İlaç üretim tesisinde şehir şebeke suyundan saf su üretim prosesi ekserji analizi
Exergy analysis of pure water production process from city water in the pharmaceutical production plant
Yazar: CANSU TULUNAY AKTUNÇ
Danışman: PROF. DR. SERDAR YAMAN
İstanbul Teknik Üniversitesi / Lisansüstü Eğitim Enstitüsü / Kimya Mühendisliği Ana Bilim Dalı / Kimya Mühendisliği Bilim Dalı
Derece: Yüksek Lisans, 2021
Konu: Kimya Mühendisliği = Chemical Engineering

Özet:
Hem dünya hem ülkemizde mevcut yaşamsal faaliyetlerimizi sürdürebilmek için enerji büyük bir gereksinimdir. Bu yaşamsal faaliyetlerinin gerçekleşebilmesi için üretmek gerekmetkedir. Yapılacak olan üretim operasyonları kaçınılmaz olarak kaynak ve enerji tüketimlerinide beraberin de getirecektir. Dünya'da var olan enerji kaynaklarının sınırlı olmasından dolayı, günümüzde kaynakların etkili kullanılması ile enerji tasarrufu yapılması büyük önem taşımaktadır. Enerji tasarrufunun gerçekleştirilmesinde en öne çıkan kısım daimi olan üretim süreçlerinin tasarım ve kurulum aşamalarında optimum enerji harcamalarının hesaplanmasının göz önünde tutulmasıdır. Bu noktada ekserji kavramı karşımıza çıkmakta olup, üretim süreçlerinde enerji kaynaklarının gerçekte ne kadar verimli kullanıldığını tespit edebilmekteyiz.
Ekserji analizi sayesinde bir sistemin ya da prosesin niceliği yanında niteliği hakkında kayıpları ve terinmezlikleri tespit edebilmekteyiz. Yapılan bu analizler sonucunda sistemin ya da prosesin en çok kayıplar yaşanan noktalarını saptayarak bunları bertaraf edecek önemler için bize yol gösterici olacaktır. Ekserji analizi, termodinamiğin ikinci kanunu ile ortaya çıkmış olup yakın dönemde bir çok alanda yürütülen çalışmalar ile göz önüne çıkmıştır. Bunun sonucu olarak üretim sistemlerinin tasarımlarından ya da işletmelerinden sorumlu olan kişilerin ekserji analizi yapma yükümlülükleri oluşmaya başlamıştır.
Bu tez çalışmasında, bir ilaç üretim tesisinde üretim operasyonlarında kullanmak üzere şehir şebeke suyundan saf su üretim prosesinin ekserji analizi yapılmıştır. Ekserji analizi için prosese dahil olan giriş ve çıkış akımları tayin edilmiştir. Buna ilave olarak bu prosesin gerçekleştiği çevre koşulları ve ekserji analizinin yapılması için gerekli kabuller   açıklanmıştır.
Ekserji analizi için yapılan denklemlerin hesaplamaları MATLAB programı kullanılarak yapılmıştır. Şehir şebeke suyundan saf su üretim prosesine dahil olan ana ekipmanların parametreleri temin edilemediğinden dolayı proseste bulunan ana yardımcı ekipmanların tek tek ekserji analizleri gerçekeştirilmiştir. Bu ekserji analizleri sırasında şehir şebeke suyunun mevsimsel dönüşümlerden etkilenmesinden dolayı kış ve yaz koşulları olmak üzere iki farklı koşulda hesaplamalar yapılmıştır.
Bu prosese uygulanan ekserji analizleri sonucunda 29.18% ekserji verimi ile en büyük ekserji kaybının ısı değiştirici eşanjörün kış mevsiminde yaptığı ısıtma modu olduğu tespit edilmiştir. Kış mevsiminde şehir şebeke suyunun sıcaklık değerlerinin, proses tasarımında kabul edilen ortalam sıcaklık değerlerinden daha düşük olmasından dolayı sistemde çok fazla enerji harcaması ile ısıtma sağlandığı anlaşılmıştır.

Abstract:
Energy is a great necessity in order to sustain our current vital activities both in the world and in our country. In order for these vital activities to take place, it is necessary to produce. The production operations to be carried out will inevitably lead to resource and energy consumption. Due to the limited energy resources available in the world, it is of great importance to save energy by using the resources effectively today. The most prominent part of realizing energy savings is the calculation of optimum energy expenditure during the design and installation stages of the permanent production processes. At this point, the concept of exergy emerges and we can determine how efficiently energy resources are actually used in production processes.
Thanks to exergy analysis, we can determine the quality of a system or process as well as its losses and insufficiencies. As a result of these analyzes, it will determine the points where the most losses are experienced in the system or process and will guide us in the measures to eliminate them. Exergy analysis has emerged with the second law of thermodynamics and has been brought into consideration with studies carried out in many fields recently. As a result, the obligations of those responsible for the designs or operations of the production systems to make exergy analysis have started to arise.
Within the scope of this thesis study, pure water production process from city water supply in a drug production facility has been taken as basis. The water used as a raw material in pharmaceutical production processes must have pure water properties. For this reason, the establishment of facilities that produce their own pure water from city water supply in order to eliminate the costs and logistical problems arising from providing pure water ready-made in pharmaceutical production facilities is a gain. Certain criteria are essential in the creation of pure water content, the process in question operates 7/24 in pharmaceutical production facilities and indirectly affects drug production costs. Any improvement that can be made in the pure water production process is of significant importance both financially and in terms of more efficient use of water resources.
The usage areas of pure water in a drug production facility are mainly preferred over the addition of the drug product as a medium. In addition, pure water is required in the cleaning steps of the equipment used in production operations and in the analysis processes in laboratory environments.
This thesis study consists of five main chapters. The work done in these sections is summarized below.
In the first part of this thesis, the literature researches are given and reference is made to the sources taken as reference in the exergy analysis.
In the second part of this thesis, the concept and types of exergy, exergy transfer mechanisms, the differences between energy and exergy, and finally, exergy analysis methods are examined.
In the third part of this thesis, the information obtained about the process of obtaining pure water from the city water supply of a pharmaceutical factory selected to study within the scope of the thesis is shared.
In the fourth part of this thesis, the exergy analysis of the process of obtaining pure water from city water supply are shared. The calculations of the equations for exergy analysis were made using the MATLAB program. Since the parameters of the main equipment included in the pure water production process from the city water supply could not be obtained, the exergy analyzes of the main auxiliary equipment in the process were carried out one by one. During these exergies analyzes, calculations were made under two different conditions, namely winter and summer conditions, due to the influence of city water supply from seasonal changes. According to these conditions, it is assumed that the city water supply enters the system at two different temperature values.
While making exergy calculations, since the water temperature in the local cooling unit is assumed to be at 10oC inlet temperature during winter, the local cooler does not go into circulation due to this temperature below 15oC. For this reason, it is assumed that it does not work with the local cooler in the winter season and it has been predicted that there will be no exergy loss. In the exergy calculations made for the pump equipment, the pump power has been taken as constant and it has been assumed that the pump will operate at the same performance in winter and summer seasons.
In the exergy calculation made as the process total, the incoming and outgoing exergy values of each equipment according to the seasons were evaluated together.
In the last part of this thesis, the exergy analyzes made on the selected process are interpreted and the improvements that can be made to the process as a result are evaluated.
As a result of the exergy analysis conducted within the scope of this thesis study, the highest loss was observed in the heating mode of the heat exchanger heat exchanger in the winter season according to the exergy efficiency in the pure water production system from the city network water. As the convergent value with this, the cooling mode of the heat exchanger in the winter and summer season and the heating mode in the summer are respectively. Exergy efficiency was found to be the highest value for the pump involved in the process. In addition, the local cooling unit has been found to have high exergy efficiency, but it is known that it is not used very actively in the process, depending on the heating share as a result of seasonal conditions and water circulation.
As a result of the exergy analysis applied to this process, it was determined that the biggest exergy loss with 29.18% exergy efficiency was the heating mode of the heat exchanger heat exchanger in winter. As the temperature values of the city network water in winter are lower than the average temperature values accepted in the process design, it has been understood that the system is heated with a lot of energy consumption.
Within the scope of this thesis, some suggestions have been made for the improvements to be made in the current process. The first recommendation is to replace the pump used in the process with a variable speed pump. In this way, savings will be achieved in particular system losses and spent energy. The second suggestion is to add a parallel unit to increase the exergy efficiency of the local cooling unit in summer. The third suggestion is to add one more heat exchanger parallel to the heat exchanger unit. In this way, cooling or heating can be done gradually and exergy efficiency can be increased. As a final recommendation, a transfer system should be provided for the heat exchanger heat exchanger to send the water that comes out as codens water in heating mode to the boiler room for recovery rather than being discarded as waste.