Modeling the coagulation of charged particles

Journal ArticleOne important mechanism in the growth of soot particles is to understand the role of particle charge in the coagulation of the particles. A previously developed model has been extended to include the coagulation of charged particles. The model includes neutral particles and charged particles (up to three charges). The enhancement factors for the coagulation between neutral and charged particles, and between like-charged particles, have been computed. These factors have been used in a computer code for simulating the coagulation of charged particles. The results included the predictions of the percentage of charged particles with different charges after the coagulation process. The simulation of the particle number and size evolution agrees well with published experimental data

Fundamentals of mercury oxidation in flue gas

ReportThis report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof

The role of open innovation in development of futuristic technologies for carbon capture in coal-fired power plants: an academic perspective

pre-printCoal is an important fossil fuel resource for electricity generation which also contributes to significant CO2 emissions. The process of capturing carbon dioxide for utilization and sequestration is an important area of research in this domain. Academia-industry collaborations are playing a significant role in the development of oxy-fired combustion (OFC) and Chemical -looping Combustion (CLC), two technologies under consideration for burning coal in a primarily oxygenated environment to obtain a pure stream of CO2

Carbon dioxide effects on metal vaporization during coal combustion

Journal ArticleCoal combustion products may take one of two forms. Residual ash (> 1 micron) is formed by particle shrinkage and breaking during combustion. Some material will vaporize and later recondense. During recondensation, these molecules have a high affinity for submicron particles because of the large surface area to volume ratio

Work in Progress: Flexibility and Professional Preparation via a Multidisciplinary Engineering Curriculum

This paper reports on one institution’s work-in-progress to build innovation and creativity into a flexible, ABET accredited undergraduate Engineering B.S. degree that provides a variety of choices to undergraduate engineering students. The new Engineering Plus degree has a core set of required foundational courses in engineering, a multi-year design sequence, and allows for self-defined pathways. The new curriculum also offers three defined degree pathways that have been chosen based on an examination of student “fate” data: secondary education, pre-medical, and environmental studies, with additional pathways planned for the near future. The fate analysis examined the paths of students who were enrolled in an engineering or STEM major in one year and samples their major choice in the following year. This analysis maps the flow of students into and out of the major with demographic slicers to more closely understand these inmigration and out-migration choices. This paper will detail the development of the program and its related research inquiry which includes a qualitative comparison of the students who are drawn to this new approach to engineering

Fundamentals of Mercury Oxidation in Flue Gas

The objective of this project is to understand the importance of and the contribution of gas-phase and solid-phase coal constituents in the mercury oxidation reactions. The project involves both experimental and modeling efforts. The team is comprised of the University of Utah, Reaction Engineering International, and the University of Connecticut. The objective is to determine the experimental parameters of importance in the homogeneous and heterogeneous oxidation reactions; validate models; and, improve existing models. Parameters to be studied include HCl, NO{sub x}, and SO{sub 2} concentrations, ash constituents, and temperature. This report summarizes Year 3 results for the experimental and modeling tasks. Experiments have been completed on the effects of chlorine. However, the experiments with sulfur dioxide and NO, in the presence of water, suggest that the wet-chemistry analysis system, namely the impingers, is possibly giving erroneous results. Future work will investigate this further and determine the role of reactions in the impingers on the oxidation results. The solid-phase experiments have not been completed and it is anticipated that only preliminary work will be accomplished during this study

Clean Coal Program Research Activities

Although remarkable progress has been made in developing technologies for the clean and efficient utilization of coal, the biggest challenge in the utilization of coal is still the protection of the environment. Specifically, electric utilities face increasingly stringent restriction on the emissions of NO{sub x} and SO{sub x}, new mercury emission standards, and mounting pressure for the mitigation of CO{sub 2} emissions, an environmental challenge that is greater than any they have previously faced. The Utah Clean Coal Program addressed issues related to innovations for existing power plants including retrofit technologies for carbon capture and sequestration (CCS) or green field plants with CCS. The Program focused on the following areas: simulation, mercury control, oxycoal combustion, gasification, sequestration, chemical looping combustion, materials investigations and student research experiences. The goal of this program was to begin to integrate the experimental and simulation activities and to partner with NETL researchers to integrate the Program's results with those at NETL, using simulation as the vehicle for integration and innovation. The investigators also committed to training students in coal utilization technology tuned to the environmental constraints that we face in the future; to this end the Program supported approximately 12 graduate students toward the completion of their graduate degree in addition to numerous undergraduate students. With the increased importance of coal for energy independence, training of graduate and undergraduate students in the development of new technologies is critical

Chemical Looping with Oxygen Uncoupling (CLOU) Studies at the University of Utah

Chemical-looping with oxygen uncoupling (CLOU) is one of the emergent fuel combustion technologies being currently investigated which has the potential to assist with CO2 capture from coal-fired power plants. CLOU involves the combustion of fuel in the presence of gaseous-phase oxygen released from the decomposition of an "oxygen carrier" (OC) metal oxide (e.g. CuO). Compared to Chemical-looping Combustion (CLC), the CLOU process has the promise of reducing the fuel reactor volume and the OC inventory.. The CLC process requires slower pre-gasification reaction of the solid fuel into synthesis gas, which is eventually oxidized by the circulating oxygen carrier. The presentation discusses components of the program at the University of Utah including laboratory-scale fluidized bed experiments, process modelling, and construction of a new 100-200 kW process development unit (PDU). The goal of the laboratory-scale experiments is to derive kinetics for the reduction and oxidation of the OCs. The process model is being used to explore material and energy balance scenarios. These scenarios are looking at the amount of OC circulated and, given the kinetics, OC inventories needed. The process model also shows potential heat recovery. Finally, the PDU design considerations are discussed and updates on the construction given

Fundamentals of Hazardous Solid Waste Incineration in a Rotary Kiln Environment

With landfill costs increasing and regulations on landfilling becoming more stringent, alternatives to conventional hazardous waste treatment strategies are becoming more desirable. Incineration is presently a pennanent, proven solution for the disposal of most organic contaminants, but also a costly one, especially in the case of solids which require some auxiliary fuel. The goal of this research is to develop an understanding of the phenomena associated with the evolution of contaminants from solids in the primary combustor of an incineration system. A three fold approach has been used. First, a bench-scale Particle Characterization Reactor was developed to study the transport phenomena on a particle basis, where the controlling processes are mainly intrapanicle. Second, a Bed Characterization Reactor was built to examine the controlling transport phenomena within a bed of panicles, where the processes are primarily interparticle. The results of these studies can be applied to any primary combustor. Finally a pilot-scale rotary kiln was developed to study the evolution of contaminants from solids within a realistic temperature and rotation environment. This paper describes results obtained in a study using a commercial sorbent contaminated with toluene. The data are from the Particle Characterization Reactor and the Rotary-Kiln Simulator. The results show that the method of contamination and charge size do not have a large effect on desorption, while temperature and contaminant concentration are imponant parameters in the evolution of contaminants in a rotary kiln. Preliminary modeling efforts for the kiln are also discussed

Effects of Fuel Components and Combustion Particle Physicochemical Properties on Toxicological Responses of Lung Cells

The physicochemical properties of combustion particles that promote lung toxicity are not fully understood, hindered by the fact that combustion particles vary based on the fuel and combustion conditions. Real-world combustion-particle properties also continually change as new fuels are implemented, engines age, and engine technologies evolve. This work used laboratory-generated particles produced under controlled combustion conditions in an effort to understand the relationship between different particle properties and the activation of established toxicological outcomes in human lung cells (H441 and THP-1). Particles were generated from controlled combustion of two simple biofuel/diesel surrogates (methyl decanoate and dodecane/biofuel-blended diesel (BD), and butanol and dodecane/alcohol-blended diesel (AD)) and compared to a widely studied reference diesel (RD) particle (NIST SRM2975/RD). BD, AD, and RD particles exhibited differences in size, surface area, extractable chemical mass, and the content of individual polycyclic aromatic hydrocarbons (PAHs). Some of these differences were directly associated with different effects on biological responses. BD particles had the greatest surface area, amount of extractable material, and oxidizing potential. These particles and extracts induced cytochrome P450 1A1 and 1B1 enzyme mRNA in lung cells. AD particles and extracts had the greatest total PAH content and also caused CYP1A1 and 1B1 mRNA induction. The RD extract contained the highest relative concentration of 2-ring PAHs and stimulated the greatest level of interleukin-8 (IL-8) and tumor necrosis factor-alpha (TNFα) cytokine secretion. Finally, AD and RD were more potent activators of TRPA1 than BD, and while neither the TRPA1 antagonist HC-030031 nor the antioxidant N-acetylcysteine (NAC) affected CYP1A1 or 1B1 mRNA induction, both inhibitors reduced IL-8 secretion and mRNA induction. These results highlight that differences in fuel and combustion conditions affect the physicochemical properties of particles, and these differences, in turn, affect commonly studied biological/toxicological responses