A COMPARATIVE STUDY OF GASOLINE AND CNG, AS A POTENTIAL FUEL IN KOREA

Bhupendra Singh Chauhan,Haeng Muk Cho 대한기계학회 2008 대한기계학회 춘추학술대회 Vol.2008 No.11

Gasoline engine have proved its utility in light, medium and heavy duty vehicle in every sector of the world community. The concern about long term availability of petroleum and the increasing threat for the environment by the increasing load of vehicular emission, compel the technology to upgrade itself for meeting the challenges. CNG is environmentally clean alternative to the existing SI Engines with out much change in the hardware. Many researchers have found this as a potential substitute to meet the energy requirement. Higher octane number and higher self ignition temperature make it a good gaseous fuel. Although power output is slightly lesser than the gasoline it’s thermal efficiency is better than the gasoline for the same SI Engine. Results showed that reduced CO, hydrocarbon emissions is a favorable outcome, with slight increase in NO<SUB>x</SUB> emission when compared with gasoline fuel to dual fuel mode in the existing SI Engines.

Ionic Conductivity of Gd³⁺ Doped Cerium Pyrophosphate Electrolytes with Core-Shell Structure

Singh, Bhupendra,Jeon, Sang-Yun,Kim, Ji-Hye,Park, Jun-Young,Bae, Chulsung,Song, Sun-Ju The Electrochemical Society 2014 Journal of the Electrochemical Society Vol.161 No.4

<P>In this work, 10% Gd<SUP>3+</SUP>-doped cerium pyrophosphates (CGPs) with core-shell structure are synthesized by reacting Ce<SUB>0.9</SUB>Gd<SUB>0.1</SUB>O<SUB>2</SUB> with H<SUB>3</SUB>PO<SUB>4</SUB> in a two-step solid-state slow digestion method. Use of high P/(Ce+Gd) ratio in initial reaction mixture gives a core-shell morphology composed of crystalline CGP core and amorphous phosphate (P<SUB>m</SUB>O<SUB>n</SUB>) shell. The amorphous phosphate helps in densification of CGP pellets during sintering, without causing the appearance of any impurity. Variation of ionic conductivity of CGPs with temperature is studied in unhumidified and humidified air conditions, and is explained on the basis of microstructure, phosphate content and proton conduction mechanism. The basic dissolution of protons occurs in the crystalline pyrophosphate phase of material bulk at the oxygen vacancies formed due to the aliovalent doping of Gd<SUP>3+</SUP> and acidic dissolution of protons occurs in the amorphous phase due to the hydrolysis of P<SUB>m</SUB>O<SUB>n</SUB> groups. Ionic conductivities of CGP samples vary in 10<SUP>−3</SUP>−10<SUP>−2</SUP> range in 90-230°C range in humidified air and maximum conductivity obtained is 2.91 × 10<SUP>−2</SUP> S cm<SUP>−1</SUP> at 190°C, <I>p</I>H<SUB>2</SUB>O = 0.16 atm. The <I>p</I>H<SUB>2</SUB>O dependence and long term response (for 450 h) of the ionic conductivity in humidified air is analyzed for potential application as electrolyte in proton-conducting ceramic electrolyte fuel cells.</P>

Mn²⁺-Doped CeP₂O₇ Composite Electrolytes for Application in Low Temperature Proton-Conducting Ceramic Electrolyte Fuel Cells

Singh, Bhupendra,Kim, Ji-Hye,Jeon, Sang-Yun,Park, Jun-Young,Song, Sun-Ju The Electrochemical Society 2014 Journal of the Electrochemical Society Vol.161 No.1

<P>The proton conducting Ce<SUB>1-x</SUB>Mn<SUB>x</SUB>P<SUB>2</SUB>O<SUB>7</SUB> (x = 0.05, 0.075, 0.1, 0.125 and 0.15) composite electrolytes were synthesized by two-step slow digestion method with different P/(Ce+Mn) molar ratio. X-ray diffraction (XRD) patterns show that powders as-calcined at 300°C contain pyrophosphate as the only crystalline phase, but sintering at 400°C leads to the formation of a composite with additional crystalline phases of proton conducting metaphosphate, polyphosphate and orthophosphate. The microstructure of sintered pellets of Ce<SUB>1-x</SUB>Mn<SUB>x</SUB>P<SUB>2</SUB>O<SUB>7</SUB> (CMP) was analyzed by scanning electron microscopy (SEM). The CMP samples with high phosphate content become denser on sintering. The variation of ionic conductivity with temperature is studied in unhumidified and humidified air for the potential application of CMPs as electrolytes in proton-conducting ceramic electrolyte fuel cells (PCFCs). Among various CMP samples, Ce<SUB>0.9</SUB>Mn<SUB>0.1</SUB>P<SUB>2</SUB>O<SUB>7</SUB> with P/(Ce+Mn) = 2.7 shows maximum conductivity of 6.54 × 10<SUP>−6</SUP> S cm<SUP>−1</SUP> at 450°C in unhumidified air and 1.78 × 10<SUP>−2</SUP> S cm<SUP>−1</SUP> at 170°C in humidified air with water vapor pressure (<I>p</I>H<SUB>2</SUB>O) of 0.12 atm. The ionic conductivity of CMPs increases with the increasing <I>p</I>H<SUB>2</SUB>O and Ce<SUB>0.9</SUB>Mn<SUB>0.1</SUB>P<SUB>2</SUB>O<SUB>7</SUB> shows maximum conductivity of 2.24 × 10<SUP>−2</SUP> S cm<SUP>−1</SUP> at 170°C in <I>p</I>H<SUB>2</SUB>O = 0.16 atm.</P>

Cerium Pyrophosphate-based Proton-conducting Ceramic Electrolytes for Low Temperature Fuel Cells

Bhupendra Singh,김지혜,임하니,송선주 한국세라믹학회 2014 한국세라믹학회지 Vol.51 No.4

Acceptor-doped cerium pyrophosphates have shown significant proton conductivity of >10-2 S cm-1 in the range of 100 - 300oCand are considered promising candidates for use as electrolytes in proton-conducting, ceramic electrolyte fuel cells (PCFCs). But,cerium pyrophosphates themselves do not have structural protons, and protons incorporate into their material bulk only as impuritieson exposure to a hydrogen-containing atmosphere. However, proton incorporation and proton conduction in these materialsare expected to be affected by factors such as the nature (ionic size and charge) and concentration of the aliovalent dopant, processinghistory (synthesis route and microstructure), and the presence of residual phosphorous phosphate (PmOn) phases. An exactunderstanding of these aspects has not yet been achieved, leading to large differences in the magnitude of proton conductivity ofcerium pyrophosphates reported in various studies. Herein, we systematically address some of these aspects, and present anoverview of factors affecting proton conductivity inacceptor-doped CeP2O7.

Template free facile synthesis of mesoporous mordenite for bulky molecular catalytic reactions

Singh, Bhupendra Kumar,Kim, Yongseon,Baek, Seung Bin,Meena, Abhishek,Sultan, Siraj,Kwak, Ja Hun,Kim, Kwang S. THE KOREAN SOCIETY OF INDUSTRIAL AND ENGINEERING 2018 Journal of Industrial and Engineering Chemistry Vol.57 No.-

<P><B>Abstract</B></P> <P>The synthesis of highly stable mesoporous zeolites is one of the great challenges in materials science. Soft and hard templating methods have widely been applied to synthesize mesoporous zeolites having different pore diameters and structures. Here, we report a facile and template free hydrothermal synthesis of mesoporous mordenite (MOR) by controlling synthesis conditions. The small nanoparticles of ∼50–80nm were self-assembled into 2–3μm MOR. Intracrystalline mesopores of ∼3–5nm were abundantly observed throughout the MOR nanoparticles. Synthesized mesoporous MOR demonstrated significantly improved catalytic efficiencies (∼100%), 3–5 times higher than its conventional counterparts (CBV 10A and CBV 21).</P> <P><B>Highlights</B></P> <P> <UL> <LI> Template free facile synthesis of mesoporous mordenite (syn MOR). </LI> <LI> The small nanoparticles of ∼50–80nm were self-assembled into a 2–3μm MOR. </LI> <LI> Intracrystalline mesoporous structure obtained without any acid/base treatment. </LI> <LI> ∼3–5nm mesopores were abundantly observed throughout the MOR nanoparticles. </LI> <LI> Syn MOR demonstrated 3–5 times higher efficiencies than conventional counterparts. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>A facile and template free hydrothermal synthesis of mesoporous mordenite (MOR) which demonstrated significantly enhanced catalytic efficiencies and selectivity due to large pore size (3–5nm).</P> <P>[DISPLAY OMISSION]</P>

Fast ionic conduction in tetravalent metal pyrophosphate-alkali carbonate composites: New potential electrolytes for intermediate-temperature fuel cells

Singh, Bhupendra,Bhardwaj, Aman,Gautam, Sandeep K.,Kumar, Devendra,Parkash, Om,Kim, In-Ho,Song, Sun-Ju Elsevier 2017 Journal of Power Sources Vol.345 No.-

<P><B>Abstract</B></P> <P>Here we present a report on synthesis and characterization of tetravalent metal pyrophosphate (TMP) and alkali carbonate (A<SUB>2</SUB>CO<SUB>3</SUB>; A = Li and/or Na) composites. The TMP-carbonate composites are prepared by mixing indium-doped tin pyrophosphate or yttrium-doped zirconium pyrophosphate with Li<SUB>2</SUB>CO<SUB>3</SUB> or an eutectic mixture of Li<SUB>2</SUB>CO<SUB>3</SUB>-Na<SUB>2</SUB>CO<SUB>3</SUB> in different wt.% ratios. The phase composition, microstructure and electrical conductivity of the sintered specimen are analyzed. In addition, the effect of different TMP and A<SUB>2</SUB>CO<SUB>3</SUB> phases is investigated. A maximum ionic conductivity of 5.5 × 10<SUP>−2</SUP> S cm<SUP>−1</SUP> at 630 °C is observed in this study with a Sn<SUB>0.9</SUB>In<SUB>0.1</SUB>P<SUB>2</SUB>O<SUB>7</SUB>-Li<SUB>2</SUB>CO<SUB>3</SUB> composite. Based on the literature data, TMP-carbonate composites can be considered to be primarily a proton and oxygen-ion co-ionic conductor and, therefore, have strong potential as electrolytes in fuel cells in 500–700 °C range.</P> <P><B>Highlights</B></P> <P> <UL> <LI> New tetravalent metal pyrophosphate (TMP)-alkali carbonate composites are reported. </LI> <LI> TMP-carbonate composites sintered at 750 °C are dense. </LI> <LI> SIP21-L10 composite showed max. conductivity of 5.5 × 10<SUP>−2</SUP> S cm<SUP>−1</SUP> at 630 °C. </LI> <LI> Conductivity of TMP-carbonate is comparable to ceria-carbonate composites. </LI> </UL> </P>

Electrical Behavior of CeP₂O₇Electrolyte for the Application in Low-Temperature Proton-Conducting Ceramic Electrolyte Fuel Cells

Singh, Bhupendra,Im, Ha-Ni,Park, Jun-Young,Song, Sun-Ju The Electrochemical Society 2012 Journal of the Electrochemical Society Vol.159 No.12

Performance and emission studies on an agriculture engine on neat Jatropha oil

Bhupendra Singh Chauhan,Naveen Kumar,조행묵 대한기계학회 2010 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.24 No.2

Diesel engines have proven their utility in the transportation, agriculture, and power sectors in India. They are also potential sources of decentralized energy generation for rural electrification. Concerns on the long-term availability of petroleum diesel and the stringent environmental norms have mandated the search for a renewable alternative to diesel fuel to address these problems. Vegetable oils have been considered good alternatives to diesel in the past couple of years. However, there are many issues related to the use of vegetable oils in diesel engine. Jatropha curcas has been promoted in India as a sustainable substitute to diesel fuel. This study aims to develop a dual fuel engine test rig for evaluating the potential suitability of Jatropha oil as diesel fuel and for determining the performance and emission characteristics of an engine with Jatropha oil. The experimental results suggest that engine performance using Jatropha oil is slightly inferior to that of diesel fuel. The thermal efficiency of the engine was lower, while the brake-specific fuel consumption was higher with Jatropha oil compared with diesel fuel. The levels of nitrogen oxides (NOx) from Jatropha oil during the entire duration of the experiment were lower than those of diesel fuel. The reduction of NOx was found to be an important characteristic of Jatropha oil as NOx emission is the most harmful gaseous emission from engines; as such, its reduction is always the goal of engine researchers and makers. During the entire experiment, carbon monoxide (CO), hydrocarbon (HC), and carbon dioxide (CO2) emissions in the case of using Jatropha oil were higher than when diesel fuel was used. The higher density and viscosity of Jatropha oil causes lower thermal efficiency and higher brakespecific fuel consumption. The performance and emission characteristics found in this study are significant for the study of replacing diesel fuel from fossils with Jatropha oil in rural India, where the availability of diesel has always been a problem.

Template free facile synthesis of mesoporous mordenite for bulky molecular catalytic reactions

Bhupendra Kumar Singh,김용선,백승빈,Abhishek Meena,Siraj Sultan,곽자훈,김광수 한국공업화학회 2018 Journal of Industrial and Engineering Chemistry Vol.57 No.-

The synthesis of highly stable mesoporous zeolites is one of the great challenges in materials science. Soft and hard templating methods have widely been applied to synthesize mesoporous zeolites having different pore diameters and structures. Here, we report a facile and template free hydrothermal synthesis of mesoporous mordenite (MOR) by controlling synthesis conditions. The small nanoparticles of ∼50–80 nm were self-assembled into 2–3 μm MOR. Intracrystalline mesopores of ∼3–5 nm were abundantly observed throughout the MOR nanoparticles. Synthesized mesoporous MOR demonstrated significantly improved catalytic efficiencies (∼100%), 3–5 times higher than its conventional counterparts (CBV 10A and CBV 21).

Cerium Pyrophosphate-based Proton-conducting Ceramic Electrolytes for Low Temperature Fuel Cells

Singh, Bhupendra,Kim, Ji-Hye,Im, Ha-Ni,Song, Sun-Ju The Korean Ceramic Society 2014 한국세라믹학회지 Vol.51 No.4

Acceptor-doped cerium pyrophosphates have shown significant proton conductivity of > $10^{-2}Scm^{-1}$ in the range of $100-300^{\circ}C$ and are considered promising candidates for use as electrolytes in proton-conducting, ceramic electrolyte fuel cells (PCFCs). But, cerium pyrophosphates themselves do not have structural protons, and protons incorporate into their material bulk only as impurities on exposure to a hydrogen-containing atmosphere. However, proton incorporation and proton conduction in these materials are expected to be affected by factors such as the nature (ionic size and charge) and concentration of the aliovalent dopant, processing history (synthesis route and microstructure), and the presence of residual phosphorous phosphate ($P_mO_n$) phases. An exact understanding of these aspects has not yet been achieved, leading to large differences in the magnitude of proton conductivity of cerium pyrophosphates reported in various studies. Herein, we systematically address some of these aspects, and present an overview of factors affecting proton conductivity inacceptor-doped $CeP_2O_7$.