Mobilya endüstrisinde yaşam döngüsü analizi yaklaşımı ile çevreci tasarım ve sürdürülebilir stratejiler
Eco-design and sustainable strategies for the furniture industry through life cycle approach
Yazar: MERVE MERMERTAŞ
Danışman: PROF. DR. FATMA GERMİRLİ BABUNA
İstanbul Teknik Üniversitesi / Fen Bilimleri Enstitüsü / Çevre Mühendisliği Ana Bilim Dalı / Çevre Bilimleri, Mühendisliği ve Yönetimi Bilim Dalı
Derece: Yüksek Lisans, 2018
Konu: Çevre Mühendisliği = Environmental Engineering

Özet:
Günümüzde küresel bir sorun haline gelen iklim değişikliği konusu tüm dünyayı etkileyen niteliğiyle şüphesiz günümüzün en önemli küresel problemleri arasında yer almaktadır. Küresel ısınmaya sebep olan sera gazı emisyonlarının küresel ölçekte artmaya devam etmesi, doğal kaynakların azalması ve bunlara bağlı olarak ekolojik bozulmaların artması iklim değişikliğinin olumsuz etkilerini giderek daha fazla hissedilir kılmaktadır. Olumsuz yönde gerçekleşen bu gidişatın yavaşlatılması için ülkeler arası iklim sözleşmelerinin imzalanması ve çevreye en az etkili üretim ve iş modellerinin geliştirilmesini teşvik eden politikaların oluşturulması günümüzde bu konunun önemini bir kez daha vurgulamaktadır. 
Bu sebeple endüstri alanlarında sürdürülebilirliği ve çevreci olma özelliğini odak noktasına alan değişimler yaşanmaktadır. Daimî olabilme yeteneği olarak tanımlanabilecek sürdürülebilirlik kavramı günümüzde yaşanan küresel sorunlara çözüm olma niteliği taşımakta ve bu özelliğe sahip ürün ve sistemlerin geliştirilmesi için stratejik uygulamaların hayata geçirilmesini gerektirmektedir. 
Mobilya, günlük yaşamın her alanında yer edinen, yaşama yönelik, herkesin kullandığı ve insan yaşam kalitesini doğrudan etkileyen bir üründür. Nüfus artış hızındaki yükselme oranları ile beraber mobilyaya olan talep artmakta ve gün geçtikçe daha çok bilgi ve maddi sermaye gerektiren bir sektör haline gelmektedir. 
Yaşam Döngüsü Analizi her türlü ürün, hizmet ve sistemlerin gelişim ve uygulama süreçlerinde projenin maliyeti ve performansı gibi parametrelerin dışında çevre sorunlarına sebep olma potansiyeli ve doğal kaynakların tükenmesine ilişkin parametrelerin ölçülmesinde kullanılmaktadır. YDD, bilimsel metodolojilere dayanarak ürün ve sistemlerin çevresel performansını kapsamlı bir şekilde değerlendirme ve ölçme yöntemidir. YDD, söz konusu ürün ya da sistemin hammaddelerinin elde edilmesiyle başlayan ve ilgili tüm üretim, ulaşım, kullanım ve kullanım ömrünü tamamladıktan sonra atık olarak bertaraf edilme süreçlerini dahil ederek çevresel etkileri hesaplamak, raporlamak ve yönetmek için kullanılmaktadır. Yaşam döngüsü süreçlerindeki çevresel etkilerin bütünleşik bir şekilde değerlendirilebilmesi çevresel yönetim konularında kararların alınabilmesine büyük katkı sağlamaktadır. YDA ilkeleri, çerçevesi ve raporlanması ISO 14040 serisi standartları ile açıklanmaktadır. 
Bu tez çalışmasında Türkiye'de üretimi gerçekleşen mobilya ürünlerine yönelik hammadde çıkarılması ve işlenmesi aşamasından başlayarak tüm üretim, dağıtım, kullanım, bakım ve yaşam sonu süreçlerinde oluşan çevresel etkilerin YDD yaklaşımı ile ortaya konması hedeflenmiştir. Bunun dışında beşikten mezara yapılan bu değerlendirme sonuçlarına göre ürünlerin yaşam ömürleri boyunca oluşan çevresel etkilerin azaltılmasına yönelik çeşitli stratejiler geliştirilmiş ve ürünler arası karşılaştırmalar yapılmıştır. Yapılan çalışmalarda sektörde üretim yapan üreticilere, karar verici mercilere ve konu üstüne akademik çalışmalar yapan araştırmacılara da yol göstermesi hedeflenmiştir. Çalışma kapsamında Küresel Isınma Potansiyeli, Asidifikasyon, Ötrofikasyon, Fotokimyasal Sis Oluşumu ve Ozon Tabakasındaki İncelme Potansiyeli çevresel etkileri ele alınmıştır. Hesaplamalarda kullanılan fonksiyonel birim 10 yıllık kullanım ömrü üzerinden çalışma masası için 1m2 olup ofis koltuğu ve kanepelerde 1 adet oturma birimidir. Yaşam Döngüsü modelleri GaBi DB Versiyon 6.115 kullanılarak yapılmıştır. Tüm sonuçlar EPA TRACI 2.1 çevresel etki karakterizasyon faktörlerine göre alınmıştır. 
Alınan sonuçlar tüm etki kategorilerinde en fazla etkinin Kanepe 2 ürünü hariç hammadde çıkarımı ve işlenmesi aşamasından kaynaklı olduğunu göstermiştir. Ürünler yaşam ömürlerini tamamladıklarında tüketici tarafından bertaraf edilme yöntemlerine ilişkin envanter verilerine ulaşılamadığı için bu aşama uluslararası NSF kuruluşunun ve BIFMA'nın ortaklaşa geliştirdiği ürün kategori kurallarında geçen %80 düzenli depolama ve %20 yakma tesisine 32 km mesafe ile gittiği kabulü yapılmış olup bu kabulün tüm ürünlerde yaşam sonu aşaması için OTİ'de çevresel fayda sağladığı sonucu alınmıştır.  Hammadde çıkarımı ve işlenmesi aşamasında oluşan çevresel etkilerin diğer aşamalara göre daha fazla oluşu ürünlerde kullanılabilecek alternatif, hızlı yenilenebilir ve doğal malzemeler kullanılarak üretilebilen ürün tasarımlarının geliştirilmesinin önemini ortaya koymaktadır.
Aynı amaca hizmet veren ürünler arası yapılan karşılaştırmalar göstermiştir ki ürünler arasındaki tasarımsal farklılıklar, kullanılan malzemeler ve nihai ürünün talep edildiği tüketici lokasyonları ve bu noktalara olan taşıma yöntemleri ürünlerin yaşam ömürleri boyunca oluşan çevresel etkilerde önemli paya sahiptir. Kanepe 2 ürünü için yapılan detaylı proses ve etki dağılımları incelendiğinde dağıtım ve kullanım aşamasındaki çevresel etkilerin en fazla oluşu taşımada kullanılan yöntemlerin ve mesafelerin önemine dikkat çekmektedir. Bu sebeple, ürünün bu aşamada oluşan çevresel etkilerini azaltabilmek için mesafeler ve taşıma yöntemleri üzerine senaryolar geliştirilmiştir. Yapılan incelemelerde ürünün sürdürülebilir olmasını sağlayan ekonomik boyutları da göz önünde bulundurularak yurt dışı pazarına yapılan taşıma yöntemlerinin temiz ulaştırma araçları ile gerçekleştirilmesinin benimsenmesi gerektiği önerisinde bulunulmuştur.  
Ülkemizde YDD konusunda çok az çalışmanın yapılmış olması ve bu çalışmanın mobilya sektörü için Türkiye'de yapılmış ilk YDA olması çalışmanın değer ve önemini arttırmaktadır.

Abstract:
Climate change is one of the most significant global problems of our time that has already had observable effects on our environment. From shifting precipitation patterns that increase the risk of catastrophic flooding to more intense heat waves that cause wildfires and threaten natural habitat are such examples for the impacts of climate change globally today. As the amount of greenhouse gas emissions due to anthropogenic sources increase, the cumulative level of ecological deterioration increase as well and leads to irreversible changes in major ecosystems and the planetary climate system. To preclude the effects of climate change and environmental problems, intergovernmental climate agreement and policies are developing that encourage the development of least ecological effective production systems and business models emphasizing the importance of this issue.
Eco-design and sustainability strategies are increasingly adopted to industrial processes to ensure the minimization of environmental impacts. Sustainability that may describe as the ability of enduring provides the solution to the global problems that we faced on our world today. However, the challenge is to select the most appropriate strategy to reach an efficient use of resources that ensure a satisfactory product from an environmental point of view. Therefore, comprehensive environmental profile studies need to be developed to define the most effective hotspots to provide sustainable value chain management and also for the right implementation of eco-design principles.
Environmental impacts of production and consumption can be controlled and reduced by using life cycle assessment and eco-design instruments which typically involve the analysis of complex product systems. Those approaches can be adapted to any products for addressing the further development and implementation of measures with which to promote more sustainable options.
Furniture is a product that takes place in each area of daily life and oriented towards living that is used by everyone and directly affects the quality of life. It covers a broad set of products used daily for functions such as storage, hanging, lying, sitting, working and eating. Typical products which can all be made of different materials with a variety of designs are chairs, desks, wardrobes, kitchens, bed structures and sofas. The need for furniture is increasing all around the world with the increasing population and urbanization and this situation is reflected directly in the furniture industry. It is also becoming increasingly necessary to produce environmentally friendly and human healthy furniture which expected to play a more active role in the future.
Life Cycle Assessment (LCA) is the analytical framework for quantifying the impact on the environment and the resources used by a product, service or system over its entire life cycle. For most product systems, this means the period when raw materials extracted from nature to the period when these materials are processed, as well as, manufacture of the product, distribution to the user, use phase and the product's eventual end of life treatment methods. A wide range of disciplines, including engineers, product designers, project managers, and material scientists use LCA because it supports the process of identifying and improving the environmental performance of products or production systems. The success of achieving environmentally sustainable development rests on how it affects the environment. So, as the new ecological problems emerge and greenhouse reduction goals develop globally, LCA plays as an essential role used to assess mitigation strategies and policy goals.
LCA application is standardized through a series of international standards called the ISO 14040 series. Conformity to these standards assures that all the steps for an LCA performed transparently and reproducibly. A fundamental requirement for all LCA applications establishes four clearly defined phases which are goal and scope definition, inventory analysis, impact assessment and interpretation of results. The goal and scope definition phase specifies the objectives of the study, the functional unit and the description of the system boundary. The inventory phase is a process of quantifying material and energy requirements, solid wastes and other releases to the environment over the entire life cycle of the manufactured product. The LCA impact analysis phase uses the inventory to calculate the potential environmental impacts. The interpretation component of the LCA interprets the results throughout each life cycle stage of a product depend on the goal of the study.
The objective of this thesis study is to analyze the environmental impacts of different types of furniture products produced in Turkey via LCA approach. The evaluated furniture products are a desk, office chairs, and sofas. The product life cycle studied is cradle to grave which includes five main stages: raw material extraction and processing, materials transportation to the fabric gate, production, distribution, use and end of life. According to the results of this cradle to grave analysis, various strategies were developed to reduce the potential environmental impacts occurring throughout the entire life span of a sofa product and also comparisons between two different office chairs and sofas made. During the study, it is also aimed to produce useful data for the producers in the furniture sector, decision makers and academic researchers in this field. Global warming potential (GWP), acidification potential (AP), eutrophication potential (EP), photochemical ozone creation potential (smog) (POCP) and ozone depletion potential (ODP) are the investigated impact categories. 
The functional unit for the office chairs and sofas are one unit of seating and for the desk is one square meter (1m2) of workspace, maintained for ten years. The modeling type of the LCA study is attributional. The LCA model of the products were created by using GaBi DB Version 6.115 software system. The results are based on characterization factors from the US EPA Tool for the Reduction and Assessment of Chemical and Other Environmental Impacts called TRACI 2.1 Impact Categories. The limitations of the study were reduced to minimum by following the BIFMA PCR for Seating: UNCPC 3811 and BIFMA PCR for Office Furniture Workspace Products: UNCPC 3814.
The primary data collection was accomplished in the form of spreadsheet and questionnaires and supplemented by conversations with the manufacturer in Turkey, and the bill of materials gathered from the material suppliers. All relevant background data necessary for the materials used in the model are included in the GaBi database. For consistency and completeness of data, GaBi 6 Software-System and Databases for Life Cycle Engineering DB Version 6.115 is used. It provides the life cycle inventory database in all branches to assess the potential environmental burdens of a product from the cradle to the grave. All input and output flows, type of materials used, energy consumption, transportation, and wastes are primary data taken from the manufacturer. Once the data is collected, it was imported into GaBi where the modeling was carried out. The data for the LCA is based on 12 consecutive months for all products. 
Allocation is avoided for the main materials, ancillary materials and packaging materials used to manufacture the product. Each input was taken from manufacturer per one product. The total amount of annual energy consumed in the atelier where production occurs was allocated by using total numbers of unit produced in the atelier. For some wastes that company has total yearly generation data only such as; packaging waste, boiler ash, and clinker, the amount per one product generation was calculated by using the total production percentage of a product group in all manufacturing activities of the facility. Afterward, the amount was divided by the total number of product production. The mass allocation for the end of life stage was made as 80% landfill and 20% incineration as stated in the PCRs. The end of life distance data have been taken from the US EPA WARM model as 32 kilometers. 
All inputs and outputs to unit processes for which data available were included in the calculation. Data gaps were filled by conservative assumptions with average or generic data. There is no neglected unit process more than 1% of total mass and energy flows. The total neglected input and output flows are also not exceed 5% of energy usage or mass as indicated in the PCRs. The amount of water use for regular cleaning of products was ignored. Since the amount of water to damp the rag is only a couple drop of water, it was taken under cut-off criteria. The infrastructure, building site, production of manufacturing equipment and personnel activities are excluded in this LCA study. The specific data coverages are geographical, time period and technology. 
The results indicate that the most significant contributor to the environmental impacts during the life cycle of a desk is the material acquisition and pre-processing stage. This stage demonstrated the essential inputs in all environmental impact categories consistently. After this mentioned stage, the contribution of the end of life stage causes the highest impact on Global Warming Potential (GWP).
The greatest contributor to all impact categories during the life cycle of office chair 1 is the raw material acquisition and pre-processing stage. This stage is mainly affected by aluminum used in mechanism and furniture leg, polyurethane foam used for the main case and textile used for cladding. GWP is affected 75,6% because of raw material stage while other impact categories such as Acidification Potential (AP), Eutrophication Potential (EP), Photochemical Ozone Creation Potential (smog) (POCP), and Ozone Depletion Potential (ODP) are affected 88%, 84,8%, 79,8%, 99,6% respectively by raw material processes. The Manufacturing stage is the second most significant contributor in all impact categories. This stage is mainly affected by cardboard used in packaging and nylon and paper packaging wastes on landfill. As for the end of life stage, more than 60% of impacts occur because of the landfill process.
The obtained LCA results for the office chair 2 indicate that life cycle stages have the relatively same ratio of contribution processes with office chair 1 since they have similar raw materials and manufacturing processes but different designs. So, the comparison between those two products showed that office chair 2 has more environmental impacts besides ODP. The product has more effect in GWP, AP, EP, and POCP as the ratio of 17%, 42%, 48%, and 39% respectively. The reason of office chair 2 has less impact in ODP is the product has no movable mechanism with chrome gas column. These findings show the importance of product design on environmental impacts.
The results for the cradle to grave life cycle analysis of Sofa 1 showed that greatest contributor to GWP, AP, EP, POCP, and ODP is the raw material acquisition and processing stage with the ratio of 53,3%, 75,5%, 77,1%, 65,3%, and 93,8% respectively. After this mentioned stage, the contribution of manufacturing stage causes the highest impact besides GWP. As for the GWP, the second contributor is the end of life stage with 17,3% ratio due to the craft paper and electricity consumption. The manufacturing, distribution and usage, and transportation stages have 14,6%, 8%, and 6,8% contribution on GWP respectively.
The results for the cradle to grave life cycle analysis of Sofa 2 showed that most significant contributor to the GWP and POCP is the distribution and use stage which is mainly because of the cargo plane to distribute the product all around the world. In order to decrease the impacts at this stage, two different scenarios developed which one of them is on distribution distance and the other one is on distribution type. The distribution distances were reduced from 6000km (to USA) and 2334 km (to EU) to 1448 km (in Turkey only). The distribution type was changed to understand how the distribution type affects environmental burdens. The type of distribution to USA and Europe was assigned as container ship and truck respectively rather than cargo plane. In real situation, the product is distributed to EU and USA with cargo plane. For both of the scenarios, reduction occurs in all environmental burdens. However, the biggest reduction is when the distribution type changes with 33% reduction in GWP for the whole life cycle of a product. On the other hand, when the distribution distance reduced, the reduction in the GWP for the entire life cycle of the product is 22%.
The contribution of raw material acquisition and processing stage for the product Sofa 2 GWP impact is 31,4% while the other end of life, manufacturing, and transportation stages have 19,3%, 6,4%, and 4,8% contributions respectively. The raw material stage GWP impact primarily dominated by the textile used for cladding (65,51%), plywood (15,05%) and fiber (%7,51) used. Therefore, it is recommended to concentrate further efforts on used textile. Either substituting new materials instead of the used textile or optimizing the textile manufacturing process can yield lower environmental impacts. Other processes of interest are waste treatment processes such as landfill (70,7%) and incineration (29,3%) for the end of life stage and cardboard packaging material (36%) for the manufacturing stage.
This LCA study is the first of its kind as it targets the products that are globally distributed. Due to a lack of significant LCA applications in Turkey compared to US and European countries, it is being developed swiftly to show the manufacturers commitment to sustainability. Apart from obtaining the effective recommendations on minimizing the environmental impacts by pointing out the environmental hotspots, pioneering steps towards spreading LCA specific to Turkish furniture production are taken.