Abstract
Drying and cooling are preparatory operations typically applied in the soybean processing industry to reduce the moisture content and temperature of the flakes fed to the extractor. Although these parameters are important for a safe and optimal process of extraction, limited or even inexistent schemes for their control are available. To deal with this problem, the current investigation suggests the use of a PID controller to manipulate the speed of the conveyor belt in order to keep the temperature of the flakes in the discharge of the dryer–cooler close to 61 °C without exceeding the acceptable outlet moisture content range from 9.9 to 12.3 % dry basis (d.b.). Closed-loop responses for the controlled variables when considering simultaneous arbitrary disturbances on operating conditions confirmed the reliability of the current control strategy. A dynamic model represented by a system of two partial differential equations obtained by energy and mass balances for the solute in the bed was used as a virtual conveyor-belt dryer-cooler. Its consistency was checked by a comparison between experimental and calculated results for moisture content and temperature at the exit of a size-scale dryer–cooler of soybean flakes at typical industrial operating conditions. The ISE technique and the simplex method of optimization were used to tune the set of PID parameters in which process control was stable.
Similar content being viewed by others
Abbreviations
- Cp l :
-
Specific heat of liquid water, J kg−1 °C−1
- Cp s :
-
Specific heat of dry flaked soybean, J kg−1 °C−1
- Cp v :
-
Specific heat of vapor water, J kg−1 °C−1
- H :
-
Absolute air humidity, kg kg−1
- h m :
-
Heat transfer coefficient, J s−1 °C−1 kg−1
- K D :
-
Derivative time, s
- K I :
-
Integral time, s
- k m :
-
Effective mass transfer coefficient, s−1
- K P :
-
Proportional gain, m s−1 °C−1
- L :
-
Length of the conveyor belt, m
- M :
-
Moisture content of expanded soybean flakes on a dry basis, kg kg−1
- M e :
-
Equilibrium moisture content of expanded soybean flakes on a dry basis, kg kg−1
- M i :
-
Inlet moisture content of expanded soybean flakes on a dry basis, kg kg−1
- M o :
-
Outlet moisture content of expanded soybean flakes on a dry basis, kg kg−1
- R h :
-
Relative air humidity, decimal
- T g :
-
Air temperature, °C
- T si :
-
Inlet temperature of expanded soybean flakes, °C
- T so :
-
Outlet temperature of expanded soybean flakes, °C
- T s :
-
Temperature of expanded soybean flakes, °C
- t :
-
Time, s
- T s_sp :
-
Set-point of temperature, °C
- τ :
-
Residence time in the conveyor belt dryer–cooler
- u c :
-
Speed of the conveyor belt, m s−1
- x :
-
Axial position along the conveyor belt, m
References
Wijeratne WB, Nelson AI (1991) Processing and utilization of soybean and diversification of end-uses through extrusion processing. In: Jambunathan R (ed) Uses of tropical grain legumes: proceedings of a consultants meeting. ICRISAT, Patancheru, pp 195–202
Liu K (1997) Soybeans: chemistry, technology, and utilization. Chapman and Hall, New York
Hulse JH (1991) Nature, composition, and utilization of grain legumes. In: Jambunathan R (ed) Uses of tropical grain legumes: proceedings of a consultants meeting. ICRISAT, Patancheru, pp 11–27
CONAB (2011) Acompanhamento da Safra Brasileira de Grãos. Safra 2010/2011, Quarto Levantamento, Janeiro, Companhia Nacional de Abastecimento
USDA (2011) Oilseeds: world markets and trade. Foreign agricultural service, Circular Series FOP 05-11, May, United States Department of Agriculture
Lamsal BP, Murphy PA, Johnson LA (2006) Flaking and extrusion as mechanical treatments for enzyme-assisted aqueous extraction of oil from soybeans. J Am Oil Chem Soc 83:973–979
de Moura JMLN, Campbell K, Mahfuz A, Jung S, Glatz CE, Johnson L (2008) Enzyme-assisted aqueous extraction of oil and protein from soybeans and cream de-emulsification. J Am Oil Chem Soc 85:985–995
de Moura JMLN, de Almeida NM, Jung S, Johnson LA (2010) Flaking as a pretreatment for enzyme-assisted aqueous extraction processing of soybeans. J Am Oil Chem Soc 87:1507–1515
Campbell KA, Glatz CE, Johnson LA, Jung S, de Moura JMLN, Kapchie V, Murphy P (2011) Advances in aqueous extraction processing of soybeans. J Am Oil Chem Soc 88:449–465
de Moura JMLN, de Almeida NM, Johnson LA (2009) Scale-up of enzyme-assisted aqueous extraction processing of soybean. J Am Oil Chem Soc 86:809–815
de Moura JMLN, Maurer D, Jung S, Johnson LA (2011) Pilot-plant proof-of-concept for integrated, countercurrent, two-stage, enzyme-assisted aqueous extraction of soybeans. J Am Oil Chem Soc 88:1649–1658
Rosenthal A, Pyle DL, Niranjan K (1998) Simultaneous aqueous extraction of oil and protein from soybean: mechanisms for process design. Food Bioprod Process 76:224–230
Johnson LA (2008) Oil recovery from soybeans. In: Johnson LA, White PJ, Galloway R (eds) Soybeans: chemistry, production, processing, and utilization. AOCS Press, Urbana, pp 331–375
Johnson LA, Lusas EW (1983) Comparison of alternative solvents for oils extraction. J Am Oil Chem Soc 60:229–242
Johnson LA (1998) Theoretical, comparative and historical analyses of alternative technologies for oilseeds extraction. In: Wan PJ, Wakelyn PJ (eds) Technology and solvents for extracting oilseeds and nonpetroleum oils. AOCS Press, Champaign, pp 4–47
Campbell KA, Glatz CE (2009) Mechanisms of aqueous extraction of soybean oil. J Agric Food Chem 57:10904–10912
Bredeson DK (1983) Mechanical oil extraction. J Am Oil Chem Soc 60:211–213
Rittner H (1984) Conditioning of oil-bearing materials for solvent extraction by extrusion. J Am Oil Chem Soc 61:1200–1203
Nelson AI, Wijeratne WB, Yeh SW, Wei SW, Wei TM, Wei LS (1987) Dry extrusion as an aid to mechanical expelling of oil from soybeans. J Am Oil Chem Soc 64:1341–1347
Mateos GG, Latorre MA, Lázaro R (2002) Processing soybeans. American Soybean Association, St. Louis
Pipa F, Frank G (1989) High-pressure conditioning with annular gap expander. A new way of feed processing. Adv Feed Technol 2:22–30
Custódio AF (2003) Modelagem e simulação do processo de separação de óleo de soja-hexano por evaporação, MSc Dissertation, UNICAMP, Campinas, Brazil
Johnson LA (2000) Recovery of fats and oils from plant and animal sources. In: O’Brien RD, Farr WE, Wan PJ (eds) Introduction to fats and oils technology. AOCS Press, Champaign, IL, pp 108–135
Valduga E, Tonel E, Tatsch PO, Silva MF, Treichel H (2011) Evaluation of process parameters in the industrial scale process of soybean oil extraction using experimental design methodology. J Food Process Eng 34:351–362
AOCS (2004) Official methods and recommended practices of the American Oil Chemist’s Society, 5th edn. AOCS Press, Champaign
Persson J, Wennerholm M, O’Halloran S (2008) Handbook for Kjeldahl Digestion. A recent review of the classical method with improvements developed by FOSS, FOSS, Hillerød, Denmark
Zanoelo EF, Abitante A, Meleiro LA (2008) Dynamic modeling and feedback control for conveyors-belt dryers of mate leaves. J Food Eng 84:458–468
Jensen S, Meleiro LAC, Zanoelo EF (2011) Soft-sensor model design for control of a virtual conveyor-belt dryer of mate leaves (Ilex paraguariensis). Biosyst Eng 108:75–85
Deshpande SD, Bal S (1999) Specific heat of soybean. J Food Process Eng 22:469–477
Barrozo MAS, Sartori DJM, Freire JT, Achcar JA (1996) Discrimination of equilibrium moisture equations for soybean using nonlinearity measures. Drying Technol 14:1779–1794
Rosenthal A, Pyle DL, Niranjan K, Gilmore S, Trinca L (2001) Combined effect of operational variables and enzyme activity on aqueous enzymatic extraction of oil and protein from soybean. Enzyme Microb Technol 28:499–509
Author information
Authors and Affiliations
Corresponding author
About this article
Cite this article
da Silva Hofmann, A.M., Benincá, C., Kotovicz, V. et al. Experiments, Modeling and Control of a Dryer–Cooler of Expanded Raw Soybean Flakes in a Hexane Extraction Plant. J Am Oil Chem Soc 89, 1929–1938 (2012). https://doi.org/10.1007/s11746-012-2089-8
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11746-012-2089-8