Project Overview

Problem:

In 2013 alone, 8.3 billion K-cups were produced, which is enough to wrap around the equator of the Earth 10.5 times. Due to the combination of #7 plastic, a paper filter, an aluminum lid, and ground coffee inside the cup, it is not recyclable. All of the components end up in landfills, despite all of them except the plastic cup being individually recyclable or compostable. Not only are K-cups bad for the environment, they are also expensive costing consumers around 68 cents per cup vs. 44 cents per cup from bagged beans. 54% of Americans over the age of 18 drink at least three cups of coffee each day, on average, and because of its convenience the Keurig machine has dominated the market for these coffee-drinkers. We sought to design a coffee machine that would utilize bagged beans to enhance its sustainability, but would clean itself in order to provide the convenience that consumers expect and desire.

Solution:

As part of an Industrial Ecology class, a teammate and I deconstructed the Keurig machine to learn about all of its parts and mechanisms. We then performed an "EcoAudit" on the machine's components to determine its energy requirements, water usage, and carbon footprint, and re-designed it to be more sustainable. The key components of our re-designed coffee machine were a bamboo casing, cork insulator, and a self-cleaning system to allow for use of unpackaged coffee grounds. I earned a citation for academic excellence in the class, for "excellence throughout the course: active participation in class discussions, high quality assignments, and creativity and attention to detail above and beyond expectation in the term project and presentation.”

Design Process

Keurig Machine Deconstruction

My teammate and I deconstructed a Keurig machine and sorted through all of its parts over the course of 8 hours (only a fraction of the parts are shown here!). We then performed an EcoAudit on the components and determined that between its materials, manufacturing, transport, use, and disposal, the Keurig machine required approximately 6,900 MJ of energy and 11,000 L of water, and produced a 413 kg carbon footprint.

K-Cup Components

The K-cups utilized by Keurig machines are dismally unfriendly to the environment, given their #7 non-recyclable plastic and their detainment of compostable paper filters and coffee grounds. During our analysis, we found that a large portion of the Keurig machine's carbon footprint was a result of the use of K-cups. A key focus of our project was to eliminate the need for K-cups by incorporating a convenient way of using bagged coffee beans.

Design Matrix

To determine which other components of the coffee machine we wanted to change, we carefully assessed their functions, constraints, and free variables, and determined what our objectives would be for their re-design.

Materials Analysis

We focused our re-design of the product on the phase of the product's life that consumed the most energy and water: the use phase, when consumers utilize the product to brew their coffee. We honed in on the insulation component and performed a thermal analysis on various materials to determine that cork would be the optimal material. This analysis included comparison of thermal insulation vs. embodied energy (1), thermal insulation vs. CO2 footprint (2), and embodied energy vs. price (3), among other metrics. We additionally decided to replace the ABS casing with bamboo through a similar analysis.

Self-Cleaning "Works Like" Prototyping

A key component of our design was the self-cleaning system that would allow the user to brew their own coffee from a bag, instead of coffee grounds in a K-cup. We utilized a vacuum to perform an initial cleaning of the coffee chamber, which we tested with a shop vacuum attachment with a mesh filter in the end to represent the coffee chamber. This vacuum was able to effectively remove coffee grounds from this "works like" prototype, but we realized we needed to add another component to completely clean the chamber.

Model of Self-Cleaning System

Our final design included of a vacuum plus high-pressure air nozzles to completely clear the coffee chamber of grounds after each use.

Sustainable Coffee Machine