications of alternative energies. The book concludes with chapters on hybrid energy technology, hybrid energy schemes, other energy conversion methods, and applied energy issues. The book takes advantage of practical and application-based learning, presenting the information in various forms such as essential notes followed by practical projects, assignments, and objective and practical questions. In each chapter, a small section introduces some elements of applied energy design and innovation, linking knowledge with applied energy design and practice. The comprehensive coverage gives students the skills not only to master the concepts in the course, but also apply them to future work in this area.

Bio-energy generation in an affordable, single-chamber microbial fuel cell integrated with adsorption hybrid system: effects of temperature and comparison study

ABSTRACT A microbial fuel cell (MFC) integrated with adsorption system (MFC-AHS) is tested under various operating temperatures with palm oil mill effluent as the substrate. The optimum operating temperature for such system is found to be at ∼35°C with current, power density, internal resistance (Rin), Coulombic efficiency (CE) and maximum chemical oxygen demand (COD) removal of 2.51 ± 0.2 mA, 74 ± 6 mW m−3, 25.4 Ω, 10.65 ± 0.5% and 93.57 ± 1.2%, respectively. Maximum current density increases linearly with temperature at a rate of 0.1772 mA m−2 °C−1, whereas maximum power density was in a polynomial function. The temperature coefficient (Q10) is found to be 1.20 between 15°C and 35°C. Present studies have demonstrated better CE performance when compared to other MFC-AHSs. Generally, MFC-AHS has demonstrated higher COD removals when compared to standalone MFC regardless of operating temperatures. Abbreviations: ACFF: activated carbon fiber felt; APHA: American Public Health Association; CE: Coulombic efficiency; COD: chemical oxygen demand; ECG: electrocardiogram; GAC: granular activated carbon; GFB: graphite fiber brush; MFC: microbial fuel cell; MFC-AHS: microbial fuel cell integrated with adsorption hybrid system; MFC-GG: microbial fuel cell integrated with graphite granules; POME: palm oil mill effluent; PTFE: polytetrafluoroethylene; SEM: scanning electron microscope

Adsorption Equilibrium for Heavy Metal Divalent Ions (Cu2+, Zn2+, and Cd2+) into Zirconium-Based Ferromagnetic Sorbent

Zirconium-based ferromagnetic sorbent was fabricated by coprecipitation of Fe2+/Fe3+ salts in a zirconium solution and explored as a potential sorbent for removing the Cu2+, Zn2+, and Cd2+ from aqueous solution. The sorbent could easily be separated from aqueous solution under the influence of external magnetic field due to the ferromagnetism property. A trimodal distribution was obtained for the sorbent with average particle size of 22.74 μm. The –OH functional groups played an important role for efficient removal of divalent ions. The surface of the sorbent was rough with abundant protuberance while the existence of divalent ions on the sorbent surface after the sorption process was demonstrated. Decontamination of the heavy metal ions was studied as a function of initial metal ions concentration and solution pH. Uptake of the heavy metal ions showed a pH-dependent profile with maximum sorption at around pH 5. The presence of the ferromagnetic sorbent in solution at different initial pH has shown a buffering effect. Equilibrium isotherms were analyzed using Langmuir, Freundlich, Dubinin-Radushkevich, and Temkin isotherm models. Adequacy of fit for the isotherm models based on evaluation of and ARE has revealed that heavy metal ions decontamination was fitted well with the Freundlich model.

Comparison of Biodiesel Production between Homogeneous and Heterogeneous Base Catalysts

Homogeneous base catalyst has wide acceptability in biodiesel production because of their fast reaction rates. However, postproduction costs incurred from aqueous quenching, wastewater and loss of catalysts led to the search for alternatives. Heterogeneous base catalyst is developed to cater these problems. The advantages of heterogeneous catalyst are their high basicity and non-toxicity. This work compared the production of biodiesel using two different kind of catalysts that is homogeneous catalyst (sodium hydroxide, NaOH and potassium hydroxide, KOH) and heterogeneous catalysts (calcium, oxide, CaO catalyst derived from chicken and ostrich eggshells). Transesterification of waste cooking oil (WCO) and methanol in the presence of heterogeneous base catalyst was conducted at an optimal reaction condition (calcination temperature for catalyst: 1000 °C; catalyst loading amount: 1.5 wt%; methanol/oil molar ratio: 10:1; reaction temperature: 65 °C; reaction time: 2 hours) with 97% biodiesel yield was obtained. While, the homogeneous base catalyst gave higher biodiesel yield of 98% at optimum operating condition (catalyst concentration: 0.75 wt%; methanol/oil molar ratio: 6:1; reaction temperature: 65 °C; reaction time: 1 hours). The slight difference in the biodiesel yield was due to the stronger basic strength in the homogeneous catalyst and were not statistically not different (p=0.05). However, despite these advances, the ultimate aim of producing biodiesel at affordable low cost and minimal-environmental-impact is yet to be realized.

Stress Corrosion Cracking, Crack Growth Prediction, and Risk-Based Inspection of Industrial Refrigerated Ammonia Tanks

Abstract This study briefly reviews various influencing factors governing stress corrosion cracking (SCC), cracking mechanisms, and a few conventional crack detection or evaluation techniques. An i...

Energy sustainability study of a rural ICT telecenter at the Bario highland

The eBario project has won the eAsia Award and the Mondialogo Engineering Award in 2004 and 2005 respectively for it’s successful implementation of an Information and Telecommunications Technology Center (ICT) and solar renewable energy-incentive rural community project at the Bario Highland of Sarawak, East Malaysia, Borneo (http://www.unimas.my/ebario/). Although solar photovoltaic (PV) energy has been opted for power generation at the ICT Telecenter for the past five years, there is still a need to investigate the cost-effectiveness of the current energy setup as well as to conduct sustainability study taking into account factors such as system efficiency, weather, costs of fuel, operating costs, as well as to explore the feasibility of implementing alternative energy resources for the rural ICT Telecenter. Recent theoretical study conducted has shown that renewable combined power systems are more sustainable in terms of supplying electricity to the ICT Telecenter, and in a more cost-effective way compared to a standalone PV system which is subject to the cloud and the recent dense haze problems. For that purpose, two combined power systems are being put into consideration namely PV-Hydro and PV-Hydro-Fuel Cell, where the total simulated annualized cost for these two system configurations are US

AN UPDATE OF A SIMULATION STUDY OF PASSIVELY HEATED RESIDENTIAL BUILDINGS

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Waste ostrich- and chicken-eggshells as heterogeneous base catalyst for biodiesel production from used cooking oil: Catalyst characterization and biodiesel yield performance

76,010 respectively as far as the present location is concerned. The PVHydro-Fuel Cell produces electrical energy at the amount of 3,577 kWh/yr while the annual energy consumption is 3,203 kWhr/yr. On the other hand, PV-Hydro produces 3,789 kWhr/yr of electricity annually load which consumes energy at 3,209 kWhr/yr. Results thus obtained has shown that the PVHydro scheme is expected to have advantages over the existing PV standalone system. Firstly, it is more cost-effective. Secondly, it provides the best outcomes for the local indigenous community and the natural highland environments both for now and the future. Thirdly, it also able to relate the continuity of both economic and social aspects of the local society as a whole. As the combined PV-Hydro system had been chosen, plus for completeness purposes, the present paper also discussed the custom design and construction of a small waterwheel breast-shot hydro-generator, suited to the local location and existing water energy resources. Energy saving design calculations and Sankey diagram showing the energy flows for the new combined system are also given herein. Finally, the energy system performance equations and the performance curves introduced in this study provide a new simple method of evaluating renewable energy systems.© 2007 ASME