Saturday, March 3, 2012

THE "GREEN" BOTTLE-IS IT A MIRAGE?

Fast dwindling fossil fuel reserves make it imperative that their consumption is progressively brought down all over the world and renewable sources of energy are discovered on a a priority consideration. Solar energy, Wind energy, Wave energy, Geothermal energy etc have shown enough promises but requires higher investment and efforts to get translated into commercially viable technologies for mass adoption. Ultimately the cost consideration far outweighs any technological challenge since scientists have enough foundation to come out with technically feasible ideas. So far many of the renewable energy production has been sustained by supportive fiscal policies of many governments but if these alternative options are to be a permanent feature, generation cost and capital cost intensity will have to come down drastically.

Food packaging, intended to give protection to the food inside, has been depending on glass bottles and sanitary cans till about 4-5 decades ago. But there has been a paradigm shift in the packaging industry practices since then with more emphasis on plastics of different types. There are at least a dozen fundamental plastics, most of them polymers, made from petroleum chemicals and with various combinations they provide almost 90% of the packaging resources to the food and pharmaceutical industry. It has not been easy for the packaging industry to win approval of the plastics for packing foods because of the fear of migration of unsafe chemicals that may leach into the food during processing and storage. Well laid down protocols of safety and standard testing practices have made it  possible to get many plastic materials safety cleared during the last two decades.

If plastics are safe and universally acceptable to one and all, plastic industry should have been the happiest lot but one factor that weighs heavily against plastics is their indestructibility and lack of biodegradability. It takes almost 800 years for most plastics to get degraded and even when they are degraded the artifacts produced tend to pollute the environment inviting the wrath of the "Green Movement". Besides recycled plastics do not appear to have all the original functional properties characteristic of the virgin material. Due to innovative policy orchestrations at the level of the governments in many countries, use of plastics is increasingly being frowned upon mainly because of their pollution potential and use of ultra thin films with 20 microns or less are banned in many places. Many shopping malls are charging extra for providing carry bags made from plastics, forcing many consumers to take their own bags for shopping. Of all the plastic materials used by the food and beverage industry Poly (ethylene Terephthalate) commonly known as PET is most conspicuous by its extensive use for manufacture of bottles for soft drinks and bottled water.

PET is a polymer of ethyleneterephthalate monomer and its transparency, physical strength and amenability to easy fabrication, make it eminently suited for bottling operations. Especially its low oxygen permeability allows the content inside immune to oxidative spoilage and consequent quality deterioration. To day almost all soft drinks manufactured in the world are packed in PET bottles. More than 60% of the world production of PET resins is absorbed by the fiber industry for the manufacture of textile yarns while about 30% goes to the bottling industry. As this is derived from petroleum chemicals and their biodegradability credentials are poor, the soft drink industry is strenuously striving to replace these bottles with more sustainable materials. It is true PET bottles do undergo recycling, most of the recycled material going to the carpet industry and some for recycled bottles but still the industry is not happy with its dependence on fossil fuel.     

Beverage bottles, made from PET has two main components. MEG (Mono Ethylene Glycol) makes up about 30 percent of a bottle's weight and it has been possible to make the same from plant sources, especially sugarcane, grown abundantly in Brazil, India and other countries. The other component, called PTA (Purified Tere Phthalic Acid), makes up 70 percent of a bottle's weight. Though scientists have been able to make PTA from plant materials at laboratory level, manufacture on an industrial scale has posed severe challenges. According to recent reports production capacity for MEG is slated to increase dramatically and from one plant producing it to day, there are others getting ready to take up production soon. The environmental groups agitating against plastics are extending massive public support for creating plastics from plant sources as they generate smaller amounts of greenhouse gases, compared to plastics made from petroleum.


A larger issue is whether the world can afford to divert an edible source of food like sugarcane for non-edible packaging materials. Probably a more appropriate approach would be to develop technology for using agricultural waste products, like corn stalks or other materials left over from farming, as feed material for producing plastics. Growing crops for plastic can also cause a lot of land diversion which in turn may affect the price of food to a significant extent. Though some of the beverage giants have declared their intent to use agricultural waste products, such as corn husks, pine bark or orange peels etc, to make its plastic bottles, how far and how long it will take is any body's guess. Regardless of how they are produced, plant based plastics can still create litter and solid waste problems posing another challenge. it is time appropriate legislation is considered for forcing the industry to finance recycling operations and facilitate more increased plastic recycling without creating environmental problems and save water and energy use as much as possible. Considering all these uncertainties, a 100% "green" bottle remains a mirage though in future one cannot rule out dramatic breakthrough in this area.


V.H.POTTY
http://vhpotty.blogspot.com/
http://foodtechupdates.blogspot.com

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