- Bioplastic are a category of plastics derived from renewable bio-based resources.
- Conventional plastics are made from petroleum-based raw materials, bioplastics are made from 20 percent or more of renewable materials.
- Bioplastic can be both biodegradable and non-biodegradable.
- Bio-plastics can also be non-biobased but biodegradable.
Types of Bioplastics
Depending on the feedstock used for making bioplastics there are two main types of bioplastics:
PLA (polyactic acid)
- It is typically made from the sugars in corn starch, cassava or sugarcane.
- The starch is comprised of long chains of carbon molecules; similar to the carbon chains in plastic from fossil fuels form a long-chain polymer (a large molecule consisting of repeating smaller units) that is the building block for plastic.
- Hence, it is biodegradable, carbon-neutral and edible.
- It is made by microorganisms, sometimes genetically engineered, that produce plastic from organic materials.
- The microbes are deprived of nutrients like nitrogen, oxygen and phosphorus, but given high levels of carbon.
- They produce PHA as carbon reserves, which they store in granules until they have more of the other nutrients they need to grow and reproduce.
- Companies can then harvest the microbe-made PHA, which has a chemical structure similar to that of traditional plastics.
- Because it is biodegradable and will not harm living tissue.
- PHA is often used for medical applications such as sutures, slings, bone plates and skin substitutes; it is also used for single-use food packaging.
Advantages of Bioplastics
- Reduced use of fossil fuel resources.
- Smaller carbon footprint.
- Bioplastics do produce significantly fewer greenhouse gas emissions than traditional plastics over their lifetime.
- Faster decomposition.
- Bioplastic is also less toxic and does not contain bisphenol A (BPA), a hormone disrupter that is often found in traditional plastics.
Bioplastics in India
- In India there are 16 companies that make bioplastics.
- In Indian case, bioplastics are those that are biodegradable.
- Bioplastics are relatively expensive.
- PLA can be 20 to 50 percent more costly than comparable materials.
- Since they are made from the byproducts of food crops a bioplastic carry bag could cost almost thrice as much.
- In order to decompose biodegradable bioplastics we need industrial composter.
- However, most Indian cities lack facilities to compost bioplastics.
- Further the raw material used for bioplastics manufacture in India is imported mostly from Europe or China. This makes manufacture of bioplastic expensive in India.
- While bioplastics degradation is fast in industrial composting facilities, it takes years in the natural environment.
- This might increase the litter due to wrong perception that bioplastics are naturally decomposed.
- Bioplastics production results in pollutants, due to the fertilizers and pesticides used in growing the crops.
- The bioplastics also contributes to more ozone depletion than the traditional plastics, and required extensive land use.
- Indian companies should manufacture raw material indigenously to bring down the cost.
- Innovation in feedstock is another way to reduce the cost of industrial composting like use of ‘second-generation” and “third-generation” feedstock
- For example, feedstock made from tapioca starch and vegetable oil is naturally compostable.
- The most important innovation is the use of non-food crops like saw dust, organic mixed-waste etc.
- Another feedstock is algae like it is done in Israel.
- Further India should have a policy including sops like subsidies for electricity consumption, lower rates of Goods and Services Tax and lower import duties for bioplastic manufacturers.
- Municipalities should step up in improving composting infrastructure.
- Further separate recycling streams are necessary to be able to properly discard bioplastics.