9.+Life+Cycle+Assessment

9.2 Introduction
====Life-Cycle Assessment (LCA) is a method used to measure the energy use and waste associated with the production of a product or process from cradle to grave (see chapter 6: //Cradle to Grave.//) LCA involves making detailed measurements of the whole process of manufacturing of a product starting with the mining or harvesting of the materials used and ending with the final disposal of the product. The International Organization for Standardization (ISO) defines LCA as, “compilation and evaluation of the inputs, outputs and the potential environmental impacts of a product system throughout its life cycle." ==== ====Similar life cycle methods in the past have not considered second generation impacts, such as the energy used in building a kiln used to manufacture raw materials. LCA is the only method to assess the environmental, social and economic impacts of a product over its entire life span (see chapter 7://Triple Bottom Line//.) LCAs allow manufacturers to quantify how much raw material and energy is used and how much solid, liquid and gas waste is generated at each stage of the product’s life. Stages may include:====

[[image:Life cycle image.jpg width="313" height="253" align="right" caption="figure 9.1 Stages of life cycle assessment"]]

 * ====Extraction and treatment of raw materials====
 * ====Material Processing====
 * ==== Manufacturing and packaging ====
 * ==== Transport and distribution ====
 * ==== Product use and storage ====
 * ==== Disposal, including recycling ====
 * ==== End of Life ====

====The ultimate goal of the LCA is to reduce the environmental impacts of products and processes by setting a decision-making standards for companies, governments and designers to implement sustainable practices and development. Up until recently, product designers have been primarily concerned with process of life cycles up to and including the manufacturing step. New standards encourage product designers to consider how their products will be used by customers and what environmental hazards might arise. They must also consider how their products are to be recycled. Special consideration must be taken to avoid contaminating soil, water and air where the products are manufactured.====

** 9.3 Metrics of LCA **
==== There are numerous tools used to assess and analyze life cycles. These tools fall into two types: input-output analysis tools and process-based analysis tools. I nput-output LCA relies on tools that have become widely used by economists. These economic input-output tools segment national and regional economies into sectors and follow the flows of money. Input-output analysis can also be used to provide an estimate of the total energy or carbon emissions of a product. Process-based life-cycle assessments follow supply chains.====

**9.4 Assessing the life cycle** **of a product:**
====There are four steps used to analyze the life cycle of a product or process: //Determine the Scope and Boundaries, Life Cycle Inventory, Life Cycle Impact Assessment// and //Improvement Analysis or Interpretation.// These steps are defined below:====

1. **__//Determine the scope and boundaries//:__**
====The first step in a LCA is to determine the scope and boundaries of the assessment. One must identify the reason for conducting the assessment as well as the product, process or service being studied and the functional unit that will be used. A functional unit is used as a reference unit to describe the performance of the product systems. It is especially important to identify a functional unit when comparing two products (//paper vs. plastic),// this creates equivalence between the two products. System boundaries must also be established during this stage, which means the limits placed on the data collection of the LCA. Setting boundaries becomes complicated in that the more in depth the research, the better results, but cost and time are critical components of the study and must be considered when establishing boundaries. Creating a budget may help in setting realistic system boundaries.====

[[image:process.gif width="290" height="214" align="right" caption="figure 9.2 Common inputs and outputs of a process"]]**2.** //__**Life cycle inventory**:__//
====The second, and often most data intensive and time consuming step of the LCA process is called //Life Cycle Inventory.// It is during this step that the inputs and outputs of the product's life cycle are addressed. Inputs include: raw materials, energy, chemicals and anything else that is required in the processing of the product. The outputs include: the product, by-products, emissions, solid waste and any other results of the process. Collecting inventory on processes can be very tedious because there are often hundreds of inputs and outputs associated with the LCA of any one product.====

**3. __//Life cycle impact assessment//__:**
====Once an extensive inventory of inputs and outputs has been compiled, an assessment of the environmental impacts must be done. This step is called the //Life Cycle Impact Assessment.// The impacts assessed often include: environmental impacts such as deforestation, solid waste generation and smog formation; natural resource use such as water, energy and mineral use; and sometimes social impacts such as employment.====

**//4. __Improvement analysis or interpretation:__//**
====The fourth and final step in a LCA is called //Improvement Analysis or Interpretation.// As the title suggests, the purpose of the final step is to interpret the results of the LCA and offer suggestions for improvement. If the LCA was conducted on a single produce, design modifications that might improve environmental performance may be suggested. If the LCA was done to compare two similar products, this step might consist of suggesting the more environmentally desirable product.====

9.5 Case Study: Coffee
During our visit, we were able to witness first hand the roll that coffee plays in the culture, economy and land use of Costa Rica. In 2006, coffee was said to be the third most common and single most economically beneficial export from Costa Rica. Because of its importance not only to Costa Rica, but to most of the world, it is important to understand the environmental implications associated with coffee production in order to improve the current system.

Cradle to Grave: Coffee
Coffee must be grown and treated before it can be consumed. It takes about 4 to 8 weeks from the time the coffee bean is planted until a seedling appears. At that point it is placed in the shade where it can be protected from the sun’s harmful rays. Once the coffee plant reaches two feet, roughly 9 to 18 months later, it will be planted in the ground. It takes 3 years until the tree will produce fruit, and 6 years until it has reached maturity. A coffee plant will continue to produce fruit for 20-25 years. At the growing and treating stage of coffee’s lifespan the main environmental costs are water, land use and fertilizer.
 * __Growing and treating coffee__**

__**Transportation**__ Transporting of coffee beans occurs multiple times over the course of its lifespan. It is transported as a raw bean to be dehusked and dried, then to be roasted, again to be processed and packaged and at least once more to be sold at the market. A large portion of coffee production costs and emission are from transportation. The coffee is usually transported by ship and truck.

__**Roasting**__ Coffee is roasted right before consumption to enhance the flavor of the beans. The bea ns are roasted anywhere from 3 to 30 minutes at temperatures between 188 to 282 degrees Celsius depending on t he darkness of the roast. Light roasted coffee maintains the original flavor of the raw bean, while dark roasted coffee takes on the flavor of the roasting process. This roasting process requires a lot of energy and water.

__**Brewing**__ There are numerous ways to brew coffee, but all of them require the beans to be ground and water to be heated. This process often requires electricity.

__**Coffee Grounds**__ Coffee grounds must be disposed of after brewing. The three most common disposal methods are; waste water; solid waster; and recycling, or composting. When the coffee grounds are dumped down the drain, they are transported to the waster water treatment plant. There they are separated from the water and treated according to that plants protocol. Grounds that are placed in the trash end up in the landfill or solid waste facility. Coffee grounds that are put into compost bins will quickly break down due to the small size of the grounds. They will enrich the nitrogen content of the compost. The environmental impact of this stage varies greatly depending on the disposal method used.

9.6 LCA Results:
A LCA was conducted on the production of coffee to identify: 1) energy use 2) water use and 3) carbon emissions. Below are the results of the study:

__**Energy:**__ Table 1 presents the amount of energy required during each process. To produce one cup of coffee, roughly 1.94 Mega Joules of energy is required. This is about the same amount of kinetic energy as two school buses traveling 50 mph. The majority of energy is required at the end of the life cycle, where the coffee is brewed. Much of the loss of energy is due to the fact that large plants have ways of reclaiming energy, consumer products do not. Water is a large component in the growing, processing and preparation of coffee. Irrigation is the largest water user in the whole process, using 25 liters of water per one cup of coffee. That is 250 times the amount of water as a single cup of coffee. Table 2 shows the amount of water used in each process.
 * __Water Use:__**



__**Carbon Emissions:**__ The carbon emissions are measured based on a European energy mixture for vehicle fuel, energy use, processing procedures etc. Table 3 shows the amount of carbon emissions for each part of the process, equalling 114 pounds of carbon dioxide equivalent per single cup of coffee produced. Cultivation, brewing and washing are the most notable carbon emitters. Carbon emissions coming from cultivation are largely due to diesel farming equipment. Carbon emissions from brewing and washing are due to the power plants that provide energy to heat water.

9.7 Conclusion
A LCA is a method used to measure the energy and waste required over the entire lifespan of a product or service. This assessment can be especially beneficial to businesses that wish to decrease their carbon footprint. To conduct a LCA one must follow the four phases of a LCA: 1) determine the scopes and boundaries of the assessment 2) collect inventory of all the inputs and outputs associated with the product being assessed 3) determine the environmental impacts based on the inventory collected 4) Interpret results and offer suggestions for reducing harmful impacts. These four steps must be used in each stage of the products lifespan, from cradle to grave.

9.8 References

 * Allen, David T., and David R. Shonnard. "Risk and Life-Cycle Frameworks for Sustainablilty."//Sustainable Engineering//. USA: Pearson Higher Ed, 2011. 2.3.1.-2.3.2. Print.
 * ===== Heller, Martin C., and Gregory A. Keoleian. "Life Cycle-Based Sustainability Indicators for Assessment of the U.S. Food System."//Center for Sustainable Systems// (2000): 59. Web. =====
 * "LCA." //LCA food//. N.p., n.d. Web. 2 July 2012. ."LCA of Coffee."
 * //Appropedia//. N.p., 26 Nov. 2011. Web. 1 July 2012. .
 * Sarté, S. Bry. //Sustainable infrastructure: the guide to green engineering and design//. Hoboken, N.J.: Wiley, 2010. Print.