by Dr Swati Nandi Chakraborty
Increasing demand for rising population and income drive lead the world to produce twice the plastic waste as two decades ago. The policies to overcome the problem are falling short according to the report of Organization for Economic Cooperation and Development (OECD). According to the report, globally only 9% of plastic waste is recycled whereas 22% is mismanaged. Plastic account for 3.4% of global greenhouse gas emission. Bans and imposing taxes on single use plastics exist in more than 120 countries but are not showing enough result to reduce overall pollution.
Reducing pollution from plastic will require immediate action through innovation, product designing and finding the environment friendly solution. It require improved waste management infrastructure by creating a separated well functioned secondary market for recyclable plastic.
With the increase in the world population and agriculture operation, crop production grows with a total global crop production of 11.7 billion tons in 2020, which also generated abundant biomass resources in the form of waste throughout the food supply chain. The best examples being fruit and vegetable wastes, like peels, roots, stems and leaves etc. This type of fruit waste contributing valuable components in starch, protein, lignocellulose, phenols and lipids which are potential bioplastics raw materials. These types of materials streams into the production of “green materials” is an emerging option for ecofriendly production.
Bio plastics are bio-based, durable and degradable plastics and their synthesis routes from various sources are now the main aim for environment scientists. The environmental and economic parameters of the most well-known synthetic bioplastics on the market are compared with existing fossil-based plastics.
Depending on the kind of plastic, they may also be biodegraded by microorganisms, opening up new avenues for recycling and helping to foster the growth of a circular economy through practices like composting and anaerobic digestion.
Today, almost every monomer required for the production of drop-in polymers chemically equivalent replacements for fossil-derived polymers which can be obtained from biomass like seed wastes. Moreover, biomass from different seed part can support the synthesis of novel polymers that are not easily derived from fossil resources.
Starches which constitute a significant portion of seed waste are the main material used for non-synthetic starch-based bioplastics produced by direct processing of the starch into biofilms.
Uses of bioplastic benefits over environment pollution
The environmental problems arising due to improper disposal of the plastic wastes could be solved through the bioplastics in coming days. The main advantage of bioplastic products is that they are produced from renewable resources rather than fossil resources. The usage of renewable resources would contribute to a reduction of greenhouse gases emission through the reduced carbon footprint. Compared to petrochemical plastics, the bioplastics production can emit about 80% less carbon dioxide.
The production of bioplastics also consumes 65% less energy than the production of petrochemical plastics. Additionally, the bioplastics can avoid some of the environmental problems like uncontrolled dumping on land and disposal at sea causing of marine pollution and related emission of toxic substances. Though, effective implementations of collection, sorting and recycling practices and public awareness are also essential to reward the benefits of bioplastics.
Starch-based biopolymers are gaining popularity because they are cheap, renewable and easy to recycle. In addition, starch is seen as a potentially useful input in the manufacture of biopolymers. Starch-based plastics made up the second largest portion of the bioplastics market after polylactic acid (PLA). Linear amylose is responsible for bioplastics' elasticity, whereas amylopectin's branching structure regulates tensile strength and elongation.
Representation of bioplastic advantages
The environmental benefits from utilization of bioplastics are one of the driving forces to expand their further use. Germany, predicted that the world market for bioplastics in 2021 will be three times larger than that in 2014, generating a total of USD 5.8 billion in revenue. In India, Dr Bio branded is available in Ludhiana having manufacturing capacity of compostable bioplastics is around 8,000 tonnes per annum as reported.
What are the benefits of using bioplastic products over other conventional plastic?
Requires 65% less energy to produce than traditional petroleum-based plastics
Bioplastic emits 68% fewer greenhouse gases
Renewable Resource unlike natural gas or crude oil that’s a finite resource, bio waste seeds is available, functional and renewable
Biodegradability are also high rather than filling up our landfills, these plastics degrade quickly and can break down even as quick as 45-90 days
No toxic fumes – When they’re incinerated, bioplastics don’t emit any toxic fumes
FDA-approved bioplastic Generally Recognized as Safe polymer and is safe for food contact
Sources of starch bioplastics
Starch based bioplastic are mainly sourced from fruits and vegetable wastes which are generally found at our households and are discarded by human without knowing its potential and advantages. Here are list of sources of seed waste material from which starch are extracted for the production of bioplastics:
Corn plastic is a non-petroleum material made by converting corn into PLA.
Waste mango could be a good choice for the low-cost obtaining biopolymers such as starch and cellulose, which are very useful for the production of plastic biodegradable. Bioplastic composed of starch and micro cellulose from mango waste could also new opportunities for fast degrading biomaterials of agricultural waste application.
Biodegradable plastic prepared from non-edible starch (tamarind seeds) could be the source of bioplastic.
Bioplastics from yellow pumpkin have been successfully synthesized and the resulting film has a biodegradable characteristic for 20 days. The mechanical properties of bioplastics are highly determined by the composition of starch, additionally where the higher the chitosan content, the value of tensile strength and modulus of young increases.
Jackfruit seed has a high starch content (about 30% of fresh seed weight) and is easy to collect in large quantities and extract starch. Therefore, it is suitable as a raw material source for bioplastics and at the same time takes advantage of the source of fruit seeds that can be considered waste products, increasing the value of crops.
Date fruit production is not only devoted to its consumption as dried fruit but also to an increasing manufacturing industrial sector. Co-products from the date fruit industry (date flesh and seeds) have become an environmental problem for the growing and processing areas. So bioplastic production from date seed could add much more profitable solution for making different bioplastic component. For making starch based bioplastic these seed waste also good source.
Bioplastic process flow
Cost plays a major role as costly product are majorly rejected in the market, polythene is cheaper which is why it is globally used but the harmful effect from it is deteriorating the environment to a major extend this is the reason why cheaper and ecofriendly alternative ways are being developed.
Photo source: Internet
Starch based bioplastic is one of the cheaper alternatives compared to PLA based and cellulose based bioplastic. PLA based bioplastic is the most commercially developed bioplastic but its production is costly compared to starch-based bioplastic. Thus, the global market for bioplastics made from starch is expanding at a phenomenal rate.
Other advantages of adopting compostable bio plastics are that they have the same tensile strength as conventional plastic. Physically, there is no visual difference between the bioplastic and conventional plastic for the end consumer, and doesn’t require much adaptation.
Compostable bioplastics are processed at around 130 to 140 degrees Celsius at which most pathogens get killed and these types of biocomposite can also be vanished within a month in landfilling only.
In recent times, the plastic waste problem in India has brought users closer to the realisation that we need to transition to materials like compostable bioplastics more in number to reach sustainable solution readily.
About the Author:
Dr Swati Nandi Chakraborty is an environment enthusiast and researcher with adept proficiency on the
implementation of sustainable development, e-waste management and life cycle assessment area.
You can reach her at email@example.com