Tsang, H.F. Andrew , Yung, KC (2017). Management of Food Shelf Life and Energy Efficiency with Adaptive Food Preservation System (AFPS) Appliance. Journal of Food Technology Research, 4(1): 16-31. DOI: 10.18488/journal.58.2017.41.16.31
This paper demonstrates how Adaptive Food Preservation System (AFPS) Appliance reduces the total energy expenditure in food preservation via reduction of food wastage and of thermal gradient between food storage space and the Appliance compartment. It is motivated by the fact that current energy efficiency effort in refrigerators predominantly focuses compressor efficiency, directly or indirectly. However, if foods are wasted before being consumed, the energy consumed along the Cold Chain (manufacturing and logistics) and in household refrigeration will both be wasted. Enhanced by AFPS Packages and Active Thermal Insulation, an AFPS Appliance has two functionalities - Shelf Life Management is responsible for food wastage reduction while Energy Efficiency Management is the responsible for reducing energy consumption through reduction of thermal gradient. The optimal compartment temperature range for the Appliance to reduce thermal gradient is between 10°C and 15°C, which results in a reduction of thermal gradients by 69.6% (between compartment and chiller) and 38.2% (between compartment and freezer), when compared with that of today’s refrigerator. Experimentation on simulated compartment and chiller shows a 50.2% reduction. Sources of deviation and the corresponding rectifications are proposed to bring the reduction up close to 69.6%.
The paper's primary contribution is finding that the Appliance’s energy efficiency can be reduced with active insulation by reducing the thermal gradient (between foods and compartment space). The paper also contributes the first logical analysis of Shelf Life Management by networking with supermarkets, other AFPS Appliances in the neighborhoods, etc.
Experimental Model Validation and Control of a Lactic Fermentation Process
ADCOSBIO, 2015. ADCOSBIO Technical Report, Phase II. University of Craiova, UEFISCDI, PN-II-PT-PCCA-2013-4-0544.
BIOSTAT, 2006. BIOSTAT a plus operating manual, Micro – DCU system operating manual, MFCS/DA user manual. Sartorius BBI Systems GmbH.
Caraman, S. and D. Selișteanu, 2013. Pilot and laboratory bioreactors and equipment for fermentation bioprocesses and wastewater treatment processes. Workshop on Optimization Based Control and Estimation, Supélec, Gif sur Yvette, France.
Dima, A., 2015. Monitoring of biotechnological processes parameters. Master Thesis, University of Craiova.
Dochain, D., 2008. Automatic control of bioprocesses. London, UK: ISTE and John Wiley & Sons.
Eppendorf, E., 2012. New brunswick BioFlo®/CelliGen®115 benchtop fermentor & bioreactor operating manual, M1369-0050.
Kostov, G., M. Angelov, P. Koprinkova-Hristova, M. Ignatova and A. Orsoni, 2009. Modeling of oxygen effect on kinetics of batch fermentation process for yogurt starter culture formation. Proc. of 23rd European Conference on Modelling and Simulation, Madrid, Spain, IBS-109.
Lan, C.Q., G. Oddone, D.A. Mills and D.E. Block, 2006. Kinetics of lactococcus lactis growth and metabolite formation under aerobic and anaerobic conditions in the presence or absence of hemin. Biotechnology and Bioengineering, 95(6): 1070-1080. View at Google Scholar | View at Publisher
Nisipeanu, I.A., E. Bunciu and R. Stănică, 2011. Bioprocesses parameters control in the case of a BIOSTAT A PLUS bioreactor. Annals of the Univ. of Craiova, Series: Automation, Computers, Electronics and Mechatronics, 8(2): 31-35. View at Google Scholar
Selişteanu, D., E. Petre and V. Răsvan, 2007. Sliding mode and adaptive sliding-mode control of a class of nonlinear bioprocesses. International Journal of Adaptive Control and Signal Processing, 21(8-9): 795-822. View at Google Scholar | View at Publisher
Taskila, S. and H. Ojamo, 2013. The current status and future expectations in industrial production of lactic acid by lactic acid bacteria. In: Lactic acid bacteria – R & D for food, health and livestock purposes (M. Kongo Ed.). InTech, Rijeka, Croatia.. pp: 615-632.
Dan Selisteanu , Monica Roman , Dorin Sendrescu (2017). Experimental Model Validation and Control of a Lactic Fermentation Process. Journal of Food Technology Research, 4(1): 7-15. DOI: 10.18488/journal.58.2017.41.7.15
In this work, the nonlinear dynamical model of a lactic fermentation process is widely analysed and control experiments are achieved. More precisely, a production of yogurt by Streptococcus termophilus and Lactobacillus bulgaricus in batch operation is taken into consideration. The process model is expressed by a set of nonlinear differential equations that describes the evolution of concentrations in the fermentation process. To validate the model, several simulations are performed in the Matlab programming and development environment. Furthermore, two experimental setups are used for batch fermentation experiments. From control point of view, the temperature and the pH are the basic dynamical factors that need monitoring and control in order to regulate the microbial growth and the lactic acid production. Different control architectures and tuning procedures are implemented. Specialized data acquisition and control software tools are used to perform the experiments. By using the features of these software tools, the time evolution of various process variables can be plotted and analysed. Several comparisons between the results obtained via simulation and with the two bioreactor setups are achieved.
This paper’s main contribution is to validate the dynamical model of a lactic fermentation process by using simulators and laboratory bioreactors. A production of yogurt by Streptococcus termophilus and Lactobacillus bulgaricus in batch operation is considered. Different control architectures and tuning procedures are implemented, and several comparisons are achieved.
Frauches-Santos, C., M.A. Albuquerque, M.C.C. Oliveira and A.A.A. Echevarria, 2014. A Corrosão e os Agentes Anticorrosivos. Revista Virtual de Quimica, 6(2): 293-309.View at Google Scholar
Leite, A.B., S.L. Bertoli and A.A.C. Barros, 2005. Chemical absorption of nitrogen dioxide. Engenharia Sanitária e Ambiental, 10(1): 49-57.
Mamrosh, D., C. Beitler, K. Fisher and S. Stem, 2008. Consider improved scrubbing designs for acid gases: Better application of process chemistry enables efficient sulfur abatement. Hydrocarbon Processing, 87(1). View at Google Scholar
Mccabe, W.L., J.C. Smith and P. Harriot, 2005. Unit operations of chemical engineering. 6th Edn., Boston: McGraw Hill.
Norman, W.S., 1962. Absorption, distillation and cooling towers. London: Longmans.
Sinnott, R.K., J.M. Coulson and J.F. Richardson, 2005. Chemical engineering design. Boston: Butterworth-Heinemann.
F. G. M. Porto , M. L. Begnini , e J. R. D. Finzer (2017). Remotion of Hydrogen Sulfide in Absorption Column. Journal of Food Technology Research, 4(1): 1-6. DOI: 10.18488/journal.58.2017.41.1.6
Some physical, chemical or electrochemical phenomena that cause the decomposition of a material, usually metallic, they can be defined as corrosion. Analyzing the adverse means and determining its characteristics, several efficient methods can be developed to prevent it, consisting in one of them the absorption of the oxidizing agent. This technique is based on significantly reduce the concentration of the compound. As the hydrogen sulfide corrosive substance, its excessive presence in gas streams intensifies the deterioration of equipment during the contact. The objective was to absorb hydrogen sulfide from biogas. The absorption study was conducted by applying a 5% sodium hydroxide solution. The device designed consisted of a cylindrical packing column, bearing a gas inlet and a distributor at the bottom, which further supports the packing, and a liquid inlet and distributor at the top. The treated gas is released from the top of the column, and the liquid is discharged at the bottom, containing hydrogen sulfide absorbed in the form of salts. In the design, the biogas flow was 15m³/h with 3% mole hydrogen sulfide and the tower was package with Rasching rings of 1.5 inches. The calculations performed have enabled the design of an absorption column 0.10 m in diameter and 3.00 m height of the packing, causing a loss in pressure of 0.5 cm water/m column.
This study contributes in the existing literature to use biogas for energy use and to perform an absorption column design to avoid corrosion by hydrogen sulfide gas. The project was developed for application in a unit installed in a farm in the city of Uberaba in Brazil.