Sunucu kabini üretiminde yaşam döngüsü değerlendirmesi
Life cycle assessment in server cabinet production
Yazar: EDA CEBE ABANOZ
Danışman: PROF. FATMA FATOŞ BABUNA
İstanbul Teknik Üniversitesi / Lisansüstü Eğitim Enstitüsü / Çevre Mühendisliği Ana Bilim Dalı / Çevre Bilimleri, Mühendisliği ve Yönetimi Bilim Dalı
Derece: Yüksek Lisans, 2021
Konu: Çevre Mühendisliği = Environmental Engineering

Özet:
İklimlerin değişmesi, nüfusun giderek artması, sanayileşmenin hızla yaygınlaşması ve artması sebebi ile endüstri kaynaklı çevresel etkiler de giderek artmaktadır. Bu nedenle son zamanlarda, çevre hakkında toplum bilincinin artması ile endüstrilerde çevreye olan etkilerin azaltılması için proje çalışmaları ve proseslerdeki çevresel etkileri azaltma eğilimleri yaygınlaşmaya başlamış, bu konudaki duyarlılık artmıştır. Bu kapsamdaki çalışmalarda en yaygın kullanılan yöntem, yaşam döngüsü değerlendirmesi (YDD)'dir. 
Son dönemde teknolojik gelişmelerin artması ve teknolojik, elektronik aletlerin kulanımının artması ile birlikte, işyerlerinde ve ofislerde sunucu kabin kullanımı yaygınlaşmıştır. Bu çalışmada 1 adet 'Sunucu Kabini Üretimi' sebebi ile oluşan çevresel etkileri YDD yöntemi kullanılarak incelenmiştir. Çalışmada yapılan hesaplamalarda GaBi yazılımı kullanılmış; üretim sistemi ile ilgili tesisten birincil veri toplanmış; gerekli olan arka plan verilerinin temini için ise Ecoinvent 3.1 veri tabanı kullanılmıştır. Çalışmada Abiyotik Element Tükenme Potansiyeli (AETP), Abiyotik Fosil Tükenme Potansiyeli (AFTP), Asitleşme Potansiyeli (AP), Ötrofikasyon Potansiyeli (ÖP), Tatlı Su Sucul Ekotoksisite Potansiyeli (TSEP), Küresel Isınma Potansiyeli (KİP), İnsan Toksisite Potansiyeli (İTP), Ozon Tabakası Tükenme Potansiyeli (OTTP), Fotokimyasal Ozon Oluşturma Potansiyeli (FOOP), Karasal Ekotoksisite Potansiyeli (KEP) ele alınan çevresel etki kategorileridir.
Sunucu kabini üretiminin ham madde ve yardımcı malzeme üretim üniteleri, malzemelerin tesise taşınması, sunucu kabinin üretimi ve atıklarının işlenmesi (geri dönüştürülmesi, arıtılması, yakılması vb.), taşıma işlemleri ile üretim faaliyetleri sonucuoluşan atıksularının arıtılmasının ve şebeke suyundan deiyonize su oluşturan paket arıtma sisteminin çevresel etkileri de sistem sınırları içerisinde tutularak incelenmiştir. 
Yapılan çalışma sonucunda, sunucu kabin üretiminde en yüksek çevresel etkiye sebep olan faktörlerin toplam etkinin ortalama %92'sinin ham madde ve yardımcı malzeme üretminden kaynaklandığı belirlenmiştir. Ham maddelerden ağırlıkça en fazla kullanılan paslanmaz çeliğin üretimi, üretim aşamasında kullanılan eritme, fırınlama sistemleri sebebi ile en yüksek çevresel etkiye sahip olduğu anlaşılmıştır. Sunucu kabin üretimi yapan tesisin, kullandığı paslanmaz çeliğin başka bir malzeme ile değiştirilmesi, ürünün istenen kalitesini olumsuz etkileyeceği için bir strateji olarak önerilemez. Enerji kullanımı, toplam etkinin AFTP için %12'sini, AP için %11'ini, ÖP için %7'sini, TSEP ve OTTP için %3'ünü, KİP için %10'unu, İTP için %1'ini ve FOOP için %4'ünü oluşturması sebebi ile en yüksek ikinci faktör olarak tespit edilmiştir. Çalışmada enerji kaynağı olarak Türkiye 2019 sektör raporunda belirtilen elektrik karışım oranlarına göre oluşturulan elektrik enerjisi prosesi kullanılmıştır. Bir sunucu kabin üretiminde toplam kullanılan enerji miktarı 294 MJ'dür. Enerji kullanımının çevresel etkisini azaltmak için, ele alınan elektrik karışımına alternatif olarak, mevcut elektrik karışımının rüzgar ve güneş enerjisi ile değiştirildiği durumlardaki çevresel etkiler kıyaslanmıştır. Yapılan çalışmaya göre; şebeke elektriği yerine rüzgar enerjisi kullanılırsa AFTP etkisinin %97, AP etkisinin %96, ÖP etkisinin %96, TSEP etkisinin %39, KİP etkisinin %97, İTP etkisinin %58, OTTP etkisinin %90,  FOOP etkisinin %93 azalacağı belirlenmiştir. Çevresel etkileri azaltmak için güneş enerjisinin de kullanılabileceği fakat etkilerinin olduğu görülmüştür. Yapılan çalışmaya göre; şebeke elektriği yerine güneş enerjisi kullanılırsa AFTP etkisinin %81, AP etkisinin %67, ÖP etkisinin %72, KİP etkisinin %79, FOOP etkisinin %57 azalacağı fakat AETP etkisinin %2385, TSEP etkisinin %16, İTP etkisinin %8, OTTP etkisinin %68 ve KEP etkisinin %38 artacağı görülmüştür.
Yapılan senaryo değerlendirilmelerine toplu olarak bakıldığında, üretimin çevresel etkilerinin azaltılması için enerji kaynağının değiştirilmesinin avantaj sağlayacağı sonucu elde edilmiştir.  İncelenen tesiste kullanılan şebeke elektriği ve doğalgaz enerjisi güneş enerjisi ile değiştirildiğinde, 10 etki kategorisinin 5'inde azalma tespit edilmiştir. Şebeke elektriği ve doğalgaz enerjisi yerini rüzgar enerjisine bıraktığında, 10 etki kategorisinin 8'inde çevresel etkilerde ciddi bir düşüş olduğu gözlemlenmiştir. Sonuç olarak, her iki alternatifi birlikte ele alındığında, rüzgar enerjisinin en doğru tercih olacağı görülmüş ve üretici firmaya bir öneri olarak sunulmuştur.  
Ayrıca, etkili sonuç karşılaştırması yapabilmek için benzer çalışmaların yerel veriler kullanılarak yoğunlaştırılması önerilmektedir.

Abstract:
Due to the change of climates, the increasing population, the rapid spread and increase of industrialization, the environmental impacts caused by the industry are also increasing. For this reason, recently, with the increase of public awareness about the environment, the tendency to reduce the environmental impacts in the projects and processes in the industries to reduce the environmental impacts has started to become widespread and the sensitivity has increased. With this increased sensitivity, programs and methods of examining environmental impacts have become widespread. The most widely used method in studies is life cycle assessment. Life cycle assessment is provides information, including resource efficiency and waste generation, where the environmental impacts of a product, service or process can be calculated, measured and reported throughout the entire life cycle, from the acquisition of raw materials to processing, production, use, end-of-life and disposal method. Life cycle assessment studies have stages these are; cradle to cradle, cradle to door, cradle to grave, door to door. In this study, life cycle assessment was made for the cradle-to-door approach.
With the recent increase in technological developments and the increase in the use of technological and electronic devices, the use of server cabinets in workplaces and offices has become widespread. Server cabinet; It is called the safes that provide the order and security of computer systems used in homes or offices. In this study, the environmental effects caused by the production of 1 "Server Cabinet" have been investigated using the LCA method. GaBi was used in the calculations in the study; primary data was collected from the facility regarding the production system; Ecoinvent 3.1 database was used to provide the necessary background data. CML 2016 method was used in this thesis study. In this thesis, some environmental impact categories was investigated and analysed. 10 environmental impact categories have been analyzed, these are; Abiotic Element Depletion Potential (AEDP), Abiotic Fossil Depletion Potential (AFDP), Acidification Potential (AP), Eutrophication Potential (EP), Freshwater Aquatic Ecotoxicity Potential (FAETP), Global Warming Potential (GWP), Human Toxicity Potential (HTP), Ozone Layer Depletion Potential (ODP), Photochemical Ozone Forming Potential (POCP), Terrestrial Ecotoxicity Potential (TETP).
In the life cycle assessment study, the GaBi 3.1 Ecoinvent program was used and CML 2016 method was used to calculate the environmental impacts of the server cainet production. Server cabinet production consists of the 7 main processes thesese are press unit, welding unit, assembly unit, washing unit, painting unit, part adding unit and packaging unit. There are 4 different press machines in the press unit of the investigated facility. The first of these cuts the steel sheet. The second pres machine cuts the corners of the cutten sheet. The third press machine drills holes for screws to be attached to the sheet. The fourth press machine bends the corners of the sheet metal. Pressed steel sheet goes to welding after pressed. 3 different types of sources are made in the investigated facility. One of the welds is gas metal arc welding, one is spot welding and the other is stud welding. Welded steel sheet enters the assembly unit. In this  section, welded steel sheet is sanded and screw and nut are mounted. The assembled steel sheets enter the 5 series connected baths to prepare for painting. In the first bath, chemical and mains water washing is applied to remove the oil on the steel sheet. In the second bath, washing is done only with mains water. In the third bath, washing process with deionized water is carried out in order to remove contaminants that may come from mains water. In the fourth bath, chemical and deionized water washing is performed to make the steel sheet rust and corrosion resistant. Finally, in the 5th bath, the steel sheet is washed with only deionized water. The steel sheets that are washed from the bath unit then go to the painting unit. Steel sheets are painted with powder paint in the painting unit by spraying method in a closed system. Water and chemicals are reused in the bath unit and painting unit, there is an environmentally friendly system. Painted steel sheets are dried. The dried steel sheets enter the part adding unit. Glass, brush, bolt, wheel and lock are added in the part adding unit. The manufactured server cabinet goes to packaging. In the packaging unit, the product is packaged with bubble bags, parcels and bands. Thus, steel sheets pass through 7 main units and a server cabinet is formed. Besides the main production processes, raw material and auxiliary material production units, the transportation of materials to the facility, the production of the server cabinet and the processing of their waste (recycling of recyclable waste, purification of waste, incineration of hazardous waste, etc.) are kept within system boundaries and their environmental impacts have been evaluated. The environmental impacts of the treatment of wastewater and the package treatment system that creates deionized water from mains water were also examined. Environmentally friendly washing baths and dyeing units are used in the investigated facility, because the water and chemicals in the bath unit and the water and paint in the dyeing unit are re-used and recycled. For this reason, no significant environmental impact occurred in these units.
It has been seen in the life cycle assessment that the factors that cause the highest environmental impact in server cabinet production are caused by the production of raw materials and auxiliary materials, which causes an average of 92% of the total effect. It has been understood that the production of stainless steel, which is mostly used among raw materials, has the highest environmental impact on each categories due to the melting and kiln systems used in the production phase. It has been understood the; high AEDP impact resulting from steel sheet production in this study, is due to the use of copper and chromium elements in production; high AFDP impact is due to use of oil, lignite, coal and natural gas; high AP impact is due to emission of NH3, HCl, NO, SO2; high EP impact is due to phosphate emission to freshwater in the long run; high FAETP impact is due to emission of nickel, beryllium, cobalt and copper; high GWP impact is due to CO2 and CH4 emissions; high HTP impact is due to emission of chromium, arsenic, volatile organic carbon; high ODP impact is due to volatile organic emission; high POCP impact is due to volatile organic and inorganic emissions; high TETP impact is due to chromium emission.
Replacing the stainless steel used by the facility producing server cabinets with another material cannot be recommended as a strategy since it will adversely affect the desired quality of the product. Therefore, the focus was on energy consumption, which causes the second highest environmental impact in 7 of the 10 impact categories. The total amount of energy used in the production of a server cabinet is 294 MJ. For electricity generation in the study were taken into account Turkey's electricity report data generated in 2019. According to these data, the process was created in the program and 2019 local electrical energy data were used in the study. Energy use as natural gas and mains electricity accounts for 12% of the total effect for AFDP due to natural gas consumption; 11% for AP due to inorganic SO₂ emission; 7% for EP due to long-term phosphate emission to freshwater and inorganic nitrogen release to air; 3% for FAETP due to barium, nickel emission to freshwater in the long run; 10% for GWP due to high CO2 emission to air; 1% for HTP that is very low impact; and %4 for POCP due to SO₂ and inorganic emission to air also non-methane volatile organic compound emission while it has been determined as the second highest factor due to the fact that it constitutes. Alternative energy sources have been evaluated in order to reduce environmental impacts to the energy source used in the investigated facility. 
Natural gas and electricity are used as energy sources in the investigated facility. Environmental impacts were compared when energy use was replaced with wind and solar energy to reduce the environmental impact. According to the study; If wind energy is used instead of mains electricity and natural gas, the AFDP effect decreases 97%, AP effect decreases  96%, EP effect decreases  96%, FAETP effect decreases 39%, GWP effect decreases 97%, HTP effect decreases 58%, ODP effect decreases 90%, POCP effect decreases 93%. However, two environmental impact categories increase when the electricity and natural gas energy source is replaced by wind energy, these categories are AEDP and KEP.  The AEDP effect increased by 89% due to emission of copper and chrome and KEP effect increases 170% due to chromium release, when the existing energy source in the investigated facility is replaced by wind energy. Therefore ıt has been observed that wind energy will be the right choice to minimize environmental impacts in 8 categories of the 10 categories. 
It has been observed that solar energy can be used to reduce environmental effects, but it reduced environmental impacts in 5 out of 10 impact categories, it also caused an increase in effect in the other 5 of the 10 environmental effect categories. According to the study; If solar energy is used instead of grid electricity, the AFDP effect will decrease by 81%, the AP effect 67%, the EP effect 72%, the GWP effect 79%, the POCP effect by 57%, but the AEDP impact will increase by 2385% due to the consumption of molybdenum, gold and silver elements, the FAETP effect by 16% due to long-term copper release to freshwater, the HTP effect by 8% due to arsenic emission, the heavy metal released into the air, the ODP effect by 68% due to organic halogen emission to air and 38% increase in KEP effect due to chrome release. Therefore, it is understood that solar energy can be used to reduce environmental effects, but it has effects.
As a result, energy type can be changed to reduce environmental impact categories in natural gas and grid electricity. When the grid electricity and natural gas energy used in the investigated facility were replaced with solar energy, a decrease in 5 of 10 impact categories was detected. When the grid electricity and natural gas energy are replaced by wind energy, it has been observed that there is a serious decrease in environmental impacts in 8 of the 10 impact categories.
Local data were used for this study. In order to make effective results comparison, it is recommended to intensify similar studies using local data.