Turning the Most Abundant Form of Trash Worldwide into Effective Corrosion Inhibitors for Applications in the Oil and Gas Industry

Abstract There is a big concern regarding waste materials that are generated daily. Cigarette butts are one of the most common forms of trash. Trillions of cigarette butts are thrown from car windows, discarded on sidewalks and beaches every year. They accumulate in landfills with minimal recycling solutions and have been known to cause severe damage to plant and aquatic life environments. Fortunately, the oil and gas industry are continuously trying to find methods to utilize such materials in our well treatments as they are cheap and would contribute to a cleaner world. Corrosion in the oil and gas industry causes well integrity issues totaling billions of dollars annually. Consequently, it is intuitive to include corrosion inhibitors in well treatments which are corrosive in nature to protect our equipment. Corrosion inhibitors are molecules that can stick and create an impermeable film on the surface of metal, thereby reducing contact with corrosive substances. Cellulose acetate filters (CAF) are the main component in cigarette butts, and they retain over 7000 compounds resulting from the combustion of tobacco. Many of these compounds contain chemical functional groups that can provide corrosion inhibition properties. The goal of this project is to test the chemicals extracted from CAF for potential applications as corrosion inhibitors. The CAF were soaked for 24 hours in solvents such as ethanol, methanol, water, isopropyl alcohol, n-hexane, dichloromethane, and a methanol/chloroform azeotrope to extract chemical compounds using a continuous Soxhlet extraction method. To determine the inhibition efficacy, T-95 low carbon steel coupons were exposed to 15 wt.% HCl solution for 6 hours with 5-60 gpt of the CAF extract at temperatures between 77-350°F. A control solution containing no corrosion inhibitor was used to establish a corrosion rate for a base case. Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FT-ICR MS) and gas chromatography/Mass Spectrometry (GC/MS) were utilized to identify molecules in the CAF extracts. At room temperature, CAF extracts were observed to provide more than 97% corrosion inhibition efficiency. At 150°F, the control solution showed a corrosion rate of 0.0985 lb/ft2, whereas the solutions containing CAF extracts were observed to maintain good corrosion inhibition efficiency at 0.0138 lb/ft2. At 200, 250, 300, and 350°F the corrosion rates observed were as low as 0.0014 lb/ft2, 0.0010 lb/ft2, 0.01 lb/ft2, and 0.0146 lb/ft2, respectively. Chemical compounds such as nicotine, benzenes, and aromatic amines are present in CAF, so it comes with no surprise that the extracts can provide corrosion inhibition properties. These results show that waste products can be used as corrosion inhibitors. Due to their low inherent value, this form of trash may provide a cheap alternative to commercial corrosion inhibitors while simultaneously protecting the environment by reducing pollution.