Evaluation of operational parameters and technology readiness for enhanced management of oilfield produced water treated by ozonation

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Switzerland : 1996), 2024-10, Vol.497, p.154848, Article 154848
• Main Authors: da Costa, Sabryna Isabelly Giordani, Weschenfelder, Silvio Edegar, Prado Cechinel, Maria Alice, Fuck, João Vítor R., Gier Della Rocca, Daniela, Marinho, Belisa Alcantara, de Carvalho Neto, Sálvio Lima, Rodrigues da Cunha, Maria de Fatima, Prazeres Mazur, Luciana, Moreira, Regina F.P.M., da Silva, Adriano, Guelli. U. de Souza, Selene M.A., U. de Souza, Antônio Augusto
• Format: Article
• Language: English
• Subjects: Energy analysis; Naphthenic acids; Oil and grease content; Real effluent; TRL; Wastewater treatment
• ISSN: 1385-8947
• DOI: 10.1016/j.cej.2024.154848

[Display omitted] •Confirmed feasibility and scalability of the ozonation from bench to pilot scale.•Use of Venturi tube for better O3 dispersion and hydrodynamic cavitation.•Highest carboxylic acid degradation efficiency of 99 % in 60 min at pH 12.•Real matrix does not need pH adjustment to achieve O&G reduction above 50 %.•Energy consumption for real matrix ozonation is lower than for synthetic one. Managing oilfield produced water (OPW) is a significant challenge for the petrochemical industry due to the high daily volumes generated and strict disposal limits for oil and grease (O&G) content. O&G levels are influenced by organic compounds known as naphthenic acids (NAs). This study explored ozonation to degrade cyclohexane carboxylic acid (CHCA, a model compound for NAs) present in a synthetic OPW matrix and reduce O&G in real OPW from offshore platforms. Experiments were conducted on four ozonation prototypes with varying effluent capacities: a simplified bench-scale prototype (200 mL), an extended bench-scale prototype (400 mL to 800 mL), a hydrodynamic cavitation reactor with Venturi (5 L), and a pilot unit reactor (25 L to 80 L). CHCA degradation ranged from 91 % to 100 % under optimized conditions for each prototype. Additionally, the ozonation treatment met the Brazilian National Environment Council’s disposal requirements for OPW in oceanic regions, achieving an O&G content below 29 mg/L within 30 min at natural pH. The energy required for degradation (ERC) decreased from 729.2 kWh/m3 to 30.3 kWh/m3 as ozonation scaled up from the simplified bench-scale system (200 mL) to the pilot scale (80 L). For real OPW, the ERC was even lower at 34.5 kWh/m3. These findings demonstrate the effectiveness of ozonation in treating OPW and underscore the importance of multi-scale studies to evaluate the technical and economic viability of this treatment technology. This contributes to the sustainable management of industrial waste even in space-restricted installations such as offshore oil production facilities.