Article
Thermodynamics
Zhihong Wu, Zhigang Guo, Jian Yang, Qiuwang Wang
Summary: In this study, the effects of different pitch of internal helical heat fins on methane steam reforming in a packed bed reactor were investigated. It was found that larger pitch increased the outlet mass flow and velocity disturbance by 9.5% and 382.3% respectively, but also brought higher flow resistance. The internal helical heat fins improved the fluid temperature and reduced the thermal resistance, with a temperature increase of 19.2 K and a thermal resistance decrease of 43.1% compared to the normal packed bed. The highest efficiency was achieved when the pitch was 120 mm, with an increase of 42.3%. Although the internal helical heat fins increased the reactor cost due to structural complexity, the total cost decreased. The lowest total cost was achieved when the pitch was 120 mm, with a decrease of 24.6% to about 1.6 USD/kg.
Article
Thermodynamics
Huajing Zhang, Chao Xu, Hangyu Yu, Hao Wu, Fei Jin, Feng Xiao, Zhirong Liao
Summary: This paper proposes a tubular fixed-bed reactor with helical fins to improve the cold spot problem and enhance the methanol conversion. The effects of geometric parameters of the helical fins, temperature, inlet flow velocity, and steam to methanol molar ratio on the reaction performance are numerically studied, showing significant influence.
Article
Chemistry, Physical
Edgar Necoechea, Jacob Needels, Chibuike Agba, Paul Erickson
Summary: A study on the effect of catalyst separation in stratified autothermal reforming was conducted, with results indicating that a short-distance, high-temperature configuration improves reactor performance. Further research is needed to determine the long-term effects of sustained high temperatures on catalyst performance.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Thermodynamics
Menghua Liu, Yixiang Shi, Ningsheng Cai
Summary: This study proposes a new tubular structure for a high-temperature proton exchange membrane fuel cell (PEMFC) integrated with a built-in packed-bed methanol steam reformer to provide hydrogen. A 2D axisymmetric non-isothermal model was developed to simulate the performance of both the tubular PEMFC and the packed-bed methanol reformer. The model considers multiple physical processes, including methanol reforming, water gas shift reaction, methanol cracking, and heat, mass, and momentum transport. The results show that stable power generation and temperature control can be achieved by controlling the methanol flow rate, working voltage, and the methanol space-time ratio.
JOURNAL OF THERMAL SCIENCE
(2023)
Article
Chemistry, Physical
Peng Yan, Yi Cheng
Summary: Methane steam reforming is expected to be the dominant method for hydrogen production in the future. The use of a membrane reactor can significantly save energy and achieve process and equipment compactness, especially for decentralized applications. This study focuses on the design of a particle-based packed-bed membrane reactor and investigates its operational window and design challenges through experimental and computational approaches, with a particular emphasis on the scale of the reactor and catalyst activity. The results reveal the optimal operation conditions for maximizing hydrogen flux and identify catalyst activity as the key limiting factor for further process intensification.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Chemistry, Physical
Rui Xie, Jie Sun, Yaolu Shi, Jinjia Wei
Summary: A baffled-type thermochemical reactor (BTR) for high-efficient hydrogen production by methanol steam reforming (MSR) has been proposed and numerically investigated. The study found that the radius of heat-exchanging tube has a significant impact on hydrogen yield (YH2) while the radius of heat-exchanging tube array has little effect. Both the inlet velocity and temperature of heat transfer fluid (HTF) affect the reactor performance. There is an optimal operating curve for each gas hourly space velocity (GHSV) to maximize YH2.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Chemistry, Physical
Hyunjin Ji, Junghun Lee, Eunyeong Choi, Jang-hyeon Cho
Summary: The study found that adding hydrogen peroxide (H2O2) to methanol reforming reactions at low temperatures can increase methanol conversion and hydrogen production, especially when methanol conversion is low. Additionally, the results showed that the addition of H2O2 did not significantly decrease the durability of the catalyst.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Chemistry, Physical
Kantilal Chouhan, Shishir Sinha, Shashi Kumar, Surendra Kumar
Summary: This paper investigates the steam reforming of biogas for hydrogen production in an industrial-scale reformer. The developed non-isothermal reactor model shows excellent agreement with previous modeling studies and lab-scale experiments. Changes in biogas compositions have been studied to optimize the performance of the industrial steam reformer, with preferable feed conditions identified for methane conversion and hydrogen yield close to thermodynamic equilibrium conditions.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Thermodynamics
Zhihong Wu, Zhigang Guo, Jian Yang, Qiuwang Wang
Summary: In this study, methane steam reforming in a packed bed reactor integrated with a diverging tube was investigated numerically to improve efficiency. The results showed that the integration of a diverging tube led to a reduction in average temperature, a decrease in pressure drop, and an increase in outlet mass flow. Both flow disturbance and thermal resistance increased as the inclination angle rose. The overall heat transfer coefficient was highest at an inclination angle of 3 degrees, increasing by 9.0% compared to a normal packed bed reactor. The integration of a diverging tube improved hydrogen yield, which increased with the inclination angle. Considering catalyst usage, flow loss, and outlet hydrogen mass flow, the highest efficiency of hydrogen production was achieved at an inclination angle of 3 degrees, increasing by 34.0%.
ENERGY CONVERSION AND MANAGEMENT
(2023)
Review
Chemistry, Physical
Haozhen Li, Chao Ma, Xinyao Zou, Ang Li, Zhen Huang, Lei Zhu
Summary: This review highlights the importance of in-situ hydrogen production using methanol as a carrier due to the hazards of hydrogen storage and transport. Two groups of catalysts, copper-based and group VIII metal-based, were investigated for their activity, selectivity, and stability. Factors such as promoters, supports, synthesis methods, and binary metal components were considered in improving catalytic performance.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Thermodynamics
Yuanyou Tang, Yang Wang, Wuqiang Long, Ge Xiao, Yongjian Wang, Weixing Li
Summary: This paper proposes a method for online methanol steam reforming and hydrogen production using waste heat recovery from an engine, and investigates the influence of key operational parameters on reforming performance through simulation and sensitivity analysis. The findings provide a valuable reference for designing and enhancing the performance of methanol reformer.
Article
Chemistry, Physical
Yifan Li, Konstantinos Kappis, Joan Papavasiliou, Zhiyong Fu, Li Chen, Haibin Li, Dimitrios E. Vlachos, George Avgouropoulos
Summary: In this study, a fuel cell based on a molten proton conductor electrolyte membrane was developed, which can operate efficiently at high temperatures through integration with a CuZn-based methanol reformer. The experiment showed that the fuel cell could provide a voltage of 0.7 V and maintain a high open circuit voltage at 220℃.
JOURNAL OF POWER SOURCES
(2022)
Article
Agricultural Engineering
Hong Liu, Yameng Li, Chaoyang Lu, Zhiping Zhang, Guanning Xiang, Xudong Yang, Quanguo Zhang
Summary: This paper studied the plate-heat transfer type bio-methanol steam reforming reactor for hydrogen fuel cell vehicles and its operation performance. The structure of the reactor was designed and optimized with different parameters. It was found that the catalyst particle size had little influence, but at a catalyst loading of 20 g and a feed rate of 1.5 mL/min, the reforming efficiency was the best, with specific hydrogen production, hydrogen production rate, and biomethanol conversion rate reaching certain values. The findings of this study can serve as a scientific reference for the further development of efficient and cost-effective bio-methanol reforming hydrogen production equipment.
BIORESOURCE TECHNOLOGY
(2023)
Article
Chemistry, Physical
Zhongliang Zhang, Yongqi Liu, Bin Zheng, Peng Sun, Jingbin Hu, Chenxi Qiu, Wenjing Hu
Summary: This study used the discrete element method to simulate the local percolation of non-spherical particles in a moving bed waste heat recovery unit (MBWHRU) for hydrogen production. A local method was applied to determine the location and intensity of percolation, and percolation maps were presented. The study found that percolation mainly occurs at the bottom, flow mechanism transition region, and near the vertical segment wall, with the most intense percolation above the orifice. Percolation is not only related to velocity gradient but also closely related to changes in multiple parameters. Increasing the mass percentage and particle size of fine particles effectively avoids percolation, especially when the particle size ratio of fine particles to coarse particles is greater than 0.5. Percolation near the vertical segment wall is particularly sensitive to particle-wall friction (>0.45), and reducing particle-particle friction and wall roughness is also beneficial to hydrogen production.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Thermodynamics
Manhee Byun, Heehyang Kim, Hyunjun Lee, Dongjun Lim, Hankwon Lim
Summary: Techno-economic analysis is conducted to assess the feasibility of methanol steam reforming in different packed-bed reactor and membrane filter systems. The effects of reaction temperature, H-2 permeance, and the number of reactors and filters on hydrogen production cost are investigated. Regression function for unit H-2 production cost is achieved based on analysis results, and operating conditions are optimized.
Article
Thermodynamics
Mohammed Asad Khan, Sudarshan Kumar
Summary: This paper reports the development of a novel self-aspirating liquid fuel-based microcombustor with a passive fuel pumping mechanism. A hydrostatic pressure-driven liquid fuel pumping mechanism is used to maintain a steady and continuous fuel supply, eliminating the need for a power-driven pump. The design allows for higher combustion efficiency and cleaner emissions, making it suitable for miniaturization.
COMBUSTION SCIENCE AND TECHNOLOGY
(2023)
Article
Thermodynamics
Satender Singh, Jithin Edacheri Veetil, Neeraj Kumbhakarna, Ratna Kishore Velamati, Sudarshan Kumar
Summary: The effect of hydrogen addition on the flame dynamics of premixed methane/air mixtures in a microchannel was investigated using numerical computations. It was found that hydrogen addition induces flame repetitive extinction and ignition, and affects the frequency and duration of the repetitive cycles. Furthermore, hydrogen addition decreases the maximum temperature and heat of the reaction, and shifts the ignition and extinction locations.
COMBUSTION THEORY AND MODELLING
(2022)
Article
Chemistry, Physical
Jithin Edacheri Veetil, Neeraj Kumbhakarna, Satender Singh, Ratna Kishore Velamati, Sudarshan Kumar
Summary: The effect of hydrogen addition on the flame dynamics of premixed C1-C4 alkane/air mixtures in a microchannel was investigated using numerical computations. The addition of hydrogen enhanced the flame stability of hydrocarbon/air mixtures in the microchannel, but had little effect on high carbon alkanes.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Energy & Fuels
Vishal Patil, Paramvir Singh, Sachin Sonage, Neeraj Kumbhakarna, Sudarshan Kumar
Summary: The formulation of effective gasoline surrogates is a challenging task. This study investigates a new approach of proposing the next generation gasoline surrogates through direct testing in a real SI engine. The results show that two of the tested surrogates closely resemble commercial gasoline fuels and can be used for modeling IC engines.
Article
Engineering, Chemical
Anand Shankar Singh, Debojit Sharma, Sukanta Kumar Dash, Mahendra Reddy Vanteru
Summary: The effect of NH, NH2, and HNO on NOx and De-NOx chemistry of a NH3/H-2/air mixture at 20 bar pressure was investigated. It was found that increasing pressure reduces NOx emissions and increases HO2 radical production. The fuel-bound NOx emissions are mainly influenced by reactions involving NH, OH, HNO, and O2, while thermal NOx is determined by reactions involving N and OH. At 20 bar pressure, N2O is further converted to NO2 and N-2, and the abundance of HO2 radicals initiates the conversion of NO to NO2.
CHEMICAL ENGINEERING & TECHNOLOGY
(2023)
Article
Energy & Fuels
Subrat Garnayak, Debojit Sharma, Sukanta K. Dash, V. Mahendra Reddy
Summary: Computational fluid dynamics and chemical kinetic analysis were conducted to explore the formation of CO and CO2 for fuel jet with different hydrocarbon alkanes in a MILD combustion environment. The results showed that the formation of CO was highest for case 3 and lowest for case 1, while the reverse trend was observed for CO2 formation. Acetylene was found to play a vital role in CO formation, while the formation of CO2 was mainly influenced by the reaction between CO and OH.
Article
Thermodynamics
Subhashree Sampath, E. V. Jithin, Neeraj Kumbhakarna, Sudarshan Kumar
Summary: Experimental investigations were conducted to study the impact of CO2 and N-2 dilution on the laminar burning velocity of CH4 and air mixtures at high temperatures. The experiments were performed for different mixture equivalence ratios and dilution conditions. Numerical predictions using different kinetic models were compared to the experimental results. The results showed that CO2 dilution resulted in a sharper decrease in burning velocity compared to N-2 dilution.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2023)
Article
Mechanics
Debojit Sharma, Subrat Garnayak, Aditya Bandopadhyay, S. K. Dash, Mahendra Reddy Vanteru
Summary: An experimental and numerical model is developed to determine the exergy balance in the process of LPG/air combustion in a gas turbine combustor. The study focuses on the influence of vortex shedding and recirculation on entropy production and exergy efficiency. The results show that thermal conduction contributes to 50% of the entropy generation, while the exergy efficiency peaks at 79.41% under fuel-rich conditions.
Article
Chemistry, Multidisciplinary
Subhankar Mohapatra, Radi Alsulami, Srinibas Karmakar, Sukanta Kumar Dash, V. Mahendra Reddy
Summary: In this study, a new hybrid swirl combustor was designed to simplify the conventional gas turbine combustor. Dual-swirl pattern with central vane swirler and circumferential tangential injection scheme was adopted to enhance heat recirculation and combustion inside the combustor. Numerical and experimental studies were conducted to understand the flow patterns and combustion characteristics. The use of the hybrid swirl resulted in lower and more distributed combustion and reduced CO and NO emissions.
Article
Energy & Fuels
Vishal Patil, Paramvir Singh, Sachin Sonage, Neeraj Kumbhakarna, Sudarshan Kumar
Summary: This study investigates the potential blending of ketone biofuels with gasoline in a spark-ignition engine. The blends of ketones, including 2-butanone, 4-Methyl-2-pentanone, cyclopentanone, and cyclo-hexanone, were tested with variable engine speed conditions in a spark ignition engine. The results show that 30% ketone fuel with 70% gasoline has lower emissions compared to pure gasoline. The scientific impact of this research is the applicability of selective ketone biofuels in SI engines for reducing hazardous emissions and the potential for cost-effectiveness in reducing dependency on fossil fuels.
Article
Thermodynamics
Upasana Priyadarshani Padhi, Aditya A. Agarwal, Sudarshan Kumar
Summary: In this study, the combustion behavior of 2-Butanone as a next generation biofuel for spark ignition engines was investigated. The laminar burning velocities of 2-Butanone were measured and compared with ethanol and gasoline. The results showed that 2-Butanone exhibited improved flame behavior compared to gasoline and ethanol under typical engine operating conditions, making it a suitable biofuel substitute for gasoline.
COMBUSTION AND FLAME
(2023)
Article
Thermodynamics
Sujeetkumar P. Deore, Prabodh Gadkari, Sanjay M. Mahajani, Sandeep Kumar, Sudarshan Kumar
Summary: This paper focuses on the design of an efficient premix burner for low calorific value producer gas. The performance of the proposed premix burner is compared with a conventional burner on a 10 kg/h capacity downdraft gasifier. The premix burner shows better flame stability, higher flame temperatures, lower emissions, and higher thermal efficiency.
Article
Energy & Fuels
Pragya Berwal, Sudarshan Kumar
Summary: The present study proposes an alternate ternary fuel blend with better combustion characteristics than natural gas/methane. Experimental measurements show that the CH4/10% NH3/H-2 ternary blend has comparable burning velocity and flame temperature with lower carbon emissions compared to a CH4 + air mixture. This proposed blend is considered a viable solution for achieving economic development, environmental improvement, and sustainable development goals.
Article
Energy & Fuels
Vijay Shinde, Amardeep Fulzele, Sudarshan Kumar
Summary: This study measures the laminar burning velocity for C1-C4 alkane fuels with air at higher mixture temperatures using an externally heated diverging channel method. The temperature exponent is obtained to explain the influence of burning velocity variation with mixture temperature at different mixture equivalence ratios. The results indicate that the decomposition of formyl radical plays a major role in enhancing the burning velocity of these fuels at elevated mixture temperatures.
Article
Energy & Fuels
Vijay Shinde, Amardeep Fulzele, Sudarshan Kumar
Summary: The externally heated diverging channel (EHDC) method was used to evaluate the laminar burning velocity (LBV) of premixed ethane-air flames under higher temperature and pressure conditions. The study found that the maximum LBV occurred at a mixture strength of 1.1 for all pressure and temperature conditions. The results were compared with literature measurements and kinetic model predictions, and it was found that the LBV measurements matched well with the predictions of the Aramco mech 1.3 model. The study also proposed variations of the pressure exponent (beta) and temperature exponent (alpha) as a function of temperature and pressure ratios, and recommended a revised power-law correlation for these variations. Sensitivity analysis showed a decrease in sensitivity for the chain branching reaction HCO + M <-> H + CO + M (R30) under all mixture conditions, due to increased third body effects, pressure, and temperature. Reaction pathway analysis revealed a significant reduction in the elemental flux for the reaction between carbon monoxide (CO) and carbon dioxide (CO2) under increased pressure and temperature.