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Category: Green Innovation

Repurposing Old Breast Pumps to Meet Ventilator Demand

Breast Pump Ventilator

The Issue at Hand

The respiratory impacts of the COVID-19 virus have made ventilators one of the most needed medical devices in hospitals. As of April 5th, the New York City Mayor Bill de Blasio warned that the city would run out of ventilators in a matter of days. Luckily, just over 3 weeks after his warning, New York has been able to keep up with demand and is now giving away extra ventilators to other areas in need.

Nonetheless, this issue caught the attention of some engineers who wanted to make a difference. Located in Maryland, Brandi Gerstner, Grant Gerstner, Alex Scott, and Rachel LaBatt modified breast pumps to create temporary ventilators and free up higher-quality ones for those who need them the most.

The Solution

To create temporary ventilators, the team needed to produce medical-grade equipment at a low cost. Following the FDA’s approval for the use of positive-pressure emergency medical equipment, Gerstner had an idea: why not try a breast pump?

The closed-loop compressor combined with a medically-based production process made the breast pump an ideal choice for a ventilator. One issue, however, was that breast pumps sucked instead of pumped. To remedy this, Gerstner broke into one of her old breast pumps and found a way to easily reverse its air-flow. To further increase its accuracy, the team soldered some pins into the pump’s electrical board and used an Arduino to control its operation.

The prototype costs about $250 to produce, which is incredibly low when compared to the $25,000 cost of a medical ventilator. While the team is well-aware their pump adaptation will not provide the same services as a high-end medical ventilator, they seek to ‘fill the gap’ and make the higher-quality ventilators more available to those who need them.

The Implementation

To ensure user safety, the ‘breath pump‘ team is working to improve and test their pump before releasing the designs. They are currently working with a pulmonologist to create a better design more suited for medical use. For FDA approval, the device will also need to be tested in a biomedical simulation lab.

Once their design gains FDA approval, the team will release their modifications in an open-source format. Unconcerned about monetary gain, they simply want to “make a difference.” While the ventilator shortage has become less of an issue, engineers like Gerstner and her team will make a large impact in the fight against COVID-19.

What You Can Do on the 50th Anniversary of Earth Day

Fifty years ago in April 1970, over 20 million Americans across the country mobilized to protest environmental degradation in what became known as the first Earth Day. After a decade of witnessing atrocious environmental spectacles like the fire on the Cuyahoga River and the oil spill off the coast of Santa Barbra, people took to the street en masse to demand governmental action. The large-scale protests pressured the Nixon administration to create the EPA that year. It also spurred monumental legislation such as an amended Clean Air Act, the Clean Water Act, and the Safe Drinking Water Act, which all passed within five years of the first Earth Day. 

Fifty years later, it’s important to remember that for many people across America, their air is still polluted and their water is not yet drinkable. Environmental legislation has struggled to protect people equally. Communities of color and low-income families across the country largely face the same environmental injustice as fifty years ago. 

 Today, we face the biggest crisis of our time — climate change. While the first Earth Day brought impactful environmental reform, this day has since become a convenient means of inaction for corporations who are actively contributing to the demise of the planet. By using Earth Day to encourage people to recycle more, Coca Cola can blissfully look past the fact that it’s the largest plastic polluter in the world. 

This Earth Day was meant to be a break in that system, reigniting the use of nation-wide direct action and protests to demand radical change that would address the climate crisis head-on — this time without leaving behind those who have been most impacted by its effects. Though the circumstances of the COVID-19 pandemic have altered this plan, the intentions of millions of people across the country and the fear of the climate crisis are the same. And just because we are all stuck at home and unable to meet each other on the streets, does not mean that our voices will go unheard. 

There are still a lot of ways you can get involved. 

Earth Day Live is a three-day online event focusing on the three major topics: strike, divest, and vote for our future. RSVP to the live stream to see speakers like Representative Alexandria Ocasio-Cortez and former Vice President Al Gore, as well as hundreds of local live streams from across the country.

If you’re looking to do more, compiled below are various petitions that you can add your name to and tools for contacting your representatives to demand environmental action. If you’re able, spend some time seeing how you can make a change from home. Though this Earth Day certainly isn’t all we had hoped it to be, the climate crisis has not stopped and neither has our need to see and create change. 

To view the list, follow this link: Create Change from Home

Making Plastic Bans Equitable

Living in DC, you’ve probably noticed that plastic straws have been done away with — for the most part — as have many plastic containers and plastic bags. These plastics are disappearing from day-to-day DC life as a result of legislation banning and taxing such items. In 2009, DC became the first local government to tax plastic bags with the Anacostia River Clean Up and Protection Act. It required all District “businesses that sell food or alcohol to charge a five-cent fee for each disposable paper or plastic bag distributed with any purchase.”

At first glance, such laws can seem like a universal win for the planet, and while it is crucial that people begin cutting plastic out of their lives in order to mitigate plastic pollution and the climate-change inducing gasses created from producing plastic, it is also necessary that lawmakers take into account the people who will be negatively impacted by plastic bans. 

For most of its history, environmentalism has left out the communities most impacted by pollution and environmental degradation, instead favoring the desires of those who have the power and money to advocate for the changes they want to see in the environment. In part, that’s why plastic straws became a national crisis rather than a lack of drinkable water in cities across America. If lead-contaminated water impacted gated, largely white communities rather than low-income communities of color, we would probably be witnessing a different story. 

You may have heard of the plastic straw ban being labeled “ableist.” First, to define this term for those who may not be familiar with it, ableism is discrimination and social prejudice against people with disabilities or who are perceived to have disabilities. To someone who is able-bodied, the lack of a plastic straw might–at worst–be an annoying inconvenience. But for folks with disabilities, a flexible straw that does not conduct heat or become too cold might be imperative for drinking a beverage, which is why outright bans without exceptions can be thoughtless and dangerous. Sure, you can expect people to carry around a reusable straw at all times, but do you remember your straw wherever you go? Or your reusable bag or water bottle? Of course not! We’re all human and mistakes are part of our gig, but forgetting an item should not cost someone their health. 

And what about plastic bag bans? Well, they have their own set of problems. Bans and bag-taxes use the same tactic of incentivizing consumers to change their behavior. A ten or five-cent tax on each bag may seem like a drop in the bucket, but it is important to consider the “burden this bill places on low-income residents, particularly those who use food assistance to purchase groceries.” For those who use public transport to get to the grocery store, remembering to carry around reusable bags can be more burdensome than simply leaving a couple in your car. Additionally, people who live in food-deserts that have to walk considerable distances to get to the grocery store may find it harder to carry home a week’s worth of groceries in paper rather than plastic bags. 

There are ways to make plastic bans more inclusionary, and many governments around the country and world have been intentional in mitigating negative impacts. For plastic straw bans, writing waivers/exemptions that allow “restaurants to give disposable, flexible plastic straws to customers who need them for physical or medical reasons” is a crucial part of making the bans equitable. However, even such waivers can be ignored by restaurants, which is why there should also be a corrective system of reporting flaws in the procedures of restaurants or companies. When New Zealand was writing the legislation for its plastic bag ban, they were warned that “the plastic bag ban could hit the poorest the hardest” by the Ministry for the Environment. To mitigate this problem, the ministry recommended giving people with Gold and Community services cards–the equivalent to the SNAP Food Benefits program in America–reusable bags for free

A National Geographic blog points out that using the plights that those in a low socioeconomic status face as a reason for why plastic bag bans should not go into effect are a common tool of plastic industry lobbyists. The author also argues that such statements overlook the more pressing issues that the poor face. An individual in financial hardship will be drastically more affected by inadequate health care rather than paying a nickel for using a plastic bag. 

Nevertheless, it’s imperative that governments consult with the communities who could be negatively impacted by plastic bans–whether that’s people with disabilities, or those of a lower socioeconomic status–and to consider their voices in the process of legislation. 

And what about DC’s plastic bag ban? Is it equitable? Well, there has been little backlash against the ban by DC’s low-income residents (which could be due to the money-power dynamics of politics) but there is more DC could be doing. All of the money raised from the tax goes into various clean-up and restoration projects for the Anacostia River. Considering the health of people as well as the environment, DC could also funnel some of this money into projects that ensure every resident has drinkable tap water. 

An article written by Madeleine Somerville for The Guardian sums up the problem of the inequity found in plastic bans well: “An eco-friendly life shouldn’t be a luxury afforded only to those with lots of time, lots of money, or both. It’s also naive to think that environmental problems such as pollution, water shortages and global warming will affect us equally, and expecting equal participation in the form of a one-size-fits-all prescription for the perfect green life is just as ignorant.” 

Environmentalists–and the laws they help create– advocating that everyone change their life-style need to acknowledge the fact that not everyone has the means to do so. Everyone should do what’s right for the environment any time they have the choice to–with room for forgiveness because it’s impossible to be perfect. For lawmakers, this means acknowledging and addressing “the limitations and systemic roadblocks in the way of making eco-friendly change” which many people face.

Green Innovation: The Smog Free Tower

Smog Free Tower

In my last post, I discussed the Dearman Engine, which posed a viable solution to the NOx emission problem. However, NOx gases are only a small part of a bigger issue: smog. Smog is produced through the burning of fossil fuels and their derivatives, and it contains a large assortment of particulates and greenhouse gasses.

Because smog is such an issue, I would like to discuss a proposed solution: the Smog Free Tower.

The tower is the work product of Dutch visionary Daan Roosegaarde and his team at Studio Roosegaarde as well as the company ENS Clean Air. Studio Roosegaarde, started in 2007, aims to find innovative ways to solve today’s environmental issues. The tower is but one of their many projects.

The Smog Free Tower

At 7 meters tall, the Smog Free Tower is designed to clean air saturated with smog. The tower does this through a process called positive ionization, which I will discuss later. Using this technique, the tower filters around 30,000 cubic meters of air every hour.

More important than capacity, however, is effectiveness. In a 2017 study completed by the Eindhoven University of Technology, the tower was said to eliminate 70% of PM10 and 50% of PM2.5 from the processed air. PM10 and PM2.5 refer to the diameter of particulate matter in microns.

Before this study, the tower went on a tour of China in 2016 to test its operation in high-smog environments. Throughout the tour, the tower functioned extremely well in a variety of locations. The success of this tour, combined with the promising results of the Eindhoven study, go far in arguing for the validity of this technology.

Still, we must ask ourselves: how does it work?

Positive Ionization

The tower processes smog in the air through principles of positive ionization. Air ionization, a well-documented practice, can be used in many applications, including the reduction of static electricity and separation of particulates from the air. Although the company’s positive ionization process is not specifically discussed, I decided to apply the principles of air ionization to attempt an explanation.

When an AC current is applied to the air, positive and negative ions are created. With a DC current, however, it is possible to create only positive or only negative ions. The process of positive ionization likely refers to the former of these two options.

The positively ionized air (primarily oxygen, nitrogen, and argon) attracts the polar compounds in smog – CO, NOx, and others. These compounds gather around the ion, clumping together and weighing it down. This not only creates larger particulates, it also helps to separate them from the air.

While the description of this process is speculative, derived from the descriptions of air ionization technology, its results are supported by ENS’s description of the system. They claim the “positive ionization technology [is used] to capture fine dust and transform it into coarse dust.” As explained in my theorized description of the process, the particles will gather and grow in size — growing from fine dust to coarse dust.

Although my description is not based on any actual information released from the company, it may portray at least a semi-accurate account of the technology.

Other Smog-Related Projects

In addition to their Smog Free Tower, Roosegaarde has two more initiatives for their Smog Free campaign. Both are designed to increase awareness of their brand and encourage the reduction of smog.

The first, a Smog Free Ring, is derived from the Smog Free Tower. The ring’s ‘stone’ takes the form of a small cube of smog encased within a larger, clear cube. The smog represents 1,000 cubic meters of filtered air, and is currently a permanent exhibit in 3 museums. Purchased by many couples, the ring costs $294.

The second venture, the Smog Free Bicycle, uses a mountable filter to clean air for the rider. The filter takes in air from the front end, filters it, and exhausts the clean air around the rider. The studio hopes to have bike share companies use this technology as a standard within cities.

Just as for the environment, there is also much benefit for the rider. He or she will now have fresh air blown into his or her face, making a smog-filled day more than rideable!

Cleaner Air, Better Future

The smog free tower, along with its counterparts, is a fantastic step in the right direction. The different designs are portable, easy to incorporate, and perform their function admirably. With more Smog Free campaigns and technologies to match, our atmosphere may just survive the future.

How Plastic Impacts Climate Change

In the minds of most, the plastic problem is most readily associated with pollution. Images of beaches covered in plastic bottles, sea turtles and fish swimming with plastic bags, and the sides of roads littered with colorful pieces of trash are the first things that come to mind. Plastic pollution is generally referred to as a separate issue from climate change, but, in fact, the production and disposal of plastics contribute significantly to climate change-inducing emissions. A 2019 report by the Center for International Environmental Law determined that the impact of plastic production on the world’s climate in one year will equate to the output of 189 coal-fired power stations, and according to a report by Yale’s Climate Connections, “today, about 4-8% of annual global oil consumption is associated with plastics… If this reliance on plastics persists, plastics will account for 20% of oil consumption by 2050.” 

Plastic is made out of crude oil, which means it is one of the many cogs of the fossil fuel industry. From cradle to grave, plastics emit greenhouse gases in nearly every phase of their long lifecycle. The same processes used to extract oil for fuel are used to extract oil for plastic–fracking, drilling wells, and land disturbance. The emissions from driving a car is more likely to be linked with intensifying climate change than using plastic utensils or taking your carry-out in a plastic container, but both have their origins in extracted fossil fuels. 

The disposal of plastic waste is equally destructive to the planet, and though recycling is a better alternative than using virgin plastic, large-scale recycling facilities are energy and resource-consuming. Even so, the greenhouse gas emissions saved from not having to extract new oil offset the small amount of greenhouse gasses produced from recycling. Making new products from recycled plastic is more than 3x more efficient in terms of greenhouse gas emissions than manufacturing those same products with virgin raw materials. Unfortunately, our plastic waste problem does not end here. The high costs of recycling paired with the low costs of obtaining virgin plastic mean that “plastic recycling is rarely profitable and requires considerable government subsidies.”

As recycling policies have changed worldwide, recycling has become an even more expensive form of waste management. Rather than investing in more or better recycling facilities, countries have increasingly turned to incineration. In only one year, in the United States alone, “The climate impact of plastic waste incineration… [was] equivalent to 1.26 million passenger vehicles driven for one year, or more than half a billion gallons of gasoline consumed.” Incineration isn’t only an injustice to the planet, it is also an extreme detriment to human health. For workers who spend their day in incineration facilities and for the communities living near these operations, the pollutants from burning plastic can seriously threaten one’s health. While landfilling plastic waste has fewer immediate greenhouse-gas associated costs, the placement of landfills presents similar injustices as incinerators do. 

Let’s recall the image of oceans filled with plastic again. Plastic floating around in the water has become as normal to the scenery as seaweed or other aquatic life, but plastic pollution in the ocean has a much more deadly effect on the planet than can be immediately perceived. When rainforests are characterized as being the greatest carbon-eating entity, it is easy to forget that our oceans are the largest natural carbon sink for greenhouse gases. Plastic chokes this process in several ways. Not only does plastic in the ocean heated up by the sun release harmful greenhouse gasses such as methane and ethylene, but microplastics also hurt one of our ocean’s biggest unsung heroes–plankton. Plankton play a crucial role in “taking carbon dioxide from the atmosphere and water and sequestering it in deep ocean sinks.” This is already an issue when at least 8 million tons of plastic waste enters our oceans each year, but with this number set to double by 2030, the seemingly imperceivable disruption of ocean plankton will have severe costs to the climate. 

No matter how plastics are disposed of, environmental degradation is inevitable. Curtailing our reliance on plastic is critical in fighting the impacts that plastic has on all scales of life–from tiny plankton in our seas, to our earth’s climate.  

Green Innovation: The Dearman Engine

The Dearman Engine

The Dearman Engine

The Problem

It is no great secret that our well-being is tied to, among other things, the contents of our air. Currently, cars, coal-burning plants, diesel-powered machines, and more are releasing dangerous amounts of Nitrogen Oxides, or variants of NOx, into our atmosphere. These chemical compounds are known green house gasses and also serve as long-term health risks.

This is clearly an issue, but what are we doing to solve it? One tech company, Dearman, has designed a new engine for peripheral systems . The so-called Dearman engine will be able to replace many diesel counterparts in cooling, heating, and power applications.

The Engine

The Dearman engine draws information from the Industrial Revolution’s steam engines – but with a twist. Instead of heating water, causing it to expand and push a piston, the engine heats up liquid nitrogen with air and hot water. During this process, the liquid nitrogen expands to 710 times its initial volume, making it much more effective than steam engines. Click on the image below to see the process as a GIF.

The engine works much like current combustion engines. As portrayed in the images below, there are 4 main stages to the stroking process. The first step of this process begins when the piston is in its ‘Return Stroke’. During this time, the piston pulls warm water into the chamber.

During the upstroke, the water is compressed and, in a position described as ‘Top Dead Centre’, the liquid nitrogen is pumped into the chamber. The nitrogen becomes gaseous, expanding rapidly with a relatively stable temperature (the reaction is largely isothermic).

The expansion of the gas pushes the piston down in the ‘Power Stroke’, turning the drive shaft. Finally, the momentum of the drive shaft pushes the piston upwards, expelling the gas and water out of the chamber. The piston then travels downwards, and the process begins again.

The Environment

Most engines emit CO2 and NOx gasses, which are harmful to the environment — and your health! The Dearman engine, however, solves this issue. The now-cooled water is recycled within the system and the nitrogen gas is exhausted. Atmospheric nitrogen, which has decreased as a result of human civilization (replaced by nitrogen compounds), is extremely beneficial to the ecosystem.

This engine not only ceases to emit nitrogen compounds, it also emits much-needed nitrogen back into the atmosphere.

The Applications

Dearman has already begun using their engine to power a variety of systems. Under the projects section of the website, the company discusses their current ventures.

The Transport Refrigeration Unit (TRU): The Dearman Engine, with its liquid nitrogen system, is ideal for cooling applications. The engine is quieter, quicker, and more efficient than its diesel counterparts — plus its clean!

The Dearman Generator (Genset): While the Dearman Genset is still in its design phases, the company hopes it will surpass diesel generators in both efficiency and emissions. The generator, because its functioning is liquid-nitrogen-based, will also provide a unique service to environments that need special cooling.

The Dearman Heat Hybrid (DHH): The Dearman Heat Hybrid is the company’s vision of a diesel-Dearman hybrid. The waste heat generated by the diesel engine can be used by the Dearman engine to increase its efficiency. Already, there has been rigorous testing of a large hybrid bus, with promising results.

The Future

The Dearman engine promises much, but it still has a long way to go. A big leap will occur when the engine gains enough power to fully operate a car — and it is only a matter of time. As mentioned above, the company has already successfully tested a hybrid engine for a bus. Technologies like the Dearman engine are entering the market at an encouraging rate, and it seems many of them are promising increased efficiency over their polluting counterparts.


Green Innovation: How has the plastics problem gotten so bad?

Plastic has become an inevitable, near unavoidable part of our lives in the 21st century. Its pervasiveness makes it difficult to view each piece of plastic as something so detrimental to our environment. But it hasn’t been this way for very long–the rapid increase in the use of plastic is a relatively new phenomenon of the past couple of decades.

Around the world, we now produce over 300 million tons of plastic waste every year. However, in 1990, we produced 120 million tons. How has this issue gotten so out of hand so quickly? And where is all of this waste going? The story of plastic reveals a convoluted tale of corporations valuing profits over all else and the dangerous trope of “out of sight, out of mind.”

The creation of plastic has undeniably served the world in positive ways–medicine, science, and technology likely would not be where it is today without the use of plastics. This, however, is not why plastic waste has doubled since 1990.

Today, single-use plastics make up 50% of yearly plastic waste. In other words, the accumulation of seemingly benign items like plastic bags – which are used for an average of 12 minutes – are choking our environment with plastic waste.

It is easy to immediately blame those who don’t bring their own reusable grocery bags to the store or who don’t carry around a Nalgene everywhere they go. It’s important to recognize, however, that the plastic industry and large beverage corporations directly shaped this consumer-focused narrative and continue to benefit from it today.

In the years before the first Earth Day in 1970, environmental demonstrations across America decried the issue of throw-away containers, holding manufacturers responsible for the waste crisis the country was beginning to see unfold.

The Keep America Beautiful campaign–backed by corporation giants like Coca-Cola–responded to this call for change by rapidly shifting the narrative of blame back on the consumer through a series of targeted, emotional advertisements that convinced the American public that pollution was, in fact, the individual’s fault.

Recycling, since then, has been seen as a way in which consumers can do their duty of keeping the environment plastic-and-trash-free. But the recycling system as we know it is broken. Worldwide, under 20% of plastics are recycled, while 25% is incinerated and the remaining 55% is discarded, with much finding its way to the ocean. In the United States, recycling rates are even worse at around 8%.

Since the 1980s, the majority of our recyclables had been shipped to China to be processed and recycled. In 2018, China changed their waste-management policies and banned nearly all imports of foreign trash.

The United States simply does not have the recycling infrastructure in place to deal with the astounding 34 million tons of plastic waste produced every year, and as such, more plastics have been added to the landfill or burned. Rather than improve our recycling systems, the U.S. has continued to export our problems to countries that are economically vulnerable.

Countries in Southeast Asia have been flooded with Western garbage in overwhelming quantities since 2018 and are then blamed as being the top polluters in the world. Recycling and the education around it has not been a priority in this country, and the consequences of our wasteful decisions are ones that we are not forced to face on a daily basis.

The plastic industry has been selling us convenience for decades, and we’ve been buying it. Many of us have grown up in an age where we’ve known nothing but a throw-away economy that craves ease above all else. The recycling system in America contributes to this mindset, as it is often assumed that as long as we throw everything in the recycling bin, we are doing enough for the planet.

But to actually combat this waste crisis and plastic pollution, the recycling system in this country must be overhauled. Small-scale solutions like Precious Plastics have shown innovative possibilities that transform how waste is viewed. Furthermore, the issue of plastic use itself must be reckoned with.

Large corporations have created a world where sustainable options are more costly, time consuming, and seemingly inconvenient. However, those of us who have the privilege to make environmental changes in our lives have a responsibility to do so.

The idea around waste needs to change. We should be mindful about where our trash goes and the consequences our decisions could have not only on the environment but on people around the world.

At the same time, no one should forget that the top three plastic polluters in the world are Coca-Cola, PepsiCo, and Nestlé – three colossal corporations with an abundance of resources and money to either stop proliferating single-use plastics or to find innovative alternatives.

While plastic pollution has been a corporation-pushed problem, we as consumers must fight for the solution or change will simply never come and profits will continue to determine the fate of our planet. In the face of the climate crisis, our futures depend on immediate action and a complete upheaval of many facets of our society, including how we accumulate and dispose of waste.

The drastic change that this planet needs to fight climate change and pollution will not come unless those who have the means to do so show corporations and the plastic industry that single-use plastics are no longer acceptable–not only through their day-to-day choices, but in the demands they make of their elected officials, as well.

Part 3: Washing and Resizing

Part 3 of Green Innovation: Recycling Plastics Series


The washing process can be completed many ways, with the main focus to remove non-plastic contaminants. For example, PRM sells many types of washers for plastic films which can be used individually or together. These include the Hot Water Washer and the Friction Washer.

The Hot Water Washer: The PRM’s Hot Water Washer works by sending plastic flakes (specifically PET) horizontally through the machine. As they travel, they are sprayed with hot water and sterilized.

The Friction Washer: Much like the hot water washer, the plastic – again PET – is sprayed with hot water as it travels throughout the machine. This time, however, the plastic is fed into the bottom of an inclined, mesh-walled cylinder. The cylinder, spinning at around 1000 rpm, flings small contaminants through the mesh and causes the plastic pieces to rub against each other, scraping of dirt and grime.


During the resizing process, plastics are cut into much smaller pieces. This makes storage and processing both easier and more efficient. In fact, although it has been posted later in the list, it often occurs before the washing process.

In PRM’s plant recycling line, for example, they use an assortment of machinery to cut plastic films down to 10 – 20 mm in size. To learn more about the resizing equipment they use, check out the size-reduction section of their website.

Stay Tuned for Part 4 of the Green Innovation: Plastics Recycling Series!

Part 2: Sorting

Part 2 of Green Innovation: Recycling Plastics Series

The bulk of sorting, at least at the consumer-level, is done by the plastic collection agencies. However, in industrial-scale recycling – where businesses sometimes send their plastics without sorting them – different methods are used. Northstar’s article on the subject discusses how these plastics can be sorted with water and heat.

By placing plastics in water, their density (relative to water) can be determined. Typically, LDPE, HDPE, and PP plastics will sink while PET, PVC, and PS plastics will float.

When heating the plastics with a flame, the plastic’s identification is more precise. The plastics that float should also produce a blue flame with white smoke. Those that have a waxy smell are usually LDPE or HDPE, but the plastic with a sweet smell is typically PP.

Of the plastics that typically sink, each has their own properties when burning. If, when melting, it has a burnt-sugar smell, the plastic is likely PET. If the plastic ignites only at higher temperatures (with a blue/green flame), it is likely PVC. Finally, if the plastic does not drip and has black, sooty smoke, it is likely PS.

It’s pretty clear, however, that this process is time-consuming and inefficient for large batches of unsorted plastics. To solve this issue, a group of researchers designed a way to process almost 1.4 tonnes of plastic every hour – with computers.

They use the unique fluorescence patterns of plastics to identify and separate them. For more information on the process check out this research paper. In the future, I may create a post about the topic, so stay ready!

If you liked this post, be prepared for Part 3 of the Green Innovation: Plastics Recycling series.

Part 1: Recycling Plastics Overview

Part 1 of Green Innovation: Recycling Plastics Series

In 2017, roughly 267.8 million tons of waste were generated by the American population. Of the 35.3 million tons of plastic, only 2.92 million tons were recycled or composted. For more information on these statistics, check out the EPA’s 2017 report.

While it would be nice to see the amount of recycled plastic increase, there is still a lingering question: what happens to the plastic that is recycled?

The plastic-recycling can be easily separated into a series of 6 steps:

  1. Collection: This step is the most well-known, and it involves all the recycling collection processes including government services, bins in public spaces, and more.
  2. Sorting: Machines sort the plastics to find which ones the plant can process and to prevent damaging the equipment or slowing the process.
  3. Washing: This step is used to remove impurities, including labels, dirt, residue, and other non-plastic things.
  4. Resizing: During this stage, the plastics are ground-up to make processing more efficient and remove possible impurities unaffected by the last step.
  5. Identification and Separation: Here, the plastic chunks are separated by their different properties in processes that will be discussed later.
  6. Compounding: During this phase, the plastic bits are combined into pellets which are then used in the manufacturing of plastic products.

In the following posts, I will discuss each in greater detail. The collection process, however, is quite straight-forward and is discussed below.


The collection process, as mentioned above, is quite simple. Plastics are collected through a variety collection methods, including trash services (retrieving designated RECYCLE-ONLY bins), non-for-profits, and recycling bins. The real “meat” of the process occurs in the following steps.

Stay posted for Part 2 of the Green Innovations: Plastics Recycling Series.

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