Team Questions | Mbaran20

1.1. What is a circular economy? Briefly describe with the help of a diagram. Be sure that your

explanation and diagram also include reuse, repurposing, and recycling!

A circular economy is one that is driven by sustainability. Where a linear economy may see a product be manufactured, used, and then disposed; a circular economy is one which would expect to extract as much use from the product, and then subsequently recover any or all material once the uses have been exhausted. Compared to a linear economy, a circular economy considers the lifespan of a product beyond disposal - optimizing products and packaging to minimize the impact or waste. This process can be described by the diagram shown below.

A circular economy begins with sustainable design with the idea of recovering materials in mind. Sustainable design ensures that packaging and the product itself does not go entirely to waste after use. Examples of this include products that are easily disassembled to extract recoverable materials.

The next major phase in a circular economy is consumption. A product designed in this type of economy would be designed with the idea of a long life in mind. In a world of planned obsolescence, a product designed to last a long time is a major step that sets a circular economy from a linear one. An example of this would be a product designed to be easily repaired.

Recycling and recovering seeks to recover as much material for reuse. This process seeks to extract the most useful and easily removable materials - metals and plastics.

https://www.ellenmacarthurfoundation.org/circular-economy/concept

1.2. Modern recycling processes must contend with losses in the life cycle of materials, mainly due to imperfect collection: not all products that could be recycled are collected, or if they are, they end up in the wrong waste stream. (e.g., Currently, only 5% of discarded cell phones go to the proper collection points—the rest end up in the domestic waste stream.) Perform Internet research and briefly report on design strategies that facilitate the (separate) collection of end-of-life products, such as labels or electronic markers. Then consider the viability of laws to achieve the same objective. What is your conclusion regarding design for recycling?

Correctly recycling products is a massive issue globally. According to Fast Company, even a developed country like the United States throws away 22 million tons of products that could be properly recycled. Some parts of the current recycling system do work well. Soda pop and beer cans are recycled well to create new aluminum beverage cans. The sorting process begins with mixed recyclables being dumped onto conveyor belts in recycling plants. These recycling systems use gravity, shakers, and spinners to sort through items. Some plants use manual labor to sort through recycling while others use robotic equipment. The small plastic recycling labels (like the numbers 1-6) are useless for robotic equipment sorting. On the other hand, manual sorting is extremely difficult and time consuming. So we see that grouping all the similarly-materialed products (100% effective sorting) is an almost impossible task. The goal is to create compressed bales of a single material with high percentage fill. However, impurities, which come from other products being sorted into the bale, destroy the value and possibility of re-use. Poorly sorted bales of plastic can be used in trash bins and park benches, but rarely for any useful re-application. There are number labels and codes on products, but sorting is still extremely difficult. Consider garbage/recycling bins in many universities. There is a lid with separate slots for waste and recycle--and yet only one bag underneath the whole contraption--combining the waste with the recycling.

The recyclability of current products is much higher than actual recycling of them. In other words, products that can be recycled are often not. This is the ultimate issue, because there has been a huge push for designing recyclable products--but if these products are never actually recycled properly, then society as a whole is just producing and buying more expensive things for no reason.

New laws could have an affect on the current recycling system. There could be middle school and high school classes promoting recycling and recyclability of materials. There could be laws that require every public trash bin to be replaced with a multi-option disposal system (slots for paper, glass, aluminum, recyclable plastics, and non-recyclable waste).

Laws like this would cost businesses and organizations a fortune purchasing these new disposal systems. Also, businesses and organizations would not directly profit from thorough waste disposal. Thus, a system could be set up to weigh recycling categories and pay companies for their thoroughly sorted recycling. However, this would require drastic measures taken by the government and enforcement of these laws will make most people unhappy. Additionally, this would require a total restructure of the current recycling system.

In summary, enforcing new laws that encourage detailed recycling will help boost the supply of high-quality recycled materials. However, this systematic change will probably not happen for a while. Economy is a large machine that takes a lot of groaning and hard work for any sort of substantial change or improvement.

https://www.fastcompany.com/90321566/all-the-ways-recycling-is-broken-and-how-to-fix-them

1.3. Grade is a measure of quality and it captures concentration levels (i.e., how pure a certain fraction is). If grade captures quality, then Recovery is a measure of quantity: it describes how much of a certain material in the input stream is made available for reprocessing. A recovery of R% means that (100 - R)% of the material going into the process is lost, ending up either in mine tailings or as a contaminant in one or more fractions.By weight, copper wire contains about 70% copper and 30% PVC. Suppose we process 1 ton of wire per hour into a copper fraction of 0.74 ton/hour, of which 0.69 is copper and 0.05 is PVC. What is the weight and composition of the tailing? And what are the grade and recovery of the copper?

1.4. Consider the following table with the energy and price data for various primary and secondary materials. Now, for the shown portable ventilator, determine the total potential recoverable value of the materials, and give a range for your answer. The main unit of the ventilator contains 0.20 kg of steel, 0.10 kg of wrought aluminum, 0.12 kg of copper, 0.70 kg of PP (polypropylene), and 0.28 kg of glass, with a total mass of1.40 kg. (It also contains small amounts of rubber and PVC, some ceramics, and some solder; ignore those for brevity.)

1.5. In countries where landfill space is scarce or expensive, municipal waste is often incinerated to reduce volume, and increasingly this is done with energy recovery, generating electricity and heat (e.g., for a regional domestic hot water system). Total energy efficiency can be up to 25%. This is much less than for regular fossil fuel power plants, mainly because waste is not a very good fuel, and because the intense waste-gas cleaning that is required uses a lot of energy. The amounts of waste are vast (in industrialized countries, typically 300 kg per person per year), and consequently the plants are large-scale, with the largest easily processing 1 million tons per year. Around 20% of the input is not burned and comes out as bottom ash: typically, just over 10% of this stream consists of metals (mainly steel, but also aluminum, copper, etc.), the bulk being a chemically inert ceramic residue enclosing the valuable metals. To improve recovery, metals, paper, and stone can be separated from the waste prior to incineration: this is not only technologically possible but even economically feasible, and it is already done at certain locations. Some of the plastic packaging can also be recovered before incineration; however, this does require end-of-life fees to make it economically attractive. The heat of combustion of PP is 46 MJ/kg. How does this compare to its GER? What if we also factor in the 25% efficiency? How “good” is “thermal recycling” in this case?

ABET PROGRAM LEARNING GOALS

[1]. An ability to identify, formulate, and solve complex engineering problems by applying principles of engineering, science, and mathematics:

(a) your 10 mini projects

(b) your homework assignments and quizzes

(d) your learning in lectures