Example LCA Study, Part III -- Comparison of Two Air Dusters

In Part II, I listed all the data used in SimaPro for the analysis and also included diagrams for the system boundaries.

In this part, Part III, I share the results of the study. I just wanted to note again that the results of this study have not been peer-reviewed and are not intended to be used in decision-making processes.

To recap the process, for each duster, I entered my data into SimaPro and chose the output to be normalized results. After running the program (analyzing the data), I then exported the data from SimaPro to an Excel file that included a table of results: Rows of impact categories and columns of materials/processes. For each impact category and material/process there is a corresponding cell with a number representing the impact. In order to adjust this data to the functional unit, I divided each cell by the number of two-minute dusting sessions I calculated in Part I (12.5 for the gas duster and 96 for bulb duster). I was then free to visualize the data any way I wanted to. Here is how we visualized the data for class:

Figure 3. Impacts of the dusters by impact category when considering the number of two-minute dusting sessions per lifetime of each product (12.5 for the gas duster and 96 for the bulb duster).

Figure 4. Impacts of the dusters by life cycle stage when considering the number of two-minute dusting sessions per lifetime of each product (12.5 for the gas duster and 96 for the bulb duster). It should be noted that use impacts were not included in the study boundary.

You can see from Figures 3 and 4 that the gas duster has a greater impact over the lifetime of the products. Freshwater ecotoxicity is the biggest impact for the gas duster and the life cycle stage with the greatest impact is the material production phase.


Because the impact of the bulb duster was so small compared to the gas duster, it was difficult to see in the above graphs the details for the bulb duster. Therefore, I made additional graphs that just show either the gas duster or the bulb duster and how big of an impact each material or process was. Grayed out text in the graph legends indicate that the amount was so small that it doesn't visually show up on the graph.

Figure 5. Relative impacts of each of the processes or materials in the making of the gas duster. Grayed out text indicates that the impact was too small to show up on the graph.

Figure 6. Relative impacts of each of the processes or materials in the making of the bulb duster. Grayed out text indicates that the impact was too small to show up on the graph.

In Figure 5, we see that the creation of the steel for the gas duster can and the creation of the gas create the biggest impact. In Figure 6, we see that the landfilling of the bulb duster and the creation of the rubber bulb (rubber + molding) creates the biggest impact.

Example LCA Study, Part II -- Comparison of Two Air Dusters

In the previous section, Part I, I explained the background for this study. This section, Part II,  includes all of the data used to conduct the LCA, plus the systems boundary.


The following two tables are the data collected and used for each duster product. Note: The process data for tin plated chromium steel was altered to reflect a recycled content of 20%.

Table 1. Data used for gas duster.

Table 2. Data used for bulb duster.

The following two figures are systems boundary diagrams for the two duster products. Note: I did not follow typical convention in creating these diagrams. Arrows indicate a process and boxes indicate a material or process. Solid arrows/boxes indicate that the process/material was included in the study. Dotted arrows/boxes indicate that the process/material was NOT included in the study.

Figure 1. System boundaries for the gas duster.

Figure 2. System boundaries for the bulb duster

In the next section, Part III, I will share the results of the LCA. 

My Visit to the Green Festival in NYC

I m spending some time in New York City right now and went to the Green Festival there. Here are my picks for the most intriguing finds:

1.  HankyBook  – Hanky book is exactly what it is – a book of little handkerchiefs. This little book sections off pieces of handkerchief to blow your nose on and keeps them neatly packed inside a printed covering.  It is easier and neater than trying to fold over a traditional handkerchief after each use, in order to keep you face, pocket and/or purse clean.
2. Care&s (pronounced “care ands”) – Anyone who had read my blog posts on crystal deodorants know that I am drawn to concentrated products. This one caught my attention, because it is the smallest does of laundry detergent I have seen and it reduces user-error by being pre-dosed. This product reduces packing, eliminates plastic packaging, reduces shipping weights and volumes, and decreases the chance of consumers adding too much detergent to the wash.
3. My Conscience, My Choice -- The founder of this site is working on an app that allows users to scan a product’s bar code and then the app suggests an alternative/equivalent product that is more environmentally and socially conscious.
4. Michelle Leon vegan belts and bags -- This fabric feels just like suede but is made from recycled film. The products are quite pricey, but will last a very long time because of the durability of the fabric. In addition to concentrated products, I am also a big fan of durable ones.
5.  ReFleece – ReFleece turns old fleece into cases for our I-thingys and ebooks. ReFleece even plans on starting a Kickstarter campaign, where you can get YOUR old fleece made into an IPad case or whatnot.

Happy Springtime Everyone! Peas-out!

Example LCA Study, Part I -- Comparison of Two Air Dusters

In my last semester in graduate school, I took a class on LCA. My semester project was a comparison of two different products that use a stream of gas for dusting purposes (a gas duster and bulb duster). Here is a summary of my project. My goal in this blog post is to give an example of one way to do LCA. I also hope to link some of the terminology to a separate blog post for definitions and explanations.

Part one of this blog post includes the general information for the study.

Overview of Materials and Methods

Two products were analyzed in this assessment: 3M DustRemover (10 oz) and Giottos AA1900 Rocket Air Blaster (Large).

Figure 1. Dusters analyzed in this assessment with their retail packaging (“gas duster” on the left and “bulb duster” on the right.

The tools used to conduct this analysis included a kitchen scale, measuring tape, stopwatch, SimaPro 7.3 software, and Microsoft Excel software.  Each product was disassembled and weights and/or dimensions were taken (including packaging) with the kitchen scale and measuring tape. For the gas duster, the time to empty the canister was measured using a stopwatch. The guidelines in ISO 14040:2006 were used for conducting the LCA. SimaPro 7.3 software was used to conduct the actual LCA: measurement data were entered into SimaPro, software-embedded environmental data (process data) were chosen within SimaPro, and all the data were then analyzed (normalization) by SimaPro. The results were then exported from SimaPro into Excel. Excel was used to make the functional unit adjustment to the SimaPro results and to create the data tables and graphs.

Goal

The goal of this assessment is to compare the life cycle impact of each duster. The intended audience for this assessment is Phillip White’s Problem Solving with LCA class. The results of this study have not been peer-reviewed and are not intended to be used in decision-making processes.

Functional Unit and Lifetime of Each Product

The functional unit in this study is product typical amount of time spent dusting, which is arbitrarily set at two minutes. The chosen frequency of a two-minute dusting-session is once per month.

Gas Duster

Through experimentation, I found that the gas duster lasted for 25 minutes before running out of gas. This experiment was generally conducted by using a stopwatch while using the duster to dust various things.

Because the gas in the duster “runs out”, its lifetime is calculated from the number of minutes it lasts (25 minutes) and the expected use pattern (two minutes per month):

Lifetime_{gas_duster} = 25 min dusting x (1 dust session/2 min dusting) x (1 year/12 dust sessions) = 1.042 years.

The calculation for the service lifetime for the gas duster is just the number of minutes it lasts (25 minutes) adjusted for the functional unit of two minutes of dusting per dusting-session:

Service Lifetime_{gas_duster} = 25 min dusting x (1 dust session/2 min dusting) = 12.5 dusting-sessions in the lifetime of the gas duster.

Bulb Duster

The bulb duster is a different case from the gas duster. The air in the bulb duster does not “run out”, but the bulb duster will not last forever. The rubber will wear out or the consumer will stop using it or replace it with a different duster after a while.

In this study it is assumed that the bulb duster will be discarded after eight years of use. Therefore, the lifetime of the bulb duster is straightforward:

Lifetime_{bulb_duster} = 8 years.

For the bulb duster, the expected use pattern (two minutes per month) is needed to calculate the service lifetime along with the expected lifetime of the product (eight years). Therefore, the service lifetime for the bulb duster is as follows:

Service Lifetime _{bulb_duster} = (2 min dusting/1 month) x (12 months/ 1 year) x 8 years x (1 dust session/2 min dusting) = 96 dusting-sessions in the lifetime of the bulb duster.

Data and Methods Used in SimaPro

SimaPro 7.3 was used for this analysis. The impact assessment method chosen was CML 2 Baseline 2000 v 2.04 (excluding marine ecotoxicity), with 1995 Global normalization and no weighting. CML 2 was used because it uses scientifically based midpoint values and does not have the complexity of choosing cultural perspectives for characterization (Recipe method). The following process data from SimaPro was used: ecoinvent system processes, Industry data 2.0, and ELCD. The only case where the process data match up geographically with the life cycle is in the case of the electricity data for China (for manufacturing of the products).  Interpretation in this analysis includes contribution analysis (normalized percent contributing elements and impact categories) and sensitivity analysis.

Geography and Time Period Used

The locations of manufacturing and distribution were chosen based on information on the product label, company website, and general knowledge about manufacturing. For example Guangdong Province was chosen as the manufacturing location for manufacturing in China, because it is known as a manufacturing hub for consumer goods. The chosen location for consumption and disposal was the USA.

The earliest date of the impact assessment method used is 1995. The unit process data are assumed to be recent (within the last ten years). The bulb duster has a lifetime of eight years. Therefore, the time period of the study starts in 1995 with the date of the characterization method and ends at the end of the lifetime of the bulb duster – eight years from the present, which is 2020.

In the next section, Part II, all of the data used are given and the LCA system boundary is described.