Preliminary Evaluation of Cashew Gum Exudate as a Green Scale Inhibitor

Abstract

This preliminary study explores the potential of cashew gum as a sustainable, effective inhibitor of calcium carbonate scale by characterization analysis to determine its composition, temperature-tolerance and crystallinity in relation to conventional scale inhibitors. The use of green materials has garnered attention as a promising natural compound for industrial processes. Scale formation, a pervasive issue in oil production leads to reduced efficiency and increased maintenance costs caused by blockages in pipelines etc. However, scale inhibitors have been used to control various scale types. Cashew gum, a natural polysaccharide, with its bio-degradable and eco-friendly characteristics aligns with global emphasis on sustainable, green chemistry. The preliminary analysis of the scale- inhibitory effect of cashew gum was evaluated using Thermogravimetric analysis (TGA), X-ray diffraction (XRD), Fourier-transform-infrared spectroscopy (FTIR), and Gas chromatography-mass spectrometry (GC-MS) to analyze their crystal structure, thermal stability, identify and quantify the chemical compounds. Results showed an onset degradation at 327.3 ˚C temperature with a 29% decline in mass of the sample and a calcination temperature of 525 ˚C. The XRD showed a single peak at 19.20˚indicating poor crystallinity of the extract, thus a mixture of crystalline and amorphous phases was proposed. The FTIR spectra showed a symmetrical stretching vibration of the O-H bond, characteristic of glucoside ring. The presence of C-O bonds and carbonyl moiety was observed at several low peak intensities indicating a low composition of these functional groups. The chromatogram identified six compounds linked to a functional group with 7-octadecenoic acid methyl ester having the highest peak area of 63.52 %, indicating that fatty acids are the dominant constituents in cashew gum. Its compatibility with diverse water compositions makes it a potential solution for scale inhibition. The study shows that cashew gum is a viable, eco-conscious option for mitigating scales based on its chemical composition and thermal stability.