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Final Report of a CRADA Between Pacific Northwest National Laboratory and the Ford Motor Company (CRADA No. PNNL/265): “Deactivation Mechanisms of Base Metal/Zeolite Urea Selective Catalytic Reduction Materials, and Development of Zeolite-Based Hydrocarbon Adsorber Materials”

Description: Reducing NOx emissions and particulate matter (PM) are primary concerns for diesel vehicles required to meet current LEV II and future LEV III emission standards which require 90+% NOx conversion. Currently, urea SCR as the NOx reductant and a Catalyzed Diesel Particulate Filter (CDPF) are being used for emission control system components by Ford Motor Company for 2010 and beyond diesel vehicles. Because the use of this technology for vehicle applications is new, the relative lack of experience makes it especially challenging to satisfy durability requirements. Of particular concern is being able to realistically simulate actual field aging of the catalyst systems under laboratory conditions. This is necessary both as a rapid assessment tool for verifying improved performance and certifiability of new catalyst formulations, and to develop a good understanding of deactivation mechanisms that can be used to develop improved catalyst materials. In addition to NOx and PM, the hydrocarbon (HC) emission standards are expected to become much more stringent during the next few years. Meanwhile, the engine-out HC emissions are expected to increase and/or be more difficult to remove. Since HC can be removed only when the catalyst becomes warm enough for its oxidation, three-way catalyst (TWC) and diesel oxidation catalyst (DOC) formulations often contain proprietary zeolite materials to hold the HC produced during the cold start period until the catalyst reaches its operating temperature (e.g., >200°C). Unfortunately, much of trapped HC tends to be released before the catalyst reaches the operating temperature. Among materials effective for trapping HC during the catalyst warm-up period, siliceous zeolites are commonly used because of their high surface area and high stability under typical operating conditions. However, there has been little research on the physical properties of these materials related to the adsorption and release of various hydrocarbon species found in the engine ...
Date: February 14, 2013
Creator: Gao, Feng; Kwak, Ja Hun; Lee, Jong H.; Tran, Diana N.; Peden, Charles HF; Howden, Ken et al.
Partner: UNT Libraries Government Documents Department

Status Report on the Development of Research Campaigns

Description: Research campaigns were conceived as a means to focus EMSL research on specific scientific questions. Campaign will help fulfill the Environmental Molecular Sciences Laboratory (EMSL) strategic vision to develop and integrate, for use by the scientific community, world leading capabilities that transform understanding in the environmental molecular sciences and accelerate discoveries relevant to the Department of Energy’s (DOE’s) missions. Campaigns are multi-institutional multi-disciplinary projects with scope beyond those of normal EMSL user projects. The goal of research campaigns is to have EMSL scientists and users team on the projects in the effort to accelerate progress and increase impact in specific scientific areas by focusing user research, EMSL resources, and expertise in those areas. This report will give a history and update on the progress of those campaigns.
Date: June 30, 2013
Creator: Baer, Donald R.; Baker, Scott E.; Washton, Nancy M. & Linggi, Bryan E.
Partner: UNT Libraries Government Documents Department

Composite Synthesis Methodology Development: Nanocrvstalline SiC and Ti3SiC2 Alloys for Reactory Materials – Outline of initial synthesis capabilities M4CT-13PN0405034

Description: We have identified three initial preceramic polymers to help produce the SiC-based alloys for this project and have developed simple processing steps to make SiC-based alloy ceramics. The use of unfilled SMP-10 (Polycarbosilane) or SMP-877 (Methyl-Polycarbosilane) is not feasible due to the large mass losses that occur during pyrolysis. The pre-gelling steps below save time when those two polymers are filled with powders. The use of SL-MS30 provides us with a SiC-filled polymer that can be used to test out the CNT mats without further complications due to other powders.
Date: March 29, 2013
Creator: Henager, Charles H.; Alvine, Kyle J.; Shin, Yongsoon; Jiang, Weilin & Nguyen, Ba Nghiep
Partner: UNT Libraries Government Documents Department

Use of Polyphosphate to Decrease Uranium Leaching in Hanford 300 Area Smear Zone Sediments

Description: The primary objective of this study is to summarize the laboratory investigations performed to evaluate short- and long-term effects of phosphate treatment on uranium leaching from 300 area smear zone sediments. Column studies were used to compare uranium leaching in phosphate-treated to untreated sediments over a year with multiple stop flow events to evaluate longevity of the uranium leaching rate and mass. A secondary objective was to compare polyphosphate injection, polyphosphate/xanthan injection, and polyphosphate infiltration technologies that deliver phosphate to sediment.
Date: September 30, 2012
Creator: Szecsody, James E.; Zhong, Lirong; Oostrom, Martinus; Vermeul, Vincent R.; Fruchter, Jonathan S. & Williams, Mark D.
Partner: UNT Libraries Government Documents Department

Computational Proteomics: High-throughput Analysis for Systems Biology

Description: High-throughput (HTP) proteomics is a rapidly developing field that offers the global profiling of proteins from a biological system. The HTP technological advances are fueling a revolution in biology, enabling analyses at the scales of entire systems (e.g., whole cells, tumors, or environmental communities). However, simply identifying the proteins in a cell is insufficient for understanding the underlying complexity and operating mechanisms of the overall system. Systems level investigations are relying more and more on computational analyses, especially in the field of proteomics generating large-scale global data.
Date: January 3, 2007
Creator: Cannon, William R. & Webb-Robertson, Bobbie-Jo M.
Partner: UNT Libraries Government Documents Department

Filtration Understanding: FY10 Testing Results and Filtration Model Update

Description: This document completes the requirements of Milestone 2-4, Final Report of FY10 Testing, discussed in the scope of work outlined in the EM31 task plan WP-2.3.6-2010-1. The focus of task WP 2.3.6 is to improve the U.S. Department of Energy’s (DOE’s) understanding of filtration operations for high-level waste (HLW) to improve filtration and cleaning efficiencies, thereby increasing process throughput and reducing the Na demand (through acid neutralization). Developing the cleaning/backpulsing requirements will produce much more efficient operations for both the Hanford Tank Waste Treatment and Immobilization Plant (WTP) and the Savannah River Site (SRS), thereby significantly increasing throughput by limiting cleaning cycles. The scope of this work is to develop the understanding of filter fouling to allow developing this cleaning/backpulsing strategy.
Date: April 4, 2011
Creator: Daniel, Richard C.; Billing, Justin M.; Burns, Carolyn A.; Peterson, Reid A.; Russell, Renee L.; Schonewill, Philip P. et al.
Partner: UNT Libraries Government Documents Department

NID Copper Sample Analysis

Description: The current focal point of the nuclear physics program at PNNL is the MAJORANA DEMONSTRATOR, and the follow-on Tonne-Scale experiment, a large array of ultra-low background high-purity germanium detectors, enriched in 76Ge, designed to search for zero-neutrino double-beta decay (0νββ). This experiment requires the use of germanium isotopically enriched in 76Ge. The MAJORANA DEMONSTRATOR is a DOE and NSF funded project with a major science impact. The DEMONSTRATOR will utilize 76Ge from Russia, but for the Tonne-Scale experiment it is hoped that an alternate technology, possibly one under development at Nonlinear Ion Dynamics (NID), will be a viable, US-based, lower-cost source of separated material. Samples of separated material from NID require analysis to determine the isotopic distribution and impurities. DOE is funding NID through an SBIR grant for development of their separation technology for application to the Tonne-Scale experiment. The Environmental Molecular Sciences facility (EMSL), a DOE user facility at PNNL, has the required mass spectroscopy instruments for making isotopic measurements that are essential to the quality assurance for the MAJORANA DEMONSTRATOR and for the development of the future separation technology required for the Tonne-Scale experiment. A sample of isotopically separated copper was provided by NID to PNNL in January 2011 for isotopic analysis as a test of the NID technology. The results of that analysis are reported here. A second sample of isotopically separated copper was provided by NID to PNNL in August 2011 for isotopic analysis as a test of the NID technology. The results of that analysis are also reported here.
Date: September 12, 2011
Creator: Kouzes, Richard T. & Zhu, Zihua
Partner: UNT Libraries Government Documents Department

Landscape Measures of Rangeland Condition in the BLM Owyhee Pilot Project: Shrub Canopy Mapping, Vegetation Classification, and Detection of Anomalous Land Areas

Description: In 2006, the BLM tasked PNNL to collaborate in research being conducted under the Owyhee Uplands Pilot Project to assess rangeland condition. The objective of this effort was to provide Owyhee Uplands Pilot Project with a sophisticated suite of data and tools to assist in evaluating the health and condition of the Owyhee Uplands study area. We focused on three technical areas. The first involved enhancing existing algorithms to estimate shrub canopy cover in the Lower Reynolds Creek Watershed. The second task involved developing and applying a strategy to assess and compare three vegetation map products for the Idaho portion of the Owyhee study area. The third task developed techniques and data that can be used to identify areas exhibiting anomalous rangeland conditions (for example exotic plants or excessive bare soil exposure). This report documents the methods used, results obtained, and conclusions drawn.
Date: December 28, 2007
Creator: Tagestad, Jerry D. & Downs, Janelle L.
Partner: UNT Libraries Government Documents Department

200-BP-1 Prototype Hanford Barrier -- 15 Years of Performance Monitoring

Description: Monitoring is an essential component of engineered barrier system design and operation. A composite capacitive cover, including a capillary break and an evapotranspiration (ET) barrier at the Hanford Site, is generating data that can be used to help resolve these issues. The prototype Hanford barrier was constructed over the 216-B-57 Crib in 1994 to evaluate surface-barrier constructability, construction costs, and physical and hydrologic performance at the field scale. The barrier has been routinely monitored between November 1994 and September 1998 as part of a Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA) treatability test of barrier performance for the 200 BP 1 Operable Unit. Since FY 1998, monitoring has focused on a more limited set of key water balance, stability, and biotic parameters. In FY 2009, data collection was focused on: (1) water-balance monitoring, consisting of precipitation, runoff, soil moisture storage, and drainage measurements with evapotranspiration calculated by difference; (2) stability monitoring, consisting of asphalt-layer-settlement, basalt-side-slope-stability, and surface-elevation measurements; (3) vegetation dynamics; and (4) animal use. September 2009 marked 15 years since the start of monitoring and the collection of performance data. This report describes the results of monitoring activities during the period October 1, 2008, through September 30, 2009, and summarizes the 15 years of performance data collected from September 1994 through September 2009.
Date: September 30, 2011
Creator: Ward, Anderson L.; Draper, Kathryn E.; Link, Steven O. & Clayton, Ray E.
Partner: UNT Libraries Government Documents Department

Germanium-76 Sample Analysis: Revision 3

Description: The MAJORANA DEMONSTRATOR is a large array of ultra-low background high-purity germanium detectors, enriched in 76Ge, designed to search for zero-neutrino double-beta decay (0{nu}{beta}{beta}). The DEMONSTRATOR will utilize 76Ge from Russia. The first one-gram sample was received from the supplier for analysis on April 24, 2011. The second one-gram sample was received from the supplier for analysis on July 12, 2011. The third sample, which came from the first large shipment of germanium from the vendor, was received from Oak Ridge National Laboratory (ORNL) on September 13, 2011. The Environmental Molecular Sciences facility, a DOE user facility at PNNL, was used to make the required isotopic and chemical purity measurements that are essential to the quality assurance for the MAJORANA DEMONSTRATOR. The results of these analyses are reported here. The isotopic composition of a sample of natural germanium was also measured twice. Differences in the result between these two measurements led to a re-measurement of the second 76Ge sample.
Date: September 19, 2011
Creator: Kouzes, Richard T.; Zhu, Zihua & Engelhard, Mark H.
Partner: UNT Libraries Government Documents Department

LNAPLs do not Always Float: An Example Case of a Viscous LNAPL under Variable Water Table Conditions

Description: An intermediate-scale experiment was conducted to investigate the behavior of a viscous LNAPL under variable water table conditions. Two LNAPL volumes were released from a small source zone on top of the flow cell into a partly saturated, homogeneously packed porous medium. Following a 30-day redistribution period, the water table was increased 0.5 m in 50 minutes. After the water table rise, LNAPL behavior was monitored for an additional 45 days. Fluid saturation scans were obtained periodically with a fully automated dual-energy gamma radiation system. Results show that both spills follow similar paths downwards. LNAPL drainage from the unsaturated zone was relatively slow and a considerable residual LNAPL saturation was observed after 30 days of drainage. Most of the mobile LNAPL moved into the capillary fringe during this period. After the water table rise, LNAPL moved up in a delayed fashion. After 45 days, the LNAPL has moved up only approximately 0.2 m. Since the LNAPL has only moved up a limited amount, nonwetting fluid entrapment was also limited. The experiment was simulated using the STOMP multifluid flow simulator. A comparison indicates that the simulator is able to predict the observed phenomena well, including residual saturation formation in the vadose zone, and limited upward LNAPL movement after the water table rise. The results of this experiment show that viscous mobile LNAPL, subject to variable water table conditions, does not necessarily float on the water table and may not appear in an observation well.
Date: March 20, 2006
Creator: Oostrom, Mart; Hofstee , C & Wietsma, Thomas W.
Partner: UNT Libraries Government Documents Department

Advances in Geochemical Testing of Key Contaminants in Residual Hanford Tank Waste

Description: This report describes the advances that have been made over the past two years in testing and characterizing waste material in Hanford tanks.
Date: November 4, 2005
Creator: Deutsch, William J.; Krupka, Kenneth M.; Cantrell, Kirk J.; Brown, Christopher F.; Lindberg, Michael J.; Schaef, Herbert T. et al.
Partner: UNT Libraries Government Documents Department

Biomolecular Simulation of Base Excision Repair and Protein Signaling

Description: The goal of the Biomolecular Simulation of Base Excision Repair and Protein Signaling project is to enhance our understanding of the mechanism of human polymerase-, one of the key enzymes in base excision repair (BER) and the cell-signaling enzymes cyclic-AMP-dependent protein kinase. This work used molecular modeling and simulation studies to specifically focus on the • dynamics of DNA and damaged DNA • dynamics and energetics of base flipping in DNA • mechanism and fidelity of nucleotide insertion by BER enzyme human polymerase-β • mechanism and inhibitor design for cyclic-AMP-dependent protein kinase. Molecular dynamics simulations and electronic structure calculations have been performed using the computer resources at the Molecular Science Computing Facility at the Environmental Molecular Sciences Laboratory.
Date: March 3, 2006
Creator: Straatsma, TP; McCammon, J. A.; Miller, John H.; Smith, Paul E.; Vorpagel, Erich R.; Wong, Chung F. et al.
Partner: UNT Libraries Government Documents Department

NID Copper Sample Analysis

Description: The current focal point of the nuclear physics program at PNNL is the MAJORANA DEMONSTRATOR, and the follow-on Tonne-Scale experiment, a large array of ultra-low background high-purity germanium detectors, enriched in 76Ge, designed to search for zero-neutrino double-beta decay (0νββ). This experiment requires the use of germanium isotopically enriched in 76Ge. The DEMONSTRATOR will utilize 76Ge from Russia, but for the Tonne-Scale experiment it is hoped that an alternate technology under development at Nonlinear Ion Dynamics (NID) will be a viable, US-based, lower-cost source of separated material. Samples of separated material from NID require analysis to determine the isotopic distribution and impurities. The MAJORANA DEMONSTRATOR is a DOE and NSF funded project with a major science impact. DOE is funding NID through an SBIR grant for development of their separation technology for application to the Tonne-Scale experiment. The Environmental Molecular Sciences facility (EMSL), a DOE user facility at PNNL, has the required mass spectroscopy instruments for making these isotopic measurements that are essential to the quality assurance for the MAJORANA DEMONSTRATOR and for the development of the future separation technology required for the Tonne-Scale experiment. A sample of isotopically separated copper was provided by NID to PNNL for isotopic analysis as a test of the NID technology. The results of that analysis are reported here.
Date: February 1, 2011
Creator: Kouzes, Richard T. & Zhu, Zihua
Partner: UNT Libraries Government Documents Department

Simulations of The Dalles Dam Proposed Full Length Spillwall

Description: This report presents results of a computational fluid dynamics (CFD) modeling study to evaluatethe impacts of a full-length spillwall at The Dalles Dam. The full-length spillwall is being designed and evaluated as a structural means to improve tailrace egress and thus survival of juvenile fish passing through the spillway. During the course of this study, a full-length spillwall at Bays 6/7 and 8/9 were considered. The U.S. Army Corps of Engineers (USACE) has proposed extending the spillwall constructed in the stilling basin between spillway Bays 6 and 7 about 590 ft farther downstream. It is believed that the extension of the spillwall will improve egress conditions for downstream juvenile salmonids by moving them more rapidly into the thalweg of the river hence reducing their exposure to predators. A numerical model was created, validated, and applied the The Dalles Dam tailrace. The models were designed to assess impacts to flow, tailrace egress, navigation, and adult salmon passage of a proposed spill wall extension. The more extensive model validation undertaken in this study greatly improved our confidence in the numerical model to represent the flow conditions in The Dalles tailrace. This study used these validated CFD models to simulate the potential impacts of a spillwall extension for The Dalles Dam tailrace for two locations. We determined the following: (1)The construction of an extended wall (between Bays 6/7) will not adversely impact entering or exiting the navigation lock. Impact should be less if a wall were constructed between Bays 8/9. (2)The construction of a wall between Bays 6/7 will increase the water surface elevation between the wall and the Washington shore. Although the increased water surface elevation would be beneficial to adult upstream migrants in that it decreases velocities on the approach to the adult ladder, the increased flow depth would enhance dissolved ...
Date: February 25, 2008
Creator: Rakowski, Cynthia L.; Perkins, William A.; Richmond, Marshall C. & Serkowski, John A.
Partner: UNT Libraries Government Documents Department

Micron-Size Zero-Valent Iron Emplacement in Porous Media Using Polymer Additives: Column and Flow Cell Ex-periments

Description: At the Hanford Site, an extensive In Situ Redox Manipulation (ISRM) permeable reactive barrier was installed to prevent chromate from reaching the Columbia River. However, chromium has been detected in several wells, indicating a premature loss of the reductive capacity in the aquifer. Laboratory experiments have been conducted to investigate whether barrier reductive capacity can be enhanced by adding micron-scale zero-valent iron to the high-permeability zones within the aquifer using shear-thinning fluids containing polymers. Porous media were packed in a wedge-shaped flow cell to create either a heterogeneous layered system with a high-permeability zone between two low-permeability zones or a high-permeability channel sur-rounded by low-permeability materials. The injection flow rate, polymer type, polymer concentration, and injected pore volumes were determined based on preliminary short- and long-column experiments. The flow cell experiments indicated that iron concentration enhancements of at least 0.6% (w/w) could be obtained using moderate flow rates and injection of 30 pore volumes. The 0.6% amended Fe0 concentration would provide approximately 20 times the average reductive capacity that is provided by the dithionite-reduced iron in the ISRM barrier. Calculations show that a 1-m-long Fe0 amended zone with an average concentration of 0.6% w/w iron subject to a groundwater velocity of 1 m/day will have an estimated longevity of 7.2 years.
Date: March 20, 2006
Creator: Oostrom, Mart; Wietsma, Thomas W.; Covert, Matthew A. & Vermeul, Vince R.
Partner: UNT Libraries Government Documents Department

Analysis of Non-Enzymatically Glycated Peptides: Neutral-Loss Triggered MS3 Versus Multi-Stage Activation Tandem Mass Spectrometry

Description: Non-enzymatic glycation of tissue proteins has important implications in the development of complications of diabetes mellitus. While electron transfer dissociation (ETD) has been shown to outperform collision-induced dissociation (CID) in sequencing glycated peptides by tandem mass spectrometry, ETD instrumentation is not yet available in all laboratories. In this study, we evaluated different advanced CID techniques (i.e., neutral-loss triggered MS3 and multi-stage activation) during LC-MSn analyses of Amadori-modified peptides enriched from human serum glycated in vitro. During neutral-loss triggered MS3 experiments, MS3 scans triggered by neutral-losses of 3 H2O or 3 H2O + HCHO produced similar results in terms of glycated peptide identifications. However, neutral losses of 3 H2O resulted in significantly more glycated peptide identifications during multi-stage activation experiments. Overall, the multi-stage activation approach produced more glycated peptide identifications, while the neutral-loss triggered MS3 approach resulted in much higher specificity. Both techniques offer a viable alternative to ETD for identifying glycated peptides when that method is unavailable.
Date: October 15, 2008
Creator: Zhang, Qibin; Petyuk, Vladislav A.; Schepmoes, Athena A.; Orton, Daniel J.; Monroe, Matthew E.; Yang, Feng et al.
Partner: UNT Libraries Government Documents Department

Secondary Waste Cast Stone Waste Form Qualification Testing Plan

Description: The Hanford Tank Waste Treatment and Immobilization Plant (WTP) is being constructed to treat the 56 million gallons of radioactive waste stored in 177 underground tanks at the Hanford Site. The WTP includes a pretreatment facility to separate the wastes into high-level waste (HLW) and low-activity waste (LAW) fractions for vitrification and disposal. The LAW will be converted to glass for final disposal at the Integrated Disposal Facility (IDF). Cast Stone – a cementitious waste form, has been selected for solidification of this secondary waste stream after treatment in the ETF. The secondary-waste Cast Stone waste form must be acceptable for disposal in the IDF. This secondary waste Cast Stone waste form qualification testing plan outlines the testing of the waste form and immobilization process to demonstrate that the Cast Stone waste form can comply with the disposal requirements. Specifications for the secondary-waste Cast Stone waste form have not been established. For this testing plan, Cast Stone specifications are derived from specifications for the immobilized LAW glass in the WTP contract, the waste acceptance criteria for the IDF, and the waste acceptance criteria in the IDF Permit issued by the State of Washington. This testing plan outlines the testing needed to demonstrate that the waste form can comply with these waste form specifications and acceptance criteria. The testing program must also demonstrate that the immobilization process can be controlled to consistently provide an acceptable waste form product. This testing plan also outlines the testing needed to provide the technical basis for understanding the long-term performance of the waste form in the disposal environment. These waste form performance data are needed to support performance assessment analyses of the long-term environmental impact of the secondary-waste Cast Stone waste form in the IDF
Date: September 26, 2012
Creator: Westsik, Joseph H. & Serne, R. Jeffrey
Partner: UNT Libraries Government Documents Department

Transactive Control and Coordination of Distributed Assets for Ancillary Services

Description: The need to diversify energy supplies, the need to mitigate energy-related environmental impact, and the entry of electric vehicles in large numbers present challenges and opportunities to power system professionals. Wind and solar power provide many benefits, and to reap the benefits the resulting increased variability—forecasted as well as unforecasted—should be addressed. Demand resources are receiving increasing attention as one means of providing the grid balancing services. Control and coordination of a large number (~millions) of distributed smart grid assets requires innovative approaches. One such is transactive control and coordination (TC2)—a distributed, agent-based incentive and control system. The TC2 paradigm is to create a market system with the following characteristics: • Participation should be entirely voluntary. • The participant decides at what price s/he is willing to participate. • The bids and responses are automated. Such an approach has been developed and demonstrated by Pacific Northwest National Laboratory for energy markets. It is the purpose of this project to develop a similar approach for ancillary services. In this report, the following ancillary services are considered: • spinning reserve • ramping • regulation. These services are to be provided by the following devices: • refrigerators • water heaters • clothes dryers • variable speed drives. The important results are summarized below: The regulation signal can be divided into an energy-neutral high frequency component and a low frequency component. The high frequency component is particularly well suited for demand resources. The low frequency component, which carries energy non-neutrality, can be handled by a combination of generators and demand resources. An explicit method for such a separation is obtained from an exponentially weighted moving average filter. Causal filters (i.e., filters that process only present and past values of a signal) introduce delays that can be issues in some signal processing applications that treat ...
Date: September 18, 2013
Creator: Subbarao, Krishnappa; Fuller, Jason C.; Kalsi, Karanjit; Somani, Abhishek; Pratt, Robert G.; Widergren, Steven E. et al.
Partner: UNT Libraries Government Documents Department

Rh-Based Mixed Alcohol Synthesis Catalysts: Characterization and Computational Report

Description: The U.S. Department of Energy is conducting a program focused on developing a process for the conversion of biomass to bio-based fuels and co-products. Biomass-derived syngas is converted thermochemically within a temperature range of 240 to 330°C and at elevated pressure (e.g., 1200 psig) over a catalyst. Ethanol is the desired reaction product, although other side compounds are produced, including C3 to C5 alcohols; higher (i.e., greater than C1) oxygenates such as methyl acetate, ethyl acetate, acetic acid and acetaldehyde; and higher hydrocarbon gases such as methane, ethane/ethene, propane/propene, etc. Saturated hydrocarbon gases (especially methane) are undesirable because they represent a diminished yield of carbon to the desired ethanol product and represent compounds that must be steam reformed at high energy cost to reproduce CO and H2. Ethanol produced by the thermochemical reaction of syngas could be separated and blended directly with gasoline to produce a liquid transportation fuel. Additionally, higher oxygenates and unsaturated hydrocarbon side products such as olefins also could be further processed to liquid fuels. The goal of the current project is the development of a Rh-based catalyst with high activity and selectivity to C2+ oxygenates. This report chronicles an effort to characterize numerous supports and catalysts to identify particular traits that could be correlated with the most active and/or selective catalysts. Carbon and silica supports and catalysts were analyzed. Generally, analyses provided guidance in the selection of acceptable catalyst supports. For example, supports with high surface areas due to a high number of micropores were generally found to be poor at producing oxygenates, possibly because of mass transfer limitations of the products formed out of the micropores. To probe fundamental aspects of the complicated reaction network of CO with H2, a computational/ theoretical investigation using quantum mechanical and ab initio molecular dynamics calculations was initiated in ...
Date: August 1, 2013
Creator: Albrecht, Karl O.; Glezakou, Vassiliki Alexandra; Rousseau, Roger J.; Engelhard, Mark H.; Varga, Tamas; Colby, Robert J. et al.
Partner: UNT Libraries Government Documents Department

A Computational Approach to Understanding Aerosol Formation and Oxidant Chemistry in the Troposphere

Description: An understanding of the mechanisms and kinetics of aerosol formation and ozone production in the troposphere is currently a high priority because these phenomena are recognized as two major effects of energy-related air pollution. Atmospheric aerosols are of concern because of their effect on visibility, climate, and human health. Equally important, aerosols can change the chemistry of the atmosphere, in dramatic fashion, by providing new chemical pathways (in the condensed phase) unavailable in the gas phase. The oxidation of volatile organic compounds (VOCs) and inorganic compounds (e.g., sulfuric acid, ammonia, nitric acid, ions, and mineral) can produce precursor molecules that act as nucleation seeds. The U.S. Department of Energy (DOE) Atmospheric Chemistry Program (ACP) has identified the need to evaluate the causes of variations in tropospheric aerosol chemical composition and concentrations, including determining the sources of aerosol particles and the fraction of such that are of primary and secondary origin. In particular, the ACP has called for a deeper understanding into aerosol formation because nucleation creates substantial concentrations of fresh particles that, via growth and coagulation, influence the Earth's radiation budget. Tropospheric ozone is also of concern primarily because of its impact on human health. Ozone levels are controlled by NOx and by VOCs in the lower troposphere. The VOCs can be either from natural emissions from such sources as vegetation and phytoplankton or from anthropogenic sources such as automobiles and oil-fueled power production plants. The major oxidant for VOCs in the atmosphere is the OH radical. With the increase in VOC emissions, there is rising concern regarding the available abundance of HOx species needed to initiate oxidation. Over the last five years, there have been four field studies aimed at initial measurements of HOx species (OH and HO? radicals). These measurements revealed HOx levels that are two to four ...
Date: April 18, 2006
Creator: Francisco, Joseph S.; Kathmann, Shawn M.; Schenter, Gregory K.; Dang, Liem X.; Xantheas, Sotiris S.; Garrett, Bruce C. et al.
Partner: UNT Libraries Government Documents Department

Final Report of a CRADA Between Pacific Northwest National Laboratory and the General Motors Company (CRADA No. PNNL/271): “Degradation Mechanisms of Urea Selective Catalytic Reduction Technology”

Description: Diesel engines can offer substantially higher fuel efficiency, good driving performance characteristics, and reduced carbon dioxide (CO2) emission compared to stoichiometric gasoline engines. Despite the increasing public demand for higher fuel economy and reduced dependency on imported oil, however, meeting the stringent emission standards with affordable methods has been a major challenge for the wide application of these fuel-efficient engines in the US market. The selective catalytic reduction of NOx by urea (urea-SCR) is one of the most promising technologies for NOx emission control for diesel engine exhausts. To ensure successful NOx emission control in the urea-SCR technology, both a diesel oxidation catalyst (DOC) and a urea-SCR catalyst with high activity and durability are critical for the emission control system. Because the use of this technology for light-duty diesel vehicle applications is new, the relative lack of experience makes it especially challenging to satisfy the durability requirements. Of particular concern is being able to realistically simulate actual field aging of the catalyst systems under laboratory conditions, which is necessary both as a rapid assessment tool for verifying improved performance and certifiability of new catalyst formulations. In addition, it is imperative to develop a good understanding of deactivation mechanisms to help develop improved catalyst materials. In this CRADA program, General Motors Company and PNNL have investigated fresh, laboratory- and vehicle-aged DOC and SCR catalysts. The studies have led to a better understanding of various aging factors that impact the long-term performance of catalysts used in the urea-SCR technology, and have improved the correlation between laboratory and vehicle aging for reduced development time and cost. This Final Report briefly highlights many of the technical accomplishments and documents the productivity of the program in terms of peer-reviewed scientific publications (2 total), reports (3 total including this Final Report), and presentations (5 total).
Date: December 13, 2011
Creator: Kim, Do Heui; Lee, Jong H.; Peden, Charles HF; Howden, Ken; Kim, Chang H.; Oh, Se H. et al.
Partner: UNT Libraries Government Documents Department

Interim Report: Uranium Stabilization Through Polyphosphate Injection - 300 Area Uranium Plume Treatability Demonstration Project

Description: This report presents results from bench-scale treatability studies conducted under site-specific conditions to optimize the polyphosphate amendment for implementation of a field-scale technology demonstration to treat aqueous uranium within the 300 Area aquifer of the Hanford site. The general treatability testing approach consists of conducting studies with site sediment and under site conditions, in order to develop an effective chemical formulation for the polyphosphate amendments and evaluate the transport properties of these amendments under site conditions. Phosphorus-31 (31P) NMR was utilized to determine the effects of Hanford groundwater and sediment on the degradation of inorganic phosphates. Static batch tests were conducted to optimize the composition of the polyphosphate formulation for the precipitation of apatite and autunite, as well as to quantify the kinetics, loading and stability of apatite as a long-term sorbent for uranium. Dynamic column tests were used to further optimize the polyphosphate formulation for emplacement within the subsurface and the formation of autunite and apatite. In addition, dynamic testing quantified the stability of autunite and apatite under relevant site conditions. Results of this investigation provide valuable information for designing a full-scale remediation of uranium in the 300 aquifer.
Date: July 31, 2007
Creator: Wellman, Dawn M.; Pierce, Eric M.; Richards, Emily L.; Butler, Bart C.; Parker, Kent E.; Glovack, Julia N. et al.
Partner: UNT Libraries Government Documents Department