ORGANGE PEEL AND PINE BACK WASTE AS MEDIA FOR METAL REMOVAL FROM CRUDE OIL

Abstract

Crude oil contains trace metal species that hinders performance during refining, poison catalysts, and results to environmental contamination. Conventional metal-removal processes,  such  as  hydrotreating  and  solvent  extraction,  are  energy-intensive  and  costly. In this study, organic wastes such as orange peel and pine bark were evaluated as alternative media for extracting metal-containing complexes from crude oil. Model experiments using iron, nickel and metal free phthalocyanines dissolved in toluene showed that all complexes were transferred intact into the adsorbent. Hydroxylated species and free ions coupled with the pH of the adsorbent were suspected as the major factors responsible for extraction. Across the formulations tested, more acidic organic waste systems consistently delivered higher extraction efficiencies. The methodology was then applied to a Nigerian crude oil sample to assess performance under realistic conditions. Organic waste effectively extracted metalloporphyrin and other metal species while maintaining good phase separation. A simple filtration-based workflow enabled recovery  of  the  organic  waste  with  minimal  energy  input,  demonstrating  the  potential  for operationally straightforward and metal-removal processes. Overall, this work establishes orange peel and pine bark as efficient, mechanistically understood, and potentially low- energy media for the extraction of metal species from crude oil, offering a promising basis for next-generation upgrading technologies.