scholarly journals Development of a Catalytic Combustor with Thin-Honeycomb Substrate

2017 ◽  
Author(s):  
Byungchul Choi ◽  
Gyeongho Park ◽  
Daeseok Kim
Keyword(s):  
Catalytic Combustor

Micromachined Methanol Steam Reforming System Integrated With Catalytic Combustor Using Carbon Nanotubes as Catalyst Supports

2006 ◽  
Author(s):  
Dae-Eun Park ◽  
Tae-Kyu Kim ◽  
Sejin Kwon ◽  
Choong-Ki Kim ◽  
Euisik Yoon
Keyword(s):  
Carbon Nanotubes ◽  
Processing System ◽  
Pt Catalyst ◽  
Catalyst Supports ◽  
Fuel Processing ◽  
Reforming Catalyst ◽  
Coating Method ◽  
Catalytic Hydrogen ◽  
Catalytic Combustor ◽  
First Time

In this paper we have successfully demonstrated a new micromachined fuel processing system including vaporizer, catalytic combustor and methanol steam reformer. This fuel processing system utilizes the thermal energy generated from the catalytic hydrogen combustion to heat up the entire system. For the first time, we have used carbon nanotubes as a supporting structure of Pt catalyst for combustion. The catalytic combustor could supply the energy to heat the reformer and maintain its working temperature. We have also developed a new coating method of reforming catalyst (Cu/ZnO/Al2O3) and observed that adequate amount of hydrogen can be generated for PEMFC. We have successfully reported the feasibility of the proposed fuel processing system in each assembled component.

Study on a Vapor-Feed Air-Breathing Direct Methanol Fuel Cell Assisted by a Catalytic Combustor

2015 ◽  
Vol 12 (1) ◽  
Author(s):  
Wei Yuan ◽  
Hong-Rong Xia ◽  
Jin-Yi Hu ◽  
Zhao-Chun Zhang ◽  
Yong Tang
Keyword(s):  
Fuel Cell ◽  
Direct Methanol Fuel Cell ◽  
Cell Performance ◽  
Catalyst Loading ◽  
High Concentration ◽  
Methanol Vapor ◽  
Air Breathing ◽  
Direct Methanol ◽  
Catalytic Combustor ◽  
Methanol Fuel Cell

Feeding vaporized methanol to the direct methanol fuel cell (DMFC) helps reduce the effects of methanol crossover (MCO) and facilitates the use of high-concentration or neat methanol so as to enhance the energy density of the fuel cell system. This paper reports a novel system design coupling a catalytic combustor with a vapor-feed air-breathing DMFC. The combustor functions as an assistant heat provider to help transform the liquid methanol into vapor phase. The feasibility of this method is experimentally validated. Compared with the traditional electric heating mode, the operation based on this catalytic combustor results in a higher cell performance. Results indicate that the values of methanol concentration and methanol vapor chamber (MVC) temperature both have direct effects on the cell performance, which should be well optimized. As for the operation of the catalytic combustor, it is necessary to optimize the number of capillary wicks and also catalyst loading. In order to fast trigger the combustion reaction, an optimal oxygen feed rate (OFR) must be used. The required amount of oxygen to sustain the reaction can be far lower than that for methanol ignition in the starting stage.

Modeling Heat and Mass Transfer Correlations for Flow Through Micro Channels in Monolith Honeycomb Catalytic Combustor

2009 ◽  
Author(s):  
Juan Yin ◽  
Yi-wu Weng
Keyword(s):  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Catalytic Combustion ◽  
Operating Conditions ◽  
Performance Characteristics ◽  
Predicting Performance ◽  
Micro Channels ◽  
Characteristics Analysis ◽  
Flow Through ◽  
Catalytic Combustor

This paper investigated performance characteristics analysis of catalytic combustion by utilizing 1-D models incorporated heat and mass transfer correlations. The 1-D numerical results were compared with 2-D models studies and experimental data. The performance characteristics were mainly the effects of operating conditions on methane conversion rate. The comparable analysis confirmed that 1-D model can success in predicting performance of catalytic combustion when empiric inter-phase heat and mass transfer correlations are used and appropriate operating conditions are chosen.

An Improved Design of Microchannel Fuel Processors

2005 ◽  
Author(s):  
Hye-Mi Jung ◽  
Sung-Dae Yim ◽  
Sukkee Um ◽  
Young-Gi Yoon ◽  
Gu-Gon Park ◽  
...  
Keyword(s):  
Numerical Model ◽  
Steam Reforming ◽  
Kinetic Equations ◽  
Methanol Conversion ◽  
Steel Plates ◽  
Catalyst Loading ◽  
Contact Method ◽  
Micro Channel ◽  
Catalytic Combustor ◽  
Improved Design

This paper focuses on a new systematic configuration of micro-channel fuel processors, particularly designed for portable applications. An alternative integration method of the micro-channel fuel processors is attempted to overcome the serious thermal unbalance and to minimize the system volume by introducing the direct contact method of the sub-components. An integrated micro-channel methanol processor was developed by assembling unit reactors, which were fabricated by stacking and bounding micro-channel patterned stainless steel plates, including fuel vaporizer, catalytic combustor and steam reformer. Commercially available Cu/ZnO/Al2O3 catalyst (ICI Synetix 33-5) was coated inside micro-channel of the unit reactor for steam reforming. The steam reforming reaction was conducted in the temperature range of 200°C to 260°C in the basis of reformer side end-plate and the temperature was controlled by varying methanol feeding into the combustor. More than 99% of methanol was converted at 240°C of reformer side temperature. A mechanism-based numerical model aimed at enhancing physical understanding and optimizing designs has been developed for improved micro-channel fuel processors. A two-dimensional numerical model in the reformer section created to model the phenomena of species transport and reaction occurring at the catalyst surface. The mass, momentum, and species equations were employed with kinetic equations that describe the chemical reaction characteristics to solve flow-field, methanol conversion rate, and species concentration variations along the micro-channel. This mechanism-based model was validated against the experimental data from the literature and then applied to various layouts of the micro-channel fuel processors targeted for the optimal catalyst loading and fuel reforming purpose. The computer-aided models developed in this study can be greatly utilized for the design of advanced fast-paced micro-channel fuel processors research.

scholarly journals Alternate Fuels and the Gas Turbine Catalytic Combustor

1979 ◽  
Author(s):  
W. C. Pfefferle
Keyword(s):  
Nitrogen Oxides ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Soot Formation ◽  
Raw Materials ◽  
Tar Sands ◽  
Aromatic Content ◽  
Percent Conversion ◽  
Catalytic Combustor ◽  
Alternate Fuels

Inasmuch as conventional gas turbine combustors often produce soot even with the present low aromatic content fuels, the production of acceptable liquid turbine fuels from hydrogen deficient raw materials such as coal and tar sands requires large quantities of high cost hydrogen if conventional combustors are to be used. The economics of producing alternate turbine fuels would be improved if high aromatic content fuels could be burned in gas turbines without soot formation. Gas turbines using the catalytic combustor not only can efficiently burn highly aromatic fuels without soot formation but can meet all existing or proposed regulations on emissions of hydrocarbons, carbon monoxide, and nitrogen oxides. Under certain conditions, high fuels can be burned with as little as 10 to 15 percent conversion of the fuel nitrogen to nitrogen oxides. In view of the potential savings, any program for alternate fuels should take into account the opportunities offered by the catalytic combustor.

Improvements to an Air Bypass System on a Kawasaki M1A-13X Engine

2004 ◽  
Author(s):  
Suresh R. Vilayanur ◽  
John Battaglioli
Keyword(s):  
Flow Analysis ◽  
Effective Area ◽  
Inlet Temperature ◽  
Flow Area ◽  
Detailed Measurement ◽  
Pressure Drops ◽  
Operating Range ◽  
Flow Losses ◽  
Catalytic Combustor ◽  
Improved Design

A new bypass system using an improved design has been fabricated and tested on a Kawasaki M1A-13X gas turbine engine. The engine and catalytic combustor are currently installed at the City of Santa Clara’s Silicon Valley Power municipal electrical generating stations and connected to the utility grid. The use of a bypass system with a catalytic combustor, incorporating the Xonon Cool Combustion™ technology, on an M1A-13X system increases the low emissions load turndown and ambient operating range without impacting engine efficiency. The increased operating range is achieved because the bypass system provides the required adiabatic combustion temperature (Tad) in the combustor’s post-catalyst burn out zone without changing the turbine inlet temperature. A detailed measurement of the pressure drops, in the old bypass system, revealed that there were large flow losses present, particularly in the re-injection spool piece and the extraction plenum. Since it was determined that the spool had the highest pressure loss, this was the component targeted for improvement. The analysis coupled with detailed measurements on the reinjection piece revealed that the effective area actually varied with flow As the flow changed, so did the flow mechanics inside and exiting the spool piece. Therefore, in order to achieve the design target, the flow area of the spool piece had to be optimized at the predicted capacity flow rate. CFD analysis of the spool piece revealed the regions of losses in the re-injection piece. This analysis along with a one-dimensional flow analysis of the entire system enabled the design of new spool re-injection piece. Once the design was completed, the new bypass system was fabricated and tested. Bypass flow capacity was increased by about 22%. This was achieved by alleviating regions of flow losses and also by using a new “scoop” design for the bypass reinjection tubes. As expected, engine turndown capacity and ambient operating range were improved with the new design.

scholarly journals Evaluation of a Catalytic Combustor in a Gas Turbine-Generator Unit

1990 ◽  
Author(s):  
Shinichi Kajita ◽  
Yasutaroh Tanaka ◽  
Junichi Kitajima
Keyword(s):  
Control System ◽  
Gas Turbine ◽  
Development Program ◽  
Combustion Efficiency ◽  
Turbine Generator ◽  
Operation Test ◽  
Generator Unit ◽  
Catalytic Combustor ◽  
Generator Output ◽  
Very High

As a final step of the Catalytic Combustor Development Program, a catalytic combustor developed was tested in a 150-kW gas turbine-generator unit. A digital control system was developed to improve its controllability for a transient operation, and a 200-hr continuous operation test was performed to asses the durability of the catalyst. During the test, an excellent performance of the control system was verified, and a very high combustion efficiency of more than 99% and a ultra-low NOx level of less than 5.6 ppm (at 15% O2) were achieved at a 150-kW generator output. In addition, the combustion efficiency has been maintained at over 98% for 200 hours of operation. However, the catalyst exposed to 200 hours of operation showed signs of deactivation.

Sign in / Sign up

Export Citation Format

Share Document