Near‐infrared reflectance spectroscopy based online moisture measurement in copra

Moisture in raw Copra (dried mature coconut) is an important quality parameter in the process of extraction of Coconut oil. The online and instantaneous measurement of moisture in copra chips with Near‐Infrared Reflectance Spectroscopy (NIRS) has been explored in this work. To do so, a NIRS moisture sensor with in‐house designed wireless backhaul network was commissioned at an industrial‐scale oil mill in Southern India. The accuracy of the results was validated with laboratory‐tested values. Furthermore, a chemometric analysis of NIRS signals captured from copra samples was carried out to accurately measure the moisture content. The moisture sensor was interfaced with a Supervisory Control and Data Acquisition (SCADA) system through a wireless communication network designed and developed in‐house. The system was trialed for 13 months. The system enabled for monitoring the process parameters of the oil extraction process from a safe and convenient distance away from critical instruments. The moisture content values predicted by the online NIRS sensors closely matched laboratory values (over 70% of the data was within the standard allowable tolerances). The system enabled for smarter operation, aided in improving process capability, reduced manpower, and energy requirements. PRACTICAL APPLICATIONS: The moisture content of the copra plays a crucial role in the oil extraction process and drives the market price of copra. Typically, moisture content of <7% is acceptable to the industry. High moisture content can make the copra vulnerable to fungal and pestilential attack. The in‐situ and online measurement of moisture can help improve the process of extraction of oil by considering optimum moisture and temperature. Through this process, the oil extraction efficiency and yield can be increased. By adaptively adjusting the temperature of the cooker, the energy requirements of running the plant are also optimized.