Bioplastics are often touted as being eco-friendly, but do they live up to the hype?
From Wastewater to Bioplastic
Systems are being developed by Kartik Chandran and Columbia University students to make biodegradable bioplastic from solid and liquid waste. Chandran employs a diverse colony of microbes that feeds on volatile fatty acids like the acetic acid in vinegar as a source of carbon.
Wastewater is fed into a bioreactor to power the system. Inside, microbes (as opposed to the bacteria that make plastic) transform the waste's organic carbon into volatile fatty acids. The second bioreactor receives the outflow and feeds the plastic-producing bacteria on the volatile fatty acids. These microorganisms are constantly going through hunger and feast cycles, where they store the carbon molecules as PHA.
To more effectively create the volatile fatty acids, Chandran is working with concentrated waste streams, such as food waste and solid human waste. His study is concentrated on increasing PHA production while also incorporating waste into the procedure. Chandran stated, "We want to get the most [from both systems].
He thinks his integrated system would be more affordable than the present processes for making bioplastic, which entail purchasing sugars to create PHA. "This is quite good [economically] if you connect wastewater treatment or manage food waste concerns with bioplastic production," Chandran said. Because if we were to scale up and enter the commercial realm, we would be compensated for both producing bioplastics and collecting food waste. Chandran wants to complete the cycle so that waste materials will frequently be used as a resource that may be used to create valuable goods like bioplastics in the future.
Other Promising Alternatives
Whole Cycle In California, bioplastics are also creating PHA from organic waste, including food scraps, plant stalks and leaves that are not edible, garden trash, and unrecycled paper or cardboard. This bioplastic is compostable, marine-degradable (meaning that if it ends up in the ocean, it might serve as fish or bacteria food), and non-toxic. It is used to produce bags, containers, flatware, water, and shampoo bottles. PHA can be processed by Full Cycle at the end of its useful life and used to create new virgin plastic.
Instead of more expensive food crops, Pennsylvania-based Renmatix uses woody biomass, energy grasses, and crop leftovers. Its technology uses heat and water to extract sugars from biomass in a relatively rapid, simple, and low-cost manner as opposed to acids, solvents, or enzymes. The building blocks for bioplastics and other bioproducts are made from biomass's sugars and lignin.
Researchers at Michigan State University are attempting to reduce the cost of producing bioplastic by utilising cyanobacteria, sometimes referred to as blue-green algae, which utilise sunlight to synthesise chemical compounds through photosynthesis. These scientists modified cyanosis to continuously excrete the sugar that they naturally make rather than feeding their plastic-producing bacteria sugars from corn or sugarcane. The sugar that the recyclable cyanos make is subsequently consumed by the bacteria that create plastic.
Methane gas from sewage treatment facilities or landfills is being converted into bioplastic by Stanford University researchers and the California-based firm Mango Materials. The methane is fed to bacteria that make plastic, which convert it into PHA, which the company then sells to companies that make plastic. It is utilised for plastic shampoo bottles, caps, and polyester fibres that may be woven into clothes made of natural materials. The bioplastic can be naturally ingested by marine animals if it gets to the ocean and biodegrades back into methane.
Polycarbonate is being produced from sugars and carbon dioxide at the University of Bath in England for use in bottles, lenses, coatings for phones, and DVDs. BPA, which is not permitted in infant bottles, and the hazardous substance phosgene are used in the production of conventional polycarbonate plastic. By adding carbon dioxide to the sugars at ambient temperature, the Bath researchers have discovered a less expensive and risky method of doing it. The bioplastic can be broken down by soil microorganisms into carbon dioxide and sugar.
Then there are those who are coming up with creative alternatives to plastic entirely. Packaging materials made from the agar in red marine algae are produced by the Japanese design business AMAM. The U.S. Department of Agriculture is working to create a food-wrapping material that is edible, biodegradable, and 500 times more effective at preserving food than conventional plastic film. Additionally, the New York-based Ecovative company creates Mushroom Materials, which include biodegradable packaging, tiles, planters, and more, using mycelium, the vegetative branching component of a fungus.
When all aspects of their life cycle are taken into account—land use, pesticides and herbicides, energy use, water use, greenhouse gas and methane emissions, biodegradability, recyclability, and more—it is currently difficult to say that bioplastics are more environmentally friendly than conventional plastics. Bioplastics do, however, offer promise to help diminish plastic pollution and reduce our carbon footprint as researchers across the world try to produce greener kinds and more effective production methods.
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