The need for companies to uphold environmental sustainability in their operations, products or services has posed substantial challenges to environmental professionals, managers and designers. Developing more economically and environmentally sustainable products requires the use of a logical framework as wells as tools, principles, objectives and definitions. One of such frameworks used to ascertain the ecological sustainability of a product is life cycle assessment (LCA), which is a methodology used to evaluate the environmental impacts related to all the phases of a product’s life, that is from the stage of raw material extraction, processing of materials, manufacturing, distribution, usage, repairing and maintaining the product to its disposal. LCA works in three ways: collecting an inventory of the environmental releases, material inputs and relevant energy; assessing the prospective impacts related to the recognized releases and materials inputs; and analyzing the results in order to come up with a more informed decision. According to Baumann (2004), LCA involves four main phases, which include goals and scope, life cycle inventory (LCI), life cycle impact assessment, and interpretation. The goals and scope of the study establishes the study context and elucidates how the results will be communicated.
This study took into account the LCA aspects of a 100 ml cup of coffee. In this regard, this paper identifies all the input streams from the natural environment, all the processes and manufacturing steps for each of the components of coffee, and all the probable outputs throughout the product’s complete use to its disposal (Guinee, 2002).
The main objective of this project is to undertake a life cycle analysis for a cup of coffee. This project at identifying the environmental impacts associated with all the processes from cradle-to-crave relating to the production and use of a cup of coffee (100ml). The following are the specific objectives associated with this project:
- Review all the total resources utilized during the production and use of one cup of coffee including energy and carbon emissions;
Scope of the Study
This study takes into account the complete life cycle for a cup of coffee from the extraction and processing of raw materials through its use and disposal. The coffee sample used for this study is Caffè Americano, which is made by Starbucks. The focus of this study is on the environmental impacts assessment; as a result, the life cycle cost analysis was not a part of this study.
Data Collection and Analysis
This section discusses the environmental analysis of one cup of Caffè Americano. A life cycle analysis was undertaken basing on the guidelines provided by Environmental Protection Agency (EPA). The environmental data evaluated in this study included energy and material consumption including water. Environmental data relating to the production phase of coffee were collected from published sources. Other environmental data were collected by a review of published results.
Life Cycle Inventory Analysis
LCI entails formulating an inventory of the flows to and from the product/service. The examples of inventory flows are raw materials, water, land, releases to air and energy among others. In order to develop an inventory, there is a need to develop a flow model for the processes as well as the outputs and inputs. It is imperative to note that this inventory is specific in the sense that the inputs were measured per 100 ml of coffee, which is assumed to be equivalent to one cup of coffee. Life cycle impact assessment entails assessing the significance of the prospective environmental effects depending on the results of the LCI flow (Guinee, 2002). Interpretation of the results entails quantifying, checking and evaluating information from the life cycle inventory results regarding the impact assessment. Allen & Shonnard (2011) point out that the results obtained from impact assessment and inventory analysis are summarized in the interpretation phase to provide a framework for decision making. Specifically, interpretation entails formulating recommendations and conclusions for the assessment by identifying the issues depending on the results of LCA and LCIA; evaluating the study regarding the consistency checks, sensitivity and completeness; and highlighting the recommendations, limitations and conclusions.
Growing and Treatment
Prior to the consumption of coffee, it should be grown in the farm and then treated. Planting a coffee plant commences with a bean, wherein a bean obtained from the coffee tree is planted in soil. After about 4-8 weeks, the seedling begins to appear and it is placed in a location that is shaded in order to avoid the seedlings from burning due to direct sunlight. When planting, the farmer tends to the seedling for duration of about 9-18 months until the plants are 2 feet long, after which the small coffee tree is now ready for planting in a plantation. The coffee tree bears fruit during its first 3 years; however, it does not attain maturity until after six years, when the tree is wholly mature and is in optimal yield (Innveden et al., 2009). A coffee tree has a lifespan of about 20-25 years of producing coffee.
The function of roasting is to enhance the flavor of raw coffee beans. During roasting, the coffee bean is subjected to chemical reactions aimed at enhancing its flavor and destabilizing the coffee. The destabilized coffee often stays fresh for 1 month whereas the coffee bean remains stable for a much longer period. In this regard, coffee is often roasted prior to selling to the consumer. Roasting coffee commences with separating the beans from the debris that are usually mixed with the coffee beans (Innveden et al., 2009). After sorting, coffee is weighed according to a batch size, after which it is put in a roaster for about 3-30 minutes according to the required outcome. The roasting temperature range is about 188-282 degrees Celsius. The duration for roasting coffee has a substantial impact on the coffee flavor. In this regard, the lesser the duration for roasting, the lighter color of the coffee bean.
Coffee is grown in several parts of the world. A significant proportion of carbon emissions and production costs are derived from transportation. At the processing plants, coffee is often trucked in between the processes and fields. When coffee is shipped off the plant, transportation entails mainly trucks and boats, which consume a substantial amount of fuel (Innveden et al., 2009).
When making a cup of coffee, beans should be ground first to attain the required consistency followed by running hot boiling water over them in a process referred to as brewing. Brewing is done with the main objective of extracting caffeine and coffee flavor from the roasted coffee beans. It is imperative to note that ground coffee should not be boiled together with water since it results in a bad flavor in the cup of coffee. Brewing coffee can be done using three methods: steeping, boiling and pressurization (Crawford , 2011). Steeping coffee is done using a French press, which is a cylindrical glass apparatus having a metal plunger fitting firmly in the glass cylinder. Coffee and hot water are put together in the French press after what they are brewed for duration of about 5-10 minutes. Coffee grounds can be separated from the coffee solution by pressing down the plunger. Steeping results in a stronger cup of coffee since the ground coffee is in contact with the hot water for a relatively longer period of time. The longer the ground coffee stays in contact with hot water, the more the extraction of the coffee oils and flavor is.
Boiling is the oldest technique used for brewing coffee and usually entails mixing ground coffee and water in a pot and then boiling them. Boiling coffee for a long time results in bitter taste. Pressurization makes use of pressurized water and gravity pressure. Brewing using gravity pressure produces drip coffee, which is the most common technique for brewing coffee in the United States. Under gravity pressurization, a filter is often filled with ground coffee after which hot water is slowly passed to flow through the filter. The liquid dripping out of the filter is consumed. Pressurized water brewing (sometimes referred to as espresso) entails heating and pressurizing water, which is then forced to flow through coffee grounds. This brewing method uses more ground coffee per ounce of liquid coffee when compared to other brewing methods (Baumann, 2004).
After brewing one cup of coffee, the remaining coffee grounds should be disposed of as either waste water, solid waste or recycled. The remains of coffee grounds put in trash often end up in regional solid waste facility. The remaining coffee grounds that have been washed down the drain are often transported as waste sewer through sewer lines ending up in the waste water treatment plant, after which the coffee grounds are separated and treated in accordance with the protocols of a particular plant. Recycled coffee grounds are either used to improve soil fertility or composted. Composting of the remaining coffee grounds helps in enriching the nitrogen content of particular compost. Coffee grounds compost relatively fast owing to the small size of individual coffee grounds. When used in enriching soil, coffee grounds release nitrogen, which increases the acidity of the soil. The figure below shows the coffee cycle (Hendrickson, Lave & Matthews, 2005).
Life Cycle Inventory Analysis
The analysis of life cycle inventory for one cup of coffee entails the following:
- Cultivation: this step entailed the collection of literature data, especially for pesticide use, fertilizer and energy. Pesticide and fertilizer production data were gathered from commercially available databases whereas phosphorus and nitrogen emissions were computed using estimation methods. The average production of coffee per one hectare varies depending on the characteristics and types of the land for cultivation and a number of ecological factors such as the age of the coffee plants. According to Guinee (2002), the approximate yield is about 2-6.5 quintals of processed coffee per one hectare. Processing of coffee beans can take place using two methods, wet method or dry method. Coffee berries can be dried using the sun or using machines that consume relatively high amounts of oil of about 0.11 l/kg.
- Processing: processing of coffee mainly entails brewing and packaging. The direct energy and material input during the processing phase include electricity and packing materials. The direct outputs during coffee processing include air emissions and waste water.
- Transport: transportation activities take place at different phases of coffee production include:
- Fertilizers and pesticides transported to farmers;
- Green coffee transported from coffee growers to the processing plant;
- Packaged coffee from the processing plants to the points of sale and wholesalers;
- Disposal: wastes are produced at different stages of coffee production including coffee chaff, packaging and coffee grounds. This study assumed that all these wastes were recycled.
Results and Discussion
This life cycle assessment was undertaken to identify carbon emissions, water use and energy use regarding production and the use of the study. The results for this study are summarized in the following tables. It is imperative to note that processing entails handling and cleaning of green coffee, grinding, roasting, conditioning and filling and packing of coffee.
Energy Required to Produce One Cup of Coffee
The following table 1 shows the amount of energy needed during each of the processes involved in the production of coffee. In order to process and produce a single cup of coffee, about 1.94 mega joules of energy is needed. Most of the energy is needed towards the end of the coffee cycle during brewing. However, a substantial amount of energy is lost, because large processing plants can reclaim lost energy whereas consumers of coffee cannot reclaim the energy lost in the process.
Water is one of the largest inputs used during growing, preparation and processing of coffee. The largest water user during the entire process consumes liters of water for one cup of coffee of about 100 ml. This translates to about 250 times that amount of water present in a single cup of coffee.
This study measured carbon emissions based on the processing procedures, energy use and transport among others. The following table below indicates the quantity of carbon emissions needed for each of the processes in the coffee cycle, which gives a total of 114 pounds of carbon dioxide for one cup of coffee. Washing, brewing and cultivation are the most outstanding emitters of carbon. Carbon emissions as a result of cultivating are relatively large because of the diesel farming equipment. Similarly, carbon emissions emerging from washing and brewing are relatively large because of the energy used by power plants to heat water.
Life cycle analysis can be effectively used to measure the waste and energy required during the lifespan of a service or a product. This assessment can be beneficial for businesses aiming at decreasing their carbon footprint. In order to undertake a life cycle assessment, it is imperative to ascertain the boundaries and scope of the assessment, gather inventory of all the outputs and inputs of the product being evaluated, determine the environmental impacts depending on the inventory gathered, and interpret the results and provide suggestions to mitigate the detrimental impacts. From the study, it is apparent that the coffee cycle involves growing and treatment, roasting, transportation, brewing and waste management. The study has found out that in order to process and produce a single cup of coffee, about 1.94 mega joules of energy is needed. Most of the energy is needed towards the end of the coffee cycle during brewing
The quantity of carbon emissions needed for each of the processes in the coffee cycle gives a total of 114 pounds of carbon dioxide for one cup of coffee. Washing, brewing and cultivation are the most outstanding emitters of carbon. Carbon emissions as a result of cultivating are relatively large because of diesel farming equipment. Similarly, carbon emissions emerging from washing and brewing are relatively large because of the energy used by power plants to heat water.