Continuous system of freeze concentration of sucrose solutions: Process parameters and energy consumption

Continuous processes to freeze-concentrate aqueous solutions of sucrose are proposed that integrates the falling film technique, fractionated thawing, and block freeze-concentration. Data reported in our previous studies were used to study the two first techniques. Block freeze concentration tests w...

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Detalles Bibliográficos
Autores: Pazmiño, Natalie Valeria, Raventós Santamaria, Mercè|||0000-0002-1144-6847, Hernández Yáñez, Eduard|||0000-0002-5337-6947, Gulfo, Rafael, Robles, C., Moreno, F.L., Ruiz, Y.
Tipo de recurso: artículo
Fecha de publicación:2017
País:España
Institución:Universitat Politècnica de Catalunya (UPC)
Repositorio:UPCommons. Portal del coneixement obert de la UPC
Idioma:inglés
OAI Identifier:oai:upcommons.upc.edu:2117/102036
Acceso en línea:https://hdl.handle.net/2117/102036
Access Level:acceso abierto
Palabra clave:Sucrose
Freeze concentration
Sugar
Concentration index
Efficiency
Energy.
Crioconcentració
Àrees temàtiques de la UPC::Enginyeria agroalimentària::Indústries agroalimentàries::Indústria del sucre
Descripción
Sumario:Continuous processes to freeze-concentrate aqueous solutions of sucrose are proposed that integrates the falling film technique, fractionated thawing, and block freeze-concentration. Data reported in our previous studies were used to study the two first techniques. Block freeze concentration tests were performed to recover the solutes present in the diluted fractions. Starting with a solution with 5% w/w solids, a concentrated liquid with 20% w/w solids and an effluent with 0.3% w/w solutes were obtained. The falling film freeze technique effectively concentrated the sucrose solution. Fractionated thawing increased the recovery of solutes retained in the ice from 39 to 50%. Block freeze concentration increased solute recovery to 95%. A concentration index of 4.0 and a concentration efficiency of 98.5% were obtained by integrating the techniques. Under the assumptions considered in this work, theoretically the energy consumption of the process can reach a value of 10.3 kWh/1000 kg of ice removed, which represents a saving of 30% compared to the energy consumption of the most efficient evaporation systems.