Proceedings Volume 1434

Environmental Sensing and Combustion Diagnostics

Joseph J. Santoleri
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Proceedings Volume 1434

Environmental Sensing and Combustion Diagnostics

Joseph J. Santoleri
View the digital version of this volume at SPIE Digital Libarary.

Volume Details

Date Published: 1 April 1991
Contents: 4 Sessions, 16 Papers, 0 Presentations
Conference: Optics, Electro-Optics, and Laser Applications in Science and Engineering 1991
Volume Number: 1434

Table of Contents

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Table of Contents

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  • Incineration Systems Applications, Permitting, and Monitoring Overview
  • Infrared Techniques Applied to Incinerations Systems
  • Continuous Emission Monitors
  • Analyzers and Sensors for Process Control and Environmental Monitoring
  • Continuous Emission Monitors
Incineration Systems Applications, Permitting, and Monitoring Overview
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Incinerator technology overview
Joseph J. Santoleri
In the 1960's, much effort was expended on cleaning up the air and water. Air Quality and Water Quality Acts were written and inpleinented in many states and coninunities. New products such as unleaded gasoline and water base paints were developed to aid in minimizing pollution. Conversion from oil fired combustion systems to natural gas fired for comfort and industrial heating was the normal practice. In 1970, the Clean Air Act was passed. There was concern on how to safely dispose of hazardous wastes. Indiscriminate dumping of chemical process wastes had been the practice since the birth of the chemical industry in the USA. Land dumping, inadequate landfills, and river-ocean dumping were the most economical ways to dispose of chemical wastes. Processes that would have reduced or eliminated wastes were disregarded as being too costly. Many of the major chemical companies who regarded a safe environment as their responsibility installed waste treatment and disposal facilities on their plant sites. Many of these plants elected to use incinerators as the treatment process. This was not always the most economical method, but in many cases it was the only method of disposal that provided a safe and sure method of maximum destruction. Environmental concern over contamination from uncontrolled land disposal sites, and the emergence of tougher regulations for land disposal provide incentives for industry to employ a wide variety of traditional and advanced technologies for managing hazardous wastes. Incineration systems utilizing proper design, operation, and maintenance provides the safest and in the long run, the most economical avenue to the maximum level of destruction of organic hazardous wastes.
Developing a trial burn plan
Walter S. Smith, Tony Wong, Gary L. Williams, et al.
The Resource Conservation and Recovery Act (RCRA) was designed to ensure that incineration facilities which treat hazardous wastes operate in an environmentally responsible manner. Under the requirements of RCRA, a trial burn must be conducted in order to obtain a fmalized operating permit. A trial burn is a test which determines whether an incinerator is capable of meeting or exceeding RCRA performance standards. If the standards are met, then the trial burn should identify the operating conditions necessary to ensure the incinerator's ability to meet or exceed the performance standards throughout the life of the permit. Development of the trial burn must incorporate interests of both the permit writer and the applicant. The permit writer wishes to obtain sufficient data necessary to establish the final permit conditions. The applicant wishes to obtain a final permit which allows the greatest flexibility of incinerator operating parameters. The areas of interest to be discussed, which allow the applicant and permit writer to achieve their goals, include understanding the problem, selecting a waste feed, choosing the principal organic hazardous constituents (POHCs), determining operating conditions, choosing appropriate sampling methods, and obtaining representative samples (QAIQC). The purpose of this paper is to give an overview of what is required to develop a trial burn plan.
Infrared Techniques Applied to Incinerations Systems
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Infrared monitoring of combustion
Stephen C. Bates, Philip W. Morrison Jr., Peter R. Solomon
The use of FTIR spectroscopy for combustion monitoring is described. A combination of emission, transmission, and reflection FTIR spectroscopy yields data on the temperature and composition of the gases, surfaces and suspended particles in the combustion environment. Detection sensitivity of such trace exhaust gases as CO, CO2, SO2, NO(x), and unburned hydrocarbons is at the ppm level. Tomographic reconstruction converts line-of-sight measurements into spatially resolved temperature and concentration data. Examples from various combustion processes are used to demonstrate the capabilities of the technique. Industrial measurements are described that have been performed directly in the combustion zone and in the exhaust duct of a large chemical recovery boiler. Other measurements of hot slag show how FTIR spectroscopy can determine the temperature and optical properties of surfaces.
Gaseous incinerator emissions analysis by FTIR (Fourier transform infrared) spectroscopy
William F. Herget, Jack C. Demirgian
The use of FTIR spectroscopy, coupled with computer programs for species quantification, has now become reasonably well-established as a technique for quantitative analysis of gases and vapors. Classical Least Squares (CLS) fitting procedures allow rapid calculation of species concentrations even when there is severe overlap of spectral features. A major driving force in the development of FTIP-CLS procedures has has been in the field of auto exhaust emissions analysis. Other areas where the technique has found application are indoor and outdoor air pollution monitoring, general combustion product analysis, process control, and the analysis of trace species present in nearly pure gases. In almost all applications the analyses can be carried out by technicians not trained in spectroscopy once the species of interest have been identified and the wavenumber regions for analysis have been established.
Emissions monitoring by infrared photoacoustic spectroscopy
Wayne Jalenak
The pollution of the atmosphere and the air we breathe is of major concern today. In order to protect the health and welfare of people and to understand how pollutants affect our atmosphere, monitoring of the air for various pollutants is needed. There are numerous ways to do this monitoring, and a variety of analytical techniques to accomplish it. One of these techniques is infrared photoacoustic spectroscopy. Photoacoustic spectroscopy is based upon the detection of acoustic waves which are generated when a substance absorbs radiant energy. It has been used in many different fields of research including trace gas analysis. The first part of this paper reviews the principles and characteristics of infrared photoacoustic spectroscopy. The second part will describe the development of a portable instrument based upon this technique. The application of this instrument to some problems in industrial hygiene and emissions monitoring will also be discussed.
Continuous Emission Monitors
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Multicomponent analysis using established techniques
David L. Dillehay
Recent environmental concerns have greatly increased the need, application and scope of real-time continuous emission monitoring systems. New techniques like Fourier Transform Infrared have been applied with limited success for this application. However, the use of well-tried and established techniques (Gas Filter Correlation and Single Beam Dual Wavelength) combined with sophisticated microprocessor technology have produced reliable monitoring systems with increased measurement accuracy.
Laser diagnostic techniques in a resonant incinerator
Christopher P. Cadou, Pamela Logan, Ann Karagozian, et al.
Optical diagnostics play a key role in the development of a unique, high volumetric heat release rate incinerator design at UCLA. In the device, a derivative of an aerospace dump combustor, a pre-mixed flame is stabilized within a rectangular duct by a sudden expansion in cross section at the dump plane. Wastes injected into hot, oxidative recirculation regions downstream of the dump plane experience much larger residence times than those of the bulk flow. Particle Image Velocimetry is used to study the velocity field in the combustion cavity. The results confirm the existence of the recirculation regions and illustrate the effect of waste injection on them. Planar Laser-Induced Fluorescence of the OH radical illustrates the propagation of a vortical reaction zone (flame) into the combustion cavity and its interaction with the recirculation zones.
Field and laboratory studies of Fourier transform infrared spectroscopy in continuous emissions monitoring applications
Grant M. Plummer
Entropy Environmentalists, Inc. has performed a number of field and laboratory studies using a FTIR spectrometer for the analysis of gas phase samples and sample streams. The field studies, undertaken in conjunction with the U.S. Environmental Protection Agency (EPA), included several weeks of continuous monitoring at a hazardous waste incinerator, a sewage sludge incinerator, and a coal-fired boiler. Results of the analyses of both cold and hot samples, using several types of infrared absorption cells, will be discussed and compared to the results of other continuous monitoring systems.
Use of Fourier transform spectroscopy in combustion effluent monitoring
Gordon S. Howe, Bruce C. McIntosh
FTIR spectroscopy is a well demonstrated technique for laboratory analysis. However, its application in stationary source monitoring for waste incinerators and other sources of combustion is viewed with considerable caution. The E.I. du Pont de Nemours & Co. has committed significant resources to pioneer the use of FTIR analysis in continuous emission monitoring applications. Applications criteria derived from their experience will enhance the success of many future applications. The success of Du Pont's current efforts in this field will aid in opening the door to the widespread acceptance and use of this significant environmental technology.
Analyzers and Sensors for Process Control and Environmental Monitoring
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Laser-induced fluorescence in contaminated soils
Paul W. Lurk, Stafford S. Cooper, Philip G. Malone, et al.
A fiber-optic fluorometer that uses laser excitation has been developed to perform field screening of contaminated soils at hazardous waste sites. The unit uses a nitrogen laser and an optical multichannel analyzer to develop data on contaminate concentrations in soil in place at a site. The unit operates with a soil cone penetrometer and can obtain data down to a maximum depth of approximately 50 meters. Use of this equipment allows rapid mapping of the distribution of leaked or spilled contaminants that contain fluorescing components. The soil fluorometer has been particularly useful in tracking the movement of hydrocarbons, such as diesel fuel or gasoline.
In situ monitoring for hydrocarbons using fiber optic chemical sensors
Stanley M. Klainer, Johnny R. Thomas, Dileep Keshav Dandge, et al.
The use of FOCS for environmental applications, namely, for monitoring spills of HC or leaking underground HC storage tanks, is discussed. The current FOCS design comes in two configurations: the field unit, permanently installed at one or more monitoring sites, and connected to a central monitoring station, and the hand-held unit, designed for rapid on-site evaluation. The sensor's performance in HC vapor at 100 percent relative humidity and at 20 C, and at the vapor-water interface is illustrated.
Compact Raman instrumentation for process and environmental monitoring
Michael M. Carrabba, Kevin M. Spencer, R. David Rauh
Raman spectroscopy is a powerful noninvasive tool for elucidating chemical structure. Like infrared spectroscopy, it has many potential practical applications, such as process monitoring, environmental sensing, clinical analysis, forensic identification, and as a detector for use with analytical instruments. Until recently, however, Raman has been considered mainly in the context of basic research. The present generation of high performance Raman instruments tend to be large, complex and expensive, and thus have been of primary interest only to specialists in the field. This paper will discuss the development of a compact Raman spectrometer system consisting of a diode laser, fiber optics of excitation and collection, and a compact spectrograph with charge coupled device (CCD) detection.
Kinetic studies of phosgene reduction via in situ Fourier transform infrared analysis
Stuart Farquharson, J. Paul Chauvel Jr.
Phosgene, a common reactant in the production of polyurethanes and polycarbonates, is unfortunately hazardous (threshold limit value equals 0.1 ppm). Consequently, the detection and elimination of atmospheric releases are paramount safety and environmental concerns. Proper design of systems to mitigate phosgene requires knowledge of the reaction kinetics for the chemistry involved. This paper presents our investigation of the reactions for phosgene with steam and ammonia. A Fourier transform infrared spectrometer (FTIR) equipped with a large volume (15 L), temperature controlled (+0.5 degree(s)C), 24.5 cm path length cell was used to measure the reaction kinetics. The reaction of phosgene with steam at 110 degree(s)C followed first order kinetics (t1/2 equals 10.2 min.) producing carbon dioxide and hydrogen chloride. The reaction of phosgene with ammonia at 80 degree(s)C followed second order kinetics (t1/2 equals 1.2 min.) producing ammonium chloride and urea. It was found, however, that at 25 degree(s)C this reaction follows a previously unreported pathway producing ammonium chloride and ammonium isocyanate at a faster rate (t1/2 equals 15 sec.). Based on this reaction, a pilot scale scrubbing tower was built with a manifold to mix ammonia with ppm levels of phosgene. A complete description of the experimental conditions, the reaction pathways as a function of temperature, and the performance of the ammonia scrubbing tower are given.
Gradient microbore liquid chromatography with dual-wavelength absorbance detection: tunable analyzers for remote chemical monitoring
Andrew W. Sulya, Leslie K. Moore, Robert E. Synovec
On-column sampling, preconcentration and gradient separation using microbore liquid chromatography ((mu) LC) will be described. Both thermal gradient (TG) and transient mobile phase gradient (TMPG) elution methods have been developed and evaluated. A previously developed dual- wavelength absorbance detector is incorporated in the analyzer, thus providing real-time correction for adverse refractive index (RI) effects that normally hinder remote single fiber optic absorbance measurements. An absorbance detection limit of 3 X 10-4 AU is routinely achieved and chromatographic baseline conditions remain stable even during very steep gradients, in which the solvent RI changes rapidly with time. Sampling and preconcentrating analytes by a factor of 1000 is illustrated and is shown to be ideally suited for trace analysis of water samples. The result is a tunable analyzer that provides rapid characterization of samples typically not amenable to selective analyzer monitoring due to their high degree of complexity or due to low concentrations of analytes of interest. TG-(mu) LC, is quite simple, requiring a single pump; while TMPG-(mu) LC, incorporating a single pump and two injection valves, offers more selectivity than TG-(mu) LC. Both gradient techniques offer preconcentration and rapid, optimized separation conditions, giving an improvement over isocratic separations that employ a single mobile phase.
Advances in analytical chemistry
William F. Arendale, Richard T. Congo, Bruce J. Nielsen
Interest in chemical sensor and analyzer technology has sky rocketed in recent years due to a growing desire to increase our understanding and control of processes. Through advances in instrumentation, analytical chemists can provide analyses for smaller samples and more dilute solutions. Implementation of computer programs based on multivariate statistical algorithms makes possible obtaining reliable information from long data vectors that contain large amounts of extraneous information, for example, noise and/or analytes that we do not wish to control. Three examples are described. Each of these applications requires the use of techniques characteristic of modern analytical chemistry. The first example, using a quantitative or analytical model, describes the determination of the acid dissociation constant for 2,2'-pyridyl thiophene using archived data. The second example describes an investigation to determine the active biocidal species of iodine in aqueous solutions. The third example is taken from a research program directed toward advanced fiber optic chemical sensors. The second and third examples require heuristic or empirical models.
Continuous Emission Monitors
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Extractive sampling systems for continuous emissions monitors
John R. White
Continuous Emissions Monitoring systems (CEMs) have become an important part of the industrial, municipal, and infectious waste incineration industry. With the promulgation of stringent emissions limits and source emissions monitoring requirements, and with permit approvals and operating penalties dependent upon the accuracy and dependability of the CEM, most new and existing incineration facilities now recognize that the CEM system can often mean the difference between success and failure. Since the early 1980's, extractive sampling systems have been the technology of choice, due to the inherent difficulties in sampling from a typical incineration process. Some of these difficulties include: high temperatures, high particulate levels (dependent on the type of waste fuel being fired), the presence of acid-gases in the sample stream, high moisture levels, and wide fluctuations in the incineration process resulting in significant variations in emissions levels and sampling conditions. In addition, the requirement for lower emissions levels has resulted in the use of new control technologies which can often negatively affect the performance of a CEM system. A good example is the use of ammonia injection (either Selective Catalytic Reduction or Thermal DeNOx processes) for the control of NOx emissions, which results in an ammonia slip which can potentially interfere with the CEM measurement of either NOx or SO2 emissions. Extractive sampling systems, when designed to meet the specific application requirements and when assembled of reliable components constructed of the proper materials, have been proven in most difficult incineration installations. Extractive sampling systems offer the flexibility to overcome even the inherent difficulties usually encountered with industrial, municipal and infectious waste incinerators.