Implementation of Pinch Technology in Local Industry as an Energy Management Tool
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Date
2017-05
Authors
Hanoun, Arwa
Antari, Lena
Batta, Manar
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Abstract
Energy efficiency has become an important feature in the design of process plants especially with the rising cost of energy and the more stringent environmental regulations being implemented worldwide.
The energy sector in Palestine suffers from severe shortage and ambiguous future. Our industries and institutions suffers from bad energy management and bad efficiency as well. From this background, this research has started.
This study assesses the possibility of implementing the pinch principle to retrofit the energy recovery possibilities in food sector. Two factories located in Nablus city were selected for this study. The first one is Al-Arz ice cream factory and the other is Al-Safa dairy factory. Pinch concept was used to enhance the heat recovery between hot and cold streams with a heat exchanger network (HEN) as needed.
Al-Arz factory is one of the biggest ice cream producers in westbank, it has a capacity of 8 million liter of ice cream monthly. This study was made to focus on the milk pasteurization process as a big opportunity for energy saving.
Seven major scenarios were identified to reduce utility cost demand of heating and cooling process. These scenarios were designed based on changing the ∆Tmin starting with ∆Tmin=5℃ and ending with ∆Tmin=15℃.
After comparing results obtained from the different scenarios, it was observed that the maximum HX capital cost was 2753 NIS/year, while the minimum total energy cost was 152057 NIS/year. Also the minimum HX capital cost was 1019NIS/year, while the maximum total energy cost was 73658 NIS/year.
A reference case called "Zero case" was used to benchmark with other scenarios to obtain the optimum heat recovery and savings. It was observed that the maximum total energy saving was 391991 NIS/year and minimum total energy savings of 310816 NIS/year.
In Al-Safa factory, about 1700 L/year of cheese is produced per year, about 80% of this amount is whey and disposed through sewage network. Whey in Al-Safa factory was taken as a case study for recovery of whey. Evaporation process was the main concern, it was studied to concentrate feed whey from 6.5% to 26% to be used in other food industry.
Six main energy saving scenarios were suggested to study the optimization of the evaporation process. Two of the scenarios were studied with single evaporator, while the other four were suggested to be applied with multiple effect evaporator.
After comparing results obtained from the different scenarios, it was observed that the maximum evaporator capital cost was 17417 NIS/year, in the 3-stage evaporation system with the minimum total energy cost was 6947 NIS/year while the minimum evaporator capital cost was 8850NIS/year, with the maximum total energy cost was 19536 NIS/year in the single evaporation system. The final results indicated that the 3 stage evaporation system is more effective and feasible to be adopted.