Memon, SF,Lewis, E,Ali, MM,Pembroke, JT,Chowdhry, BS,

U-bend Evanescent Wave Plastic Optical Fibre Sensor for Minute Level Concentration Detection of Ethanol Corresponding to Biofuel Production Rate

2017 IEEE SENSORS APPLICATIONS SYMPOSIUM (SAS)

2017

January

Published

1

()

Biofuel Production Algae Ethanol Concentration Sensing Evanescent Wave Principle Plastic Optical Fibre (POF) U-bend Sensor Visible light spectrum (VIS) FIELD ABSORPTION SENSOR PROBE

Biofuel processing applications require concentration measurement of bio-ethanol during its evolution by algae in a proprietary chemical process to optimize the chemical parameters and the resulting yield of bio-ethanol. The production rate of bio-ethanol is initially very low with correspondingly minute concentration changes. This study presents a highly sensitive U-bend evanescent wave plastic optical fibre sensor for ethanol concentration measurement in water corresponding to the production rate limit of bio-ethanol by algae (cyanobacteria) i.e. 0.1-0.5g per liter per day or 0.0126% v/v - 0.0633% v/v in terms of percent volume concentration of a solution or % volume/volume concentration. The sensor was fabricated using low cost, large core (1000 mu m diameter) plastic optical fibre (POF) and investigated in the broadband visible light spectrum (VIS) and specifically at 630nm wavelength. Real-time measurements show that the sensor provides a significant response in the range of 0.00633% v/v to 0.0633% v/v concentration of ethanol in water which corresponds to detection of change in refractive index as low as 10(-7). Moreover, sensitivity of sensor was derived for the above range as 0.6448 O. D/%v/v with 97.14% of linearity in results at 630nm wavelength, here O. D refers to optical density. unit of absorbance. It indicates that the proposed sensor represents a viable solution for real time and very low level concentration sensing in biofuel processing applications.