Caffeine Extraction from Spent Coffee Grounds by Solid-liquid and Ultrasound-assisted Extraction: Kinetic and Thermodynamic Study




Caffeine, Solid-liquid Extraction, Ultrasound-assisted Extraction, Kinetics Study, Thermodynamics


Coffee is the most essential drink today, aside from water, the high consumption of coffee and the byproducts of its soluble industries such as spent coffee grounds can have a negative effect on the environment as a source of toxic organic compounds. Therefore, caffeine removal from the spent coffee ground can be applied as a method to limit the effect of its production on the environment. The aim of this study is to determine the kinetics and thermodynamics parameters and develop models for both processes based on the process parameters by using traditional solid-liquid extraction and Ultrasound-assisted extraction methods. The processes were performed at a temperature range of 25 to 55 °C for traditional and ultrasound baths, and experimental time ranged from 5- 60 min. The results demonstrated that under the above conditions, the extraction process applies to the pseudo-first-order reaction, where the rate constant K value increases with temperature. The transition state parameters were also discussed where these parameters indicated that the system of the process exhibited an activated complex formation state resulting in a thermodynamically unfavorable process, and the thermodynamic parameters at the equilibrium state were also evaluated in terms of the obtained yield percentage. The results also showed that the ultrasound-assisted bath process showed a spontaneous behavior at temperatures of 45 °C and 55 °C with D°G of -1192.9703 and - 2725.25 J/mole. On the other hand, for the traditional method,  the extraction process was approaching a spontaneous behavior with the temperature increasing where at 25 °C the D°G value was 10379.944 J and at a temperature of 55 °C it reached 8004.26 J/mole.


P. Esquivel and V. M. Jiménez, “Functional properties of coffee and coffee by-products,” Food Research International, vol. 46, no. 2, pp. 488–495, 2012.

U. Arnold and E. Ludwig, “Analysis of free amino acids in green coffee beans,” Zeitschrift für Lebensmittel-Untersuchung und Forschung volume, vol. 203, no. 4, pp. 379–384, 1996.

E. P. Alves, O. Salcedo-Puerto, J. Nuncira, S. Emebu, and C. Mendoza-Martinez, “Renewable energy potential and CO2 performance of main biomasses used in Brazil,” Energies, vol. 16, no. 9, p. 3959, 2023.

H. A. Kibret, Y.-L. Kuo, T.-Y. Ke, and Y.-H. Tseng, “Gasification of spent coffee grounds in a semi-fluidized bed reactor using steam and CO2 Gasification Medium,” Journal of the Taiwan Institute of Chemical Engineers, vol. 119, pp. 115–127, 2021.

M. Ramón-Gonçalves, E. Gómez-Mejía, N. Rosales-Conrado, M. E. León-González, and Y. Madrid, “Extraction, identification and quantification of polyphenols from spent coffee grounds by chromatographic methods and chemometric analyses,” Waste Management, vol. 96, pp. 15–24, 2019.

A. Vandeponseele, M. Draye, C. Piot, and G. Chatel, “Study of influential parameters of the caffeine extraction from spent coffee grounds: From Brewing Coffee Method to the waste treatment conditions,” Clean Technologies, vol. 3, no. 2, pp. 335–350, 2021.

S. Hassan and A. Al Yaqoobi, “Assessment of ultrasound-assisted extraction of caffeine and its bioactivity,” Journal of Ecological Engineering, vol. 24, no. 3, pp. 126–133, 2023.

C. V. Rigueto, M. T. Nazari, C. F. De Souza, J. S. Cadore, V. B. Brião and J. S. Piccin., “Alternative techniques for caffeine removal from wastewater: An overview of opportunities and challenges,” Journal of Water Process Engineering, vol. 35, p. 101231, 2020.

N. E. Torres Castillo, J. S. Ochoa Sierra, M. A. Oyervides-Muñoz, J. E. Sosa-Hernández, H. M. Iqbal, R. Parra-Saldívar and e. m. Melchor-Martínez, “Exploring the potential of coffee husk as caffeine bio-adsorbent – a mini-review,” Case Studies in Chemical and Environmental Engineering, vol. 3, p. 100070, 2021.

F. Rodrigues, M. A. Nunes, R. C. Alves, and M. B. Oliveira, “Applications of recovered bioactive compounds in cosmetics and other products,” Handbook of Coffee Processing By-Products, pp. 195–220, 2017.

A. Zabaniotou and P. Kamaterou, “Food waste valorization advocating circular bioeconomy - a critical review of potentialities and perspectives of spent coffee grounds biorefinery,” Journal of Cleaner Production, vol. 211, pp. 1553–1566, 2019.

K. M. Abed, B. M. Kurji, and B. A. Abdul-Majeed, “] Extraction and Modelling of Oil from Eucalyptus camadulensis by Organic Solvent,” Journal of Materials Science and Chemical Engineering, vol. 03, no. 08, pp. 35–42, 2015.

B. Weldegebreal, M. Redi-Abshiro, and B. S. Chandravanshi, “Development of new analytical methods for the determination of caffeine content in aqueous solution of Green Coffee Beans,” Chemistry Central Journal, vol. 11, no. 1, 2017.

I. B. Gerke, F. Hamerski, A. de Paula Scheer, and V. R. da Silva, “Solid–liquid extraction of bioactive compounds from yerba mate (Ilex paraguariensis) leaves: Experimental study, kinetics and modeling,” Journal of Food Process Engineering, vol. 41, no. 8, p. e12892, 2018.

M. Spiro and R. M. Selwood, “The kinetics and mechanism of caffeine infusion from coffee: The effect of particle size,” Journal of the Science of Food and Agriculture, vol. 35, no. 8, pp. 915–924, 1984.

X. Gu, J. Cai, Z. Zhang, and Q. Su, “Dynamic ultrasound-assisted extraction of Catechins and caffeine in some tea samples,” Annali di Chimica, vol. 97, no. 5–6, pp. 321–330, 2007.

N. A. Al-Khirsan and A. M. Al-Yaqoobi, “Extraction of essential oil from eucalyptus leaves by combination of solvent extraction and ultrasound-assisted extraction techniques,” Second International Conference On Iinnovation In Software Architectur And Computational Systems (ISACS 2022), 2023.

N. A. Al-khirsan and A. M. Al-yaqoobi, “Extraction of essential oil from eucalyptus leaves by combination of hydro-distillation and ultrasound-assisted extraction techniques,” 8th Engineering G And 2nd International Conference for College Of Engineering – UniversityOf Baghdad: COEC8-2021 Proceedings, 2023.

R. Upadhyay, K. Ramalakshmi, and L. Jagan Mohan Rao, “Microwave-assisted extraction of chlorogenic acids from green coffee beans,” Food Chemistry, vol. 130, no. 1, pp. 184–188, 2012.

X. Pan, G. Niu, and H. Liu, “Microwave-assisted extraction of tea polyphenols and tea caffeine from green tea leaves,” Chemical Engineering and Processing: Process Intensification, vol. 42, no. 2, pp. 129–133, 2003.

S. T. Mgoma, M. Basitere, and V. V. Mshayisa, “Kinetics and thermodynamics of oil extraction from South African hass avocados using hexane as a solvent,” South African Journal of Chemical Engineering, vol. 37, pp. 244–251, 2021.

S. Ibrahim Hamadamin, “Effect of the dried limes (citrus aurantifolia) on the caffeine kinetic extraction in black tea leaves (kinetic and thermodynamic study),” Bulletin of the Chemical Society of Ethiopia, vol. 36, no. 3, pp. 697–705, 2022.

A. Jurinjak Tušek, M. Benković, A. Belščak Cvitanović, D. Valinger, T. Jurina and J. Gajdoš Kljusurić, “Kinetics and thermodynamics of the solid-liquid extraction process of total polyphenols, antioxidants and extraction yield from Asteraceae Plants,” Industrial Crops and Products, vol. 91, pp. 205–214, 2016.

L. Peng, A. D. Mendelsohn,T. J. LaTempa, S. Yoriya, C. A. Grimes and T. A. Desai., “Long-term small molecule and protein elution from tio2 nanotubes,” Nano Letters, vol. 9, no. 5, pp. 1932–1936, 2009.

D. Paunovic, S. Mitic. D. Kostic, M. Mitic,B. Stojanovic and J. Pavlovic , “Kinetics and thermodynamics of the solid-liquid extraction process of total polyphenols from Barley,” Savremene tehnologije, vol. 3, no. 2, pp. 58–63, 2014.

D. K. Saxena, S. K. Sharma, and S. S. Sambi, “Kinetics and thermodynamics of cottonseed oil extraction,” Grasas y Aceites, vol. 62, no. 2, pp. 198–205, 2011.

S. B. Santos, M. A. Martins, A. L. Caneschi, P. R. Aguilar, and J. S. Coimbra, “Kinetics and thermodynamics of oil extraction from jatropha curcasL. using ethanol as a solvent,” International Journal of Chemical Engineering, vol. 2015, pp. 1–9, 2015.




How to Cite

Raheem, S., Al-yaqoobi, A., Znad, H., & Abid, H. R. (2024). Caffeine Extraction from Spent Coffee Grounds by Solid-liquid and Ultrasound-assisted Extraction: Kinetic and Thermodynamic Study. Iraqi Journal of Chemical and Petroleum Engineering, 25(1), 49-57.

Publication Dates







Published Online First