Gemi Kaynaklı Atıkları Alan Bir Atık Kabul Tesisinde Karbon Ayak İzinin Belirlenmesi

Abstract

Şüphesiz son yılların en popüler gündem maddelerinden biri olan küresel ısınma ve iklim değişikliği yeryüzündeki yaşamı tehdit eden en büyük tehlikelerden biridir. İklim değişikliğine ve küresel ısınmaya neden olan sera gazı emisyonlarının minimize edilmesi ve bilimsel araştırmaların sonuçlarına göre önleyici tedbirlerin ivedilikle alınması gerekmektedir. Bu önlemlerden global olan en büyük başarı Kyoto Protokolü ile sağlanmıştır. Bu protokol ile emisyon salımlarından sorumlu ülkelerin karbon salımlarını minimize etmesi gerektiği, karbon salımlarını hesaplamak için ülkelere emisyon salım kotaları getirildiği belirtilmiştir. Bu kotaları aşmamak için seragazı emisyonlarına neden olan emisyonların karbon ayakizi hesabının yapılması ve seragazı envanterlerinin oluşturulması ve bu kotaların altında kalacak çalışmaların gerektiği vurgulanmıştır. Bundan dolayı da protokole taraf ülkeler, sektörlere karbon ayakizi hesaplamalarına gereken önemi vermesi gerektiği vurgulanmıştır. Karbon ayak izi, birim karbondioksit cinsinden ölçülen, üretilen sera gazı miktarı açısından insan faaliyetlerinin çevreye verdiği zararın ölçüsüdür. Toplam sera gazı emisyon miktarının birim karbondioksit eşdeğeri cinsinden ifade edilmesi ile karbon ayak izi belirlemesi yapılmaktadır. IPCC, GHG Protokol, UNFCCC, ISO 14064 standardı bu konuda ülkelere, işletmelere, üreticilere ve tüketicilere vb. yol gösterici olmaktadır. Alınacak önlemler ve yapılacak değişiklikler enerji kullanımında öngörülecek verimlilik çalışmaları öncelikle sürdürülebilir karbon yönetimini gerektirecektir. Sürdürülebilir bir karbon yönetimi sorumlulukların ve idari yapılanmanın kurumsal iklim değişikliği yönetimi yaklaşımı ile belirlenmesini gerektirmektedir. Şirketler ve kuruluşlar, karbon yönetim stratejisini geliştirirken mevcut yönetim sistemini idari yapılanma, veri toplama, raporlama ve paydaşları bilgilendirme boyutlarını dikkate almak kaydı ile iyi analiz ederek karbon yönetimine ilişkin öğeleri sistemine entegre etmeli ve iç hesaplama ve izleme yöntemlerini saptayarak zaman ve maliyet kazancı sağlayacaktır. Bu çalışma ile ülkemizde, dünyada ve birçok avrupa ülkesinde karbon ayak izi konusundaki yaklaşımları, farklılık gösteren işletmelerdeki metodoloji seçimleri hesaplamaları ve sonuçları incelenmiştir. Seçilen bir atık kabul tesisinde gemilerden atık alınmasını, atığın bertarafına kadar olan süreci incelenmiş, proses çalışması yapılmış, elde edilen veriler doğrultusunda tesise ait sera gazı emisyon envanteri çıkarılmıştır. Sera gazı envanterine yönelik işletmeden kaynaklanan karbon salımlarını azaltmak için çeşitli senaryolar öngörülmüştür. Bu senaryolar sonucunda sera gazı emisyon değerleri IPCC verilerine göre hesaplanmış ve maliyet analizleri çıkarılmıştır.

Greenhouse gases are those that can absorb and emit radiation within the thermal infrared range. This process is the fundamental cause of the greenhouse effect. In order, the most abundant greenhouse gases in Earth's atmosphere are: water vapor, carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), ozone (O3) and CFCs. Greenhouse gases greatly affect the temperature of the Earth. Since 1750, the burning of fossil fuels and extensive clearing of native forests has contributed to a 40% increase in the atmospheric concentration of carbon dioxide, from 280 ppm in 1750 to 392.6 ppm in 2012. Anthropogenic carbon dioxide (CO2) emissions (i.e., emissions produced by human activities) come from combustion of carbon-based fuels, principally wood, coal, oil, and natural gas. Greenhouse gases can be emitted through transport, land clearance, production and consumption of food, fuels, manufactured goods, materials, wood, roads, buildings, and services. For simplicity of reporting, it is often expressed in terms of the amount of carbon dioxide, or its equivalent of other greenhouse gases, emitted. Once the size of a carbon footprint is known, a strategy can be devised to reduce it, e.g. by technological developments, better process and product management, carbon capture, consumption strategies, carbon offsetting and others. The most effective way to decrease a carbon footprint is to either decrease the amount of energy needed for production or to decrease the dependence on carbon emitting fuels. Global warming and climate change, one of the most popular agenda topics at recent years, is one of the biggest dangers that threaten life on earth. It is required to minimize greenhouse gas emissions that cause global warming and climate change and to take preventive measures according to results of scientific research urgently. Because climate change has become an irrepressible problem, extensive studies have been initiated under the guidance of United Nations (UN) and international organizations since the end of 1980s. As a result of these studies and together with ''United Nations Climate Change Framework Convention'', Kyoto Protocol was signed in 1997. Kyoto Protocol aims to reduce six greenhouse gases including carbon dioxide, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons, and sulphur hexafluoride. The issue which is principally addressed in Kyoto Protocol is making necessary legal regulations in order to motive institutions and organizations to reduce human-driven greenhouse gas emissions. Energy sector, compared to other sectors, occupies an important place in greenhouse gas emission. Because of this, the countries that signed the Kyoto Protocol have made their studies, environmental and energy policies concentrated on minimizing environmental pollution, further to that on for minimizing environmental impacts. On a global scale, the greatest success has been achieved by Kyoto Protocol. This protocol, which is the most important step, aims at reducing the number of gas generators by forcing them to pay a price as such in polluter pays principle. With this protocol, it has been stated that the countries which are responsible for emissions need to minimize carbon emissions and that emission quotas have been set for the countries to calculate carbon emissions. It is emphasized that carbon footprint calculation of emissions which cause greenhouse gas emissions need to be done not to exceed these quotas and greenhouse gas inventories need to be created. It is also stressed that there should be studies which will be below these quotas. Consequently, it is emphasized contracting party countries require to calculate carbon footprint of the sectors and give due importance to create greenhouse gas emission inventories. Carbon footprint, measured in the unit of carbon dioxide, is a measure of the damage that is caused by human activities in terms of the amount of greenhouse gases produced. Determination of the carbon footprint is performed by denominating total greenhouse gas emission amount in the unit carbon dioxide equivalent. IPCC, GHG, Protocol, UNFCCC and ISO 14064 are guides used for calculation of carbon footprint for the countries, facilities, manufacturers, consumers etc. Sustainable carbon management requires responsibilities and administrative structure which determine with corporate climate change management approach. Countries existing management system when developing the administrative structure of carbon management strategy, data collection, reporting and takes into account the size of informing stakeholders. This situation should integrate better analyze the elements of the system related to carbon management and internal calculations and provide time and money by detecting tracking method. In this study, carbon footprint of a port reception facility for ship generated waste was determined. First, process units of the reception facility have been investigated. Main units include waste collecting (bilge water, sludge, waste oil, wastewater, solid waste), storing, processing and disposal. Then, carbon footprint was calculated for the facility by using IPCC guidelines. The sources of carbon emissions are electricity consumption, heating oil consumption used in the boilers, fuel consumption of the cranes and forklifts, fuel consumption of waste reception vessels and water consumption in the facility. Finally, different scenarios have been proposed to minimize the emissions caused by the facility. In addition, cost analysis of these scenarios have been done. Total amount of greenhouse gas emissions of the facility was 3217 tonnes of CO2 in 2013. 46% of this total amount was from the fuel used for waste reception vessels; 39% was from electricity consumption; 7% was from heating oil consumption used in the boilers; 6% was from water consumption; 2% was from fuel consumption of company cars and less than 1% was from fuel consumption of the cranes and forklifts. The scenarios, which have been proposed to minimize emissions from the facility, include installation of a pyrolysis unit in order to produce marine fuels; addition of DAF and NF-UF membrane system to the wastewater treatment unit; replacing natural gas instead of heating oil in the boilers; switching to led diodes, changing the fuel of company cars or replacing them with electric cars; buying carbon credit and afforesting. Installation a pyrolysis unit would decrease the total greenhouse gas emissions 100%. Addition of NF-UF system to the wastewater treatment unit would reduce the total emissions at the rate of 10%. Use of natural gas in the boilers and replacement of company cars with electric ones would decrease total greenhouse gas emissions 2% and 1%, respectively. Buying carbon credit and afforesting would zero the greenhouse gas emissions. By using these alternatives, it is possible to neutralize the greenhouse gas emissions caused by the facility.