Kriston Brooks

Abstract The aviation industry is seeking economical and technically viable approaches to providing sustainable alternatives to petroleum-based jet fuel. For example, the Federal Aviation Administration (FAA) Destination 2025 (FAA 2025) has a goal to develop cleaner jet fuels, explore new ways to meet environmental and energy goals, and foster development towards one billion gallons of renewable jet fuel for aviation use by 2018. Alternative jet fuels via Fischer–Tropsch (F–T) and hydrotreated vegetable oils (HEFA) have already been approved for use in jet fuel blends of up to 50%. Other conversion processes, such as alcohol to jet (ATJ), are in various stages of development. This chapter focuses on opportunities for production of jet fuel blend components through an ethanol intermediate via a number of processing routes. These are then compared to conversion routes through other oxygenated intermediates, such as higher alcohols (eg, butanol). Higher alcohols provide technically simple conversion chemistry routes to jet blend components, but are currently produced in small quantities (relative to fuels) for the chemical market. Ethanol on the other hand is widely produced as both a fuel and a chemical and has an established distribution infrastructure. Furthermore, renewable ethanol volumetric yields via fermentation surpass those of higher alcohols. Ethanol conversion processes can produce both paraffinic and cyclic molecules. However, the conversion pathway from ethanol through ethylene is more challenging than from higher alcohol-derived olefins. Mixed oxygenated intermediates can also belong in the ATJ category, but are not yet at the same stage of development as alcohols. The major market drivers for producing alternative jet fuel components, including ATJ, are climate change, cost stability, and national security. Biologically derived ATJ fuels can provide significant climate change benefits by reducing CO2 life cycle emissions, possibly exceeding 80%. In addition, they produce lower levels of sulphur oxides and particulate matter. Because jet fuel accounts for 40% of an airline’s operating costs, reducing price fluctuations associated with petroleum is another significant driver. Finally, dependence on foreign oil could be minimized using alternative fuels. As a result of these drivers, government agencies as well as the private sector have set aggressive targets to increase their consumption of alternative fuels. In addition to targets, the government has provided favourable policies to incentivize alternative aviation fuel use. Carbon taxes abroad and potentially in the United States will drive up prices of petroleum-based fuels, making alternative fuels more competitive. Government incentives in the form of renewable fuel credits are expected to further improve alternative fuel viability. Energy Information Agency (EIA) projections suggest there may be a significant surplus of ethanol over that required for gasoline blending, potentially filling 4% of jet fuel demand in 2020. EIA projections also suggest there is a positive price differential between ethanol intermediate and jet fuel in future scenario projections, unless oil prices drop to the Low Oil Case. Ethanol currently has a price and market share advantage over other alcohols, such as butanol. However, development of ethanol to jet technology lags butanol to jet technology. Reported production costs for raw ethanol, projected ethanol supplies over that needed for gasoline blending, and the presence of existing infrastructure all suggest that ethanol is a viable intermediate for the production of alternative jet fuel components.

Hydrogen-based direct reduced iron (H2-DRI) is an alternative pathway for low-carbon steel production. Yet, the lack of established process and business models defining “green steel” make it difficult to understand what the respective H2 price has to be in order to be competitive with commercial state-of-the-art natural gas DRI. Given the importance of establishing break-even H2 prices and CO2 emission reduction potentials of H2-DRI, this study conducted techno-economic analyses of several design and operation scenarios for DRI systems. Results show that renewable H2 use in integrated DRI steel mills for both heating and the reduction of iron ore can reduce direct CO2 emissions by as much as 85%, but would require an H2 procurement cost of $1.63 per kg H2 or less. When using H2 only for iron ore reduction, economic viability is reached at an H2 procurement cost of $1.70 per kg, while achieving a CO2 emission reduction of 76% at the plant site. System design optimization strategies a...

Treatment processes have been proposed that will utilize crossflow filtration to concentrate sludge waste streams at the Department of Energy's Hanford Site. Challenges associated with solid–liquid separation of the waste streams drive a necessary evaluation of available Hanford high level waste (HLW) filtration data. Limiting flux conditions during crossflow filtration are elucidated with the formation of a cake layer on the membrane surface. A mass transfer coefficient between the gel and bulk concentrations plays a critical role in determining filter flux. A correlation between the gel concentration and mass transfer coefficient is made to assist in determining filter performance of select HLW streams. As a process alternative to crossflow filtration, gravity settling of waste streams may be deployed as a solid–liquid separation technique. However, this results in a contrasting performance with the centrifuged solids concentration. A method was developed to estimate expected ...

A focus of the U.S. Department of Energy is to improve production yield and reduce the cost of Low Enriched Uranium (LEU)-molybdenum alloy (U-10Mo) monolithic fuel plates that will be replacing High Enriched Uranium (HEU) oxide dispersion fuels used currently in the United States High Performance Research Reactors (USHPRR). One area of improvement is lowering the transverse waviness and longitudinal waviness that can be present within the cold rolled foils following rolling operations. Traditional rolling manufacturing techniques for other metal foils use winders to pull and straighten the foil as it is rolled back and forth to the final thickness. This approach cannot be used to roll thin U-10Mo foils (0.008–0.025″ thick) because only small castings can be rolled due to nuclear criticality safety concerns. As a result, the fuel foils are too short (∼1–2 m in length) to use traditional winders. Therefore, it is crucial to identify other rolling parameters (i.e., roller friction, axi...

Industrial and public interest in hydrogen technologies has risen strongly recently, as hydrogen is the ideal means for medium to long term energy storage, transport and usage in combination with renewable and green energy supply. In a future energy system, the production, storage and usage of green hydrogen is a key technology. Hydrogen is and will in future be even more used for industrial production processes as a reduction agent or for the production of synthetic hydrocarbons, especially in the chemical industry and in refineries. Under certain conditions material based systems for hydrogen storage and compression offer advantages over the classical systems based on gaseous or liquid hydrogen. This includes in particular lower maintenance costs, higher reliability and safety. Hydrogen storage is possible at pressures and temperatures much closer to ambient conditions. Hydrogen compression is possible without any moving parts and only by using waste heat. In this paper, we summar...

Battelle has developed a mesoscale combustor/evaporator that provides a lightweight and compact source of heating, cooling, or energy generation for both man-portable and stationary applications. The device uses microscale flow channels that increase the available surface area for heat transfer and reduce the fluid boundary layer. These characteristics in turn result in heat fluxes for hydrocarbon/air combustion in excess of 25 W/cm2 and thermal efficiencies of 80 to 90%. Furthermore, high heat transfer rates allow for short channels and reduced pressure drops. Recent development efforts have focused on obtaining low emissions and improving the combustor/evaporator fabrication process. By using spatially varying stoichiometry inside the combustor, catalyst coated microchannels, and increased coolant temperature, the combustor’s CO and NOx emissions were reduced to below California standards for hot water heaters and boilers. The fabrication process photochemically machines thin meta...

This is the annual report for the Market Transformation project as required by DOE EERE's Fuel Cell Technologies Office. We have been provided with a specific format. It describes the work that was done in developing evaluating the performance of 5 kW stationary combined heat and power fuel cell systems that have been deployed in Oregon and California. It also describes the business case that was developed to identify markets and address cost.

Recent efforts and interest in combined heat and power (CHP) have increased with the momentum provided by the federal government support for penetration of CHP systems. Combined heat and power fuel cell systems (CHP-FCSs) provide consistent electrical power and utilize the heat normally wasted in power generation for useful heating or cooling with lower emissions compared to alternative sources. A recent study investigated the utilization of CHP-FCSs in the range of 5 to 50KWe in various commercial building types and geographic locations. Electricity, heating, and water heating demands were obtained from simulation of the U.S. Department of Energy (DOE) commercial reference building models for various building types. Utility rates, cost of equipment, and system efficiency were used to examine economic payback in different scenarios. As a new technology in the early stages of adoption, CHP-FCSs are more expensive than alternative technologies, and the high capital cost of the CHP-FCS...

This is the annual report for the Hydrogen Storage Engineering Center of Excellence project as required by DOE EERE's Fuel Cell Technologies Office. We have been provided with a specific format. It describes the work that was done with cryo-sorbent based and chemical-based hydrogen storage materials. Balance of plant components were developed, proof-of-concept testing performed, system costs estimated, and transient models validated as part of this work.

Fuel processing is used to extract hydrogen from conventional vehicle fuel and allow fuel cell powered vehicles to use the existing petroleum fuel infrastructure. Kilowatt scale micro-channel steam reforming, water-gas shift and preferential oxida-tion reactors have been developed capable of achieving DOE required system performance metrics. Use of a microchannel design effectively supplies heat to the highly endothermic steam reforming reactor to maintain high conversions, controls the temperature profile for the exothermic water gas shift reactor, which optimizes the overall reaction conversion, and removes heat to prevent the unwanted hydrogen oxidation in the prefer-ential oxidation reactor. The reactors combined with micro-channel heat exchangers, when scaled to a full sized 50 kWe automotive system, will be less than 21 L in volume and 52 kg in weight.

In this perspective on hydrogen carriers, we focus on the needs for the development of robust active catalysts for the release of H2 from aqueous formate solutions, which are non-flammable, non-toxic, thermally stable, and readily available at large scales at reasonable cost. Formate salts can be stockpiled in the solid state or dissolved in water for long term storage and transport using existing infrastructure. Furthermore, formate salts are readily regenerated at moderate pressures using the same catalyst as for the H2 release. There have been several studies focused on increasing the activity of catalysts to release H2 at moderate temperatures, i.e., < 80 °C, below the operating temperature of a proton exchange membrane (PEM) fuel cell. One significant challenge to enable the use of aqueous formate salts as hydrogen carriers is the deactivation of the catalyst under operating conditions. In this work we provide a review of the most efficient heterogeneous catalysts that have ...

For our work, ammonia borane (AB) was selected as the initial hydride material to be used in a system sub-model. Ammonia borane's high hydrogen content (up to 19.6 wt% H2) and its stability under ambient conditions make it attractive for hydrogen storage. The Chemical Hydride Center of Excellence has done fundamental studies on AB to understand the hydrogen release chemical kinetics, thermal stability and some engineering aspects (2-3). AB releases hydrogen through an exothermic reaction making the system model significantly different than the ...

ABSTRACT Microchannel reactors have unique capabilities for onboard hydrocarbon fuel processing, due to their ability to provide process intensification through high heat and mass transfer, leading to smaller and more efficient reactors. The catalyst requirements in microchannel devices are demanding, requiring high activity, very low deactivation rates, and strong adherence to engineered substrate. Each unit operation benefits from microchannel architecture: the steam reforming reactor removes heat transfer limitations, allowing the catalyst to operate at elevated temperatures at the kinetic limit; the water gas shift reactor uses unique temperature control to reduce catalyst volume requirements; the PROX reactor provides high CO conversion and minimizes H2 oxidation through effective control of reactor temperature.

ABSTRACT Microchannel reactors have unique capabilities for onboard hydrocarbon fuel processing, due to their ability to provide process intensification through high heat and mass transfer, leading to smaller and more efficient reactors. The catalyst requirements in microchannel devices are demanding, requiring high activity, very low deactivation rates, and strong adherence to engineered substrate. Each unit operation benefits from microchannel architecture: the steam reforming reactor removes heat transfer limitations, allowing the catalyst to operate at elevated temperatures at the kinetic limit; the water gas shift reactor uses unique temperature control to reduce catalyst volume requirements; the PROX reactor provides high CO conversion and minimizes H2 oxidation through effective control of reactor temperature.