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Process Considerations in the Biodesulfurization of Crude Oil
No full textBiodesulfurization offers an attractive alternative to conventional hydrodesulfurization due to the mild operating conditions and reaction specificity afforded by the biocatalyst. The enzymatic pathway existing in Rhodococcus has been demonstrated to oxidatively desulfhrize the organic sulfbr occurring in dibenzothiophene while leaving the hydrocarbon intact. In order for biodesulfiization to realize commercial success, a variety of process considerations must be addressed including reaction rate, emulsion formation and breakage, biocatalyst recovery, and both gas and liquid mass transport. This study compares batch stirred to electro-spray bioreactors in the biodesulfurization of both model organics and actual crudes in terms of their operating costs, ability to make and break emulsions, ability to effect efficient reaction rates and enhance mass transport. Further, sulfim speciation in crude oil is assessed and compared to the sulfur specificity of currently available biocatalyst
Bio-Treatment of Energetic Materials Using White-Rot Fungus
No full textThe nitramine explosive, octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX), is used by militaries around the world in high yield munitions and often in combination with hexahydro- 1,3,5-trirdtro- 1,3,5- triazine (RDX). Improper handling and disposal of manufacturing wastewater may lead to environmental contamination. In the past wastewater was collected in disposal lagoons where it evaporated, and deposited large amounts of explosives on the lagoon floor. Although lagoon disposal is no longer practiced, thousands of acres have been already contaminated. RDX and, to a lesser extent, HMX have leached through the soil subsurface and contaminated groundwater ( 1,2). Likewjse, burning of substandard material or demilitarization of out-of-date muriitions has also led to environmental contamination. The current stockpile of energetic materials at DOE sites requires resource recovery or disposition (RRD). A related challenge exists in the clean-up of the DOE sites where soil and ground water are contaminated with explosives. Current technologies such as incineration, molten salt process, supercritical water oxidation are expensive and have technical hurdles. Open burning and open detonation(OB/OD) is not encouraged by regulatory agencies for disposal of explosives. Hence, there is need for a safe . technology to degrade these contaminants. The fi.mgal process does not employ open burning or open detonation to destroy energetic materials. The fimgal process can be used by itself, or it can augment or support other technologies for the treatment of energetic materials. The proposed enzyme technology will not release any air pollutants and will meet the regulations of Clean Air Act amendments, the Resource Conservation and Recovery Act, and the Federal. Facilities Compliance Act. The goal for this project was to test the ability of white-rot fungus to degrade HMX. In our study, we investigated the biodegradation of HMX using white-rot fungus in liquid and solid cultures. The degradation of HMX was studied at 1, 10, 100 and 1000 ppm levels. In all cases, HMX was degraded. In general, the rate of degradation of HMX increased with increase in HMX concentration. Because of encouraging findings, further optimization of this method and eventual field testing of this technology is recommended. This research was pefiormed in collaboration with Utah State University
Radionuclide Distribution Coefficients for Sediments Collected from Borehole 299-E17-21: Final Report for Subtask 1a
No full textOver 360 distribution coefficients (KJ for cesium, iodine, selenium, Strontium, technetium, and uranium were measured in fiscal year 1998 using 20 sediments collected fkom borehole 299-El 7-21 on the Hanford Site as part of the Immobilized Low-Activity Waste-Performance Assessment (ILAW-PA). Additionally, the pH and cation-exchange capacity (a measure of the total quantity of cations that a sediment can adsorb) of these sediment samples were measured. The sediment samples originated from the Hanford formation (informal name). Statistical analyses, using Student's t-test and correlation were conducted with the measured values. There were no significant differences between layers 1 and 2 for the selenium, strontium, technetium, and uranium & values (statistics could not be applied to evaluate layer 3 &values). Significant differences between the cesium and iodine&values for layem 1 and 2 were observed. However, these differences were modest and would likely not warrant the added complexity of using three distinct ®ions to represent the Hanford formation in the ILAW-PA model. Generally, the &values of layer 3 were more similar to those of layer 2 than those of layer 1. Conservative and best estimates of radionuclide & values were calculated based on the results from these measurements. The best estimate was chosen to be the calculated median value; whereas the con- servative estimate was the miniium value, except for the conservative uranium&estimate that was based on the second-to-lowest value because of the presence of an unusually low value that was not consistent with other values from this borehole or previous reported values. Overall, the estimates are consistent with values used for the ILAW-PA, with some notable excep- tions. The conservative & estimates for technetium and uranium are approximately the same as those used for the ILAW-PA. The conservative ~alues for cesium, selenium, and strontium were appreciably more conservative than necessary. The conservative iodine value is appreciably less than that used in the ILAW-PA and was based on a literature review of & values measured using Hanford Site sediments. The cause for the lower iodine &values measured in borehole 299-E 17-21 sediments is not known, though the sediments used in this study clearly had appreciably lower concentrations of fme materials than the Hanford Site sediments previously used in iodine sorption measurements. These differences in &values underscore the importance of basing& estimates for the ILAW-PA on measurements using site-specific sediments
Application of Integrated Reservoir Management and Reservoir Characterization to Optimize Infill Drilling
No full textInitial drilling of wells on a uniform spacing, without regard to reservoir performance and characterization, must become a process of the past. Such efforts do not optimize reservoir development as they fail to account for the complex nature of reservoir heterogeneities present in many low permeability reservoirs, and carbonate reservoirs in particular. These reservoirs are typically characterized by: o Large, discontinuous pay intervals o Vertical and lateral changes in reservoir properties o Low reservoir energy o High residual oil saturation o Low recovery efficienc
Long Range Neutron Detection: A Progress Report
No full textThe detection of neutron sources horn a considerable distance constitutes a problem that must be treated separately from the bulk of other neutron-detection applications. This report analyzes this problem, describes a number of possible approaches, and describes the design and construction of a square-meter detection system using the approach of moderator-free directional neutron detection. Although experimental results are not the focus of this report a few preliminary results are offered in the last section. Both theoretical and preliminary experimental results confirm that usefi.d detection of neutron sources for national-security applications is relatively easy at a distance of 50 meters, yet becomes somewhat challenging from a distance of 100 meters. The square-meter detection system designed for this effort was intended to be, in decreasing order of priority, optimally capable of neutron-source detection at 100 meters, lightweight and easy to use, and low in cost. Thus, the majority of design decisions were driven by the need to maximize sensitivity for remote source detection. Several surprises resulted from this design effort. First, we discovered that%, rather than cadmium or gadolinium, must be used as a shielding material. Second, we discovered that a relatively open collimator is best for remote detection. These and other design decisions are described in detail in the third section of this report. The final detector weighs roughly 45 kg and inco~orates hardware with a cost of roughly $1OOK. Of course, lighter or cheaper detection systems could be designed with some reduction in sensitivity. As designed, our l-square-meter moderator-free detection system is expected to be superior to conventional moderate-and-capture detection for some applications
Partitioning Rectangular and Structurally Nonsymmetric Sparse Matrices for Parallel Processing
No full textA common operation in scientific computing is the multiplication of a sparse, rectangular or structurally nonsymmetric matrix and a vector. In many applications the matrix- transpose-vector product is also required. This paper addresses the efficient parallelization of these operations. We show that the problem can be expressed in terms of partitioning bipartite graphs. We then introduce several algorithms for this partitioning problem and compare their performance on a set of test matrices
Feasibility of High Frequency Acoustic Imaging for Inspection of Containments
No full textThe Nuclear Regulatory Commission has a program at the Oak Ridge National Laboratory to provide assistance in their assessment of the effects of potential degradation on the structural integrity and Ieaktightness of metal containment vessels and steel liners of concrete containment in nuclear power plants. One of the program objectives is to identify a technique(s) for inspection of inaccessible portions of the containment pressure boundary. Acoustic imaging has been identified as one of these potential techniques. A numerical feasibility study investigated the use of high-frequency bistatic acoustic imaging techniques for inspection of inaccessible portions of the metallic pressure boundary of nuclear power plant containment. The range-dependent version of the OASES Code developed at the Massachusetts Institute of Technology was utilized to perform a series of numerical simulations. OASES is a well developed and extensively tested code for evaluation of the acoustic field in a system of stratified fluid and/or elastic layers. Using the code, an arbitrary number of fluid or solid elastic layers are interleaved, with the outer layers modeled as halfspaces. High frequency vibrational sources were modeled to simulate elastic waves in the steel. The received field due to an arbitrary source array can be calculated at arbitrary depth and range positions. In this numerical study, waves that reflect and scatter from surface roughness caused by modeled degradations (e.g., corrosion) are detected and used to identify and map the steel degradation. Variables in the numerical study included frequency, flaw size, interrogation distance, and sensor incident angle.Based on these analytical simulations, it is considered unlikely that acoustic imaging technology can be used to investigate embedded steel liners of reinforced concrete containment. The thin steel liner and high signal losses to the concrete make this application difficult. Results for portions of steel containment embedded in concrete are more encouraging in that they indicate that the intrinsic backscatter from degradations representing thickness reductions from 10 to 80% the shell thickness are sufficient to permit detection. It is recommended that a controlled experimental program be conducted in which sensor levels are calibrated against degradations to determine if current sensor technology can input sufficient power into the system to provide return levels within the dynamic range of the receivers
Reactivation of an Idle Lease to Increase Heavy Oil Recovery Through Application of Conventional Steam Drive Technology in a Low Dip Slope and Basin Reservoir in the Midway-Sunset Field, San Jaoquin Basin, California
No full textThis project reactivates ARCO's idle Pru Fee property in the Midway-Sunset field, California and conducts a continuous steamflood enhanced oil recovery demonstration aided by an integration of modern reservoir characterization and simulation methods. Cyclic steaming was used to reestablish baseline production within the reservoir characterization phase of the project. During the demonstration phase begun in January 1997, a continuous steamflood enhanced oil recovery was initiated to test the incremental value of this method as an alternative to cyclic steaming. Other economically marginal Class III reservoirs having similar producibility problems will benefit from insight gained in this project. The objectives of the project are: (1) to return the shut-in portion of the reservoir to optimal commercial production; (2) to accurately describe the reservoir and the recovery process; and (3) to convey the details of this activity to the domestic petroleum industry, especially to other producers in California, through an aggressive technology transfer program
Tomographic Site Characterization Using CPT, ERT, and GPR
No full textThe U.S. Department of Energy (DOE) is responsible for the cleanup of inactive DOE sites and for bringing DOE sites and facilities into compliance with federal, state and local laws and regulations. The DOE's Office of Environmental Management (EM) needs advanced technologies that can make environmental restoration and waste management operations more efficient and less costly. These techniques are required to better characterize the physical, hydrogeological, and chemical properties of the subsurface while minimizing and optimizing the use of boreholes and monitoring wells. Today the cone penetrometer technique (CPT) is demonstrating the value of a minimally invasive deployment system fix site characterization. Applied Research Associates is developing two new sensor packages for site characterization and monitoring. The two new methods are: . Electrical Resistivity Tomography (ERT) and . Ground Penetrating Radar (GPR) Tomography. These sensor systems are now integrated with the Cone Penetrometer Technique (CPT). The results of this program now make it possible to install ERT and GPR units by CPT methods and thereby reduce installation costs and total costs for ERT and GPR surveys. These two techniques can complement each other in regions of low resistivity where ERT is more effective and regions of high resistivity where GPR is more effective. The results show that CPT-installed GeoWells can be used in both ERT and GPR borehole tomographic subsurface imaging. These two imaging techniques can be used for environmental site characterization and environmental remediation monitoring. Technologies used for site characterization and monitoring have numerous and diverse applications within site clean-up and waste management operations
Task 3.14 - Demonstration of Technologies for Remote Power Generation in Alaska
No full textIn over 165 villages in Alaska, the use of fossil fuel supplies or renewable energy resources could greatly reduce the cost of electricity and space heating. Currently, diesel generators are the most commonly used electrical generating systems; however, high fuel costs result in extremely high electrical power costs reIative to the lower 48 states. The reduction of fuel costs associated with the use of indigenous, locally available fuels running modular, high-efficiency power- generating systems would be extremely beneficial