Professor Ir. Dr. Abdul Aziz Bin Abdul Raman 's research interests are in mixing using stirred vessels, green technology and advanced wastewater treatment. He has supervised more than 100 PhD and Master students and has published about 300 papers in high impact journals and conference proceedings. He was one of the highly cited researchers in 2020 and 2021 by Clarivate. Besides being a fellow of Academy of Sciences Malaysia, he is also a fellow of The Institution of Chemical Engineers, UK and Institution of Engineers, Malaysia. Professor Abdul Aziz is also a practicing chemical engineer especially in the field of environmental sustainability.
Hydrogen peroxide (H2O2) is commercially produced by catalytic oxidation of anthrahydroquinone, w... more Hydrogen peroxide (H2O2) is commercially produced by catalytic oxidation of anthrahydroquinone, which is energy-intensive. Electrochemical production of hydrogen peroxide production through oxygen reduction reaction (ORR) is a sustainable approach, primarily due to its significance in energy conversion systems such as fuel cells. Low temperature fuel cells use graphite as a cathode for H2O2 synthesis. However, the catalytic activity of a graphite cathode for a two-electron oxygen reduction reaction must be improved. Nitrogen doping is an efficient approach to modify the electrochemically active surface of the graphite cathode. Therefore, quantum chemical approaches are essential to comprehend the molecular nature of the processes at the cathode. DFT/B3LYP/6-31G* method was employed and bond dissociation energy (BDE) analysis was performed to determine the feasibility of H2O2 production at graphite and nitrogen-doped graphite (Graphite-N) cathodes. According to the suggested mechanism, oxygen adsorption is the first step of the ORR. Calculated values showed that with energy value of 23.50 kcal/mol oxygen adsorption at the Graphite-N cathode is energetically more favorable than the graphite cathode (Ead = 65.08 kcal/mol). Considering the ORR mechanism, a second-electron oxygen reduction is identified as a key step for both H2O and H2O2 production. Therefore, BDEs were compared at the second-electron oxygen reduction step. On average, − 320.92 and − 286.04 kcal/mol of BDEs for graphite and Graphite-N cathodes showed the feasibility of H2O2 production at the Graphite-N cathode. The results are in agreement with the literature. Thus, it is concluded that nitrogen doping of the graphite cathode increases the feasibility of H2O2 production.Graphical abstract
Chemical Engineering Research & Design, May 1, 2021
Abstract This study aimed to develop Refuse Derived Fuel (RDF) with high Calorific Value (CV) fro... more Abstract This study aimed to develop Refuse Derived Fuel (RDF) with high Calorific Value (CV) from mixed hazardous wastes and biomass. The potential utilization of newly developed RDF in cement production as a fuel substitute for coal has been investigated. In this work, five types of mixed hazardous industrial wastes (rubber waste, mixed waste, paint sludge, palm oil sludge and wastewater treatment plant sludge) and three biomass types (sawdust, paddy husk and empty fruit bunch) have been used. The newly developed RDF developed in this study has a CV of approximately 18,652 kJ/kg, and its volatile matter, fixed carbon and ash content of 32 %, 40% and 28%, respectively. The study is revealed that substituting 5 ton/hour of RDF in the coal only emits about 301 mg/m3 of NOx, which is within the regulatory limits in Malaysia. Besides, the emission of heavy metals, including Zinc, Arsenic, Lead, Copper, Antimony, and Chromium, was also within the regulatory limits. RDF in cement manufacturing kilns is economically and environmentally attractive, as the combustion of RDF allows for a reduction of about 2.25 kg of CO2 per kg compared to coal. In terms of the efficiency of clinker and stack gas emission values, the substitution of 15 % of RDF to the coal at a feeding rate of 5 ton per hour in cement production did not cause any processing and quality issues in the existing cement production process. The result revealed that substituting 15 % of RDF with the coal in 5000 ton/day cement plant may reduce 112.8 USD/hour in operating cost. Additionally, 140 USD/hour of net saving could be achieved by saving 2.52 ton/hour of CO2 emitted from the cement production. Overall, the results concluded that RDF is a very promising resource recovery and waste treatment option for hazardous waste management.
Advanced oxidation process involves production of hydroxyl radical for industrial wastewater trea... more Advanced oxidation process involves production of hydroxyl radical for industrial wastewater treatment. This method is based on the irradiation of UV light to photocatalysts such as TiO2 and ZnO for photodegradation of pollutant. UV light is used for irradiation in photocatalytic process because TiO2 has a high band gap energy which is around 3.2 eV. There can be shift adsorption to visible light by reducing the band gap energy to below 3.2 eV. Doped catalyst is one of the means to reduce band gap energy. Different methods are used for doped catalyst which uses transition metals and titanium dioxide. The band gap energy of three types of transition metals Fe, Cd and Co after being doped with TiO2, are around 2.88 ev, 2.97ev and 2.96 ev, respectively which are all below TiO2 energy. Some of the transition metals change the energy level to below 3.2 eV and the adsorption shifts to visible light for degradation of industrial pollutant after being doped with titanium dioxide. This paper...
Hydrogen peroxide (H2O2) is commercially produced by catalytic oxidation of anthrahydroquinone, w... more Hydrogen peroxide (H2O2) is commercially produced by catalytic oxidation of anthrahydroquinone, which is energy-intensive. Electrochemical production of hydrogen peroxide production through oxygen reduction reaction (ORR) is a sustainable approach, primarily due to its significance in energy conversion systems such as fuel cells. Low temperature fuel cells use graphite as a cathode for H2O2 synthesis. However, the catalytic activity of a graphite cathode for a two-electron oxygen reduction reaction must be improved. Nitrogen doping is an efficient approach to modify the electrochemically active surface of the graphite cathode. Therefore, quantum chemical approaches are essential to comprehend the molecular nature of the processes at the cathode. DFT/B3LYP/6-31G* method was employed and bond dissociation energy (BDE) analysis was performed to determine the feasibility of H2O2 production at graphite and nitrogen-doped graphite (Graphite-N) cathodes. According to the suggested mechanism, oxygen adsorption is the first step of the ORR. Calculated values showed that with energy value of 23.50 kcal/mol oxygen adsorption at the Graphite-N cathode is energetically more favorable than the graphite cathode (Ead = 65.08 kcal/mol). Considering the ORR mechanism, a second-electron oxygen reduction is identified as a key step for both H2O and H2O2 production. Therefore, BDEs were compared at the second-electron oxygen reduction step. On average, − 320.92 and − 286.04 kcal/mol of BDEs for graphite and Graphite-N cathodes showed the feasibility of H2O2 production at the Graphite-N cathode. The results are in agreement with the literature. Thus, it is concluded that nitrogen doping of the graphite cathode increases the feasibility of H2O2 production.Graphical abstract
Chemical Engineering Research & Design, May 1, 2021
Abstract This study aimed to develop Refuse Derived Fuel (RDF) with high Calorific Value (CV) fro... more Abstract This study aimed to develop Refuse Derived Fuel (RDF) with high Calorific Value (CV) from mixed hazardous wastes and biomass. The potential utilization of newly developed RDF in cement production as a fuel substitute for coal has been investigated. In this work, five types of mixed hazardous industrial wastes (rubber waste, mixed waste, paint sludge, palm oil sludge and wastewater treatment plant sludge) and three biomass types (sawdust, paddy husk and empty fruit bunch) have been used. The newly developed RDF developed in this study has a CV of approximately 18,652 kJ/kg, and its volatile matter, fixed carbon and ash content of 32 %, 40% and 28%, respectively. The study is revealed that substituting 5 ton/hour of RDF in the coal only emits about 301 mg/m3 of NOx, which is within the regulatory limits in Malaysia. Besides, the emission of heavy metals, including Zinc, Arsenic, Lead, Copper, Antimony, and Chromium, was also within the regulatory limits. RDF in cement manufacturing kilns is economically and environmentally attractive, as the combustion of RDF allows for a reduction of about 2.25 kg of CO2 per kg compared to coal. In terms of the efficiency of clinker and stack gas emission values, the substitution of 15 % of RDF to the coal at a feeding rate of 5 ton per hour in cement production did not cause any processing and quality issues in the existing cement production process. The result revealed that substituting 15 % of RDF with the coal in 5000 ton/day cement plant may reduce 112.8 USD/hour in operating cost. Additionally, 140 USD/hour of net saving could be achieved by saving 2.52 ton/hour of CO2 emitted from the cement production. Overall, the results concluded that RDF is a very promising resource recovery and waste treatment option for hazardous waste management.
Advanced oxidation process involves production of hydroxyl radical for industrial wastewater trea... more Advanced oxidation process involves production of hydroxyl radical for industrial wastewater treatment. This method is based on the irradiation of UV light to photocatalysts such as TiO2 and ZnO for photodegradation of pollutant. UV light is used for irradiation in photocatalytic process because TiO2 has a high band gap energy which is around 3.2 eV. There can be shift adsorption to visible light by reducing the band gap energy to below 3.2 eV. Doped catalyst is one of the means to reduce band gap energy. Different methods are used for doped catalyst which uses transition metals and titanium dioxide. The band gap energy of three types of transition metals Fe, Cd and Co after being doped with TiO2, are around 2.88 ev, 2.97ev and 2.96 ev, respectively which are all below TiO2 energy. Some of the transition metals change the energy level to below 3.2 eV and the adsorption shifts to visible light for degradation of industrial pollutant after being doped with titanium dioxide. This paper...
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