Characterization of selected plant seed oils as anti-foam agents in natural gas treatment units

Vegetable oils are non-toxic and biodegradable and are gaining attention as replacements for toxic antifoam and defoamer formulations in the oil and gas industry. Severe foaming may occur at the water wash section of natural gas treatment units resulting in low gas purification. This study evaluated some vegetable oils’ physical and compositional properties as suitable substitutes in antifoam/defoamer formulations. Vegetable oils were extracted from palm kernel, coconut, soya bean, groundnut, castor nut, tiger nut, pecan nut, and walnut using the Soxhlet extraction method. Extracted oils were analyzed for percentage oil recovery, peroxide value, viscosity, specific gravity, percentage free fatty acid (FFA), iodine value, and saponification value and compared with two commercial defoamers. The results showed that coconut, walnut, and palm kernel gave significantly higher oil recoveries of 54, 52, and 50%, respectively. Percentage FFA in castor oil, pecan oil, and walnut oil was considerably higher at 7.40, 5.80, and 5.2%, respectively. Coconut and palm kernel oil had lower iodine values of 9.54 and 18.85g/100g and saponification values of 54.65 and 72.44mgKOH/g, respectively. The viscosity of palm kernel and coconut oils at 30 °C compared well with one of the commercial defoamers. At 55 °C, palm kernel, coconut, and groundnut oil gave a significantly low viscosity of 5.27, 3.7, and 0.95cSt. The specific gravity and pH of all the oil samples were similar to those of the commercial defoamers. From the analysis of the results, coconut and palm kernel oils were found to have better antifoam and defoamer properties than the other oils. As such, they are suitable for use in antifoam/defoamers formulations.