Triethylene glycol recovery by an energetically intensified thermosyphon-assisted falling film distillation unit: Experimental assessment on a pilot-scale unit and in-silico comparison with a conventional column from natural gas processing

• Published in: Chemical engineering and processing Vol. 176; p. 108970
• Main Authors: Peruzzo, Tiago, Battisti, Rodrigo, Alves, José Luiz Francisco, Manenti, Flavio, Marangoni, Cintia, Machado, Ricardo Antonio Francisco
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.06.2022
• Subjects: Dehydration; Energy saving; Falling film distillation; Heat pipe; Natural gas; Triethylene glycol; Triethylene glycol; Falling film distillation; Dehydration; Energy saving; Heat pipe; Natural gas
• ISSN: 0255-2701; 1873-3204
• DOI: 10.1016/j.cep.2022.108970

•A novel thermosyphon-assisted distillation process for TEG recovery is proposed.•The innovative heat supply ensures a uniform energy distribution along the column.•Destubcal unit saves about 38.4% in energy compared to a conventional column.•The pilot-scale unit has compact dimensions with a 49% of column size-reduction.•Destubcal is a feasible alternative for TEG regeneration in natural gas processing. Facing the emerging needs for energy-enhanced separation units, this work evaluated the triethylene glycol (TEG) regeneration, used as a dehydrating agent of natural gas from wells, by a novel thermosyphon-assisted falling film distillation technology, called Destubcal. The pilot-scale device has an innovative heat supply through a two-phase closed thermosyphon, which ensures a uniform energy distribution along the entire distillation tube. Based on current operating data from industrial water-rich TEG streams, different operating conditions were performed in the pilot-scale unit. The best recovery ratio (99.0%) was obtained with an evaporator temperature of 180 °C and a feed flow rate of 15 L/h. However, in order to maximize the bottom TEG composition, the best experimental condition achieved was 17 L/h and bottom temperature of 152.07 °C, due to an evaporator temperature of 170 °C. As a result, the Destubcal unit saved around 38.4% in energy requirement and reduced 49% the column height when compared to a conventional distillation column for the same recovery degree. Therefore, the proposed Destubcal technology can be considered a feasible alternative as recovery column for TEG regeneration in natural gas beneficiation units, with advantages of reduced dimensions and energy-saving operation. [Display omitted]