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DOE OSTI2025

IDAES GTEP 0.1 Release

The Institute for the Design of Advanced Energy Systems (IDAES) Generation and Transmission Expansion Planning (GTEP) package provides a Pyomo-based implementation of a modular, flexible, Generalized Disjunctive Programming (GDP) formulation for power infrastructure planning problems. This package is designed with the following goals in mind: - Abstract GTEP modeling away from any particular case study or fixed modeling assumptions (e.g., technologies, temporal resolution, spatial resolution, policy implications, etc.) - Admit flexible decision sets and heterogeneous parameterization - Allow high-level modeling options to be understood easily, chosen modularly, and changed rapidly

AS↗
DOE OSTI2011

Bypass Flow Study

Fluid dynamics experiments are being conducted in the matched-index-of-refraction flow system at the Idaho National Laboratory to develop benchmark databases. The data will be used to assess computational fluid dynamics solutions of the momentum equations, scalar mixing, and turbulence models for the flow ratios between coolant channels and bypass gaps in the interstitial regions of typical prismatic standard fuel element or upper reflector block geometries of typical modular high-temperature gas-cooled reactors in the limiting case of negligible buoyancy and constant fluid properties. The experiments use particle image velocimetry to measure the velocity fields that will populate the bypass flow study database. The matched-index-of-refraction modular high-temperature gas-cooled reactor bypass flow experiment measures flow velocity fields in the coolant channels and interstitial gaps between typical prismatic block standard fuel elements (SFEs) or upper reflector blocks.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2012

Trip Report-Produced-Water Field Testing

Los Alamos National Laboratory (LANL) conducted field testing of a produced-water pretreatment apparatus with assistance from faculty at the Texas A&M University (TAMU) protein separation sciences laboratory located on the TAMU main campus. The following report details all of the logistics surrounding the testing. The purpose of the test was to use a new, commercially-available filter media housing containing modified zeolite (surfactant-modified zeolite or SMZ) porous medium for use in pretreatment of oil and gas produced water (PW) and frac-flowback waters. The SMZ was tested previously in October, 2010 in a lab-constructed configuration ('old multicolumn system'), and performed well for removal of benzene, toluene, ethylbenzene, and xylenes (BTEX) from PW. However, a less-expensive, modular configuration is needed for field use. A modular system will allow the field operator to add or subtract SMZ filters as needed to accommodate site specific conditions, and to swap out used filters easily in a multi-unit system. This test demonstrated the use of a commercial filter housing with a simple flow modification and packed with SMZ for removing BTEX from a PW source in College Station, Texas. The system will be tested in June 2012 at a field site in Pennsylvania for treating frac-flowback waters. The goals of this test are: (1) to determine sorption efficiency of BTEX in the new configuration; and (2) to observe the range of flow rates, backpressures, and total volume treated at a given flow rate.

42 ENGINEERING↗
DOE OSTI2012

Determination of the impact of glycolate on arp and mcu operations

Savannah River Remediation (SRR) is evaluating an alternate flowsheet for the Defense Waste Processing Facility (DWPF) using glycolic acid as a reductant. An important aspect of the development of the glycolic acid flowsheet is determining if glycolate has any detrimental downstream impacts. Testing was performed to determine if there is any impact to the strontium and actinide sorption by monosodium titanate (MST) and modified monosodium titanate (mMST) or if there is an impact to the cesium removal at the Modular Caustic-Side Solvent Extraction Processing Unit (MCU). Sorption testing was performed using both MST and modified MST (mMST) in the presence of 5,000 and 10,000 ppm (mass basis) glycolate. 10,000 ppm is the estimated bounding concentration expected in the DWPF recycle stream based on DWPF melter flammable gas model results. The presence of glycolate was found to slow the removal of Sr and Pu by MST, while increasing the removal rate of Np. Results indicate that the impact is a kinetic effect, and the overall capacity of the material is not affected. There was no measurable effect on U removal at either glycolate concentration. The slower removal rates for Sr and Pu at 5,000 and 10,000 ppm glycolate could result in lower DF values for these sorbates in ARP based on the current (12 hours) and proposed (8 hours) contact times. For the highest glycolate concentration used in this study, the percentage of Sr removed at 6 hours of contact decreased by 1% and the percentage of Pu removed decreased by nearly 7%. The impact may prove insignificant if the concentration of glycolate that is returned to the tank farm is well below the concentrations tested in this study. The presence of glycolate also decreased the removal rates for all three sorbates (Sr, Pu, and Np) by mMST. Similarly to MST, the results for mMST indicate that the impact is a kinetic effect, and the overall capacity of the material is not affected. The presence of glycolate did not change the lack of affinity of mMST for U. Pre-contacting the MST or mMST with glycolate did not have a significant effect on the performance of the materials when compared to tests having the same concentration of glycolate present in the simulant. These findings suggest that the glycolate is likely influencing removal by sorbate complexation and not by depositing onto or forming a film on the surface of the MST solids. Since the DF values are salt batch dependent, it is not possible to a priori quantify the impacts of glycolate on future processing campaigns. However, we recommend that the impacts of glycolate be evaluated during each salt batch qualification when a final processing concentration is defined, and recommendations can then be made on how to mitigate negative impacts, if needed. Impacts to the performance of the MST or mMST could be mitigated by increasing contact time or increasing sorbent concentrations. In addition to the MST and mMST testing, testing was performed to determine if there is an impact to the cesium removal at Modular Caustic-Side Solvent Extraction Processing Unit (MCU). An Extraction-Scrub-Strip (ESS) test routine was used to simulate cesium removal at the MCU. For this, SRNL performed three ESS tests, using the same basic aqueous waste simulant and solvent. For one test, SRNL added 5,000 ppm (mass basis) of glycolate and added 10,000 ppm of glycolate to a second test. A control test contained no glycolate. The results of all three tests were virtually identical for all the extraction, scrub and strip tests. (A single data point in the 5,000 ppm test is physically impossible and SRNL is currently resolving this obvious error.) At this time, SRNL concludes that the presence of up to 10,000 ppm of glycolate does not affect cesium removal by the current solvent system used in the MCU. Although not tested, the impact of glycolate for the Next Generation Solvent - that replaces BOBCalixC6 with MaxCalix - is expected to be very similar to that for the baseline solvent. Testing is needed to confirm. Additional testing is recommended to both further examine the nature of the interaction of glycolate with MST and mMST and also to help address some postulated risks on ARP/MCU operations with implementation of the glycolate flowsheet. The additional testing includes FTIR and Raman spectroscopy to examine the surface of the MST and mMST particles, iodometric titrations to determine the peroxide content in the mMST before and after exposure to glycolate, particle size measurements of the MST and mMST from the experiments performed with glycolate, and measurements of soluble Ti in the supernate from these glycolate experiments. With regards to MCU impacts, the following tests are also recommended based on the premortem risk assessment.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
DOE OSTI2012

Novel Low Cost, High Reliability Wind Turbine Drivetrain

Clipper Windpower, in collaboration with United Technologies Research Center, the National Renewable Energy Laboratory, and Hamilton Sundstrand Corporation, developed a low-cost, deflection-compliant, reliable, and serviceable chain drive speed increaser. This chain and sprocket drivetrain design offers significant breakthroughs in the areas of cost and serviceability and addresses the key challenges of current geared and direct-drive systems. The use of gearboxes has proven to be challenging; the large torques and bending loads associated with use in large multi-MW wind applications have generally limited demonstrated lifetime to 8-10 years. The large cost of gearbox replacement and the required use of large, expensive cranes can result in gearbox replacement costs on the order of $\$$1M, representing a significant impact to overall cost of energy (COE). Direct-drive machines eliminate the gearbox, thereby targeting increased reliability and reduced life-cycle cost. However, the slow rotational speeds require very large and costly generators, which also typically have an undesirable dependence on expensive rare-earth magnet materials and large structural penalties for precise air gap control. The cost of rare-earth materials has increased 20X in the last 8 years representing a key risk to ever realizing the promised cost of energy reductions from direct-drive generators. A common challenge to both geared and direct drive architectures is a limited ability to manage input shaft deflections. The proposed Clipper drivetrain is deflection-compliant, insulating later drivetrain stages and generators from off-axis loads. The system is modular, allowing for all key parts to be removed and replaced without the use of a high capacity crane. Finally, the technology modularity allows for scalability and many possible drivetrain topologies. These benefits enable reductions in drivetrain capital cost by 10.0%, levelized replacement and O&M costs by 26.7%, and overall cost of energy by 10.2%. This design was achieved by: (1) performing an extensive optimization study that deter-mined the preliminary cost for all practical chain drive topologies to ensure the most competitive configuration; (2) conducting detailed analysis of chain dynamics, contact stresses, and wear and efficiency characteristics over the chain's life to ensure accurate physics-based predictions of chain performance; and (3) developing a final product design, including reliability analysis, chain replacement procedures, and bearing and sprocket analysis. Definition of this final product configuration was used to develop refined cost of energy estimates. Finally, key system risks for the chain drive were defined and a comprehensive risk reduction plan was created for execution in Phase 2.

17 WIND ENERGY↗
DOE OSTI2012

Determination of the Impact of Glycolate on ARP and MCU Operations

Savannah River Remediation (SRR) is evaluating an alternate flowsheet for the Defense Waste Processing Facility (DWPF) using glycolic acid as a reductant. An important aspect of the development of the glycolic acid flowsheet is determining if glycolate has any detrimental downstream impacts. Testing was performed to determine if there is any impact to the strontium and actinide sorption by monosodium titanate (MST) and modified monosodium titanate (mMST) or if there is an impact to the cesium removal, phase separation, or coalescer performance at the Modular Caustic-Side Solvent Extraction Processing Unit (MCU). Sorption testing was performed using both MST and modified MST (mMST) in the presence of 5000 and 10,000 ppm (mass basis) glycolate. 10,000 ppm is the estimated bounding concentration expected in the DWPF recycle stream based on DWPF melter flammable gas model results. The presence of glycolate was found to slow the removal of Sr and Pu by MST, while increasing the removal rate of Np. Results indicate that the impact is a kinetic effect, and the overall capacity of the material is not affected. There was no measurable effect on U removal at either glycolate concentration. The slower removal rates for Sr and Pu at 5000 and 10,000 ppm glycolate could result in lower DF values for these sorbates in ARP based on the current (12 hours) and proposed (8 hours) contact times. For the highest glycolate concentration used in this study, the percentage of Sr removed at 6 hours of contact decreased by 1% and the percentage of Pu removed decreased by nearly 7%. The impact may prove insignificant if the concentration of glycolate that is returned to the tank farm is well below the concentrations tested in this study. The presence of glycolate also decreased the removal rates for all three sorbates (Sr, Pu, and Np) by mMST. Similar to MST, the results for mMST indicate that the impact is a kinetic effect, and the overall capacity of the material is not affected. The presence of glycolate did not change the lack of affinity of mMST for U. Pre-contacting the MST or mMST with glycolate did not have a significant effect on the performance of the materials when compared to tests having the same concentration of glycolate present in the simulant. These findings suggest that the glycolate is likely influencing removal by sorbate complexation and not by depositing onto or forming a film on the surface of the MST solids. Since the DF values are salt batch dependent, it is not possible to a priori quantify the impacts of glycolate on future processing campaigns. However, we recommend that the impacts of glycolate be evaluated during each salt batch qualification when a final processing concentration is defined, and recommendations can then be made on how to mitigate negative impacts, if needed. Impacts to the performance of the MST or mMST could be mitigated by increasing contact time or increasing sorbent concentrations. Testing was performed to determine if there is an impact to the cesium removal at Modular Caustic-Side Solvent Extraction Processing Unit (MCU). An Extraction-Scrub-Strip (ESS) test routine was used to simulate cesium removal at the MCU. For this, SRNL performed three ESS tests, using the same basic aqueous waste simulant and solvent. For one test, SRNL added 5000 ppm (mass basis) of glycolate and added 10,000 ppm of glycolate to a second test. A control test contained no glycolate. The results of all three tests were virtually identical for all the extraction, scrub and strip tests.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2012

Preliminary Feasibility of Value-Added Products from Cogeneration and Hybrid Energy Systems in Wyoming

Wyoming has a wealth of primary energy resources in the forms of coal, natural gas, wind, uranium, and oil shale. Most of Wyoming's coal and gas resources are exported from the state in unprocessed form rather than as refined higher value products. Wyoming's leadership recognizes the opportunity to broaden the state’s economic base energy resources to make value-added products such as synthetic vehicle fuels and commodity chemicals. Producing these higher value products in an environmentally responsible manner can benefit from the use of clean energy technologies including Wyoming’s abundant wind energy and nuclear energy such as new generation small modular reactors including the high temperature gas-cooled reactors. The Wyoming Business Council (WBC), under direction from the State’s Legislature, commissioned the Idaho National Laboratory (INL) to complete evaluations of selected energy futures for Wyoming, focusing specifically on the benefits of hybrid energy systems that would take advantage of all of the state’s energy resources. This work was accomplished by two complementary activities. First, a collaborative effort of the Wyoming Business Council, tire University of Wyoming and the Idaho National Laboratory focused on screening-level analysis of a range of hybrid energy systems using new small modular nuclear reactors for the conversion of coal and natural gas into synthetic fuels and commodity chemicals in configurations designed to also stabilize wind power generation. This report summarizes the outcome of this first activity. Second, a more rigorous analysis led by the NGNP Industry Alliance in collaboration with the Idaho National Laboratory to evaluate the application of the high temperature, gas-cooled nuclear reactor (HTGR) to enhance coal and natural gas conversion to higher value products and electrical power. The results, conclusions, and recommendations of the HTGR applications work are presented in INL/EXT-12-26732, Energy Development Opportunities for Wyoming. The conclusions of these evaluations provide a conceptual foundation upon which Wyoming can form a partnership with industry to lay out a strategy and plan of action that can develop leading to a state-wide energy economy.

10 SYNTHETIC FUELS↗
DOE OSTI2013

Developing Load Cell Monitoring on the Mock UF 6 Feed and Withdrawal System

A proof-of-concept load cell monitoring system has been developed for the Mock Feed and Withdrawal (F&W) System at Oak Ridge National Laboratory (ORNL). This system leverages industry-standard commercial off-the-shelf (COTS) hardware and software in a modular and scalable design. The Mock F&W System was designed to simulate operations at a uranium hexafluoride (UF 6 ) gas centrifuge enrichment plant F&W area. It provides a test bed for process-monitoring technologies. Water, used as a surrogate for UF 6 , is pumped from three feed tanks, through a process surge tank, and is then cut between two tails tanks and three product tanks. The weight of the each tank is continuously monitored using a load cell monitoring system. In addition to the F&W stations, large and small accountancy stations are monitored. The Mock F&W System allows ORNL to test and evaluate capabilities of industry-standard process monitoring hardware and software. A variety of commonly used weighing indicators are connected to the load cells to monitor the weight at each station. These weighing indicators are representative of the types likely found in operating facilities. A data center modeled after those currently used for international safeguards was installed to collect and manage the weight data. This data center provides a robust and flexible test bed for testing and developing software solutions. COTS software packages that leverage industry-standard communication protocols provide a data flow architecture that is modular, interoperable, and scalable. One software package provides communication drivers to collect the raw weight data from the weighing indicators. A data historian is used to store the raw data. Custom in-house algorithms have been developed using MATLAB to analyze the raw historical data and to automatically identify process information. This information includes the number of cycles completed and the mass of material transferred from stations to the process. The process information identified by the analysis is stored in a Microsoft SQL Server database. Visualization concepts have been developed that display the analyzed process information alongside visually compelling plots and animations of the raw data. The load cell monitoring system developed on the Mock F&W System was designed as a proof of concept that could be scaled to a field trial at an operating facility. This system, built with industry standard hardware and software, has allowed ORNL to develop capabilities that provide confidence in the ability to leverage existing operator load cell monitoring equipment with minimal impact on operations. The international safeguards community is evaluating the use of load cell monitoring as an additional safeguards measure; this system demonstrates a practical solution to collect, store, analyze, and visualize load cell weight data.

commercial off the shelf↗
DOE OSTI2013

Estimating of pulsed electric fields using optical measurements.

We performed optical electric field measurements ion nanosecond time scales using the electro optic crystal beta barium borate (BBO). Tests were based on a preliminary bench top design intended to be a proof of principle stepping stone towards a modular design optical E field diagnostic that has no metal in the interrogated environment. The long term goal is to field a modular version of the diagnostic in experiments on large scale x ray source facilities, or similarly harsh environments.

Flanagan, Timothy McGuire↗
DOE OSTI2014

A High-Performance Embedded Hybrid Methodology for Uncertainty Quantification With Applications

Multiphysics processes modeled by a system of unsteady differential equations are naturally suited for partitioned (modular) solution strategies. We consider such a model where probabilistic uncertainties are present in each module of the system and represented as a set of random input parameters. A straightforward approach in quantifying uncertainties in the predicted solution would be to sample all the input parameters into a single set, and treat the full system as a black-box. Although this method is easily parallelizable and requires minimal modifications to deterministic solver, it is blind to the modular structure of the underlying multiphysical model. On the other hand, using spectral representations polynomial chaos expansions (PCE) can provide richer structural information regarding the dynamics of these uncertainties as they propagate from the inputs to the predicted output, but can be prohibitively expensive to implement in the high-dimensional global space of uncertain parameters. Therefore, we investigated hybrid methodologies wherein each module has the flexibility of using sampling or PCE based methods of capturing local uncertainties while maintaining accuracy in the global uncertainty analysis. For the latter case, we use a conditional PCE model which mitigates the curse of dimension associated with intrusive Galerkin or semi-intrusive Pseudospectral methods. After formalizing the theoretical framework, we demonstrate our proposed method using a numerical viscous flow simulation and benchmark the performance against a solely Monte-Carlo method and solely spectral method.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2014

Development of alternate methods of determining integrated SMR source terms

The Nuclear Energy Institute (NEI) Small Modular Reactor (SMR) Licensing Task Force (TF) has been evaluating licensing issues unique and important to iPWRs, ranking these issues, and developing NEI position papers for submittal to the U.S. Nuclear Regulatory Commission (NRC) during the past three years. Papers have been developed and submitted to the NRC in a range of areas including: Price-Anderson Act, NRC annual fees, security, modularity, and staffing. In December, 2012, NEI completed a draft position paper on SMR source terms and participated in an NRC public meeting presenting a summary of this paper, which was subsequently submitted to the NRC. One important conclusion of the source term paper was the evaluation and selection of high importance areas where additional research would have a significant impact on source terms. The highest ranked research area was iPWR containment aerosol natural deposition. The NRC accepts the use of existing aerosol deposition correlations in Regulatory Guide 1.183, but these were developed for large light water reactor (LWR) containments. Application of these correlations to an iPWR design has resulted in greater than a ten-fold reduction of containment airborne aerosol inventory as compared to large LWRs. Development and experimental justification of containment aerosol natural deposition correlations specifically for the unique iPWR containments is expected to result in a large reduction of design basis and beyond-design-basis accident source terms with concomitantly smaller dose to workers and the public. Therefore, NRC acceptance of iPWR containment aerosol natural deposition correlations will directly support the industry’s goal of reducing the Emergency Planning Zone (EPZ) for SMRs. Based on the results in this work, it is clear that thermophoresis is relatively unimportant for iPWRs. Gravitational settling is well understood, and may be the dominant process for a dry environment. Diffusiophoresis and enhanced settling by particle growth are the dominant processes for determining DFs for expected conditions in an iPWR containment. These processes are dependent on the areato-volume (A/V) ratio, which should benefit iPWR designs because these reactors have higher A/Vs compared to existing LWRs.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗
DOE OSTI2012

Model Based Optimal Sensor Network Design for Condition Monitoring in an IGCC Plant

This report summarizes the achievements and final results of this program. The objective of this program is to develop a general model-based sensor network design methodology and tools to address key issues in the design of an optimal sensor network configuration: the type, location and number of sensors used in a network, for online condition monitoring. In particular, the focus in this work is to develop software tools for optimal sensor placement (OSP) and use these tools to design optimal sensor network configuration for online condition monitoring of gasifier refractory wear and radiant syngas cooler (RSC) fouling. The methodology developed will be applicable to sensing system design for online condition monitoring for broad range of applications. The overall approach consists of (i) defining condition monitoring requirement in terms of OSP and mapping these requirements in mathematical terms for OSP algorithm, (ii) analyzing trade-off of alternate OSP algorithms, down selecting the most relevant ones and developing them for IGCC applications (iii) enhancing the gasifier and RSC models as required by OSP algorithms, (iv) applying the developed OSP algorithm to design the optimal sensor network required for the condition monitoring of an IGCC gasifier refractory and RSC fouling. Two key requirements for OSP for condition monitoring are desired precision for the monitoring variables (e.g. refractory wear) and reliability of the proposed sensor network in the presence of expected sensor failures. The OSP problem is naturally posed within a Kalman filtering approach as an integer programming problem where the key requirements of precision and reliability are imposed as constraints. The optimization is performed over the overall network cost. Based on extensive literature survey two formulations were identified as being relevant to OSP for condition monitoring; one based on LMI formulation and the other being standard INLP formulation. Various algorithms to solve these two formulations were developed and validated. For a given OSP problem the computation efficiency largely depends on the “size” of the problem. Initially a simplified 1-D gasifier model assuming axial and azimuthal symmetry was used to test out various OSP algorithms. Finally these algorithms were used to design the optimal sensor network for condition monitoring of IGCC gasifier refractory wear and RSC fouling. The sensors type and locations obtained as solution to the OSP problem were validated using model based sensing approach. The OSP algorithm has been developed in a modular form and has been packaged as a software tool for OSP design where a designer can explore various OSP design algorithm is a user friendly way. The OSP software tool is implemented in Matlab/Simulink© in-house. The tool also uses few optimization routines that are freely available on World Wide Web. In addition a modular Extended Kalman Filter (EKF) block has also been developed in Matlab/Simulink© which can be utilized for model based sensing of important process variables that are not directly measured through combining the online sensors with model based estimation once the hardware sensor and their locations has been finalized. The OSP algorithm details and the results of applying these algorithms to obtain optimal sensor location for condition monitoring of gasifier refractory wear and RSC fouling profile are summarized in this final report.

20 FOSSIL-FUELED POWER PLANTS↗
DOE OSTI2015

Nuclear Security for Floating Nuclear Power Plants

Recently there has been a lot of interest in small modular reactors. A specific type of these small modular reactors (SMR,) are marine based power plants called floating nuclear power plants (FNPP). These FNPPs are typically built by countries with extensive knowledge of nuclear energy, such as Russia, France, China and the US. These FNPPs are built in one country and then sent to countries in need of power and/or seawater desalination. Fifteen countries have expressed interest in acquiring such power stations. Some designs for such power stations are briefly summarized. Several different avenues for cooperation in FNPP technology are proposed, including IAEA nuclear security (i.e. safeguards), multilateral or bilateral agreements, and working with Russian design that incorporates nuclear safeguards for IAEA inspections in non-nuclear weapons states

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗
DOE OSTI2015

Feasibility studies to improve plant availability and reduce total installed cost in IGCC plants

The main purpose of this project is to look at technologies and philosophies that would help reduce the costs of an Integrated Gasification Combined Cycle (IGCC) plant, increase its availability or do both. GE’s approach to this problem is to consider options in three different areas: 1) technology evaluations and development; 2) constructability approaches; and 3) design and operation methodologies. Five separate tasks were identified that fall under the three areas: Task 2 – Integrated Operations Philosophy; Task 3 – Slip Forming of IGCC Components; Task 4 – Modularization of IGCC Components; Task 5 – Fouling Removal; and Task 6 – Improved Slag Handling. Overall, this project produced results on many fronts. Some of the ideas could be utilized immediately by those seeking to build an IGCC plant in the near future. These include the considerations from the Integrated Operations Philosophy task and the different construction techniques of Slip Forming and Modularization (especially if the proposed site is in a remote location or has a lack of a skilled workforce). Other results include ideas for promising technologies that require further development and testing to realize their full potential and be available for commercial operation. In both areas GE considers this project to be a success in identifying areas outside the core IGCC plant systems that are ripe for cost reduction and ity improvement opportunities.

01 COAL, LIGNITE, AND PEAT↗
DOE OSTI2016

Utilizing geothermal heat for hydrothermal liquefaction of algae

The distribution of utilizable geothermal reservoirs in the US is concentrated in areas of low population density. In order to increase the scale of geothermal operations, we proposed to develop a modular biofuel production facility that directly uses geothermal heat. By transforming geothermal heat to chemical potential energy (rather than electricity), the scale of existing or new geothermal operations can be increased and distributed to areas of higher population density. Simultaneously, the economics of producing biocrude oil is improved significantly where geothermal heat is used, instead of natural gas-fired systems for providing heat and power. In the Phase I project, we demonstrated that it was economically feasible to sustainably produce a biofuel by integrating geothermal heat. It was found that, for the best case scenario at a scale of 10T(biomass)/hr, it was possible to produce a biofuel for $0.26/L, as compared to crude oil at $0.3/L (current selling price). Ultimately this demonstrates that this technology can be economically sustainable when integrated with geothermal heat. We also demonstrated that the addition of modular biofuel-production technologies can be more profitable for a geothermal plant operator. For 1000kg/day scale, it was found that it could be 2.5 times more profitable for a geothermal plant operator to sell bio-oil rather than electricity (with a waste source within 20 miles of the processing facility). Furthermore, as the design of the proposed technology recycles significant heat, requiring between 5% and 20% of the total heat load of the biofuel process to be supplied by the geothermal plant, it is feasible for an operator to initially implement the technology at small scale (i.e. less than 100gal/day) with the plans of scaling up operations in the future. Implementing the technology incrementally may minimize initial the investment and financial risk for the operator. Finally, in the Phase I project, we built and tested a hydrothermal system developed at ARI. We tested three different feedstock types, pure algae feed, algae mixed with manure, and algae with in-situ catalysts (molybdenum trioxide), over a range of temperatures and residence times. In terms of oil products, our results (yield, process times and elemental balance) were similar to what was obtained at PNNL. As such our experiments matched well with the techno-economic design (mass throughput specifications), and will thus well inform the Phase II process design. The experimental data obtained on the hydrothermal treatment of algae indicated that the highest recovery of oil occurred at 250°C. This shows that HTL can be carried out 100°C lower than what is currently considered ‘state of the art’, and thus save significant energy savings. Further, it was found that oil-recovered fractions had lower amounts of nitrogen at lower temperatures, indicating that oil produced at 250°C is of higher quality than if we were to produce fuel at 350°C.

09 BIOMASS FUELS↗
DOE OSTI2016

Heart of the Hearth: Making the Popular Clean, Not the Clean Popular - Technology Research, Development, and Tools for Clean Biomass Cookstoves

This technical report summarizes the work completed by BioLite in fulfilment of the US DOE EERE award. The work plan focused on three key objectives: developing an optimized combustion system that demonstrates high combustion efficiency and low PM 2.5 and CO emissions, integrate the system into popular stove phenotypes – side-fed rocket stove architecture like the BioLite HomeStove, and the Patsari chimney stove in Mexico such that they maintain their important phenotypical characteristics, independently evaluate quantitative fuel and emissions performance of the integrated ‘Turbo-Patsari’ in Mexican households. The project activities were organized into six major tasks: A. Develop, fabricate, and test proof-of-concept prototypes B. Develop field prototypes, assess user feedback and field performance C. Define revised stove design for pre-production model, Identify manufacturing requirements and estimated cost to build, Conduct reliability, emissions, and performance testing of pre-production Turbo-Patsari D. Build pre-production Turbo-Patsari stove combustion cores E. Conduct pre-production field trials F. Summarize field trial results and evaluate Turbo-Patsari for potential volume production. A two-pronged approach was adopted for the above tasks. The first involved building a modular test platform that allowed parametric variation of multiple stove design parameters that directly affect its performance – heat output, thermal efficiency, and emissions. The second part of the approach comprised of building a surrogate Patsari based on GIRA’s specifications that could then be modified or retrofitted for optimum performance based on the learnings from the modular test platform. The following sections of the report will describe the findings of tests on these platform, the subsequent development, design, and installation of the Turbo-Patsari, and finally the in-home field trial.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2017

High temperature ceramic heat exchanger for solid oxide fuel cell

A ceramic heat exchanger with high effectiveness and low-pressure drop has been developed for application as a cathode air preheater for a Solid Oxide Fuel Cell (SOFC). At the operating conditions of SOFCs, typical metallic alloys as those used in commercial heat exchangers may undergo chromium volatilization, which is a known cathode degradation mechanism that reduces SOFC performance and life. Use of ceramics such as alumina or alumina-silicate instead of chromium-containing metal is one approach to eliminate the effects of chromium on the SOFC cathode. This project leverages the geometric design of a heat exchanger previously prototyped and tested [1] to fabricate a novel heat exchanger made from a ceramic material. All calculations of heat exchanger performance requirements are based on state of the art SOFC operating conditions. The alumina-silicate material selected to fabricate the modular prototype heat exchanger was made via a heat transfer based trade-off analysis that shows that for low pressure-drop devices, flow convection is the limiting heat transfer mechanism, and therefore wall conductivity becomes less relevant to heat transfer effectiveness. The modular design presented allows for incremental aggregation of modules to target a broad range of operating conditions typical of present and upcoming SOFC applications (e.g., 25 to 400 kWe). The completed prototype was subjected to a series of static leak/pressure tests, dynamic pressure drop tests both at ambient and realistic service temperature conditions, and finally to a matrix of heat transfer experiments to fully characterize its heat transfer effectiveness (including tests at hot gas temperatures up to 1033 K or 1400oF). The stand-alone system was demonstrated in the laboratory to successfully satisfy the design criteria at realistic operating conditions, showing a total pressure drop at the design flow of 8 g/sec of 6 kPa (vs. 3.45 kPa approximate requirement). It was also shown to have heat transfer effectiveness of 76% (with 73% being the design requirement). Moreover, the unit was shown to operate leak-free, and the ceramic elements and seals were capable of withstanding the thermal cycling resulting from the testing procedure. The heat exchanger was then integrated into a modified fuel cell test stand and tested at steady state operation. Unfortunately, the level of performance achieved was lower than expected based on laboratory performance tests. This appears to have been the result of an unforeseen loosening of a heat exchanger structural component, which resulted into a leak that prevented proper supply of hot gas to the heat exchanger. However, in general terms, the heat exchanger/fuel cell integration process provides confidence that a future application of the unit with a SOFC is feasible, assuming structural issues are addressed. It is considered that the difficulties encountered at the last stage of the program provided invaluable input in locating shortcomings of the mechanical design and integration approach. A portion of this work was presented at the ASME Power & Energy Conference, in Charlotte, NC, on June 28th 2016 in a paper entitled “Development of a Ceramic Heat Exchanger for Application as Solid Oxide Fuel Cell Cathode Air Preheater” and the corresponding paper was published in the Proceedings of the ASME 2016 Power & Energy Conference, Paper No.: PowerEnergy2016-59333 [8].

20 FOSSIL-FUELED POWER PLANTS↗
DOE OSTI2017

A summary of the results from the DOE advanced gas reactor (AGR) fuel development and qualification program

Modular high temperature gas-cooled reactor (HTGR) designs were developed to provide natural safety, which prevents core damage under all licensing basis events. The principle that guides their design concepts is to passively maintain core temperatures below fission product release thresholds under all accident scenarios. The required level of fuel performance and fission product retention reduces the radioactive source term by many orders of magnitude relative to source terms for other reactor types and allows a graded approach to emergency planning and the potential elimination of the need for evacuation and sheltering beyond a small exclusion area. Achieving this level, however, is predicated on exceptionally high coated-particle fuel fabrication quality and excellent performance under normal operation and accident conditions. The design goal of modular HTGRs is to meet the Environmental Protection Agency (EPA) Protective Action Guides (PAGs) for offsite dose at the Exclusion Area Boundary (EAB). To achieve this, the reactor design concepts require a level of fuel integrity that is far better than that achieved for all prior U.S.-manufactured tristructural isotropic (TRISO) coated particle fuel.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗