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Ghauri M.,COMSATS Institute of Information Technology | Shahzad K.,University of Punjab | Inayat A.,University of Sharjah | Ali Z.,University of Engineering and Technology Lahore | And 3 more authors.
Energies | Year: 2016

The ambient temperature high pressure oxydesulphurisation technique was investigated to reduce the sulphur content. Prince of Wales coal was chosen for this study. The focus of the study was to investigate the reduction of both pyritic and organic sulphur while changing the KMnO4/Coal ratio, agitation speed, agitator configuration, and shear. The effect of different concentrations of acetone as a solvent and effect of particle size on the sulphur removal was also studied by a series of experimental runs at ambient temperature. Heating value recovery was found to be increased with the decreased KMnO4/Coal ratio and with decreased acetone concentration. It was found that sulphur removal was enhanced with the increase in shear using a turbine impeller. The effect of particle size was more significant on the pyritic sulphur removal as compared to the organic sulphur removal while heating value recovery was found to increase with decreased desulphurization tome for both, under atmospheric and high pressure. © 2016 by the authors; licensee MDPI.

Saleem M.,University of Punjab | Saleem M.,University of Graz | Tahir M.S.,NFC Institute of Engineering and Fertilizer Research | Krammer G.,Andritz AG
Chemical Engineering and Technology | Year: 2012

The axial velocity in two different tests with pulse-jet bag filters made of needle felts on a pilot-scale test facility separating limestone dust from air under ambient conditions is measured and simulated at different cake area loads. Results reveal that the axial velocity profiles are not truly linear along the whole length of the bag. A nonuniform gas flow prevails when the bags are differently dust-loaded. The same behaviors are observed even at the end of filtration cycles at different upper pressure drop limits. At the higher upper limit, the nonuniformity is stronger. Radial velocity profiles are nearly symmetric along the length of the bag. The axial and radial velocity profiles in a filter bag have been experimentally measured under different loading conditions to verify the hypothesis that the local velocity through the filter elements depends on dust loading. The axial velocity is also modeled using a simple approach and compared to the experimental results. The actual velocity profile depends on the cake area load on the object bag as well as on its neighbors. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Tahir M.S.,Graz University of Technology | Tahir M.S.,NFC Institute of Engineering and Fertilizer Research | Khan J.R.,NFC Institute of Engineering and Fertilizer Research | Saleem M.,University of Punjab | And 2 more authors.
AIChE Annual Meeting, Conference Proceedings | Year: 2010

The electrostatic precipitator (ESP) is commonly used for the removal of particulate matter in offgas purification in process industries and other applications. During operation, the discharge electrode produces ozone [1, 2] which is considered as hazardous pollutant in off-gas treatment. This project has a focus on the investigation of ozone generation under specific operational conditions of wet electrostatic precipitators for applications in wastewater treatment and off-gas purification. Focus of this project was to determine the degradation rate of different organic constituents like acetone, isopropanol, phenol and EDTA in the rinsing water flux of a tube-type wet ESP. Objective was optimisation of the current/voltage characteristic, air flow rate and water circulation rate for efficient degradation of constituents. The results reveal that degradation efficiency of constituents in aqueous effluents by corona discharge is enhanced due to ozone formation with increasing operation voltage for fixed air flow rate. When water circulation rate is optimised nearly complete absorption of generated ozone and degradation of constituents is observed. Complete degradation of acetone, iso-propanol as well as decomposition of phenol and EDTA in water was achieved. TOC depletion and pH variation are very comparable with the results obtained by UV irradiation of ozonated effluents. The experimental results of investigating degradation of specified constituents confirm that with minor adjustments wet electrostatic precipitators work as very efficient oxidation reactors for advanced oxidation processes. Wet ESPs can well be applied for gas purification (including precipitation of particulate as well as gaseous matter), or water purification as well as simultaneous air and water purification.

Tahir M.S.,Graz University of Technology | Tahir M.S.,NFC Institute of Engineering and Fertilizer Research | Malik S.R.,NFC Institute of Engineering and Fertilizer Research | Saleem M.,University of Punjab | And 2 more authors.
AIChE Annual Meeting, Conference Proceedings | Year: 2010

The experimentally obtained corona current with brush-type discharge electrodes is significantly higher than observed for state of art electrical discharge in air with wire-type electrodes [6] and it produces significant amounts of ozone. Compared with ozone generation according to state of the art processes the specific energy demand is similar. Opposite to operation of ozone generators the gas phase does not need any pretreatment. The mechanism of ozone generation was investigated. Ozone generation was quantified over a wide rang of corona current. Ozone formation passes a maximum and will deplete with increasing corona current because of intermolecular interaction. Actually ozone formation and degradation of generated ozone is a simultaneous reaction occurring in the corona reactor. At low corona current ozone formation is the dominating reaction. High energy discharge directly attacks the generated ozone to disintegrate it into molecular oxygen plus dissociated or reactive oxygen. As a result decreased ozone concentration is observed at increased corona current. Experimental investigations were conducted to investigate the effect of stagnant air and air flow on corona current and ozone formation over a specific range of applied voltage. Experiments were conducted to investigate the degradation of various organic constituents with a corona reactor. The effect of corona discharge on TOC depletion is comparable with the effect of low pressure Hg Lamp UV irradiation. The specific energy consumption of corona discharge reactors is favorable over irradiation processes because of the incomparably higher current efficiency.

Siebenhofer M.,Graz University of Technology | Tahir M.S.,Graz University of Technology | Tahir M.S.,NFC Institute of Engineering and Fertilizer Research | Letonja P.,Graz University of Technology | And 2 more authors.
AIChE Annual Meeting, Conference Proceedings | Year: 2010

Advanced wastewater treatment, overwhelmingly based on photochemical, photocatalytical, electrochemical processes and combinations of electrochemical and photochemical measures, is an expensive technique still. The main reason for the high cost of operation is caused by the low concentration of target constituents on the one hand and, on the other hand operation efficiency expressed in terms of specific overall energy demand is low due to low current efficiency as well as low radiation efficiency of photochemical processes. Fouling of electrodes and radiation sources is a significant obstacle preventing these processes from general application. With these disadvantages of state of the art treatment processes in mind wastewater treatment by corona discharge is a very promising technical measure because discharge area and target effluent are separated through a gaseous gap and fouling of the electron emission source is avoided. This project investigates the design parameters of corona discharge facilities with consideration of the effect of the design of discharge electrodes and the effect of flow conditions on the current/ voltage characteristics as well as pollutant degradation. Several discharge electrodes were investigated. The current/voltage characteristics derived from experiments have been modeled. Discharge electrodes of optimized shape generate significantly higher corona discharge currents compared with wire type electrodes with a positive effect on degradation of pollutants. Yield of ozone formation can easily be adjusted to individual needs according to a widely adjustable operation range between corona onset and corona break through voltage.

Zafar M.S.,University of Engineering and Technology Lahore | Zafar M.S.,The University of Faisalabad | Tausif M.,University of Engineering and Technology Lahore | Mohsin M.,University of Engineering and Technology Lahore | And 2 more authors.
Water, Air, and Soil Pollution | Year: 2015

Wastewater from textile industry contains a number of pollutants which are hazardous in nature. The direct discharge of the wastewater into the environment affects its ecological status by causing various undesirable changes. As environmental fortification becomes a global anxiety, industries are finding novel solutions for mounting low-cost and environmental-friendly technologies for the dye removal from the waste. The presence of the dyes hinders sunlight penetration and disturbs the ecosystem of water. However, the treatment of wastewater with biodegradable polymer attains a vital importance as they are environmental friendly. The main objective of the work was to make an effort to develop a feasible process for the removal of dyes/color from the textile wastewater by using potato starch, which is a plant-based bio-polymer. A three-level, full-factorial design was selected, and experiments were conducted using a jar test apparatus. The main effects and interactions of dosage, pH, and temperature on the percentage color removal were analyzed. Reduction in color was analyzed using UV-2800 spectrophotometer. A three-way significant interaction was observed. However, dosage is found to be the most important parameter for dye removal using potato starch. © 2015 Springer International Publishing Switzerland.

Javed F.,University of Engineering and Technology Lahore | Javed F.,NFC Institute of Engineering and Fertilizer Research | Ahmad S.W.,University of Engineering and Technology Lahore | Rehman A.,University of Engineering and Technology Lahore | And 2 more authors.
Journal of Food Process Engineering | Year: 2015

Rice bran oil was extracted using five different solvents, namely acetone, SL-M1 (75% acetone and 25% ethanol), SL-M2 (50% acetone and 50% ethanol), SL-M3 (25% acetone and 75% ethanol) and ethanol. The effect of the solvent type on the percentage recovery of the oil has been graphically represented and discussed when the temperature, contact time, solvent-bran ratio, stirring and pH were fixed at 50C, 30 min, 5:1, 90 rpm and 7.1, respectively. The results indicated that the percentage recovery of rice bran oil was at the maximum when SL-M2 (50% ethanol and 50% acetone) was used as solvent. Further, the parametric effects on the extraction process were also investigated and critically discussed. The quality of the extracted rice bran oil was determined using Fourier Transform Infrared Spectroscopy (FTIR) analysis, saponification and acid values. Practical Application A significant amount of rice bran (contains 13-18% oil) is being wasted from rice mills of an agricultural country like Pakistan. Further, rice bran oil is an important intermediate raw material for food and pharmaceutical industries. So, the present experimental studies composed of the recovery of the oil from rice bran through an efficient and cost-effective method. For this purpose, pure ethanol, pure acetone and three compositionally different mixtures of ethanol and acetone were used as solvents for the extraction process. Parametric effects were also investigated on the extraction process to collect the data for the economic process design. © 2014 Wiley Periodicals, Inc.

Suleman Tahir M.,University of Graz | Suleman Tahir M.,NFC Institute of Engineering and Fertilizer Research | Saleem M.,University of Punjab | Siebenhofer M.,University of Graz
Journal of Electrostatics | Year: 2012

This project presents the results of investigation of current/voltage characteristics of brush type discharge electrodes (BTDE) in tube type electrostatic precipitators and the effect on operation. Experimental investigations were conducted with discharge electrodes of different wire diameter and different brush diameter. The effect of electrode geometry on current/voltage behavior was recorded. Corona current with brush type discharge electrodes was modeled and compared with experimental data. Brush type discharge electrodes produce an enhanced corona current compared with wire type discharge electrodes. Limited enhanced corona has improving effect on collection efficiency. An adjusted correlation was therefore deduced from experimentally obtained current/voltage data with BTDE. © 2011 Elsevier B.V.

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