FNB News - Use of Rice Straw for Packaging Materials - The Best Option

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PACKAGING

Use of Rice Straw for Packaging Materials - The Best Option

Tuesday, 10 December, 2019, 13 : 00 PM [IST]

Mukul Sain

We are living in a growing globalised world and we must make efforts to seek global solutions to protect the Mother Nature from pollution.

In India, everybody is aware about the winter smog in northwest India caused due to straw burning in Haryana, Punjab, Uttar Pradesh and Delhi. These states and our national capital Delhi is suffering with a thick mixture of smoke and fog.

Poor air quality is bad for everyone especially children, aged people and people with chronic respiratory conditions. Rice and wheat are the most commonly eaten grains in India.

After harvesting of paddy or rice, farmers burn the residue paddy straw, which not only causes a lot of air pollution but also affects the fertility of soil. The ban on stubble burning and initiatives like granting subsidies to the farmers to buy equipment and machines helping in rice straw management are also getting failed to take off in expected manner.

Also, one more problem, which our country is facing, is of plastic packs. India generates around 26,000 tonne of plastic per day. Uncollected plastic waste causes harm to natural environment. It affects the seas, oceans and lands. The use of plastic in packaging is increasing and the matter of concern is that the packaging is not effectively collected and around 80% of plastic is discarded as waste and 40% of this waste is uncollected.

To overcome this problem, paddy or rice straw based packaging can be the best option, which will not only resolve the problem of management of paddy straw but also help in reducing the plastic use for packaging. Traditional plastic is made from petroleum-based raw materials whereas paddy straw-based packaging is made from renewable materials. This provides a solution for two major environmental concerns i.e., crop waste disposal and plastic pollution.

There are many technologies to convert stubble waste into packaging materials. Rice straw has starch, cellulose and lignin contents. A chemical pulping technology can be used to convert straw into paper and cardboard for packaging. This method is based on extraction of cellulose from rice straw to make paper where 65% of rice straw is converted into pulp, which can be used in paper and cardboard industry. Rice straw is a very good packaging material because of compaction resistance and resiliency.

Some entrepreneurs are working to turn the agricultural fibres into biodegradable and reusable packaging materials. With this, the farmers will get financial incentive to sell the straw residue and they will not burn the crop biomass. With this, not only the economic status of farmers will rise but it will also help in replacing the main component, which causes smog in north India every winter.

A young entrepreneur startup formed by IIT Delhi students has found a novel way to take care of paddy straw. This startup called Kriya Labs has developed a simple process to convert paddy straw into fibre in which firstly, the paddy straw is cut into small pieces using a cutter and is cleaned properly to remove dirt. After that, the straw is bleached using biodegradable chemicals. To extract fibre, the straw is steamed in an autoclave reactor (a giant pressure cooker) for around 1 to 1.5 hours. Finally, a beater machine is used to extract the pulp from paddy straw. The final pulp obtained can be converted into packaging materials, plates, bowls and so on.

Bio-Lutions India, which is a Hamburg-based company with operations in Ramanagara, Bengaluru, buys waste residue from farmers and makes biodegradable and compostable packaging, which takes only three months to biodegrade. These packaging materials are used for packing the fruits and vegetables. Also, they are making tableware with the waste. Their mission is to curb the use of plastic that is choking the planet. The following picture shows a packaging material by the company:

A new technology namely bio-plastic is used for making environment-friendly packaging materials. Bio-plastic is plastic derived from renewable crop residue using starch, cellulose, protein and so on that are extracted from rice straw. Bio-plastic has a key property of biodegradability by microorganisms after disposal. Around 50% of the bio-plastics are prepared from starch by adding glycerol for better mechanical properties and good water solubility. The properties of biodegradable bio-plastic and petroleum based conventional plastic are discussed below:

Characteristics	Plastics	Bio-plastics
Composition	Petroleum	Starch of crop residue
Energy consumption in production	High	48% lower than conventional plastic
Chemicals	Toxic chemicals like Bisphenol A (BPA)	No toxic chemicals
Physical properties	Highly stable and thermoplastic	Equally stable and highly thermoplastic
Biodegradability	More than 500 years	Around 180 days. Also, it produces methane which can be used for cooking purposes
Effect on holding contents	Cannot retain the original flavour and scent of stored food	Preserve the original flavour and scent of stored food

In India, IIT Guwahati has developed biodegradable plastic, which is funded by the Department of Chemicals and Petrochemicals under Union Ministry of Chemicals and Fertilisers. Though USA is the major producer of bio-plastic but the cost is very high. IIT-G’s team is working to achieve this with lower costs.

The above-discussed bio-plastics are biodegradable or compostable plastics but it must be noted that all bio-plastics are not biodegradable. Some of them biodegrade after disposal, some can biodegrade under very specific conditions while some of them will not biodegrade under any conditions. Among all, PLA (polylactic acid or polylactide) is most promising bio-plastic produced by fermentation of starch from crops into lactic acid followed by subsequently polymerisation.

It is a very versatile bio-plastic with high transparency. By varying composition, its stability can be extraordinarily increased.

Finally, we can say that rice straw is a waste if and only if wasted. Its not a waste until wasted and with proper management, it can give us economical and environmental benefits.

(The author is M Tech, research scholar at Department of Dairy Engineering, College of Dairy Science and Technology, GADVASU, Ludhiana. He can be contacted at mukulsain95@gmail.com)