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Papers by Devinder Mahajan

Journal of Renewable and Sustainable Energy, 2017

Environmental Progress & Sustainable Energy, 2021

Environmental Chemistry Letters, 2020

Environmental Science & Technology, 2017

The occurrence state and molecular structure of extracellular proteins were analyzed to reveal th... more The occurrence state and molecular structure of extracellular proteins were analyzed to reveal the influencing factors on the water-holding capacities of protein-like substances in waste-activated sludge (WAS). The gelation process of extracellular proteins verified that advanced oxidation processes (AOPs) for WAS dewaterability improvement eliminated the water affinity of extracellular proteins and prevented these macromolecules from forming stable colloidal aggregates. Isobaric tags for relative and absolute quantitation proteomics identified that most of the extracellular proteins were originally derived from the intracellular part and the proteins originally located in the extracellular part were mainly membrane-associated. The main mechanism of extracellular protein transformation during AOPs could be represented by the damage of the membrane or related external encapsulating structure and the release of intracellular substances. For the selected representative extracellular proteins, the strong correlation (R2 > 0.97, p < 0.03) between the surface hydrophilicity index and α-helix percentages in the secondary structure indicated that the water affinity relied more on the spatial distribution of hydrophilic functional groups rather than the content. Destructing the secondary structure represented by the α-helix and stretching the polypeptide aggregation in the water phase through disulfide bond removal might be the key to eliminating the inhibitory effects of extracellular proteins on the interstitial water removal from WAS.

2012 International Energy and Sustainability Conference (IESC), 2012

ABSTRACT The Carbon monoxide (CO) present in synthesis gas (syngas) produced by the gasification ... more ABSTRACT The Carbon monoxide (CO) present in synthesis gas (syngas) produced by the gasification of biomass is detrimental to the membranes used in Hydrogen (H2) purifiers as well as in proton exchange membranes (PEM) for fuel cells. Thus, CO must be completely removed or considerably reduced in the syngas. The main objective of this paper is to convert CO to Carbon dioxide (CO2) using the Water Gas Shift reaction (WGS) for the cleanup of H2 which is used in PEM fuel cells to produce combined heat and power. In this paper, the conversion performance of a commercially available Copper Zinc oxide (CuZnO) catalyst suspended in Ethylflo-164 oil was evaluated in the WGS reaction using a syngas simulation of 66% H2 and 34% CO. The temperature and steam to CO ratio inside the reactor were found to affect the catalytic activity of CuZnO; therefore, tests were conducted to achieve maximum CO conversion at175°C, 200°C, and 225°C. The best catalytic activity occurred at 225°C as the CO concentration in the output gas was reduced to 3.46%. An increase in the steam to CO ratio further reduced the CO concentration in the output gas at both 175°C and 200°C.The results of this research will eventually be compared to the performance of other catalysts in order to build the most efficient hydrogen synthesizing and purification biomass system at Farmingdale State College. The system will be composed of a gasifier, a WGS reactor, an H2 purification system, and a H2 storage system. The ultra-pure H2 achieved by the entire biomass system will be fed to Hydrogen Fuel Cell systems generating electrical power.

Methane hydrates are inclusion compounds in which water molecules form a well-defined cage to enc... more Methane hydrates are inclusion compounds in which water molecules form a well-defined cage to encapsulate a methane molecule. The seismic data and recovery of hydrate cores from several worldwide locations show that gas hydrates are a common occurrence, both in permafrost and marine settings where high-pressure and low-temperature conditions coexist. There is growing concern of kinetic instability of methane hydrate with respect to slight temperature changes that could impact seafloor stability and methane gas arising from massive hydrate dissociation in the ocean may contribute to global warming. In sediment- hosted methane hydrates, the sediment-hydrate interaction governs the mechanical strength as well as other geophysical properties of formations or well bores in the event of a rapid release of methane. We are investigating the laboratory-scale hydrate growth and decomposition habits of hydrates formed in natural depleted sediments. The data collection is being carried out in t...

Gas production is on the increase and international trade even more so, with LNG making most prog... more Gas production is on the increase and international trade even more so, with LNG making most progress. It has been projected that by the year 2000, approximately 190 million metric tons per year of LNG could be moving in worldwide trade. The further penetration of natural gas into distant markets can be substantially increased by a new methanol synthesis process under development at the Brookhaven National Laboratory. The new methanol process is made possible by the discovery of a catalyst that drops synthesis temperatures from about 275°C to about 100°C. The new low temperature liquid catalyst can convert synthesis gas completely to methanol in a single pass through the methanol synthesis reactor. This characteristic leads to a further major improvement in the methanol plant. Atmospheric nitrogen can be tolerated in the synthesis gas, and still the volume of gas fed to the reactor can be smaller than the volume of gas that must be fed to the reactor when accommodating the very lo...

The world's abundant natural gas resources could provide methanol in fuel quantities to the u... more The world's abundant natural gas resources could provide methanol in fuel quantities to the utility system. Natural gas liquefaction is the current major option available for international export transport of natural gas. Gas production is on the increase and international trade even more so, with LNG making most progress. The further penetration of natural gas into distant markets can be substantially increased by a new methanol synthesis process under development. The new methanol process is made possible by the discovery of a catalyst that drops synthesis temperatures from about 275/sup 0/C to about 100/sup 0/C. Furthermore, the new catalyst is a liquid phase system, which permits the synthesis reaction to proceed at fully isothermal conditions. Therefore, the new low temperature liquid catalyst can convert synthesis gas completely to methanol in a single pass through the methanol synthesis reactor. This characteristic leads to a further major improvement in the methanol plan...

2012 International Energy and Sustainability Conference (IESC), 2012

ABSTRACT The optimum operating temperature of a Polymer Electrolyte Membrane (PEM) fuel cell is a... more ABSTRACT The optimum operating temperature of a Polymer Electrolyte Membrane (PEM) fuel cell is approximately 80°C. The electrochemical reaction inside a PEM fuel cell stack produces approximately 50% of electrical and 50% of heat energy. The power output of the fuel cell stack is significantly influenced by the humidity and temperature inside the power stack. Therefore, an effective cooling system is necessary for a fuel cell stack to maintain its temperature within an acceptable level to produce optimum power output. In this study, a Finite Element Analysis (FEA) computer simulation model of the bipolar plate was developed to conduct a steady-state heat transfer analysis and eliminate the expensive and laborious laboratory testing. Two different air supply systems for PEM fuel cells, namely “forced air” and “forced convection” systems, and two different bipolar plate materials, namely “aluminum” and “graphic composite”, were investigated in the heat transfer analysis. In addition, an air cooling fin was designed and integrated into a bipolar plate as a part of a power stack in order to dissipate the excessive heat and maintain the operating temperature at 80°C or less. The results show that cooling fin design can produce effective cooling mechanism for 4.8 mm thick bipolar plates.

2008 Providence, Rhode Island, June 29 - July 2, 2008, 2008

... Biofuel Production from Catalytic Thermochemical Conversion of Animal Manure and Biomass Kyou... more ... Biofuel Production from Catalytic Thermochemical Conversion of Animal Manure and Biomass Kyoung S. Ro, Ph.D., PE USDA-ARS Coastal Plains Soil, Water & Plants Research Center, 2611 W. Lucast St., Florence, SC 29501; Kyoung.Ro@ars.usda.gov Keri B. Cantrell, Ph.D. ...

Upgrading of fast pyrolysis oils produced from swtichgrass was carried out using 5 wt % Ru and 5 ... more Upgrading of fast pyrolysis oils produced from swtichgrass was carried out using 5 wt % Ru and 5 wt % Rh on a carbon support as catalysts slurried in a polyethylene glycol solvent in a 300 mL Parr batch reactor in the presence of hydrogen. A hydrodeoxygenation (HDO) reaction was evaluated in the temperature range of 200–280 °C under hydrogen pressure of 300–1000 psig. The raw pyrolysis oil and the upgraded products were characterized by gas chromatography (GC), gas chromatography/mass spectrometry (GC/MS), and Fourier transform infrared spectroscopy (FTIR) techniques to establish the effectiveness of the hydrogenation process. With Ru/C at 280 °C and 1000 psig, the GC/MS data showed the absence of acetic acid and the principal liquid product slate included alcohols, hydrocarbons, cyclic compounds, and phenolics at a relative concentration of 5.2, 21.2, 3.8, and 35.7%, respectively.

Journal of Renewable and Sustainable Energy, 2017

Environmental Progress & Sustainable Energy, 2021

Environmental Chemistry Letters, 2020

Environmental Science & Technology, 2017

The occurrence state and molecular structure of extracellular proteins were analyzed to reveal th... more The occurrence state and molecular structure of extracellular proteins were analyzed to reveal the influencing factors on the water-holding capacities of protein-like substances in waste-activated sludge (WAS). The gelation process of extracellular proteins verified that advanced oxidation processes (AOPs) for WAS dewaterability improvement eliminated the water affinity of extracellular proteins and prevented these macromolecules from forming stable colloidal aggregates. Isobaric tags for relative and absolute quantitation proteomics identified that most of the extracellular proteins were originally derived from the intracellular part and the proteins originally located in the extracellular part were mainly membrane-associated. The main mechanism of extracellular protein transformation during AOPs could be represented by the damage of the membrane or related external encapsulating structure and the release of intracellular substances. For the selected representative extracellular proteins, the strong correlation (R2 > 0.97, p < 0.03) between the surface hydrophilicity index and α-helix percentages in the secondary structure indicated that the water affinity relied more on the spatial distribution of hydrophilic functional groups rather than the content. Destructing the secondary structure represented by the α-helix and stretching the polypeptide aggregation in the water phase through disulfide bond removal might be the key to eliminating the inhibitory effects of extracellular proteins on the interstitial water removal from WAS.

2012 International Energy and Sustainability Conference (IESC), 2012

ABSTRACT The Carbon monoxide (CO) present in synthesis gas (syngas) produced by the gasification ... more ABSTRACT The Carbon monoxide (CO) present in synthesis gas (syngas) produced by the gasification of biomass is detrimental to the membranes used in Hydrogen (H2) purifiers as well as in proton exchange membranes (PEM) for fuel cells. Thus, CO must be completely removed or considerably reduced in the syngas. The main objective of this paper is to convert CO to Carbon dioxide (CO2) using the Water Gas Shift reaction (WGS) for the cleanup of H2 which is used in PEM fuel cells to produce combined heat and power. In this paper, the conversion performance of a commercially available Copper Zinc oxide (CuZnO) catalyst suspended in Ethylflo-164 oil was evaluated in the WGS reaction using a syngas simulation of 66% H2 and 34% CO. The temperature and steam to CO ratio inside the reactor were found to affect the catalytic activity of CuZnO; therefore, tests were conducted to achieve maximum CO conversion at175°C, 200°C, and 225°C. The best catalytic activity occurred at 225°C as the CO concentration in the output gas was reduced to 3.46%. An increase in the steam to CO ratio further reduced the CO concentration in the output gas at both 175°C and 200°C.The results of this research will eventually be compared to the performance of other catalysts in order to build the most efficient hydrogen synthesizing and purification biomass system at Farmingdale State College. The system will be composed of a gasifier, a WGS reactor, an H2 purification system, and a H2 storage system. The ultra-pure H2 achieved by the entire biomass system will be fed to Hydrogen Fuel Cell systems generating electrical power.

Methane hydrates are inclusion compounds in which water molecules form a well-defined cage to enc... more Methane hydrates are inclusion compounds in which water molecules form a well-defined cage to encapsulate a methane molecule. The seismic data and recovery of hydrate cores from several worldwide locations show that gas hydrates are a common occurrence, both in permafrost and marine settings where high-pressure and low-temperature conditions coexist. There is growing concern of kinetic instability of methane hydrate with respect to slight temperature changes that could impact seafloor stability and methane gas arising from massive hydrate dissociation in the ocean may contribute to global warming. In sediment- hosted methane hydrates, the sediment-hydrate interaction governs the mechanical strength as well as other geophysical properties of formations or well bores in the event of a rapid release of methane. We are investigating the laboratory-scale hydrate growth and decomposition habits of hydrates formed in natural depleted sediments. The data collection is being carried out in t...

Gas production is on the increase and international trade even more so, with LNG making most prog... more Gas production is on the increase and international trade even more so, with LNG making most progress. It has been projected that by the year 2000, approximately 190 million metric tons per year of LNG could be moving in worldwide trade. The further penetration of natural gas into distant markets can be substantially increased by a new methanol synthesis process under development at the Brookhaven National Laboratory. The new methanol process is made possible by the discovery of a catalyst that drops synthesis temperatures from about 275°C to about 100°C. The new low temperature liquid catalyst can convert synthesis gas completely to methanol in a single pass through the methanol synthesis reactor. This characteristic leads to a further major improvement in the methanol plant. Atmospheric nitrogen can be tolerated in the synthesis gas, and still the volume of gas fed to the reactor can be smaller than the volume of gas that must be fed to the reactor when accommodating the very lo...

The world's abundant natural gas resources could provide methanol in fuel quantities to the u... more The world's abundant natural gas resources could provide methanol in fuel quantities to the utility system. Natural gas liquefaction is the current major option available for international export transport of natural gas. Gas production is on the increase and international trade even more so, with LNG making most progress. The further penetration of natural gas into distant markets can be substantially increased by a new methanol synthesis process under development. The new methanol process is made possible by the discovery of a catalyst that drops synthesis temperatures from about 275/sup 0/C to about 100/sup 0/C. Furthermore, the new catalyst is a liquid phase system, which permits the synthesis reaction to proceed at fully isothermal conditions. Therefore, the new low temperature liquid catalyst can convert synthesis gas completely to methanol in a single pass through the methanol synthesis reactor. This characteristic leads to a further major improvement in the methanol plan...

2012 International Energy and Sustainability Conference (IESC), 2012

ABSTRACT The optimum operating temperature of a Polymer Electrolyte Membrane (PEM) fuel cell is a... more ABSTRACT The optimum operating temperature of a Polymer Electrolyte Membrane (PEM) fuel cell is approximately 80°C. The electrochemical reaction inside a PEM fuel cell stack produces approximately 50% of electrical and 50% of heat energy. The power output of the fuel cell stack is significantly influenced by the humidity and temperature inside the power stack. Therefore, an effective cooling system is necessary for a fuel cell stack to maintain its temperature within an acceptable level to produce optimum power output. In this study, a Finite Element Analysis (FEA) computer simulation model of the bipolar plate was developed to conduct a steady-state heat transfer analysis and eliminate the expensive and laborious laboratory testing. Two different air supply systems for PEM fuel cells, namely “forced air” and “forced convection” systems, and two different bipolar plate materials, namely “aluminum” and “graphic composite”, were investigated in the heat transfer analysis. In addition, an air cooling fin was designed and integrated into a bipolar plate as a part of a power stack in order to dissipate the excessive heat and maintain the operating temperature at 80°C or less. The results show that cooling fin design can produce effective cooling mechanism for 4.8 mm thick bipolar plates.

2008 Providence, Rhode Island, June 29 - July 2, 2008, 2008

... Biofuel Production from Catalytic Thermochemical Conversion of Animal Manure and Biomass Kyou... more ... Biofuel Production from Catalytic Thermochemical Conversion of Animal Manure and Biomass Kyoung S. Ro, Ph.D., PE USDA-ARS Coastal Plains Soil, Water & Plants Research Center, 2611 W. Lucast St., Florence, SC 29501; Kyoung.Ro@ars.usda.gov Keri B. Cantrell, Ph.D. ...

Upgrading of fast pyrolysis oils produced from swtichgrass was carried out using 5 wt % Ru and 5 ... more Upgrading of fast pyrolysis oils produced from swtichgrass was carried out using 5 wt % Ru and 5 wt % Rh on a carbon support as catalysts slurried in a polyethylene glycol solvent in a 300 mL Parr batch reactor in the presence of hydrogen. A hydrodeoxygenation (HDO) reaction was evaluated in the temperature range of 200–280 °C under hydrogen pressure of 300–1000 psig. The raw pyrolysis oil and the upgraded products were characterized by gas chromatography (GC), gas chromatography/mass spectrometry (GC/MS), and Fourier transform infrared spectroscopy (FTIR) techniques to establish the effectiveness of the hydrogenation process. With Ru/C at 280 °C and 1000 psig, the GC/MS data showed the absence of acetic acid and the principal liquid product slate included alcohols, hydrocarbons, cyclic compounds, and phenolics at a relative concentration of 5.2, 21.2, 3.8, and 35.7%, respectively.