Valorization of the waste heat from a sulfuric unit for the refrigerated storage of ammonia
Abstract
In the Tunisian Chemical Group, the production of sulfuric acid by the contact process yields important waste heat that measure about 22 MW of 1500 tons /day. This heat is discharged into the sea which, in addition to the resulting losses, constitutes a nuisance to the environment. To overcome this problem, it was proposed to recover part of this waste and use it for an absorption refrigeration machine. Now, ammonia is stored at atmospheric pressure and a temperature of -33 ° C. So that it remains in the liquid state, significant amounts of heat must be eliminated continuously. A compression refrigeration cycle is designed for it, but consumes a huge amounts of electricity. Unlike absorption heat pumps, which consume thermal discharges of the sulfuric unit. This paper presents a technical feasibility study for the use of waste heat generated by the sulfuric unit for the refrigerated storage of ammonia. It is proposed as a solution to conduct a heat recovery loop with ejector for the production of steam from this heat waste. This steam is then used for an absorption machine to keep ammonia at the liquid state. The simulation of the loop was done by Hysys and for the absorption refrigeration machine, the calculations were done by using EES as well as Oldham and Merkel diagrams. The obtained results indicated that the generator temperature must be higher than 134 °C for the absorption machine to operate when ammonia-water is the working pair. Moreover, a COP of about 0.46 was obtained for a generator temperature of 145°C and a condensation and absorption temperature of 37°C. This COP is very satisfactory for a single effect water-ammonia refrigeration cycle which is cooling to such a low temperature.
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References
Gurprinder Singh Dhindsa. Review on performance enhancement of solar absorption refrigeration
system using various designs and phase change materials. Materials Today: Proceedings (2020).
Diovana Aparecida dos Santos Napoleao, Jose Luz Silveira, Giorgio Eugenio Oscare Giacaglia, Wendell de Queiroz Lamas, Fernando Henrique Mayworm Araujo, Diagrams of entropy for ammonia-water mixtures: application to absorption refrigeration systems, International Journal of Refrigeration(2017),
http://dx.doi.org/doi: 10.1016/j.ijrefrig.2017.06.030.
Rasoul Nikbakhti, Xiaolin Wang, Ahmed Kadhim Hussein, Aghil Iranmanesh. Absorption cooling systems – Review of various techniques for energy performance enhancement. Alexandria Engineering Journal (2020) 59, 707–738.
Rasoul Nikbakhti , Xiaolin Wang , Andrew Chan , Performance analysis of an integrated adsorption and
absorption refrigeration system, International Journal of Refrigeration(2020),
doi:https://doi.org/10.1016/j.ijrefrig.2020.04.019.
Md. Azhar, M. Altamush Siddiqui, Optimization of operating temperatures in the gas operated single to
triple effect vapour absorption refrigeration cycles, International Journal of Refrigeration(2017),
http://dx.doi.org/doi: 10.1016/j.ijrefrig.2017.06.033.
B. Narváez-Romo, M. Chhay, E.W. Zavaleta-Aguilar, J.R. Simões-Moreira, A Critical
Review of Heat and Mass Transfer Correlations for LiBr-H2O and NH3-H2O Absorption Refrigeration Machines
using falling liquid film technology, Applied Thermal Engineering (2017), doi: http://dx.doi.org/10.1016/
j.applthermaleng.2017.05.092.
Redko, A., Redko, O., &DiPippo, R. (2020). Principles and operation of refrigeration and heat pump systems. Low-Temperature Energy Systems with Applications of Renewable Energy, 1–45. doi:10.1016/b978-0-12-816249-1.00001-7.
Ridha Ben iffa, NahlaBouaziz, LakdarKairouani. Optimization of absorption refrigeration systems by design of experiments method. Energy Procedia 139 (2017) 280-287.
W. Salmi, J.Vanttola, M. Elg, M. Kuosa, R. Lahdelma, Using waste heat of ship as energy source for an absorption refrigeration system, Applied Thermal Engineering(2016),
doi: http://dx.doi.org/10.1016/j.applthermaleng.2016.12.131.
P. Srikhirin, S. Aphornratana, S. Chungpaibulpatana, A review of absorption refrigeration technologies, Renew. Sustain. Energy Rev. 5 (4) (2001) 343–372.
R. Shankar, T. Srinivas, Investigation on operating processes for a new solar cooling cogeneration plant. J. Solar Energy Eng. 136(3); (2014).
C. Chiranjeevi, T. Srinivas, Influence of vapor absorption cooling on humidification-dehumidification (HDH) desalination, Alex. Eng. J. 55 (3)(2016) 1961–1967.
S. G. Alvares and Ch. Trepp. Simulation of solar driven aqua-ammonia absorption refrigeration system. Int. J. Refrig. 10 (1987) 40-49.
R. D. Misra, P. K. Sahoo, A. Gupta. Application of the exergetic cost theory to the LiBr/H2O vapour absorption system. Energy 27 (2002) 1009-1025.
D. A. Kouremenos. A tutorial on reversed NH3/H2O absorption cycles for applications. Solar Energy 34 (1985) 101–115.
Y.T. Kang, Y. Kunugi, T. Kashiwagi, Review of advanced absorption cycles: performance
improvement and temperature lift enhancement. International Journal of Refrigeration 23 (2000) 388-401.
Selahattin GoÈktun, Performance analysis of a heat engine driven combined vapor compression absorption-ejector refrigerator. Energy Conversion & Management 41 (2000) 1885-1895.
S.B. Riffat, Guoquan Qiu. Comparative investigation of thermoelectric air-conditioners versus vapour compression and absorption air-conditioners. Applied Thermal Engineering 24 (2004) 1979–1993.
Pongsid Srikhirin ,Satha Aphornratana, Supachart Chungpaibulpatana. A review of absorption refrigeration technologies. Renewable and Sustainable Energy Reviews 5 (2001) 343–372.
D. Khane, K. Lamamra, C. Ben Salah (2017). Modélisation par les réseaux de neurones artificiels d’une machine de production du froid solaire par absorption. Green Energy Solar ,business center.
Nahla Bouaziz, Ridha BenIffa, Ezzedine Nehdi, Lakdar Kairouani (2014). Conception of an Absorption Refrigerating System Operating at Low Enthalpy Sources. Thermodynamics – Systems in Equilibrium and Non-Equilibrium.
S.A. Akam, Z. Ouchiha, N. Said et B. Bellal. Expérimentation d’une Boucle à Absorption NH3-H2O. Rev. Energ. Ren. : Valorisation (1999) 17-22.
Evangelos Bellos, Christos Tzivanidis, Georgios Tsifis. Energetic, Exergetic, Economic and Environmental (4E) analysis of a solar assisted refrigeration system for various operating scenarios. Energy Conversion and Management 148 (2017) 1055–1069.
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