Tissue paper production and consumption is an energy and chemical intensive process that leads to the use of more than 425,000 tones of tissue paper annually. With the rise in use of tissue paper such as cover toilet papers, kitchen paper towels, wipe and napkins and other categories that can be manufacture from recycled paper, the demand for the raw materials continue to rise in the contemporary world. If this only refers to the tissue papers, it is inevitable that paper making in general has the potential of impacting both social life and environmental quality. This implies that the paper production process has to be optimized through the use of strategies that focus on cost minimization and environmental preservation. The fibrous materials that are used in paper production from virgin pulp are obtained through environmentally degrading methods such as deforestation. The paper manufacturing industry therefore requires planning and effective application of sound strategies for environmental preservation.
In order to fully understand the environmental and social impacts of paper production supply chain, a life cycle assessment is imperative. Life cycle assessment carried out for a particular product can help in the quantification of inputs to and outputs from the production process, as well as the evaluation of the environmental impacts. The information obtained through a life cycle analysis can be applied in decision making to ensure that sound and informed decisions are made. It can also be used in process improvement as well as in providing literary support to the production policies made by organizations. The process of life cycle assessment involves the analysis of the raw material production process, the manufacturing process, distribution process to the use and disposal strategies for the process. This paper focuses on the paper production supply chain from raw material sourcing to the use and disposal of paper products. The life cycle assessment will include an assessment of life cycle inventories from the inputs through to the output of the process and a life cycle impact assessment which focuses on the environmental impacts and the social impacts of the entire paper making process.
The most commonly applied strategy in evaluating the environmental impacts of any process in the LCA. This strategy is used to evaluate and rate the life cycle environmental performance of any product. Due to the frequent use of this method, it can be assumed that the process is an essential part of environmental impact assessment practices in many regulations. Consequently, this conventional method will be applied in this process to determine the potential impacts of the paper making process.
The Life Cycle Assessment for paper products will be carried out using the conventional method proposed and used by Masternak-Janus and Rybaczewska-Blazejowska (48) which involves four main phases. The framework includes the definition of the research scope, input and output inventory, impact assessment for all the inputs, process and outputs and finally an interpretation of the results obtained through the study. The framework used is shown in the diagram below.
Figure 1: The Life Cycle Assessment Framework (Masternak-Janus and Rybaczewska-Blazejowska 48)
Goal and Scope of the Analysis
The key objective of carrying out this study is to determine the environmental and social impacts of paper making supply chain. The main process in reference is the process of manufacturing paper products from virgin pulp. In order to achieve this objectively entirely, the life cycle analysis of paper products will help to confirm the value of LCA in the evaluation of process effectiveness. This particular project will encapsulate the entire paper making supply chain from the raw materials collection points to the final product use and disposal point. As such, it can be considered as a cradle to grave analysis (PWC 3). The targeted outcomes include proposal of new strategies that can be used for the improvement of the paper making process and management of environmental impacts of the process. The scope of the study derives from the key objective of the study in that the exploration of the environmental and social impacts of the process can only be effective based on a cradle to grave approach to LCA. The production process used is the most commonly used in the paper production industry and thus the one with the greatest need for improvement and impact analysis.
To effectively address the objectives of the research, the study takes one tone of paper products as a functional unit for the analysis. The functional unit is essential to the study as it provides the opportunity for scaling the results obtained and thus application to a wide range of manufacturing capacities and also the consumption of different countries. The use of a functional unit in the LCA also enables the comparison of processes. For instance, in order to determine the comparative environmental impacts of paper production from virgin pulp with that of paper production from recycled materials, it is mandatory to use the same functional unit. The decision to use a single unit for functional purposes is based on the ease with which scaling can be achieved from a unit approximation.
System boundaries and processes
The system to be studied thus begins at the point of wood logging to the point of product consumption which may also be the point of product disposal. The life cycle of the production of paper from virgin pulp begins from the point of wood logging and goes through the chemical and pulp making processes, paper production and lastly use and disposal of the paper. To completely comprehend the impacts of the paper making process, it is critical to consider all the points of production. In this study, the defined system boundaries imply that the analysis will involve consideration of the raw material collection process and its impacts, the chemical and pulp making processes and their impacts through to the disposal of the used paper products. The Cradle to grave approach described by Sappi (4) can effectively be used to achieve the objectives of the study. The paper production process is carried out in two major units i.e. the stock preparation unit and the paper making machine. The stock preparation involves sloshing of fiber, removal of impurities and the refining of the purified fiber. This is followed by the paper making process which involves formation of paper and determination of paper properties (Masternak-Janus and Rybaczewska-Blazejowska 49). Figure 2 below presents the paper production process based on virgin pulp.
Figure 2: Paper manufacture from virgin pulp summary
Life Cycle Inventory
The paper manufacturing process is characterized by the consumption of various substances and release of many more. The environmental and social impacts of the process can be made more comprehensible through an understanding of the various emissions that come from the process. The manufacture of paper from virgin pulp is an intensive process that consumes both electricity and fossil fuel energy through the combustion processes that occur. The energy consumption rate of the process makes it impact the environment immensely through various factors. Life cycle inventory will help to understand the different process inputs and outputs for the entire process and the importance of such inputs and outputs to the process. The compilation and quantification of the materials involved in the cradle to grave process of paper making was carried out based on a framework somehow similar to that used by Masternak-Janus and Rybaczewska-Blazejowska (50). An inventory analysis of the process can be described using the model shown below.
One of the key inputs to the process of manufacturing paper from virgin pulp is the energy. The process consumes electricity through the national grid as well as fossil fuel energy such as gas, coal and oil which is used for the production of steam for electricity generation as well as for the entire process. The process typically uses raw materials which include virgin pulp from wood, resins and starch for strengthening purposes. In addition to this, the process also consumes water and additives. The water taken in is for cooling and process functions while the additives include dyes, fixing agents, and other additives. Their role is to develop the desired product qualities. All these inputs have different environmental and social impacts. After the manufacture of paper, the process gives various products. The key process outputs include paper products, waste and other polluting outcomes. Organic salts, absorbable organo halogens, phosphorus, nitrogen, and suspended solids form an essential part of the production process outputs while air emissions are also inevitable. Emissions such as sulphur IV oxide, carbon IV oxide, Nitrous oxides and carbon monoxide are the major gaseous products. Dust is also produced in the process depending on the type of fuel supply and the need for energy consumption (Sappi 4).
Life Cycle Impact Analysis
The life cycle impact analysis for the paper production process was carried out based on a procedure highlighted by PWC (13). The process involves categorization of environmental impacts depending on their degrading or nourishing capabilities of the environment. The key categories of impacts that are considered herein include water emissions, air emissions, and primary consumption of energy, resources depletion and impacts. The process involves consideration of all the processes occurring from the point of logging to use and disposal of the paper products. For this analysis, the stages of manufacturing will be followed to identify key environmental impacts and then reported on based on the different categories of impacts.
Air emissions into the environment from the paper manufacturing process can be considered detrimental to the environment. This is because such releases have very negative impacts in terms of environmental degradation. For instance, Sappi (3) highlights the impacts of the paper manufacturing process on acidification. From the previous sections of the report, the key emissions that can be related to the process of acidification include nitrous oxides, sulphur IV oxide, carbon IV oxide and CO. These gaseous products which are released from the chemical and pulp making processes as well as from the raw material processing stages all contribute to rain acidification when absorbed by rain drops from the environment. Moreover, the gaseous products also result in the deposition of acidic particulate matter on surfaces and on land, factors which affect the environmental quality. Additionally, the air emissions also result in global warming as they are held within the lower atmosphere as greenhouse gases and subsequently trap heat within the environment. Other impacts include ozone depletion and causation of respiratory infections.
Needless to say, air emissions from the paper manufacturing industry also result in various social impacts. For example, the increased risk of respiratory infections caused by inhalation of gaseous releases reduces productivity among the industry workers. Furthermore, it also results in the decrease of income levels in households since the respiratory diseases prevent others from continued employment. The air emissions from the industry should therefore be reduced and only left at allowable environmental emission standards.
Another factor considered in this analysis is the release of waste substances into water sources. The major sources of water releases in the paper manufacturing process are the chemicals and pulp making processes and the paper making process. These stages result in the release of substances such as starch, resins, dyes and fiber through the effluent streams. The substances released into water have the potential of creating impacts such as eutrophication especially where the releases are nitrate laden. This interferes with the quality of water in the water bodies and has the potential of negatively impacting aquatic life. Additionally, this also disrupts the aquatic ecosystem through changes in pH and chemical loading. Besides, water releases also result in the modification of the water systems through increase of BOD and Chemical Oxygen Demand (COD) within the effluent treatment systems. According to Sappi (3), the presence of BOD and COD results in oxygen depletion within the water bodies and organic loading in the water systems. The water releases also increase the toxicity of the water hence resulting in the death of some of the aquatic organisms. Loading water bodies with heavy metals such as calcium which are prevalent in the chemical making process also results in negative effects for humans consuming the water.
Energy consumption in the paper making process involving the use of virgin pulp is also one of the reasons behind the negative environmental impacts related to air emissions. The process uses energy from the national grid. The process through which electricity is generated can be environmentally degrading especially where fossil fuels are used for the generation. In addition to this, energy consumption during the ‘Through Air Dying Process’ used in the paper making industry also has very environmentally degrading effects since it is and energy intensive process that consumes natural resources. Fossil fuel combustion during transportation and wood logging also increase the gaseous emissions to the environment making the process environmentally degrading (PWC 14). Finally, the manufacture of paper also results on the depletion of natural resources. For instance, the first stage in the manufacturing process involves wood logging which is environmentally degrading as it is a form of deforestation. Apart from this, other resources such as energy and water are also consumed during the process. Impacts of the process on the environment include the release of noise, solid wastes and heat during the process. All these affect the environment in particular ways.
Apart from the environmental impacts of the paper making process, various social impacts can be related to the process. The environmental impacts identified are mainly negative. However, most of the social impacts that can be recognized are positive. For example, the process of paper manufacturing creates employment for numerous people; both skilled and unskilled labor is provided. Additionally, the process also helps through provision of paper for various uses. Paper uses are so many that it can almost be said to be a primary need in human life. For one, tissue paper uses alone are so diverse that they are applied in every sector; printing papers are also a mandatory part of every work environment while writing papers are an indispensable part of school life. Other purposes such as decoration and storage for which cartons are used cannot be ignored too. However, paper products are also blamed for littering although this is somewhat a problem caused by the users of these products. The disposal of paper products can be linked to positive environmental impacts for two key reasons which include the applicability of the wastes to recycle and biodegradability. Disposed paper products can reduce the negative environmental impacts when recycled through reduction of wood logging, energy consumption and release of toxic gases into the environment. For those paper products that are not taken for recycling, the biodegradable nature of the products makes them an essential input to the soil through nutritional improvement.
Results and Interpretation
The Life Cycle Analysis for paper products was aimed at determining the environmental and social impacts of the process from wood logging to the use and disposal of paper products. From the analysis carried out, the process inputs with the greatest environmental impacts per ton of product received include the combination of electricity, heat, resin and starch which produce more than 92.08 of the total environmental impact of the material used in the process. On the output side, the air emissions contribute the greatest environmental impacts. The paper making stage which involves making changes to the grade and color of paper also contributes to reduced efficiency of raw material usage which makes resource depletion rates increase. The use of electricity in the industry overrides the other categories of environmental impact such as air emissions, water releases and land and resource depletion. The impacts of different aspects in paper manufacturing from virgin pulp are shown in the chart below.
Figure 3: Tissue Paper Production from Virgin Pulp Characterization (Masternak-Janus and Rybaczewska-Blazejowska 51)
Although the chart represents the tissue paper production impacts, it can be used to hypothesize the impacts of the other paper products since tissue paper is the most cost effective of all paper types. From the chart, it can be seen explicitly that the electricity consumption affects the environment in the greatest way as previously explained.
The Life Cycle Assessment process was aimed at determining the environmental and social impacts of the paper making process. The research carried out has effectively established that manufacturing paper from virgin pulp results in great environmental and social impacts. The environmental impacts of the process are contributed to mostly by electricity, resin and starch. The environmental impacts associated with the process include air emissions, water releases, energy consumption and resource depletion. Other wastes such as organic substances, absorbable organo halogens, nitrogen and phosphorus are also prevalent in the paper manufacturing process. Air emissions from the paper manufacturing industry such as nitrogen IV Oxide, Sulphur IV oxide, carbon monoxide and carbon IV oxide which result in acidification, global warming, respiratory effects and ozone depletion all arise from the manufacture of paper from virgin pulp. Using the information received from the LCA, the process can be improved through various ways. Although the process itself cannot be changed to suit the findings of the LCA, improvements in safety procedures can be made. For instance, installation of dust removal systems such as aspirators and cyclones, and effluent treatment procedures can reduce the environmental impacts of the process.
Masternak-Janus, Aneta, Magdalena Rybaczewska- Blazejowska. Life Cycle Analysis of Tissue paper Manufacturing from Virgin Pulp. Management and Production Engineering Review 6, 3(2015): 47-54.
PWC. Life Cycle Assessment and Forest Products: A White Paper. Forest Products Association of Canada, 2010.
SAPPI. Life Cycle Assessment of Paper Products: Part One. The Basics 4, 1(2012).