Residual steam recovery in oil refineries: technical and economic analyses
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The concern about environmental issues and economic competitiveness has brought discussions on how to make processes more efficient. In Brazil, most oil refineries were introduced between the 1950s and 1980s. Since then, structural changes were carried out which resulted on differences between the quantity of steam demanded for the modified processes and the quantity of steam produced by utility plants. These differences were created by the addition of new processes and modification on the composition of the oil processed over time. This work proposes a methodology to analyze the technical and economic feasibility of the exploitation of the steam wasted in oil refineries. For these analyses, three different technologies are proposed: organic Rankine cycles (ORCs) to generate power, absorption chillers to increase a gas turbine power production, and the pre-heating boiler’s feedwater to reduce fuel consumption. The economic analysis takes into account three different scenarios. The methodology was applied to a refining unit in Brazilian Northeast. Results show that all solutions are feasible technically and economically, except for one solution in the worst-case scenario. The application of ORCs to a 30-t/h stream of steam at 3.5 bar can generate 3364.9 kW of electricity (54.15% of exergy efficiency) with a return of the investment between 4.9 and 7.6 years. For a 10-t/h stream of steam at 1.4 bar, the application of ORCs can generate 878.6 kW of electricity (50.55% of exergy efficiency) with a return of the investment between 13.9 and 22.7 years. This application was not economically feasible in the worst-case scenario. The application of absorption chillers to reduce a gas turbine inlet air temperature, using 3.68 t/h of steam at 1.4 bar, increases in 2650.0 kW (12.5%) the power generated by the turbine (43.7% of exergy efficiency for the extra power). This investment returns in between 2.6 and 4.4 years. The use of a 30-t/h stream of steam at 3.5 bar can elevate boiler’s feedwater temperature from 147.8 to 150.7 °C, which results in a 0.3% reduction in boiler’s fuel consumption (7.7% of the exergy available), which returns the investment in between 3.2 and 5.2 years.
KeywordsHeat recovery ORC Absorption chiller Pre-heating Oil refinery Energy efficiency Economic evaluation
Vitor R. Seifert gratefully acknowledges the Industrial Engineering Program, Federal University of Bahia. This author also acknowledges FAPESB (Fundação de Amparo ao Pesquisador do Estado da Bahia) for the provision of master scholarships. Ednildo A. Torres would like to thank the National Council for Scientific and Technological Development (CNPq).
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
- ABSORPTION Chiller Product Catalogue, Shuangliang. Available at: http://bit.ly/2eNxPSP. Accessed 26 July 2017.
- ANUÁRIO Estatístico Brasileiro do Petróleo, Gás Natural e Biocombustíveis 2016. Agência Nacional do Petróleo, Gás Natural e Biocombustíveis (ANP), 2016. Available at: http://bit.ly/2fE33Qj. Accessed 30 Sept 2017.
- BLOOMBERG Markets. Available at: https://www.bloomberg.com. Accessed 30 Aug 2017.
- BRAZILIAN energy balance (2016). Ministry of Mines and Energy. Available at: http://bit.ly/2Evta44 Accessed 31 Jan 2018.
- CCEE. Câmara de Comercialização de Energia Elétrica – Preços médios. Available at: http://bit.ly/2xJdPt7. Accessed 30 Sept 2017.
- CENTRAL Bank of Brazil – Taxa Selic. Available at: http://www.bcb.gov.br/pt-br/#!/n/SELICTAXA. Accessed 7 Sept 2017.
- CHEMICAL Engineering Journal. Available at: http://www.chemengonline.com/. Accessed 31 Aug 2017.
- Couper, J., Penney, W., Fair, J., Walas, S. (2005). Chemical Process Equipment: Selection and Design (2nd ed.). Gulf Professional Publishing, p. 776.Google Scholar
- Dallmann, T., & Façanha, C. (2016). Riscos Ambientais da Dieselização dos Veículos Leves. International Council on Clean Transportation. available at: https://www.theicct.org/sites/default/files/Brazil%20LDV%20Diesel%20White%20paper_PG_vFinal.pdf. Accessed 11 Sept 2018.
- Foley, G., Devault, R., & Sweetser, R. (2000). A critical look at the impact of BCHP and innovation - The Future of Absorption Technology in America. Advanced Building System. Available at: https://www.energy.gov/sites/prod/files/2013/11/f4/absorption_future.pdf. Accessed 11 Sept 2018.
- Galindo, J., Ruiz, S., Dolz, V., Royo-Pascual, L., Haller, R., Nicolas, B., & Glavatskaya, Y. (2015). Experimental and thermodynamic analysis of a bottoming organic Rankine cycle (ORC) of gasoline engine using swash-plate expander. Energy Conversion and Management, 103, 519–532.CrossRefGoogle Scholar
- General Electric (n.d.). Gate Cycle, V6.1. Release Date : June 2013. Catalog Number : 3160/00 Part Number : 168023-01.Google Scholar
- Klein, S. A. (2015). Engineering equation solver (EES). Academic Professional, V9, 901.Google Scholar
- PETROBRAS - Refinarias Available at: https://bit.ly/1TUHC9G. Accessed 14 May 2018.
- REFINARIA de Petróleo Riograndense - História. Available at: https://bit.ly/2KnwsYE. Accessed 14 May 2018.
- Shirazi, A., Taylor, R., White, S., & Morrison, G. (2016). A systematic parametric study and feasibility assessment of solar-assisted single-effect, double-effect, and triple-effect absorption chillers for heating and cooling applications. Energy Conversion and Management, 114, 258–277.CrossRefGoogle Scholar
- Silva, J. A. M. (2017). Desempenho exergoambiental do processamento de petróleo, Saarbrücken, Germany, Novas Edições Acadêmicas, v. 1. p. 209.Google Scholar
- Smith, R. (2005). Chemical process design and integration. New York: Wiley.Google Scholar
- Towler, G., & Sinnott, R. (2008). Chemical Engineering Design: Principles, Practice and Economics of Plant and Process Design. Butterworth-Heinemann, p. 1266.Google Scholar