Engineering and Sustainability

Introduction:

            The report includes a detailed discussion on the life cycle impact of plastic bottles. This product is highly utilised in daily basis by millions of individuals across the UK. This high demand of the product also reflects about the environmental impact of these bottles. It is the reason to conduct this life cycle assessment. It will also help highlight all the key areas that are to reduce the environmental impact of these bottles and maintain environmental sustainability. For the sake of ecological management, strict guidelines are followed known as ISO 14040. All the four stages will be assessed as per these guidelines which are goal and scope (ISO 14041), inventory analysis (ISO 14042), impact analysis (14043) and the interpretation of the results (ISO 14044) (Shen, Worrell and Patel, 2010).

SimaPro analysis will be done to analyse the environmental impact of these plastic bottles. LCA of these plastic bottles will include a detailed understanding of the ecological, ethical, social, and processes involved. The sustainability report will also have the interpretation of the results and the critical analysis. Assumptions and discussion of conflict and limitations will also be a part of this report.

Background and the key processes

The number of polyethylene terephthalate (PET) bottles used is 13 billion in number throughout the UK. While only 27% of these bottles are recycled, and the rest impact the environment negatively impacting its sustainability. As per the research analysis, it takes almost 1000 years to recycle these bottles. These plastic bottles impact negatively on the ground, primarily due to the toxins released from them. CO2 is also emitted from these bottles reducing the sustainability of both the soil, water and air. The production of PET bottles require 3 litres of water and 250 ml of oil. Also, they are gone through almost 12 processes in their entire life phases. This indicates that the production of these bottles creates a lot of environmental issues like extraction of raw material from the crude oil, production of the fossil fuels, energy wastage, disposal of the end product, and the extraction of the water resources. All these factors impact on the environment negatively while harming the ecosystem (Marathe, Chavan and Nakhate, 2019).

Goal and Scope

The goal of this report is to do the life cycle assessment of PET bottles. Other than this, the impact of all the related process will be analysed to evaluate PET bottles life cycle. The software that has been used to analyse the life cycle assessment is SimaPro 8.2. All the international standards of ISO 14040 will be met in this analysis.

This investigations primary purpose is to evaluate the environmental impact while sourcing out the raw materials involved. All the four stages will be analysed as outlined in the International Organisation for Standardization ISO 14040. The following figure represents the LCA framework. This report focuses on both the academic field and the environmental industry involving LCA analysis (aimed for academics and students) (Aymard, V. and Botta Genoulaz, 2017).

            The scope of the report will include the system boundaries, and the data requirements required in Simapro. It will help make, limitations, and other alternatives necessary for the raw material extraction, manufacturing, and addition. The following figure indicates about the system boundaries, which is needed for this process. It also includes the assessment of the potential human health, ecosystem quality along with the resource metrics.

Assumption

Lets interpret the system boundaries, assumptions, and the limitations required in this process:

Extraction of raw material:

Production of PET includes crude oil as the raw material, while the inputs required includes fossil fuels. These fossil fuels are for gaining energy, electricity, and the transportation. The output of the entire manufacturing process provides water, oil, and soil.

Manufacturing:

The manufacturing process of PET bottle is injection moulding which produced 10 kg of the PET bottles. The input provided to the operation of manufacturing is the electricity and the fossil fuels. Fossil fuel is used to the power the plants as well as assists in water consumption. The greenhouse gases comes as output, including air, water, and soil emissions (Shen, Worrell and Patel, 2010).

Transportation:

The assumption involved in transportation is to transport the product with Indias aid air freight to the UK. The distance in between these two areas is around 67000km. At the time of the product analysis, 10kg of the finished PET is taken into consideration. Kerosene has been used as the fossil fuel input within the flight time of 9 hours. At the same time, the output will remain the same, i.e., greenhouse gases (Heidbreder, Bablok, Drews and Menzel, 2019).

Limitations:

The limitation is due to the lack of data in both the inputs and the outputs. These limitations are energy, heat, water, and the emissions to the environment processed in the form of greenhouse gases like air, water, and soil pollution (Marathe, Chavan and Nakhate, 2019).

2.0 Life Cycle Assessment (LCA)

The above figure described tailed network analysis involving three process processes: material, manufacturing process, and the tr 1kg of the material is considered in this process considering electricity and the fossil fuels required to analyse the environmental impact. A suitable amount of resources is considered with 87.6% of the electric energy necessary to power the entire process. This amount of energy is needed to power the injection moulding machines and the other factory equipment using gas and oil  (Ko, Kwon, Lee and Jeon, 2019). While the resources necessary o source the raw materials is 8.46% with the transportation resources of 12.4%. All these values are as per the interpretation of the above described figure.

The above figure represents a complex network of the manufacturing and transportation of 1kg of the material. Many of the processes involved damage the environment like sourcing crude oil for the creation of the kerosene oil. This network provides a detailed description of the complete network analysis (Parker, 2020). The analysis of the above figure showed that 1kg of PET strongly impacts the environment compared to transportation. This is giving a reasonable interpretation of the amount of material that has been used in every part. It also indicates that the above system is highly beneficial in enhancing the sustainability and reducing environmental impacts (Heidbreder, Bablok, Drews and Menzel, 2019).   

2.1 Overall Impact Characterization

            Impact methodology has been used here in this case to express the characterisation chart. Eleven different categories are being presented in the following figure to analyse the environmental impact of PET bottles  (NAKATANI, OKUNO, FUJII and HIRAO, 2011).

            The main reason for characterisation of the life cycle assessment is to quantify all the factors that impact the eco toxicity and human toxicity. Yellow areas indicate about the raw material extraction, blue area indicates manufacturing while the red is an indication of the transportation material. The last one is a green colour which presents about fossil fuels and electricity.

            The impact categories that has been discussed in the characterisation includes carcinogens, respiratory organics, respiratory inorganics, radiation, climate change, eutrophication, land use, eco toxicity and minerals and the fossil fuels. The interpretation of figure 4 presents that raw materials favourably impact the respiratory organic, climate change, and the fossil fuels, while on the other hand manufacturing effects on carcinogens, respiratory organics, eco toxicity and the eutrophication highly. The transportation impacts the vast majority of categories with high values  (Brilhuis Meijer, 2014). 

A comparison has also been made between air (red) and sea freight (blue) to see the effect of transport on the most considerable value presented in the categorisation. Findings of figure 5 also represents that the sea freight will highly reduce negative impact on all the categories shown in the figure. The entire data is based on the distance of 6700km and the sea distance of 8000 km required to go around the landmass.

Comparison of both air and sea transportation modes:

The analysis of figures 6 illustrates the detailed damage assessment of the raw material, extraction, manufacturing and transportation based on different categories. The significant types discussed here are human health, ecosystem quality, and resources. The blue areas ecosystem and human health are significantly more substantial, with a value of 94% and 92%. On the other hand, raw material extraction and transportation impact resources electricity and fossil fuels in the form of energy equating to the value of 57% as indicated in red and green. The material also impacts on the resources with the percentage of 43  (Brilhuis Meijer, 2014). 

Human health:

Polyethylene terephthalate, also known as PET has both positive and negative effects on the human health. Plastic is used in its construction which has been utilised in the entire world, and this is why it can be used again and again by converting into different shapes and sizes. The material can be collected and recycled to make bottle also. These bottles usually contain bisphenol a, which is highly harmful for human health as the chemical can be ingested into our body, causing cancer and other hormonal problems  (NAKATANI, OKUNO, FUJII and HIRAO, 2011). 

Ecosystem quality: 

Polyethene terephthalate is a polymer where poly means many and mers means unit. The significant advantage of utilising this product is that it reduces the greenhouse gases and serves as energy conservation and energy resource conservation medium with a significantly reduced pollution. This bottle impacts the environment in many ways, especially to land and marine areas. The harmful chemicals released from these bottles create solution in both land and water affecting sea life and human life. PET is a form of plastic used globally to produce bottles, woods, replacing metals, and other materials. Energy consumption in 3D printing has a more significant environmental impact as well  (Toto, 2018). 

Climate change:

1. Plastic bottles are the leading reason to release more amount of carbon dioxide. 
2. A diverse range of bottles are burnt, landfilled or leaked into the environment and oceans. 
3. Plastic material positively impacts the oceans.
4. Oil is highly required for the manufacturing of PET bottles. 
5. Burning of plastic impacts the nature. 
6. Most of the hotels are thrown out into the environment and are not recycled. This is the leading reason of causing any diseases in humans. 

Resources:

1. Manufacturing of PET requires both ethylene glycol and terephthalic acid. 
2. Crude oil is the primary resource for manufacturing of this product. 
3. Thermoplastic synthetic material is required to shape and heat PET bottles. 
4. Both the fuel consumption and carbon dioxide emissions are required for the transport efficiency. 
5. The conversion of resources in this process is due to the weight reduction of PET bottles. 
6. A recycling compressor is required for the recycling of water bottles after using them. 

Normalisation:

Normalisation is defined as the process used to compare different categories of a known reference. This process follows the guidelines of ISO 14040. In this process, the impact of each class is evaluated by a different score. This is a way to make a comparison in between each category from relevant and other relevant levels. For example, human health is one of those categories that can be impacted by PET bottles life cycle. But quantifying the result is very challenging because it does not allow then and manipulation of data used for normalisation  (Toto, 2018). 

The following formula is required to calculate the normalisation value of the impact categories: 

N_i = C_i/R_i

Here, N_i is the normalised result, and C_i is the characterised impact while R_i is the reference impact.

The above figure is representing the normalisation values against each impact within the life cycle assessment. The diagram shows a detail indication of the manufacturing of PET. The interpretation also indicates that the manufacturing of these bottles shows the highest category of human health and only 27% of the bottles are recyclable. At the same time, the remaining products will be discarded as landfill or burnt. But the ecosystem will be affected due to the decontamination of water in soil and another agricultural land. It is also the leading reason to reduce sustainability in the oceans. 

4.6 Weighting:

The weighing stage includes different factors that are to be considered in life cycle assessment of these bottles.

The following equations discusses the factors that will be considered while weighting. 

W = WF_c * I_c

All of these factors are subjective and are considered by the life cycle assessment practitioners. It will also reflect about the social and political importance of every impact category.

The most impacted category is the human health and was signed as the weighting factor of greater than 1. While the all other factors have less weighting value than this. The resources required to process models equal to the percentage of 25 using the energy in the form of electricity and fossil fuels as transportation (Shen, Worrell and Patel, 2010). 

2.4 Single score

The single School figure represents a graphical illustration of the environmental impact using a single score despite the overall total value. The manufacturing process has the highest value of 3.45mpt. While the oil and electricity have a value of 0.8, and the importance of material extraction as per the interpretation of graphs is 0.5mpt  (Characterization Factor, 2017). 

Interpretation of results and critical analysis:

Conducting life cycle assessment in detail helps out in analysing and interpreting the most significant adverse environmental impact due to PET bottles manufacturing. The network analysis helps to stem out the raw materials and their considerable proportion required to manufacture these bottles. Both of the figures 4 and 5 helps out in analysis and evolution of life cycle assessment. The model for helps out in detailed discussion of the material recovery and the environmental impacts related to the material recovery. Life cycle assessment has many challenges as the interpretation of the above figures. Hence, there is a need to implement better quantification and the coverage of both inputs and outputs. This technique will be reliable and beneficial in dealing with the complex production and the consumption systems required in the manufacturing of PET  (Aymard and Botta Genoulaz, 2017). Also, there is a need to introduce a large amount of data in each life cycle step. This includes all the stages starting from raw material acquisition to that of the processing, transportation, utilisation and the disposal of the waste. The category that favourably impacts these bottles human health can be beneficial if there is a better implementation of the positive pathways for disposing and recycling the bottles to the consumer market. The material flow analysis also helps out in thinking about the management of plastic waste and enhancing environmental sustainability. 

Let us analyse the results that are gained through the above figures. The entire process of manufacturing requires exporting raw materials from India to the UK. It involves production transportation and the manufacturing to referring to the distribution and sales. The distance that is supposed to cover is 6700 km by air. This analysis shows an indication that production of these bottles impacts on the environment highly with 87.6%. This value indicates that the display can enhance the human health category, causing a diverse range of diseases between them. The most significant environmental impact is due to the presence of bisphenol a in these bottles. So it can be interpreted that the production of these bottles required bisphenol a, which can be highly harmful for causing cancer and hormonal problems in humans. The life cycle analysis also shows that raw material extraction is 8.46% corresponding to the production process in network analysis  (Characterization Factor, 2017). 

Along with the human impact, the manufacturing of these bottles also imposes a negative effect on the environment. The allocation of the environmental implications showed that transportation is the significant detrimental effect decreasing the environments sustainability. These damaging effects alternatively decrease the healthy human environment while enhancing health issues like and another hormonal problem. The reason of these health issues is due to the microparticles present in soil, air and water. As a result, these particles are used by human drinking, breathing, and for different agricultural purposes. 

The third impact caused by the manufacturing of these bottles is that it also decreases the ecosystems sustainability. It is due to the excretory waste material thrown into rivers and oceans. The harmful chemicals present in excretory products reduces the sustainability of ecosystem harming the marine population as well. Other wildlife habitats that are present in the ecosystem impacted due to substance that has been disposed off. So the quality of ecosystem is reducing due to the disposed materials in both oceans and the wildlife habitats. 

The entire manufacturing process has a high rate of dependency on sources required in every stage, including all transportation logistics. The energy necessary for the whole process is gained through fossil fuels in the form of electricity (Bisphenol A (BPA), 2020). The entire characterisation impact can be seen in the graphical illustration presented in figure 6. This characterisation figure shows a total of 11 categories and factors that discuss the effects of the entire manufacturing process. These eleven categories includes carcinogens, respiratory organics, respiratory inorganics, climate change, radiation ozone layer, eco toxicity, acidification, minerals land use and the fossil fuels. All these categories are being affected by transportation distance in between India and the United Kingdom. SimaPro helps to provide a detailed analysis of the extraction of raw materials to the production facility and the usage of fossil fuels. Overall the research shows that the production and the transportation are one of the leading reason to reduce the quality of the ecosystem, human health and the environment. 

The extraction of crude oil is one of the primary process involved in the manufacturing of PET bottles. A toxic by product is present due to the extraction of this natural oil. So the manufacturing process includes the emissions in soil, water and air. The fuel required for transportation is also involved in creating toxicity in the environment. As discussed about climate change is also one of the main things involved in the production process of these bottles. A significant level of climate change can be seen due to the toxic bio products environment.

The demand of PET bottles is increasing in the industry, and this product is gaining strength in the market. It is because it is light in weight and resistant to attack by the microorganism and is also not easy to degrade. How many concerns like Reliance on fossil fuels and raw materials are included in the manufacturing process raw material, which is actually crude oil, is decreasing in the environment. The product is not hundred per cent recyclable, and only 27% of these can be recycled. This is all about the in depth interpretation of life cycle assessment (Bisphenol A (BPA), 2020). 

SimaPro is acceptable and highly reliable due to the accuracy of the data and results it present. But some of the assumptions were made regarding the precise weight of materials and the energy consumption in the process of extraction, production and raw materials. 

4.0 Social and ethical dimensions

Despite the multiple benefits of plastic use, plastics raise several environmental concerns throughout their life cycle, and PET is considered non biodegradable plastic (Milios, Esmailzadeh Davani and Yu, 2018). Depending on non biodegradable materials, there are specific assessments of the impact of PET production, transportation and processing on society and the environment. Most plastic bottles are made of PET, polyethylene terephthalate, which is part of a thermoplastic polymer  (Characterization Factor, 2017). 

During the PET plastic bottle production process which requires fossil fuel based resources, for example, oil and natural gas. Fossil based resources are finite and negatively impact the environment throughout the extraction, production, and utilisation processes (Milios, Esmailzadeh Davani and Yu, 2018). Fossil fuel based resources are non renewable energy and incomplete combustion that can contribute to climate change and greenhouse gases. The emissions are aggregated into the following potential impact categories: global warming, acidification, eutrophication, photochemical ozone formation and many toxic impact categories including eco toxicity in water and soil and human toxicity via soil, water, and air (Rigamonti et al., 2014). Toxic chemicals mainly cause the effects of PET on human health. A direct exposure to humans, initially by extracting and transporting PET by inhaling and taking certain chemicals, such as benzene, VOCs and various toxic substances in a fracturing fluid, can affect the immune system and some types of cancer. PET production then consists of hazardous substances such as benzene, PAHs and styrene, when they enter the human body through inhalation, ingestion, contact with skin, air, water and soil—irritating to eyes and skin, cancer and problems with the reproductive system, resulting in weight loss at birth.

The recycling of these PET bottles will help the people use it efficiently as the use of these bottles has many needs. Many recycling industries come forward to recycle and reuse these PET bottles. Reducing waste will create safe environments by the improvisation of waste management through recycling process. In the recycling or waste management of PET, including heavy metals, dioxins, and other toxic waste from the recycling process like Phthalates and bisphenol A (BPA), it can cause fertility problems and heart diseases. It is exposed to the human body by ingestion and inhalation of ash or slag. Communities or individuals who have homes near industrial facilities such as landfills are at high risk of toxic effects on their bodies when inhaling toxins in the air or using freshwater. A canal that receives wastewater from enterprises, which then use it for cooking, cleaning and growing, can also lead to water pollution. This can cause severe symptoms in the future. Furthermore, industrial noise can adversely affect the social life of community residents  (Aymard and Botta Genoulaz, 2017). 

Depending on the impact of PET plastic bottles in different processes, industries or manufacturers must be held accountable for people in the community, including protecting workers health, ecosystems such as birds and fish that die for the erroneous search for food and the use of plastic bottles. Emphasise concerns about the impact on society and the environment. Also, the products useful life and the social and environmental consequences for enhancing sustainability in the community should be taken into account before choosing a product.

5.0 Future work and recommendations

            Future work will include considering an alternative such as Polylactic acid to prepare these bottles. This will be a hundred per cent biodegradable as it requires 65% less energy and it also generates 63% of the less greenhouse gases than PET.  Another alternative material used here is a stainless steel or a glass grade as they are competent for food and beverage use. Using this alternative is highly beneficial as it will reduce the landfill impact and decrease the demand of sourcing raw materials and transportation. Stainless steel has a shelf life of 15 to 25 years while glass has an indefinite life span if not broken. While on the other hand, the shelf life of PET is only 6 to 12 months before putting it into the landfill. Decreasing the transportation is also a beneficial recommendation because it will help reduce the environmental risk, human health issues, and the resources. Renewable energy can be used here instead of fossil fuels because it is more readily available. However, more research is required to consider both the ethical and the social aspects of the industry regarding sourcing materials from different countries like India, Africa and Asia   (Characterization Factor, 2017).

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