Adsorption Of Methylene Blue Onto Modified Factory Tea Waste: Batch And Fixed Bed Column

The aim of this work was to investigate the feasibility of chemically modified agricultural waste, namely factory tea waste (R-TW) for adsorption of methylene blue (MB) from aqueous solutions. The results revealed that modification of R-TW with sodium hydroxide (NaOH) and potassium hydroxide (KOH) which named NaOH-TW and KOH-TW respectively give the highest efficiencies for MB adsorption compared with other modification methods. R-TW, KOH-TW and NaOH-TW were characterized by Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and nitrogen adsorption/desorption isotherm analyses

Adsorption mechanism of reactive dyes onto modified coal-fired bottom ash: equilibrium and thermodynamics study / Hawaiah Imam Maarof, Norhaslinda Nasuha and Nor Aida Zubir

Adsorption has been recognized to be a promising process to remove colours from aqueous solution (Xue, et al., 2009). Utilizing of agricultural and industrial wastes as adsorbents had been explored by many researchers. However, the study of coal-fired bottom ash as adsorbent for dye adsorption is scanty reported by researcher. In fact, the influence of complex properties of coal-fired bottom ash to the adsorption system have not yet been explored in detailed. Therefore, the study on the adsorption mechanism of dye onto coal-fired bottom ash as well as modified coal-fired bottom ash is needed in improving its capability of dyes adsorption process. The physical and chemical properties of an adsorbent serve significant effects to the adsorption process. Chemical properties include the degree of ionization of the adsorbent surface, the types of functional group which are present on the adsorbent and degree to which these properties may changed by contact with the solution (Bernardin, 1985). Some adsorbents have affinity for H+ and OH' ions, which will directly affect the solution pH, solubility and adsorption capacity. The mechanism might vary from reversible to strong chemical interaction with the presence of active functional groups on the adsorbent surface (Bernardin, 1985). In this study, the equilibrium and thermodynamics studies will be carried out on specific pair of reactive dye-bottom ash and modified coal-fired bottom ash system

Electrochemical Removal of Copper Ion Using Coconut Shell Activated Carbon

In this work, coconut shell activated carbon (CSAC) electrode was evaluated to remove copper ion via electrochemical processes. CSAC electrode and graphite were applied as the cathode and the anode, respectively. The reusability of the electrode, the effects of initial pH, applied voltage and initial concentration were studied. The electrochemical process was carried out for 3 h of treatment time, and the electrodes (anode and cathode) were separated by 1 cm. The results revealed that CSAC is proven as a reusable electrode to remove copper ion, up to 99% of removal efficiency from an initial concentration of 50 ppm after it had been used three times. From the observation, the removal efficiency was optimum at an initial pH of 4.33 (without any initial pH adjustment). The applied voltage at 8 V showed a higher removal efficiency of copper ion compared to at 5 V

Compression power requirements for Oxy-fuel CO2 streams in CCS

CO2 compression systems are commonly designed assuming negligible amount of impurities in CO2 fluid, it is of practical interest to evaluate the impact of impurities in oxy-fuel streams on the compression power requirements. Compared to more traditional postcombustion and pre-combustion capture methods, oxy-fuel technology produces a CO2 stream with relatively high concentration of impurities that may require partial or a high level of removal and whose presence can be expected to increase the costs of CO2 compression. Four types of compression technologies employed include four-stage compressor with 4 intercoolers, single-stage supersonic shockwave compressor, three-stage compressor combined with subcritical liquefaction and pumping and three-stage compressor combined with supercritical liquefaction and pumping. The study depicts that decrement of the impurities content from 15 to 0.7%v/v in the CO2 streams reduced the total compression power in the compression system. The study also concludes that three-stage compressor combined with subcritical liquefaction and pumping can potentially offer higher efficiency than four-stage compressor with 4 intercoolers for almost pure CO2 streams. In the case of raw oxy-fuel mixture, that carries relatively large amount of impurities, subcritical liquefaction proved to be less feasible, while supercritical liquefaction efficiency is only marginally lower than that in the four-stage compressor with 4 intercoolers

Investigations on power requirements for industrial compression strategies for carbon capture and sequestration

The main purpose of this study is to identify the optimum multistage compression strategies for minimising the compression and intercooler power requirements for pure CO2 stream. An analytical model based on thermodynamics principles is developed and applied to determine the power requirements for various compression strategies for pure CO2 stream. The compression options examined include conventional multistage integrally geared centrifugal compressors (option A), supersonic shockwave compressors (option B) and multistage compression combined with subcritical (option C) and supercritical liquefaction (option D) and pumping. In the case of determining the power demand for inter-stage cooling and liquefaction, a thermodynamic model based on Carnot refrigeration cycle is applied. From the previous study by [1], the power demand for inter-stage cooling duty was assumed to have been neglected. However, based on the present study, the inter-stage cooling duty is predicted to be significantly higher and contributes approximately 30% of the total power requirement for compression options A, C and D, while reaches 58% when applied to option B. It is also found that compression option C can offer higher efficiency than other compression strategies, while supercritical liquefaction efficiency is only marginally higher than that in the compression option A

Proceedings of International Technical Postgraduate Conference 2022

This conference proceedings contains articles on the various research ideas of the academic & research communities presented at the International Technical Postgraduate Conference 2022 (TECH POST 2022) that was held at Universiti Malaya, Kuala Lumpur, Malaysia on 24-25 September 2022. TECH POST 2022 was organized by the Faculty of Engineering, Universiti Malaya. The theme of the conference is “Embracing Innovative Engineering Technologies Towards a Sustainable Future”.  TECH POST 2022 conference is intended to foster the dissemination of state-of-the-art research from five main disciplines of Engineering: Electrical Engineering, Biomedical Engineering, Civil Engineering, Mechanical Engineering, and Chemical Engineering. The objectives of TECH POST 2022 are to bring together innovative researchers from all engineering disciplines to a common forum, promote R&D activities in Engineering, and promote the dissemination of scientific knowledge and research know-how between researchers, engineers, and students. Conference Title: International Technical Postgraduate Conference 2022Conference Acronym: TECH POST 2022Conference Date: 24-25 September 2022Conference Location: Faculty of Engineering, Universiti Malaya, Kuala Lumpur Malaysia (Hybrid Mode)Conference Organizers: Faculty of Engineering, Universiti Malaya, Kuala Lumpur, Malaysia