Mainland High School
Lord of the Trash Rings: ISTF 09-2004
Waste Management Proposals
Plasma Gasification
Plasma arc gasification is a processes of waste disposal in which waste is forced through an arc of ionized particles of an inert gas, which heats the substance and the air around it to a plasma. This breaks down all the molecular bonds in the substance down to the most rudimentary level possible. The byproducts of this process are a hydrogen rich synthetic gas that can be used for fuel and a very hard and durable substance called slag. The exact make up of the gas and the slag is dependent on the substance being gasified.

Image courtesy of How Stuff Works

The way this is accomplished is a small copper tube that's tapered at the end is filled with an inert gas. The copper is then electrified so that an arc of electricity jumps over the gap on the tapered end. This heats up the gas and causes it to expand, forcing it out of the hole. As the gas passes through the electric arc, it is superheated to a plasma, resulting in a "plasma torch". The waste is then pushed through this torch and obliterated. This whole whole process is undertaken inside of a sealed container so that the desirable gasses can be gathered and used elsewhere.

The gasses produced are cooled and in the process their heat creates steam which turns turbines to recapture some of the energy input. The gas is then cleaned of dangerous components like chlorine or sulphur. What remains is a gas that can be burned and used for fuel. This "syngas" is composed of carbon monoxide, carbon dioxide and hydrogen gas.

Image courtesy of Victory Gasworks

The slag produced is a glassy substance that traps any toxins like heavy metals, any organic toxins will have already been obliterated. This substance does not leach out these toxins, and has already has been tested and complies with EPA standards. If this slag is airated while cooling, it becomes rock wool. Rock wool is an excellent insulator and could replace other more harmful forms of insulation.

This process has been used in many places to dispose of municipal solid waste, and has proven to be much more efficient than conventional incineration.
Pyrolysis is a catalyzed process of heating up a material so that the chemical bonds will break. With plastic waste, the object is to break the polymers bonds at 400ēC. The plastic then becomes a gas that is captured and cooled into a crude oil which can then be further processed. Pyrolysis of plastic in the forms of PVC and polystyrene can release toxic gases. Polymer Energy boasts that the acceptable plastic does not need to be sorted and that their process can handle a mixture of up to 25% other waste products in the sample, including e-waste (computers). When using pyrolysis, emissions are considerably lower than those from incineration or gases released from land-fills.

In an e-mail dated Febuary 8th, 2010, Doug Woodring stated:
"One good thing is that is likely this plastic can be turned into fuel [pyrolysis], maybe even on the boat itself while at sea, and this could help to subsidize the larger cost of a clean up."
Dr. Kevin O'Connor at the University College Dublin, teamed up with Professor Walter Kaminsky at the Uiversity of Hamburg, to develop a technique using pyrolysis (to liquify the polystyrene into styrene oil) and bacterium to convert styrene oil into a biodegradable plastic called PHA, polyhydroxalkanoate. This process would allow polystyrene to no longer accumulate in landfills but become a fuel to produce PHA, an environmentally-friendly plastic which when discarded does degrade.

White-Rot Fungi
Adam Gusse and colleagues at the University of Wisconsin at LaCrosse have determined that one species of white-rot fungi (Phanerochaete chrysosporium) can break down extremely durable phenolic resins present in plastics. These fungi have already been documented as being able to digest polystyrene. Moreover, experiments have shown, that these fungi are capable of decomposing polycarbonate plastic that is pretreated with ultraviolet light exposure and heat. Scientists at Utah State University have patented the application of white-rot fungi for biodegradation of many environmental pollutants.
Enzymes are water-soluable, bio-molecules that are used in an organism’s bodily processes to speed up or catalyze biochemical reactions such as digestion and respiration. They are made up of a protein and a cofactor which can be an organic group (prosthetic group), a cation, positively charged metal ion (activator), or an organic molecule (coenzyme). Enzmyes are commonly used in the food and brewery industry and as detergents. Three methods of affecting enzyme-bonding techniques are: temperature, pH, and the concentration of the enzyme.

Enzymes are that speed up reactions by lowering the activation energy required for the reaction to occur. Here is an analogy:
To fasten a screw into a piece of wood, many carpenters would agree it is much easier to use a drill bit first on the wood to create a ideal hole/indent in order to easier twist in the screw. Now if you can think of the screw as one reactant and the piece of wood as the other then the drill bit would be the enzyme. Just like a reactant with an enzyme, a hole in the wood requires a specifically shaped hole for the screw to go in that it is neither too big nor too small but absolutely right. So in short just like it is easier to secure a screw inside an already-drilled hole it is equally easier for one reactant to react with another reactant when an enzyme can lower the the required activation energy.
16-year old Daniel Burd won top honors at Canada's Science Fair in Ottowa with his discovery of an enzyme that can decompose plastic in as little as 3 months. The teen isolated two strains of bacteria, Pseudomonas and Sphingomonas. He accomplished this by combining landfill dirt, yeast and tap water, then added ground up plastic bags. The degradation process was maximized at a temperature of 37ēC. He witnessed that the plastic indeed degraded faster under these conditions than when it was simply discarded. In an interview, Daniel stated that his process would be easy to replicate on an industrial scale, all one needs is "a fermenter, your growth medium, your microbes and your plastic bags." Daniel's method is much more environmentally friendly than other methods of biodegrading plastic with the use of toxic heavy metal additives, oxo-degradable plastics.
Synthetic Enzymes
Natural catalysts are used daily in the production of new medicines/other necessary chemicals and food. Issues arise when trying to find a catalyst, because each molecule has an individual shape. These individual shapes require the scientists to find an individual catalyst each time, but creating a specified enzyme would prove to bring much relief due to its unique abilities to self-adapt to its surrounding factors. Chemists at Ohio State University have now announced that they have the ability to produce synthetic enzymes. This new technology will soon be applied to numerous applications to shorten the time for tedious trial-and-error experimenting that is required to find the ideal shape. This remarkable breakthrough was made by a team of inventors including: Umit S. Ozkan, Lingzhi Zhang, Xueqin Wang, and Sittichai Natasakhawat. The inventors have stated that they are able to design an enzyme for any application necessary.

An enzyme that could facilitate the breakdown of plastic would help the complete disposal of plastics; but, it would need to be produced in considerable quantities.


16-year old discovers plastic-eating microbe: Is this the answer to our plastic problem?

A Bittersweet Symphony called D2W

Aitkin County Plasma Gasification Study

A revolution in Recycling - Bugs that Eat Plastic

Dr Kevin O'Connor

Eco-Friendly Way of Decomposing BPA-Containing Plastic

Enzymes Function and structure

Fungus Eats Enduring Plastic

Fungus is a Hot Solution to Disposing of BPA Laden Plastics

Florida county plans to vaporize landfill trash

How Plasma Converters Work

InEnTec: Process Details

Ohio State University Synthetic Enzymes

Plasma Arc Gasification of Municipal Solid Waste

Plasma Gasification

Plasma gasification: Clean Renewable Fuel Through Vaporization of Waste

Polymer Energy FAQ's

Polymer Energy Technology

Pyrolysis as Recovering Value from Waste

Synthetic Enzymes a Reality

Synthetic Molecules Emulate Enzyme Behavior For The First Time

Talking Trash with Dr. Louis J. Circeo

Teen Decomposes Plastic Bag in Three Months

The Fungus among Us: Use of White Rot Fungi to Biodegrade Environmental Pollutants

The Future is Rotting Plastic

WCI student Isolates Microbe that Lunches on Plastic Bags

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