Juliana Steffens

Application of Fluorescence to the Study of Crude Petroleum

Crude petroleum oils are complex mixtures of different compounds (mainly organic), which are obtained from an extensive range of different geological sources. The fluorescence of crude petroleum oils derives largely from the aromatic hydrocarbon fraction, and this fluorescence emission is strongly influenced by the chemical composition (e.g., fluorophore and quencher concentrations) and physical characteristics (e.g., viscosity and optical density) of the oil. The fluorescence spectroscopy (FS) is increasingly used in petroleum technology due the availability of better optical detection techniques, because FS offers high sensitivity, good diagnostic potential, and relatively simple instrumentation. In this work we analyzed crude petroleum at different dilution in Nujol, a transparent mineral oil. The main objective of this work was to verify the possibility to measure crude oil emission spectroscopic without use of volatile solvents. The mixtures of nujol with different -crude oil concentrations were measured with a 10xa0mm optical path cuvette thus simplifying the fluorescence spectroscopy signal detection. The emission spectra were obtained by exciting the samples with a 400xa0W Xenon lamp at 350xa0nm, 450xa0nm and 532xa0nm. The emissions of the samples were collected perpendicularly with the excitation axis.

Stand-off mapping of the soot extinction coefficient in a refinery flare using a 3-wavelength elastic backscatter lidar

In this study, a mapping of the soot extinction coefficient in an oil refinery flare using a three-wavelength elastic backscatter lidar system is presented. A log-normal aerosol size distribution was assumed for the flare, and a homogenous refractive index was assumed along the nearly horizontal beam path through the atmosphere, excluding the flare volume. The optical depth was estimated for each wavelength and from this the Angstr¨om exponent was calculated. The results were comparable with the literature, demonstrating that it is possible to distinguish small from large particles by this technique in low wind conditions.

Real-time mapping of an industrial flare using lidar

Characterization of atmospheric emissions from industrial flare stacks represents a challenge in measurement techniques because it is extremely difficult to determine the real-time concentrations of combustion products by in situ sampling, due to stack height, sensor calibration difficulties, and the dynamics of oscillations in the emission patterns. A ground based laser remote sensing (LIDAR) system has been developed for continuous and real-time monitoring of atmospheric emissions from an oil refinery located approximately 400 m from the instrument. The system is able to perform 3D scanning and profiling around the emission point. Tests were carried out using a scanning system pointed to the refinery flare. The mapping was obtained from a sequence of measurements at different zenithal and azimuthal angles resulting in a 3D image of the flare shape plus the flame itself. The measurements can be used to estimate the aerosol size distribution based on the ratios of the backscattering signal at three distinct wavelengths: 1064/532 nm, 1064/355 nm, and 532/355 nm. The method can be used in real time monitoring of industrial aerosol emissions and in the control of industrial processes. Preliminary results indicate a calibration procedure to assess the refining process efficiency based on the particle size distribution within and around the flare.

Investigation of the Europium Emission Spectra of the Europium-Oxytetracycline Complex in the Presence of Human Low-Density Lipoproteins

Low-Density Lipoprotein (LDL), often known as “bad cholesterol” is one of the responsible to increase the risk of coronary arterial diseases. For this reason, the cholesterol present in the LDL particle has become one of the main parameters to be quantified in routine clinical diagnosis. A number of tools are available to assess LDL particles and estimate the cholesterol concentration in the blood. The most common methods to quantify the LDL in the plasma are the density gradient ultracentrifugation and nuclear magnetic resonance (NMR). However, these techniques require special equipments and can take a long time to provide the results. In this paper, we report on the increase of the Europium emission in Europium-oxytetracycline complex aqueous solutions in the presence of LDL. This increase is proportional to the LDL concentration in the solution. This phenomenum can be used to develop a method to quantify the number of LDL particles in a sample. A comparison between the performances of the oxytetracycline and the tetracycline in the complexes is also made.

Lidar observation campaign of sugar cane fires and industrial emissions in the State of São Paulo, Brazil

Brazil has an important role in the biomass burning, with the detection of approximately 100,000 burning spots in a single year (2007). Most of these spots occur in the southern part of the Amazon basin during the dry season (from August to november) and these emissions reach the southeast of the country, a highly populated region and with serious urban air pollution problems. With the growing demand on biofuels, sugarcane is considerably expanding in the state of Sao Paulo, being a strong contributor to the bad air quality in this region. In the state of Sao Paulo, the main land use are pasture and sugarcane crop, that covers around 50% and 10% of the total area, respectively. Despite the aerosol from sugarcane burning having reduced atmospheric residence time, from a few days to some weeks, they might get together with those aerosol which spread over long distances (hundreds to thousands of kilometers). In the period of June through February 2010 a LIDAR observation campaign was carried in the state of Sao Paulo, Brazil, in order to observe and characterize optically the aerosols from two distinct sources, namely, sugar cane biomass burning and industrial emissions. For this purpose 2 LIDAR systems were available, one mobile and the other placed in a laboratory, both working in the visible (532 nm) and additionally the mobile system had a Raman channel available (607 nm). Also this campaign counted with a SODAR, a meteorological RADAR specially set up to detect aerosol echoes and gas-particle analyzers. To guarantee a good regional coverage 4 distinct sites were available to deploy the instruments, 2 in the near field of biomass burning activities (Rio Claro and Bauru), one for industrial emissions (Cubatao) and others from urban sources (Sao Paulo). The whole campaign provide the equivalent of 30 days of measurements which allowed us to get aerosol optical properties such as backscattering/extinction coefficients, scatter and LIDAR ratios, those were used to correlate with air quality and meteorological indicators and quantities. In this paper we should focus on the preliminary results of the Raman LIDAR system and its derived aerosol optical quantities.

Sub-visual cirrus LIDAR measurements for satellite masking improvement

Understanding the impact of cirrus cloud on modifying both the solar reflected and terrestrial emitted radiations is crucial for climate studies. Unlike most boundary layer stratus and stratocumulus clouds that have a net cooling effect on the climate, high-level thin cirrus clouds have a warming effect on our climate. However, the satellites as GOES from the NOAA series are limited to the cloud top and its reflectivity or brightness temperature, without assessing accurately the optical depth or physical thickness. Other more recent sensors as MODIS are able to determine optical depths for aerosols and clouds but when related to cirrus they are still inaccurate. Research programs as First ISCCP, FIRE, HOIST, ECLIPS and ARM have concentrated efforts in the research of cirrus, being based mainly on the observations of combined terrestrial remote sensing and airplanes instruments. LIDARs are able to detect sub-visual cirrus cloud (SVCs) in altitudes above 15 km and estimate exactly their height, thickness and optical depth, contributing with information for satellites sensors and radiative transfer models. In order to research characteristics of SVCs, the LIDAR system at Instituto de Pesquisas Energeticas e Nucleares has as objective to determine such parameters and implement a cirrus cloud mask that could be used in the satellite images processing as well as in the qualitative improvement of the radiative parameters for numerical models of climate changes. The first preliminary study shows where we compare the data lidar with Brightness temperature differences between the split-window data from GOES-10 (DSA/INPE) and CALIPSO.

Remote sensing detection of atmospheric pollutants using lidar, sodar and correlation with air quality data in an industrial area

Optical remote sensing techniques have obvious advantages for monitoring gas and aerosol emissions, since they enable the operation over large distances, far from hostile environments, and fast processing of the measured signal. In this study two remote sensing devices, namely a Lidar (Light Detection and Ranging) for monitoring the vertical profile of backscattered light intensity, and a Sodar (Acoustic Radar, Sound Detection and Ranging) for monitoring the vertical profile of the wind vector were operated during specific periods. The acquired data were processed and compared with data of air quality obtained from ground level monitoring stations, in order to verify the possibility of using the remote sensing techniques to monitor industrial emissions. The campaigns were carried out in the area of the Environmental Research Center (Cepema) of the University of Sao Paulo, in the city of Cubatao, Brazil, a large industrial site, where numerous different industries are located, including an oil refinery, a steel plant, as well as fertilizer, cement and chemical/petrochemical plants. The local environmental problems caused by the industrial activities are aggravated by the climate and topography of the site, unfavorable to pollutant dispersion. Results of a campaign are presented for a 24- hour period, showing data of a Lidar, an air quality monitoring station and a Sodar.

Measurements of Air Quality Using Lidar System

Abstract Air pollution is a widely recognized hazard to human health. In industrial cities the emission of toxic gases and particulate matter create hazardous public health situations. Is the case of the industrial complex of Cubatao, state of Sao Paulo that is one of the largest petrochemical and industrial in Brazil that has been subject of severe damage caused by massive emissions of pollutants, as a result of the progressive industrialization in the area. Therefore it is necessary to monitory the area to be able to control and to prevent ambient problems. In a partnership with the University of Sao Paulo (USP) the Brazilian oil company PETROBRAS has started off an Environmental Research Center - CEPEMA- located in the industrial site, in which the development of fieldwork will be carried out. The current joint R&D project focus on the development of real time acquisition system, together with automated multicomponent chemical analysis. Additionally fugitive emissions from oil processing and storage sites will be measured, together with the main greenhouse gases (CO 2 , CH 4 ) and aerosols. Our first effort is to assess the potential chemical species coming out of an oil refinery site and to use Raman technique LIDAR for detecting and quantifying the particular gas. Raman lidar techniques have been demonstrated which provide most valuable descriptions of the evolution of air pollution events. The vibrational and rotational Raman LIDAR signals provide simultaneous profiles of meteorological data, ozone and measurements of airborne particulate matter.

The use of lidar as optical remote sensors in the assessment of air quality near oil refineries and petrochemical sites

Petrochemical and oil refining facilities play an increasingly important role in the industrial context. The corresponding need for monitoring emissions from these facilities as well as in their neighborhood has raised in importance, leading to the present tendency of creating real time data acquisition and analysis systems. The use of LIDAR-based techniques, both for air quality and emissions monitoring purposes is currently being developed for the area of Cubatao, Sao Paulo, one of the largest petrochemical and industrial sites in Brazil. In a partnership with the University of São Paulo (USP) the Brazilian oil company PETROBRAS has implemented an Environmental Research Center - CEPEMA - located in the industrial site, in which the development of fieldwork will be carried out. The current joint R&D project focuses on the development of a real time acquisition system, together with automated multicomponent chemical analysis. Additionally, fugitive emissions from oil processing and storage sites will be measured, together with the main greenhouse gases (CO2, CH4), and aerosols. Our first effort is to assess the potential chemical species coming out of an oil refinery site and to verify which LIDAR technique, DIAL, Raman, fluorescence would be most efficient in detecting and quantifying the specific atmospheric emissions.