Underground Coal Thermal Treatment

The long-term objective of this work is to develop a transformational energy production technology by insitu thermal treatment of a coal seam for the production of substitute natural gas (SNG) while leaving much of the coalâs carbon in the ground. This process converts coal to a high-efficiency, low-GHG emitting gas fuel. It holds the potential of providing environmentally acceptable access to previously unusable coal resources. This topical report discusses the development of experimental capabilities, the collection of available data, and the development of simulation tools to obtain process thermo-chemical and geo-thermal parameters in preparation for the eventual demonstration in a coal seam. It also includes experimental and modeling studies of CO{sub 2} sequestration. Efforts focused on: ⢠Constructing a suite of three different coal pyrolysis reactors. These reactors offer the ability to gather heat transfer, mass transfer and kinetic data during coal pyrolysis under conditions that mimic in situ conditions (Subtask 6.1). ⢠Studying the operational parameters for various underground thermal treatment processes for oil shale and coal and completing a design matrix analysis for the underground coal thermal treatment (UCTT). This analysis yielded recommendations for terms of targeted coal rank, well orientation, rubblization, presence of oxygen, temperature, pressure, and heating sources (Subtask 6.2). ⢠Developing capabilities for simulating UCTT, including modifying the geometry as well as the solution algorithm to achieve long simulation times in a rubblized coal bed by resolving the convective channels occurring in the representative domain (Subtask 6.3). ⢠Studying the reactive behavior of carbon dioxide (CO{sub 2}) with limestone, sandstone, arkose (a more complex sandstone) and peridotite, including mineralogical changes and brine chemistry for the different initial rock compositions (Subtask 6.4). Arkose exhibited the highest tendency of participating in mineral reactions, which can be attributed to the geochemical complexity of its initial mineral assemblage. In experiments with limestone, continuous dissolution was observed with the release of CO{sub 2} gas, indicated by the increasing pressure in the reactor (formation of a gas chamber). This occurred due to the lack of any source of alkali to buffer the solution. Arkose has the geochemical complexity for permanent sequestration of CO{sub 2} as carbonates and is also relatively abundant. The effect of including NH{sub 3} in the injected gas stream was also investigated in this study. Precipitation of calcite and trace amounts of ammonium zeolites was observed. A batch geochemical model was developed using Geochemists Workbench (GWB). Degassing effect in the experiments was corrected using the sliding fugacity model in GWB. Experimental and simulation results were compared and a reasonable agreement between the two was observed

MINIMIZATION OF NO EMISSIONS FROM MULTI-BURNER COAL-FIRED BOILERS

The focus of this program is to provide insight into the formation and minimization of NO{sub x} in multi-burner arrays, such as those that would be found in a typical utility boiler. Most detailed studies are performed in single-burner test facilities, and may not capture significant burner-to-burner interactions that could influence NO{sub x} emissions. Thus, investigations of such interactions were made by performing a combination of single and multiple burner experiments in a pilot-scale coal-fired test facility at the University of Utah, and by the use of computational combustion simulations to evaluate full-scale utility boilers. In addition, fundamental studies on nitrogen release from coal were performed to develop greater understanding of the physical processes that control NO formation in pulverized coal flames--particularly under low NO{sub x} conditions. A CO/H{sub 2}/O{sub 2}/N{sub 2} flame was operated under fuel-rich conditions in a flat flame reactor to provide a high temperature, oxygen-free post-flame environment to study secondary reactions of coal volatiles. Effects of temperature, residence time and coal rank on nitrogen evolution and soot formation were examined. Elemental compositions of the char, tar and soot were determined by elemental analysis, gas species distributions were determined using FTIR, and the chemical structure of the tar and soot was analyzed by solid-state {sup 13}C NMR spectroscopy. A laminar flow drop tube furnace was used to study char nitrogen conversion to NO. The experimental evidence and simulation results indicated that some of the nitrogen present in the char is converted to nitric oxide after direct attack of oxygen on the particle, while another portion of the nitrogen, present in more labile functionalities, is released as HCN and further reacts in the bulk gas. The reaction of HCN with NO in the bulk gas has a strong influence on the overall conversion of char-nitrogen to nitric oxide; therefore, any model that aims to predict the conversion of char-nitrogen to nitric oxide should allow for the conversion of char-nitrogen to HCN. The extent of the HCN conversion to NO or N{sub 2} will depend on the composition of the atmosphere surrounding the particle. A pilot-scale testing campaign was carried out to evaluate the impact of multiburner firing on NO{sub x} emissions using a three-burner vertical array. In general, the results indicated that multiburner firing yielded higher NO{sub x} emissions than single burner firing at the same fuel rate and excess air. Mismatched burner operation, due to increases in the firing rate of the middle burner, generally demonstrated an increase in NO{sub x} over uniform firing. Biased firing, operating the middle burner fuel rich with the upper and lower burners fuel lean, demonstrated an overall reduction in NO{sub x} emissions; particularly when the middle burner was operated highly fuel rich. Computational modeling indicated that operating the three burner array with the center burner swirl in a direction opposite to the other two resulted in a slight reduction in NO{sub x}

Microfluidic analysis techniques for safety assessment of pharmaceutical nano- and microsystems

This chapter reviews the evolution of microfabrication methods and materials, applicable to manufacturing of micro total analysis systems (or lab‐on‐a‐chip), from a general perspective. It discusses the possibilities and limitations associated with microfluidic cell culturing, or so called organ‐on‐a‐chip technology, together with selected examples of their exploitation to characterization of pharmaceutical nano‐ and microsystems. Materials selection plays a pivotal role in terms of ensuring the cell adhesion and viability as well as defining the prevailing culture conditions inside the microfluidic channels. The chapter focuses on the hepatic safety assessment of nanoparticles and gives an overview of the development of microfluidic immobilized enzyme reactors that could facilitate examination of the hepatic effects of nanomedicines under physiologically relevant conditions. It also provides an overview of the future prospects regarding system‐level integration possibilities facilitated by microfabrication of miniaturized separation and sample preparation systems as integral parts of microfluidic in vitro models.Non peer reviewe

Combustion 2000

This report is a presentation of work carried out on Phase II of the HIPPS program under DOE contract DE-AC22-95PC95144 from June 1995 to March 2001. The objective of this report is to emphasize the results and achievements of the program and not to archive every detail of the past six years of effort. These details are already available in the twenty-two quarterly reports previously submitted to DOE and in the final report from Phase I. The report is divided into three major foci, indicative of the three operational groupings of the program as it evolved, was restructured, or overtaken by events. In each of these areas, the results exceeded DOE goals and expectations. HIPPS Systems and Cycles (including thermodynamic cycles, power cycle alternatives, baseline plant costs and new opportunities) HITAF Components and Designs (including design of heat exchangers, materials, ash management and combustor design) Testing Program for Radiative and Convective Air Heaters (including the design and construction of the test furnace and the results of the tests) There are several topics that were part of the original program but whose importance was diminished when the contract was significantly modified. The elimination of the subsystem testing and the Phase III demonstration lessened the relevance of subtasks related to these efforts. For example, the cross flow mixing study, the CFD modeling of the convective air heater and the power island analysis are important to a commercial plant design but not to the R&D product contained in this report. These topics are of course, discussed in the quarterly reports under this contract. The DOE goal for the High Performance Power Plant System ( HIPPS ) is high thermodynamic efficiency and significantly reduced emissions. Specifically, the goal is a 300 MWe plant with > 47% (HHV) overall efficiency and {le} 0.1 NSPS emissions. This plant must fire at least 65% coal with the balance being made up by a premium fuel such as natural gas. To achieve these objectives requires a change from complete reliance of coal-fired systems on steam turbines (Rankine cycles) and moving forward to a combined cycle utilizing gas turbines (Brayton cycles) which offer the possibility of significantly greater efficiency. This is because gas turbine cycles operate at temperatures well beyond current steam cycles, allowing the working fluid (air) temperature to more closely approach that of the major energy source, the combustion of coal. In fact, a good figure of merit for a HIPPS design is just how much of the enthalpy from coal combustion is used by the gas turbine. The efficiency of a power cycle varies directly with the temperature of the working fluid and for contemporary gas turbines the optimal turbine inlet temperature is in the range of 2300-2500 F (1260-1371 C). These temperatures are beyond the working range of currently available alloys and are also in the range of the ash fusion temperature of most coals. These two sets of physical properties combine to produce the major engineering challenges for a HIPPS design. The UTRC team developed a design hierarchy to impose more rigor in our approach. Once the size of the plant had been determined by the choice of gas turbine and the matching steam turbine, the design process of the High Temperature Advanced Furnace (HITAF) moved ineluctably to a down-fired, slagging configuration. This design was based on two air heaters: one a high temperature slagging Radiative Air Heater (RAH) and a lower temperature, dry ash Convective Air Heater (CAH). The specific details of the air heaters are arrived at by an iterative sequence in the following order:-Starting from the overall Cycle requirements which set the limits for the combustion and heat transfer analysis-The available enthalpy determined the range of materials, ceramics or alloys, which could tolerate the temperatures-Structural Analysis of the designs proved to be the major limitation-Finally the commercialization issues of fabrication and reliability, availability and maintenance. The program that has sought to develop and implement these HIPPS designs is outlined below

Microfluidic device for robust generation of two-component liquid-in-air slugs with individually controlled composition

Using liquid slugs as microreactors and microvessels enable precise control over the conditions of their contents on short-time scales for a wide variety of applications. Particularly for screening applications, there is a need for control of slug parameters such as size and composition. We describe a new microfluidic approach for creating slugs in air, each comprising a size and composition that can be selected individually for each slug. Two-component slugs are formed by first metering the desired volume of each reagent, merging the two volumes into an end-to-end slug, and propelling the slug to induce mixing. Volume control is achieved by a novel mechanism: two closed chambers on the chip are initially filled with air, and a valve in each is briefly opened to admit one of the reagents. The pressure of each reagent can be individually selected and determines the amount of air compression, and thus the amount of liquid that is admitted into each chamber. We describe the theory of operation, characterize the slug generation chip, and demonstrate the creation of slugs of different compositions. The use of microvalves in this approach enables robust operation with different liquids, and also enables one to work with extremely small samples, even down to a few slug volumes. The latter is important for applications involving precious reagents such as optimizing the reaction conditions for radiolabeling biological molecules as tracers for positron emission tomography

The majority legal status of women in Southern Africa: Implications for women and families

Women in many countries of southern Africa do not have majority status or have only recently gained this right. Majority status grants individuals adult legal status and the right to bring matters to court, own and administer property, have legal custody of children, and contract for marriage. This article summarizes the legal status of women in Botswana, Lesotho, South Africa, Swaziland, Zambia, and Zimbabwe. Lack of majority status contributes to the ongoing risk of poverty for women and makes them overly dependent on men. Compounding the situation in these countries is the presence of a dual legal system. Improving the situation of women and their families involves targeting changes in the legal system, influencing implementation of laws, educating women about their rights, and giving women needed support to seek their legal rights. The legal status of women must be viewed in the context of historical changes in the economic, educational, political, and cultural developments of society.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44657/1/10834_2005_Article_BF02267045.pd

EFFECTS OF HIGH-INTENSITY INTERVAL, ENDURANCE, AND COMBINED TRAINING ON VO2MAX, BODY COMPOSITION, MUSCULAR ENDURANCE

BACKGROUND: Functional training is commonly conducted using high-intensity interval training (HIIT) where heart rate exceeds 85% of age-predicted maximum. Traditional forms of HIIT have primarily been studied using cycling or running, and more work is needed to define the effects of functional HIIT and to compare it to combined training that incorporates an equal mix of traditional and functional work. The purpose of the present study was to compare 4 weeks of functional HIIT, endurance, and combined HIIT and endurance training on markers of health-related fitness. METHODS: Fifteen recreationally active participants (age= 21.8 + 3.1 years, BMI = 24.5 + 3.9 kg/m2, VO2max = 33.6 + 8.7 ml/kg/min, percent body fat = 33.2 + 8.9 %) were divided into 3 groups: HIIT, endurance, or combined training. HIIT workouts consisted of 3 rounds of 8 bodyweight exercises with a 2:1 work-rest ratio, and participants were coached to exercise maximally or near-maximally during each block with heart rate recorded continuously throughout each session. Endurance exercise was performed on a treadmill at an intensity of 60-70% heart rate reserve (HRR) for 30 minutes. All participants completed 3 exercise sessions per week over 4 weeks, with the combined group completing 6 sessions of HIIT and 6 sessions of endurance exercise. VO2max, body composition, and muscular endurance (1-minute push-ups, curl-ups, and weighted goblet box squats) were measured pre- and post-training. Separate factorial ANOVAs were used to assess changes in each dependent variable with Bonferroni post-hoc testing. RESULTS: Significant main effects for time were found for VO2max (p=0.01) with improvements in the HIIT group post-training (p=0.014). Significant interaction (p=0.013) and main effects for time (p=0.013) were observed for lean body mass with significant increases in the HIIT group (p&lt0.001). Push-ups and curl-ups displayed significant main effects for time (p&lt0.001 and p=0.001, respectively), with improvements in the HIIT(push-ups: p=0.005; curl-ups: p=0.016) and combined (push-ups: p=0.007; curl-ups:p=0.001) groups. CONCLUSIONS: Engaging in functional HIIT 3 days per week for 4 weeks improves VO2max and lean body mass. HIIT and combined training are effective for improving muscular endurance, but more than 6 sessions of HIIT are necessary to induce changes in aerobic fitness or body composition