Alternative technique for biodiesel quality control using an optical fiber long-period grating sensor

Abstract

Recebido em 12/12/06; aceito em 15/3/07; publicado na web em 17/7/07Alternative Technique for Biodiesel Quality Control Using an Optical Fiber Long-Period Grating Sensor. We report the use of an optical fiber sensor to measure the soybean oil concentration in samples obtained from the mixture of pure biodiesel and commercial soybean oil. The operation of the device is based on the long-period grating sensitivity to the surrounding medium refractive index, which leads to measurable modifications in the grating transmission spectrum. The proposed analysis method results in errors in the oil concentration of 0.4% and 2.6% for pure biodiesel and commercial soybean oil, respectively. Techniques of total glycerol, dynamic viscosity, density, and hydrogen nuclear magnetic resonance spectroscopy were also employed to validate the proposed method.

The production of methyl esters from waste frying oil by microwave method

“…As expected, products present lower refractive index values than oil. The obtained values of refractive index are in agreement with those previously reported in the literature studies for fatty acid esters 24–26. The lower and higher refractive index values of the analyzed samples are 1.47335 for WFO and 1.45752–1.45769 for methyl ester products, respectively.…”

Long Period Grating Based Fibre Optic Chemical Sensors

“…This is related to the complexity in fabricating of the reliable and reproducible devices that can operate at optimal sensitivity regime, i.e., at the phase matching turning point. Perhaps one of the first examples of practical application of the LPG sensor was reported by Falate et al [48] to measure the soybean oil concentration in samples obtained from the mixture of pure biodiesel and commercial soybean oil. The operation of the device was based purely on the sensitivity of the LPGs to the surrounding medium refractive index, which led to measurable modifications in the transmission spectrum.…”

“…The proposed analysis method results in errors in the oil concentration of 0.4% and 2.6% for pure biodiesel and commercial soybean oil, respectively. Techniques including total glycerol, dynamic viscosity, density, and hydrogen nuclear magnetic resonance spectroscopy were also employed to validate the method [48]. This section will describe the application of LPGs modified with sensitive thin films for measurement of indoor air quality (IAQ) and for assessment of the quality of beverages.…”

Tailoring fiber grating sensors for assessment of highly refractive fuels

“…Although refractive index is not a characteristic specified in the biodiesel standards, it can be related to the density, dynamic viscosity or other standardized properties. The first refractive index optical fiber sensor for analysis of biodiesel quality regarding the presence of vegetable oil remaining in the fuel was presented in [12].…”