Ryan Falkenstein-Smith

Flame-Assisted Fuel Cell Operating With Methane for Combined Heating and Micro Power

Solid Oxide Fuel Cells (SOFCs) operating in a Flame-assisted Fuel Cell (FFC) setup have potential for Combined Heating and micro Power applications. The feasibility of a FFC furnace operating with natural gas is investigated by using methane/ air flames. The confrontation between the FFCs operating temperature and fuel concentration under various conditions was investigated which uncovered the complex performance behavior. Variations in the fuel/ air equivalence ratio, fuel flow rate and distance between the FFC anode and burner outlet were studied. A critical distance for FFC placement above the burner outlet was uncovered, which has a significant impact on the FFCs performance. A high power density of 791mW.cm−2 was achieved which is comparable to the dual chamber SOFC and single chamber SOFC. Carbon coking was observed on the anode surface, but was not detrimental to FFC performance during testing.Copyright

Integrated Anaerobic Digester and Fuel Cell Power Generation System for Community Use

New York State is expected to experience future population growth that is increasingly concentrated in urban areas, where there is already a heavy burden on the existing energy, water and waste management infrastructure. To meet aggressive environmental standards (such as that established by the State’s “80x50” goal), future electrical power capacity must produce substantially fewer greenhouse gas emissions than currently generated by coal- or natural gas-fired power plants. Currently, biogas is combusted to produce heat and electricity via an internal combustion engine generator set. A conventional internal combustion engine generator set is 22–45 % efficient in converting methane to electricity, thus wasting 65–78 % of the biogas energy content unless the lower temperature heat can be recovered. Fuel cells, on the other hand, are 40–60 % efficient in converting methane to electrical energy, and 80–90 % efficient for cogeneration if heat (> 400 °C) is recovered and utilized for heating and cooling in the community power system. This current research studies the feasibility of a community biomass-to-electricity power system which offers significant environmental, economic and resilience improvements over centrally-generated energy, with the additional benefit of reducing or eliminating disposal costs associated with landfills and publicly-owned treatment works (POTWs). Flame Fuel Cell (FFC) performance was investigated while modifying biogas content and fuel flow rate. A maximum power density peak at 748 mWcm-2 and an OCV of 0.856 V was achieved. It should be noted that the performance obtained with the model biofuel is comparable to the performances of direct methane fueled DC-SOFC and SC-SOFC. The common trends also concluded an acceptable range for optimal performance. Although the methane to CO2 ratios of 3:7 and 2:8 produced power, they are not the strongest ratios to have optimal performance, meaning that operation should stay between the 6:4/4:6 ratio range. Lastly, the amount of air added to the biogas mixture is crucial to achieving the optimal performance of the cell. The data obtained confirmed the feasibility of a biofuel driven fuel cell CHP device capable of achieving higher efficiency than existing technologies. The significant power output produced from the sustainable biogas composition is competitive with current hydrocarbon fuel sources. This idea can be expanded for a community waste management infrastructure.Copyright

A ceramic-membrane-based methane combustion reactor with tailored function of simultaneous separation of carbon dioxide from Nitrogen

Today, industry has become more dependent on natural gases and combustion processes, creating a tremendous pressure to reduce their emissions. Although the current methods such as chemical looping combustion (CLC) and pure oxygen combustion have several advantages, there are still many limitations. A ceramic membrane based methane combustion reactor is an environmentally friendly technique for heat and power generation. This work investigates the performance of a perovskite-type SrSc0.1Co0.9O3-δ (SSC) membrane reactor for the catalytic combustion of methane. For this purpose, the mixed ionic and electronic conducting SSC oxygen-permeable planar membrane was prepared by a dry-pressing technique, and the SSC powder catalyst was spray coated on the permeation side of the membrane. Then, the prepared SSC membrane with the catalyst was used to perform the catalytic combustion of methane. The oxygen permeability of the membrane reactor was studied. Also, the methane conversion rates and CO2 selectivity at various test conditions were reported.Copyright

Thermal Transpiration Based Propulsion

Thermal transpiration based propulsion is studied. Thermal transpiration describes flowing of the gas through a narrow channel with an imposed temperature gradient. As gas flows from the cold to hot side in the chamber, a pressure gradient is created across the channel induced by the temperature gradient. Between the two sides of the chamber an aerogel substance, which functions as an excellent insulator, is used as a thermal transpiration membrane and allows gas diffuse to the hot chamber. The induced pressure gradient is the driving factor in the propulsion of air, or any gas, into the chamber and through the porous membrane. The use of a porous substance such as aerogel as the transpiration membrane and a pressure gradient served as the two requirements in order to successfully achieve thermal transpiration. The gas diffusion through the aerogel transpiration membrane indicates that the average pore size of the aerogel must be comparable with the free path of the molecules. This concept can be taken further if the outlet chamber served as a combustion reactor. The flowing gas is motivated by the heat produced from the combustion process. Along with the exceptionally low thermal conductivity of the aerogel, the gas flow permits the propulsion device to be self-sustaining. The implications of providing a self-sustaining heat source signify that no external electrical heating is required. The effectiveness of this device can be measured as a function of the porous size of the membrane and the temperature difference applied to the system and pressure gradient created.© 2014 ASME

Single-phase ceramic membranes integrated with combustion processes

La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF6428) hollow fibre oxygen-permeable membranes were fabricated by extrusion technique. The oxygen permeability of a blank hollow fibre membrane was investigated with helium as sweeping gas. The oxygen permeation flux result was reported, agreeing very well with previous work. Then the hollow fibre membrane was packed with LSCF6428 catalyst and assembled as hollow fibre membrane reactor for methane combustion, aiming to separate the CO2 in the combustion exhaust from the nitrogen in air. The CO2 selectivity at various conditions was studied.Copyright