About Bio-plastics

About Bio-plastics

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.

PHA (polyhydroxyalkanoate)

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

Challenges

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.

Way Forward

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.

Section : Environment & Ecology