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At least 1,729 records · Page 96

An alkali-free method to manufacture ramie fiber

Ramie is one of the most significant fiber resources and it needs the degumming process to produce fibers. The traditional manufacturing process of ramie fibers requires a large amount of alkali, which causes serious environmental issues. This paper presents a novel path to manufacture ramie fibers without alkali. In this study, ramie bast was pretreated by steam explosion and then treated with deep eutectic solvent. The properties of ramie fibers prepared by the novel alkali-free method, including physical properties, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and X-ray diffraction (XRD), were compared with that produced by the traditional alkali process. Results showed that the fiber qualities, including residual gum content (4.68%), average fiber fineness (1419.99 N m ) and breaking tenacity (5.98 cN/dtex), were comparable with the traditional alkali process, which all meet the requirement of the relevant Chinese National Standards. The FTIR, SEM and XRD results all confirmed the degumming ability of the novel method to manufacture ramie fibers. Furthermore, the novel method was proved to be eco-friendly. Taken together, these data indicate that the novel alkali-free method is green and effective in manufacturing ramie fibers.

42 ENGINEERING↗

Conductance Steamflow relationship

These histograms represent our calibration of conductance of a volcanic geothermal field (with a clay cap) and the observed steam flow rates. See the following paper for further description: Trainor-Guitton, Hoversten,Nordquist, Intani, Value of information analysis using geothermal field data: accounting for multiple interpretations & determining new drilling locations. SEG Abstracts 2015.

15 GEOTHERMAL ENERGY↗

Utah FORGE: Well 14-2 Logs and Data from Roosevelt Hot Spring Area

This is a compilation of logs and data from Well 14-2 in the Roosevelt Hot Springs area in Utah. This well is also in the Utah FORGE study area. Data includes: flowmeter survey (1989), geochemistry (1977-1978, 1977-1983), injection test data (1979, 1982), and spinner surveys (1989, 1985-1986). Logs include: borehole compensated sonic and gamma ray (600'-6112'), borehole geometry and gamma ray (50'-4829'), caliper (0'-1720'), compensated neutron formation density (600'-6121'), induction electric (650'-6118'), mud log (79'-6100'), steam injection survey (50'-1175'), subsurface pressure surveys (0'-6087'), and subsurface temperature surveys (0'-6106'). The file is in a compressed .zip format and there is a data inventory table (Excel spreadsheet) in the root folder that is a guide to the data that is accessible in subfolders.

14-2↗

Renewable Thermal Energy Systems Designed for Industrial Process Solutions in Multiple Industries

The need for renewable heat in industry is vital for the next decade and beyond. Industrial decarbonization is a key area that must be accelerated, to foster the removal of fossil fuels from the provision of heat, especially at low temperatures. This paper looks at the development and results of case studies for understanding the economics and potential for renewable thermal energy systems (RTES), particularly in hybrid configurations to provide industrial process heat (IPH). For the case studies, these include non-concentrating e.g., heat pumps, and concentrating collectors e.g., parabolic trough collectors and direct steam generation (DSG)-linear Fresnel collectors (LFCs). The results show that a levelized cost of heat (LCOH) of $6-$8 per million British Thermal Units (MMBTU) is possible, depending on the direct normal irradiance (DNI) and the system sizing e.g., to increase the solar fractions. In Arizona for example, with a DNI of 7.36 kWh/m2/day, the base case for the DSG-LFC system with 6hrs of thermal energy storage could potentially meet a 1 MWth load 80% of the year.

concentrated solar thermal↗

Qualification of the Nippon Instrumentation for use in Measuring Mercury at the Defense Waste Processing Facility

The Nippon Mercury/RA-3000 system installed in 221-S M-14 has been qualified for use. The qualification was a side-by-side comparison of the Nippon Mercury/RA-3000 system with the currently used Bacharach Mercury Analyzer. The side-by-side testing included standards for instrument calibration verifications, spiked samples and unspiked samples. The standards were traceable back to the National Institute of Standards and Technology (NIST). The side-by-side work included the analysis of Sludge Receipt and Adjustment Tank (SRAT) Receipt, SRAT Product, and Slurry Mix Evaporator (SME) samples. With the qualification of the Nippon Mercury/RA-3000 system in M-14, the DWPF lab will be able to perform a head to head comparison of a second Nippon Mercury/RA-3000 system once the system is installed. The Defense Waste Processing Facility (DWPF) analyzes receipt and product samples from the Sludge Receipt and Adjustment Tank (SRAT) to determine the mercury (Hg) concentration in the sludge slurry. The SRAT receipt is typically sampled and analyzed for the first ten SRAT batches of a new sludge batch to obtain an average Hg concentration. This average Hg concentration is then used to determine the amount of steam stripping required during the concentration/reflux step of the SRAT cycle to achieve a less than 0.6 wt% Hg in the SRAT product solids. After processing is complete, the SRAT product is sampled and analyzed for mercury to ensure that the mercury concentration does not exceed the 0.45 wt% limit in the Slurry Mix Evaporator (SME). The DWPF Laboratory utilizes Bacharach Analyzers to support these Hg analyses at this facility. These analyzers are more than 10 years old, and they are no longer supported by the manufacturer. Due to these difficulties, the Bacharach Analyzers are to be replaced by new Nippon Mercury/RA-3000 systems. DWPF issued a Technical Task Request (TTR) for the Savannah River National Laboratory (SRNL) to assist in the qualification of the new systems. SRNL prepared a task technical and quality assurance (TT&QA) plan that outlined the activities that are necessary and sufficient to meet the objectives of the TTR. In addition, TT&QA plan also included a test plan that provided guidance to the DWPF Lab in collecting the data needed to qualify the new Nippon Mercury/RA-3000 systems.

47 OTHER INSTRUMENTATION↗

Millisecond Oxidation of Alkanes

This project was undertaken in response to the Department of Energy's call to research and develop technologies 'that will reduce energy consumption, enhance economic competitiveness, and reduce environmental impacts of the domestic chemical industry.' The current technology at the time for producing 140 billion pounds per year of propylene from naphtha and Liquified Petroleum Gas (LPG) relied on energy- and capital-intensive steam crackers and Fluidized Catalytic Cracking (FCC) units. The propylene is isolated from the product stream in a costly separation step and subsequently converted to acrylic acid and other derivatives in separate production facilities. This project proposed a Short Contact Time Reactor (SCTR)-based catalytic oxydehydrogenation process that could convert propane to propylene and acrylic acid in a cost-effective and energy-efficient fashion. Full implementation of this technology could lead to sizeable energy, economic and environmental benefits for the U. S. chemical industry by providing up to 45 trillion BTUs/year, cost savings of $1.8 billion/year and a combined 35 million pounds/year reduction in environmental pollutants such as COx, NOx, and SOx. Midway through the project term, the program directive changed, which approval from the DOE and its review panel, from direct propane oxidation to acrylic acid at millisecond contact times to a two-step process for making acrylic acid from propane. The first step was the primary focus, namely the conversion of propane to propylene in high yields assisted by the presence of CO2. The product stream from step one was then to be fed directly into a commercially practiced propylene-to-acrylic acid tandem reactor system.

02 PETROLEUM↗

Aerogel-Based Insulation for High-Temperature Industrial Processes

Under this program, Aspen Aerogels has developed an industrial insulation called Pyrogel HT, which is 4-5 times more thermally efficient than current non-aerogel technology. Derived from nanoporous silica aerogels, Pyrogel HT was specifically developed to address a high temperature capability gap not currently met with Aspen Aerogels{trademark} flagship product, Pyrogel XT. Pyrogel XT, which was originally developed on a separate DOE contract (DE-FG36-06GO16056), was primarily optimized for use in industrial steam processing systems, where application temperatures typically do not exceed 400 C. At the time, further improvements in thermal performance above 400 C could not be reasonably achieved for Pyrogel XT without significantly affecting other key material properties using the current technology. Cumulative sales of Pyrogel HT into domestic power plants should reach $125MM through 2030, eventually reaching about 10% of the total insulation market share in that space. Global energy savings would be expected to scale similarly. Over the same period, these sales would reduce domestic energy consumption by more than 65 TBtu. Upon branching out into all industrial processes in the 400 C-650 C regime, Pyrogel HT would reach annual sales levels of $150MM, with two-thirds of that being exported.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Radionuclide Retention Mechanisms in Secondary Waste-Form Testing: Phase II

This report describes the results from laboratory tests performed at Pacific Northwest National Laboratory (PNNL) for Washington River Protection Solutions (WRPS) to evaluate candidate stabilization technologies that have the potential to successfully treat liquid secondary waste stream effluents produced by the Hanford Tank Waste Treatment and Immobilization Plant (WTP). WRPS is considering the design and construction of a Solidification Treatment Unit (STU) for the Effluent Treatment Facility (ETF) at Hanford. The ETF, a multi-waste, treatment-and-storage unit that has been permitted under the Resource Conservation and Recovery Act (RCRA), can accept dangerous, low-level, and mixed wastewaters for treatment. The STU needs to be operational by 2018 to receive secondary liquid waste generated during operation of the WTP. The STU will provide the additional capacity needed for ETF to process the increased volume of secondary waste expected to be produced by WTP. This report on radionuclide retention mechanisms describes the testing and characterization results that improve understanding of radionuclide retention mechanisms, especially for pertechnetate, {sup 99}TcO{sub 4}{sup -} in four different waste forms: Cast Stone, DuraLith alkali aluminosilicate geopolymer, encapsulated fluidized bed steam reforming (FBSR) product, and Ceramicrete phosphate bonded ceramic. These data and results will be used to fill existing data gaps on the candidate technologies to support a decision-making process that will identify a subset of the candidate waste forms that are most promising and should undergo further performance testing.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

Energy Saving Melting and Revert Reduction (E-SMARRT): Precision Casting of Steel

This project addresses improvements in metal casting processes by reducing scrap and reducing the cost of production, due to scrap reduction from investment casting and yield improvement offered by lost foam casting as compared to no-bake or green sand molding. The objectives for the investment casting portion of the subtask are to improve knowledge of fracture toughness of mold shells and the sources of strength limiting flaws and to understand the effects of wax reclamation procedures on wax properties. Applying 'clean steel' approaches to pouring technology and cleanliness in investment casting of steel are anticipated to improve incoming materials inspection procedures as they affect the microstructure and toughness of the shell. This project focused on two areas of study in the production of steel castings to reduce scrap and save energy: (1) Reducing the amount of shell cracking in investment cast steel production; (2) Investigate the potential of lost foam steel casting The basic findings regarding investment casting shell cracking were: (1) In the case of post pouring cracking, this could be related to phase changes in silica upon cooling and could be delayed by pouring arrangement strategies that maintained the shell surface at temperature for longer time. Employing this delay resulted in less adherent oxidation of castings since the casting was cooler at the time o fair exposure. (2) A model for heat transfer through water saturated shell materials under steam pressure was developed. (3) Initial modeling result of autoclave de-waxing indicated the higher pressure and temperature in the autoclave would impose a steeper temperature gradient on the wax pattern, causing some melt flow prior to bulk expansion and decreasing the stress on the green shell. Basic findings regarding lost foam casting of steel at atmospheric pressure: (1) EPS foam generally decomposes by the collapse mode in steel casting. (2) There is an accumulation of carbon pick-up at the end of the casting opposite the gate. (3) It is recommended that lost foam castings in steel be gated for a quiescent fill in an empty cavity mold to prevent foam occlusion defects from the collapse mode. The energy benefit is primarily in yield savings and lower casting weight per function due to elimination of draft and parting lines for the larger lost foam castings. For the smaller investment casting, scrap losses due to shell cracking will be reduced. Both of these effects will reduce the metal melted per good ton of castings. There will also be less machine stock required per casting which is a yield savings and a small additional energy savings in machining. Downstream savings will come from heavy truck and railroad applications. Application of these processes to heavy truck castings will lighten the heavy truck fleet by about ten pounds per truck. Using ten years to achieve full penetration of the truck fleet at linear rate this will result in a fuel savings of 131 trillion BTU over ten years.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

EVALUATION OF SOLID SORBENTS AS A RETROFIT TECHNOLOGY FOR CO2 CAPTURE FROM COAL-FIRED POWER PLANTS

Through a U.S. Department of Energy (DOE) National Energy Technology Laboratory (NETL) funded cooperative agreement DE-NT0005649, ADA Environmental Solutions (ADA) has begun evaluating the use of solid sorbents for CO{sub 2} capture. The project objective was to address the viability and accelerate development of a solid-based CO{sub 2} capture technology. To meet this objective, initial evaluations of sorbents and the process/equipment were completed. First the sorbents were evaluated using a temperature swing adsorption process at the laboratory scale in a fixed-bed apparatus. A slipstream reactor designed to treat flue gas produced by coal-fired generation of nominally 1 kWe was designed and constructed, which was used to evaluate the most promising materials on a more meaningful scale using actual flue gas. In a concurrent effort, commercial-scale processes and equipment options were also evaluated for their applicability to sorbent-based CO{sub 2} capture. A cost analysis was completed that can be used to direct future technology development efforts. ADA completed an extensive sorbent screening program funded primarily through this project, DOE NETL cooperative agreement DE-NT0005649, with support from the Electric Power Research Institute (EPRI) and other industry participants. Laboratory screening tests were completed on simulated and actual flue gas using simulated flue gas and an automated fixed bed system. The following types and quantities of sorbents were evaluated: 87 supported amines; 31 carbon based materials; 6 zeolites; 7 supported carbonates (evaluated under separate funding); and 10 hydrotalcites. Sorbent evaluations were conducted to characterize materials and down-select promising candidates for further testing at the slipstream scale. More than half of the materials evaluated during this program were supported amines. Based on the laboratory screening four supported amine sorbents were selected for evaluation at the 1 kW scale at two different field sites. ADA designed and fabricated a slipstream pilot to allow an evaluation of the kinetic behavior of sorbents and provide some flexibility for the physical characteristics of the materials. The design incorporated a transport reactor for the adsorber (co-current reactor) and a fluidized-bed in the regenerator. This combination achieved the sorbent characterization goals and provided an opportunity to evaluate whether the potential cost savings associated with a relatively simple process design could overcome the sacrifices inherent in a co-current separation process. The system was installed at two field sites during the project, Luminant's Martin Lake Steam Electric Station and Xcel Energy's Sherburne County Generating Station (Sherco). Although the system could not maintain continuous 90% CO{sub 2} removal with the sorbents evaluated under this program, it was useful to compare the CO{sub 2} removal properties of several different sorbents on actual flue gas. One of the supported amine materials, sorbent R, was evaluated at both Martin Lake and Sherco. The 1 kWe pilot was operated in continuous mode as well as batch mode. In continuous mode, the sorbent performance could not overcome the limitations of the cocurrent adsorbent design. In batch mode, sorbent R was able to remove up to 90% CO{sub 2} for several cycles. Approximately 50% of the total removal occurred in the first three feet of the adsorption reactor, which was a transport reactor. During continuous testing at Sherco, CO{sub 2} removal decreased to approximately 20% at steady state. The lack of continuous removal was due primarily to the combination of a co-current adsorption system with a fluidized bed for regeneration, a combination which did not provide an adequate driving force to maintain an acceptable working CO{sub 2} capacity. In addition, because sorbent R consisted of a polymeric amine coated on a silica substrate, it was believed that the 50% amine loaded resulted in mass diffusion limitations related to the CO{sub 2} uptake rate. Three additional supported amine materials, sorbents AX, F, and BN, were selected for evaluation using the 1 kW pilot at Sherco. Sorbent AX was operated in batch mode and performed similarly to sorbent R (i.e. could achieve up to 90% removal when given adequate regeneration time). Sorbent BN was not expected to be subject to the same mass diffusion limitations as experienced with sorbent R. When sorbent BN was used in continuous mode the steady state CO{sub 2} removal was approximately double that of sorbent R, which highlighted the importance of sorbents without kinetic limitations.

01 COAL, LIGNITE, AND PEAT↗

Next Generation Nuclear Plant Project Evaluation of Siting a HTGR Co-generation Plant on an Operating Commercial Nuclear Power Plant Site

This paper summarizes an evaluation by the Idaho National Laboratory (INL) Next Generation Nuclear Plant (NGNP) Project of siting a High Temperature Gas-cooled Reactor (HTGR) plant on an existing nuclear plant site that is located in an area of significant industrial activity. This is a co-generation application in which the HTGR Plant will be supplying steam and electricity to one or more of the nearby industrial plants.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗

High Temperature Gas-Cooled Reactor Projected Markets and Preliminary Economics

This paper summarizes the potential market for process heat produced by a high temperature gas-cooled reactor (HTGR), the environmental benefits reduced CO2 emissions will have on these markets, and the typical economics of projects using these applications. It gives examples of HTGR technological applications to industrial processes in the typical co-generation supply of process heat and electricity, the conversion of coal to transportation fuels and chemical process feedstock, and the production of ammonia as a feedstock for the production of ammonia derivatives, including fertilizer. It also demonstrates how uncertainties in capital costs and financial factors affect the economics of HTGR technology by analyzing the use of HTGR technology in the application of HTGR and high temperature steam electrolysis processes to produce hydrogen.

01 COAL, LIGNITE, AND PEAT↗

Integration of High Temperature Gas-cooled Reactor Technology with Oil Sands Processes

This paper summarizes an evaluation of siting an HTGR plant in a remote area supplying steam, electricity and high temperature gas for recovery and upgrading of unconventional crude oil from oil sands. The area selected for this evaluation is the Alberta Canada oil sands. This is a very fertile and active area for bitumen recovery and upgrading with significant quantities piped to refineries in Canada and the U.S Additionally data on the energy consumption and other factors that are required to complete the evaluation of HTGR application is readily available in the public domain. There is also interest by the Alberta oil sands producers (OSP) in identifying alternative energy sources for their operations. It should be noted, however, that the results of this evaluation could be applied to any similar oil sands area.

02 PETROLEUM↗

Evaluation of THOR TM Mineralized Waste Forms (Granular and Monolith) for the DOE Advanced Remediation Technologies (ART) Phase 2 Project

The U.S. Department of Energy's (DOE) Office of River Protection (ORP) is responsible for the retrieval, treatment, immobilization, and disposal of Hanford's tank waste. Currently there are approximately 56 million gallons of highly radioactive mixed wastes awaiting treatment. A key aspect of the River Protection Project (RPP) cleanup mission is to construct and operate the Waste Treatment and Immobilization Plant (WTP). The WTP will separate the tank waste into high-level and low-activity waste (LAW) fractions, both of which will subsequently be vitrified. The projected throughput capacity of the WTP LAW Vitrification Facility is insufficient to complete the RPP mission in the time frame required by the Hanford Federal Facility Agreement and Consent Order, also known as the Tri-Party Agreement (TPA), i.e. December 31, 2047. Therefore, Supplemental Treatment is required both to meet the TPA treatment requirements as well as to more cost effectively complete the tank waste treatment mission. The Supplemental Treatment chosen will immobilize that portion of the retrieved LAW that is not sent to the WTP's LAW Vitrification facility into a solidified waste form. The solidified waste will then be disposed on the Hanford site in the Integrated Disposal Facility (IDF). In addition, the WTP LAW Vitrification facility off-gas condensate known as WTP Secondary Waste (WTP-SW) will be generated and enriched in volatile components such as Cs-137, I-129, Tc-99, Cl, F, and SO 4 that volatilize at the vitrification temperature of 1150°C in the absence of a continuous cold cap. The current waste disposal path for the WTP-SW is to recycle it to the supplemental LAW treatment to avoid a large steady state accumulation in the pretreatment-vitrification loop. Fluidized Bed Steam Reforming (FBSR) offers a moderate temperature (700-750°C) continuous method by which LAW and/or WTP-SW wastes can be processed irrespective of whether they contain organics, nitrates, sulfates/sulfides, chlorides, fluorides, volatile radionuclides or other aqueous components. The FBSR technology can process these wastes into a crystalline ceramic (mineral) waste form. The mineral waste form that is produced by co-processing waste with kaolin clay in an FBSR process has been shown to be as durable as LAW glass. Monolithing of the granular FBSR product, which is one of the objectives of this current study, is being investigated to prevent dispersion during transport or burial/storage but is not necessary for performance. FBSR testing of a Hanford LAW simulant and a WTP-SW simulant at the pilot scale was performed by THOR Treatment Technologies, LLC at Hazen Research Inc. in April/May 2008. The Hanford LAW simulant was the Rassat 68 tank blend and the target concentrations for the LAW was increased by a factor of 10 for Sb, As, Ag, Cd, and Tl; 100 for Ba and Re (Tc surrogate); 1,000 for I; and 254,902 for Cs based on discussions with the DOE field office and the environmental regulators and an evaluation of the Hanford Tank Waste Envelopes A, B, and C. It was determined through the evaluation of the actual tank waste metals concentrations that some metal levels were not sufficient to achieve reliable detection in the off-gas sampling. Therefore, the identified metals concentrations were increased in the Rassat simulant processed by TTT at HRI to ensure detection and enable calculation of system removal efficiencies, product retention efficiencies, and mass balance closure without regard to potential results of those determinations or impacts on product durability response such as Toxicity Characteristic Leach Procedure (TCLP). A WTP-SW simulant based on melter off-gas analyses from Vitreous State Laboratory (VSL) was also tested at HRI in the 15-inch diameter Engineering Scale Test Demonstration (ESTD) dual reformer at HRI in 2008. The target concentrations for the Resource Conservation and Recovery Act (RCRA) metals were increased by 16X for Se, 29X for Tl, 42X for Ba, 48X for Sb, by 100X for Pb and Ni, 1000X for Ag, and 1297X for Cd to ensure detection by the analytic laboratory used for the demonstration and, as with the LAW simulant, without regard to potential impacts on product durability response such as TCLP. Details of the ESTD testing that was performed in April and May of 2008 are shown in Table 1 as the Operational Summary. The first eight tests were performed on LAW using a Denitration and Mineralization Reformer (DMR) temperature of 725°C and different ratios of clay:simulant of 675 g or 640 g of OptiKast clay per liter of simulant. The last four tests were performed on WTP-SW (originally referred to as LAW-Recycle) using a DMR temperature in the range of 680°C to 700°C with a mixture of 45/55 Sagger/OptiKast clay with 307 g clay/L simulant. The coal feed rates used in the FBSR processing are also shown as noted at the bottom of Table 1. It should be noted that the carbon feed rates are averaged over those periods.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

Demonstration of the BioBaler harvesting system for collection of small-diameter woody biomass

As part of a project to investigate sustainable forest management practices for producing wood chips on the Oak Ridge Reservation (ORR) for the ORNL steam plant, the BioBaler was tested in various Oak Ridge locations in August of 2011. The purpose of these tests and the subsequent economic analysis was to determine the potential of this novel woody biomass harvesting method for collection of small-diameter, low value woody biomass. Results suggest that opportunities may exist for economical harvest of low-value and liability or negative-cost biomass. (e.g., invasives). This could provide the ORR and area land managers with a tool to produce feedstock while improving forest health, controlling problem vegetation, and generating local employment.

09 BIOMASS FUELS↗

Analyses and Comparison of Bulk and Coil Surface Samples from the DWPF Slurry Mix Evaporator

Sludge samples from the DWPF Slurry Mix Evaporator (SME) heating coil frame and coil surface were characterized to identify differences that might help identify heat transfer fouling materials. The SME steam coils have seen increased fouling leading to lower boil-up rates. Samples of the sludge were taken from the coil frame somewhat distant from the coil (bulk tank material) and from the coil surface (coil surface sample). The results of the analysis indicate the composition of the two SME samples are very similar with the exception that the coil surface sample shows ~5-10X higher mercury concentration than the bulk tank sample. Elemental analyses and x-ray diffraction results did not indicate notable differences between the two samples. The ICP-MS and Cs-137 data indicate no significant differences in the radionuclide composition of the two SME samples. Semi-volatile organic analysis revealed numerous organic molecules, these likely result from antifoaming additives. The compositions of the two SME samples also match well with the analyzed composition of the SME batch with the exception of significantly higher silicon, lithium, and boron content in the batch sample indicating the coil samples are deficient in frit relative to the SME batch composition.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

Overcoming the Recalcitrance of Cellulosic Biomass by Value Prior to Pulping (CRADA Final Report)

The Value Prior to Pulping (VPP) project goal was to demonstrate the technical and commercial feasibility of introducing a new value stream into existing pulp and paper mills. Essentially the intent was to transfer the energy content of extracted hemicellulose from electricity and steam generated in the recovery boiler to a liquid transportation fuel. The hemicellulose fraction was extractedprior to pulping, fractionated, or conditioned if necessary, and fermented to ethanol. Commercial adaptation of the process to wood hemicelluloses was a prerequisite for using this less currently valued component available from biomass and wood. These hemicelluloses are predominately glucurono-xylan in hardwoods and galactoglucomannan in softwoods (with a significant softwood component of anarabino-xylan) and will yield fermentation substrates different from cellulose. NREL provided its expertise in the area of fermentation host evaluation using its Zymomonas strains on the CleanTech Partner's (CTP) VPP project. The project was focused on the production of fuel ethanol and acetic acid from hemicellulose streams generated from wood chips of industrially important hardwood andsoftwood species. NREL was one of four partners whose ethanologen was tested on the hydrolyzed extracts. The use of commercially available enzymes to treat oligomeric sugar extracts was also investigated and coupled with fermentation. Fermentations by NREL were conducted with the Zymomonas mobilis organism with most of the work being performed with the 8b strain. The wood extracts hydrolyzedand/or fermented by NREL were those derived from maple, mixed southern hardwoods, and loblolly pine. An unhydrolyzed variant of the mixed southern hardwood extract possessed a large concentration of oligomeric sugars and enzymatic hydrolysis was performed with a number of enzymes, followed by fermentation. The fermentation of the wood extracts was carried out at bench scale in flasks or smallbioreactors, with a maximum volume of 500 mL.

09 BIOMASS FUELS↗

Utility-Scale Concentrating Solar Power and Photovoltaic Projects: A Technology and Market Overview

Over the last several years, solar energy technologies have been, or are in the process of being, deployed at unprecedented levels. A critical recent development, resulting from the massive scale of projects in progress or recently completed, is having the power sold directly to electric utilities. Such 'utility-scale' systems offer the opportunity to deploy solar technologies far faster than thetraditional 'behind-the-meter' projects designed to offset retail load. Moreover, these systems have employed significant economies of scale during construction and operation, attracting financial capital, which in turn can reduce the delivered cost of power. This report is a summary of the current U.S. utility-scale solar state-of-the-market and development pipeline. Utility-scale solar energysystems are generally categorized as one of two basic designs: concentrating solar power (CSP) and photovoltaic (PV). CSP systems can be further delineated into four commercially available technologies: parabolic trough, central receiver (CR), parabolic dish, and linear Fresnel reflector. CSP systems can also be categorized as hybrid, which combine a solar-based system (generally parabolictrough, CR, or linear Fresnel) and a fossil fuel energy system to produce electric power or steam.

14 SOLAR ENERGY↗