Ricky Sommers

Refinery Evaluation of Optical Imaging to Locate Fugitive Emissions

Abstract Fugitive emissions account for approximately 50% of total hydrocarbon emissions from process plants. Federal and state regulations aiming at controlling these emissions require refineries and petrochemical plants in the United States to implement a Leak Detection and Repair Program (LDAR). The current regulatory work practice, U.S. Environment Protection Agency Method 21, requires designated components to be monitored individually at regular intervals. The annual costs of these LDAR programs in a typical refinery can exceed US

Ideal system morphology and reflectivity measurements for model development and validation

1,000,000. Previous studies have shown that a majority of controllable fugitive emissions come from a very small fraction of components. The Smart LDAR program aims to find cost-effective methods to monitor and reduce emissions from these large leakers. Optical gas imaging has been identified as one such technology that can help achieve this objective. This paper discusses a refinery evaluation of an instrument based on backscatter absorption gas imaging technology. This portable camera allows an operator to scan components more quickly and image gas leaks in real time. During the evaluation, the instrument was able to identify leaking components that were the source of 97% of the total mass emissions from leaks detected. More than 27,000 components were monitored. This was achieved in far less time than it would have taken using Method 21. In addition, the instrument was able to find leaks from components that are not required to be monitored by the current LDAR regulations. The technology principles and the parameters that affect instrument performance are also discussed in the paper.

Investigations into the polymorphs and hydration products of UO 3

This paper describes measurements being made on a series of material systems for the purpose of developing a radiative-transfer model that describes the reflectance of light by granular solids. It is well recognized that the reflectance spectra of granular materials depend on their intrinsic (n(λ) and k(λ)) and extrinsic (morphological) properties. There is, however, a lack of robust and proven models to relate spectra to these parameters. The described work is being conducted in parallel with a modeling effort1 to address this need. Each follows a common developmental spiral in which material properties are varied and the ability of the model to calculate the effects of the changes are tested. The parameters being varied include particle size/shape, packing density, material birefringence, optical thickness, and spectral contribution of a substrate. It is expected that the outcome of this work will be useful in interpreting reflectance data for hyperspectral imaging (HSI), and for a variety of other areas that rely on it.

Development of a compact gas imaging sensor employing a cw fiber-amp-pumped PPLN OPO

This work focuses on progress in gaining a better understanding of the polymorphic nature of the UO3 and UO3-water system; one of several important materials associated with the nuclear fuel cycle. The UO3-water system is complex and has not been fully characterized, even though these species are common throughout the fuel cycle. For example, most production schemes for UO3 result in a mixture of up to six different polymorphic phases, and small differences in these conditions will affect phase genesis that ultimately results in measureable changes to the end product. Here we summarize our efforts to better characterize the UO3-water system with optical techniques for the purpose of developing some predictive capability of estimating process history and utility, e.g. for polymorphic phases of unknown origin. Specifically, we have investigated three industrially relevant production pathways of UO3 and discovered a previously unknown low temperature route to β-UO3. Powder x-ray diffraction and optical spectroscopies were utilized in our characterization of the UO3-water system. Pure phases of UO3, its hydrolysis products and starting materials were used to establish optical spectroscopic signatures for these compounds. Preliminary aging studies were conducted on the α- and γ- phases of UO3.

Backscatter absorption gas imaging systems and light sources therefore

Summary form only given. Backscatter absorption gas imaging (BAGI) is a laser technique for real-time video visualization of gas plumes. A scene is illuminated with IR laser radiation as it is imaged by an IR camera. Gases absorbing at the laser wavelength become visible as they attenuate the laser backscatter. We describe the development of a BAGI instrument that is sufficiently portable for use by a walking operator. A compact and electrically efficient format was achieved by developing a miniature PPLN OPO pumped by a fiber amplifier. This effort extends earlier work in which a Nd:YAG-pumped OPO was used in a vehicle-borne imager.