Sulphur-Tolerant Anode for Solid Oxide Fuel Cell

An anode for a solid oxide fuel cell. The anode is not harmed by sulfur-containing compounds, nor is its resistance increased thereby. The anode has two layers, including a “protective” layer (A) and a layer (B) that oxidizes molecular hydrogen The protective layer has a diffusion rate for molecular hydrogen that exceeds its diffusion rate for sulfur-containing compounds, and has an oxidation rate for sulfur-containing compounds that exceeds its oxidation rate for molecular hydrogen. The first anode layer can be selected fro the group of Lanthanum Strontium Titanate (LST) and Lanthanum Strontium Vanadate (LSV), and the second anode layer is made of Gadolinium Doped Cerium oxide (GDC) and nickel. The first layer can include Yttria Stabilized Ziroonia (YSZ), and the second layer can include YSZ interspersed throughout the layer as a separate phase

Solid Oxide Fuel Cell Process and Apparatus

Conveying gas containing sulfur through a sulfur tolerant planar solid oxide fuel cell (PSOFC) stack for sulfur scrubbing, followed by conveying the gas through a non-sulfur tolerant PSOFC stack. The sulfur tolerant PSOFC stack utilizes anode materials, such as LSV, that selectively convert H2S present in the fuel stream to other non-poisoning sulfur compounds. The remaining balance of gases remaining in the completely or near H2S-free exhaust fuel stream is then used as the fuel for the conventional PSOFC stack that is downstream of the sulfur-tolerant PSOFC. A broad range of fuels such as gasified coal, natural gas and reformed hydrocarbons are used to produce electricity

Collagen Complexity Spatially Defines Microregions of Total Tissue Pressure in Pancreatic Cancer.

The poor efficacy of systemic cancer therapeutics in pancreatic ductal adenocarcinoma (PDAC) is partly attributed to deposition of collagen and hyaluronan, leading to interstitial hypertension collapsing blood and lymphatic vessels, limiting drug delivery. The intrinsic micro-regional interactions between hyaluronic acid (HA), collagen and the spatial origins of mechanical stresses that close off blood vessels was investigated here. Multiple localized pressure measurements were analyzed with spatially-matched histochemical images of HA, collagen and vessel perfusion. HA is known to swell, fitting a linear elastic model with total tissue pressure (TTP) increasing above interstitial fluid pressure (IFP) directly with collagen content. However, local TTP appears to originate from collagen area fraction, as well as increased its entropy and fractal dimension, and morphologically appears to be maximized when HA regions are encapsulated by collagen. TTP was inversely correlated with vascular patency and verteporfin uptake, suggesting interstitial hypertension results in vascular compression and decreased molecular delivery in PDAC. Collagenase injection led to acute decreases in total tissue pressure and increased drug perfusion. Large microscopic variations in collagen distributions within PDAC leads to microregional TPP values that vary on the hundred micron distance scale, causing micro-heterogeneous limitations in molecular perfusion, and narrows viable treatment regimes for systemically delivered therapeutics

Geochemical phenomena between Utica-Point Pleasant shale and hydraulic fracturing fluid

© 2019 The Authors. AIChE Journal published by Wiley Periodicals, Inc. on behalf of American Institute of Chemical Engineers. This study evaluated geochemistry between the Utica-Point Pleasant shale and reservoir/hydraulic fracturing fluid mixtures under simulated reservoir conditions in a batch reactor system. Analytical techniques were utilized to monitor fluid composition with time along with pre- and post-trial shale microscopy and phase identification analyses. Formation of iron-based precipitate was evident through results from fluid and material analyses. Ferrous iron was the predominant iron form found in the aqueous phase, with oxidation to ferric iron and subsequent precipitate formation. Geochemical modeling further supported ferric iron was the favorable phase for precipitation

Modeling of a 5 kWₑ Tubular Solid Oxide Fuel Cell based System Operating on Desulfurized JP-8 Fuel for Auxiliary and Mobile Power Applications

An onboard autothermal reformer (ATR) integrated with a SOFC stack offers potential for high energy efficiency and utilization, low emission and quiet operation avoiding cost associated with hydrogen storage and infrastructure. Such a system can be a viable and attractive option especially for military\u27s need for quiet and less pollutant Auxiliary Power Unit (APU) and Mobile Electric Power (MEP) units in temporary and permanent base camps [1,2]. A 5 kWe Solid Oxide Fuel Cell (SOFC) system operating on desulfurized JP-8 fuel was modeled using Aspen Plus process simulation software to examine the effects of oxygen to carbon ratio (O2/C) and steam to carbon ratio (H2O/C) at different ATR operating temperatures (700-850 °C), while keeping the SOFC stack temperature constant at 910 °C. Anode recycle steam and heat have been used to reform the desulfurized JP-8 fuel which would make the system lighter and compact for mobile application. The system modeling revealed a maximum net AC efficiency of 39.5% at 700 °C and a minimum of 32.6% at 850 °C ATR operating temperatures, respectively. Sensitivity analysis with respect to fuel utilization factor (Uf) and current density (j) were also conducted to identify the optimum operating window

Modeling a 5 kWₑ Planar Solid Oxide Fuel Cell based System Operating on JP-8 Fuel and a Comparison with Tubular Cell based System for Auxiliary and Mobile Power Applications

A steady state planar solid oxide fuel cell (P-SOFC) based system operating on desulfurized JP-8 fuel was modeled using Aspen Plus simulation software for auxiliary and mobile power applications. An onboard autothermal reformer (ATR) employed to reform the desulfurized JP-8 fuel was coupled with the P-SOFC stack to provide for H2 and CO as fuel, minimizing the cost and complexity associated with hydrogen storage. Characterization of the ATR reformer was conducted by varying the steam to carbon ratio (H2O/C) from 0.1 to 1.0 at different ATR operating temperatures (700-800 C) while maintaining the P-SOFC stack temperature at 850 C. A fraction of the anode recycle was used as the steam and heat source for autothermal reforming of the JP-8 fuel, intending to make the system lighter and compact for mobile applications. System modeling revealed a maximum net AC efficiency of 37.1% at 700 C and 29.2% at 800 C ATR operating temperatures, respectively. Parametric analyses with respect to fuel utilization factor (Uf) and current density (j) were conducted to determine optimum operating conditions. Finally, the P-SOFC based system was compared with a previously published [1] tubular solid oxide fuel cell based (T-SOFC) system to identify the relative advantages over one another

Techno-Economic Analysis of Hydraulic Fracking Flowback and Produced Water Treatment in Supercritical Water Reactor

The use of hydraulic fracturing for shale oil and gas development generates large quantities of flowback and produced (F/P) water as by-products. The current high treatment cost of F/P water inhibits development and profitability of shale oil and gas. The Integrated Precipitative Supercritical (IPSC) process, developed at Ohio University, could remediate F/P water produced from hydraulic fracturing with significantly lower costs than current practices. The objective of this paper is to present results of a techno-economic analysis of the IPSC process using Aspen® process software and Microsoft Excel. The Aspen® model was used to simulate the IPSC process with its output used as input for the cost analysis. Results indicated an average cost of $6.33 per barrel of F/P water treatment with a possible range from$2.93/bbl to $16.03/bbl determined through sensitivity analyses. The results further indicate that the IPSC process is economically competitive compared to existing practices

The Effect of IGFC Warm Gas Cleanup System Conditions on the Gas-Solid Partitioning and Form of Trace Species in Coal Syngas and their Interactions with SOFC Anodes

The U.S. Department of Energy is currently working on coupling coal gasification and high temperature fuel cell to produce electrical power in a highly efficient manner while being emissions free. Many investigations have already investigated the effects of major coal syngas species such as CO and H2S. However coal contains many trace species and the effect of these species on solid oxide fuel cell anode is not presently known. Warm gas cleanup systems are planned to be used with these advanced power generation systems for the removal of major constituents such as H2S and HCl but the operational parameters of such systems is not well defined at this point in time. This paper focuses on the effect of anticipated warm gas cleanup conditions has on trace specie partitioning between the vapor and condensed phase and the effects the trace vapor species have on the SOFC anode. Results show that Be, Cr, K, Na, V, and Z trace species will form condensed phases and should not effect SOFC anode performance since it is anticipated that the warm gas cleanup systems will have a high removal efficiency of particulate matter. Also the results show that Sb, As, Cd, Hg, Pb, P, and Se trace species form vapor phases and the Sb, As, and P vapor phase species show the ability to form secondary Ni phases in the SOFC anode

The Effect of Coal Syngas Containing AsH₃ on the Performance of SOFCs: Investigations into the Effect of Operational Temperature, Current Density and AsH₃ Concentration

The performance of solid oxide fuel cells (SOFCs) using simulated coal-derived syngas, with and without arsine (AsH3), was studied. Anode-supported SOFCs were tested galvanostatically at 0.25 and 0.5 A cm-2 at 750 and 800 °C with simulated coal syngas containing 0.1, 1, and 2 ppm AsH3. The tests with simulated coal syngas containing 1 ppm AsH3 show little degradation over 100 h of operation. The tests with simulated coal syngas containing 2 ppm AsH3 show some signs of degradation, however no secondary arsenide phases were found. Extended trial testing with 0.1 ppm AsH3 showed degradation as well as the formation of a secondary nickel arsenide phase in the anode of the SOFC