Garbage utilization for clean energy

Home and industrial waste contribute to garbage heaps near urban and suburban areas in the civilizations where proper collection or garbage handling system is not established. When garbage is dumped near road sides it creates health hazards for the community and even if it is dumped in landfills it generates toxic gasses and obnoxious smells which disturb people of nearby residential areas. Not all the garbage could be dumped to convert as compost for plants. It would also need a lot of effort for compost handling on such a mass scale. Although compost purports to clean environment but 100% garbage to compost conversion is simply not possible anywhere.

Alternative garbage utilization

This garbage which is a hazard to health and environment could be utilized other way round to make the environment clean and produce precious energy resources. The procedure for this arrangement is that the garbage is accumulated and stored in a big yard. Adjacent to this storage there is a boiler installation. Mechanical claw fixed with an overhead crane put the garbage in combustion chamber of boiler. Although heat content thus produced is at low ratio even then the boiler could produces high pressure steam out of it and this pressure moves the steam turbine to play a role of prime mover for power generators. The resultant electricity could be easily directed to power grid, whereas the residual steam is available to be directed to households for heating purposes. The steam may also be utilized to get clean drinking water after necessary mineralization, or even if it is not mineralized it is pure filtered water that could be utilized otherwise.

Waste gases are not sent to the atmosphere directly; instead they go through further filtration process. This filtration removes toxic gases like nitrogen oxide, dioxin, mercury and other acidic gases.

Clean environment

Constructive utilization of garbage to produce electricity would be a step towards clean environment in many ways.

It will save wastage of land to dump the garbage. Instead, that land could be utilized in cultivation or plantation of trees. The decompose-able garbage would emit methane and other gases harmful for human health. Take whatever steps to prevent it, but these landfills would produce unpleasant smells which will travel with the air to nearby urbanization and make the environment there unhygienic and may also result in epidemics.

Since the garbage would be utilized as a fuel alternative, therefore, fossil fuel requirement would be reduced to that extent. Carbon Dioxide emission by burning fossil fuel would be reduced. The extra heat through residual steam would be used in heating nearby houses of such arrangement and separate heating process wouldn’t be required.

Burning of garbage would also result in collection of precious metals that would otherwise be gone waste in dumps.

And in the last but not the least the flue gases will be filtered for the collection of fly ash. It is produced in such a huge quantity that with the introduction of a small industrial process the fly ash could be utilized in preparing bricks.

Cost comparison of electricity

Statistics show coal fired power plant’s average efficiency is 35-42%. Thus only 35% of burnt coal is converted in to energy, and rest is wasted through flue gases. Since heat content produced through burning of garbage is very low as compared to coal, therefore, garbage or waste fired power plant shows efficiency higher than 80%.

In conventional power plants fuel has to be purchased. That fuel cost adds to the unit cost of output energy. Where as in case of waste to energy facility most of the plants charge for per ton of garbage they consume. That tipping charges are additional revenue to the plant and is definitely a reduction of cost from both the sides.

The labor or manpower cost is common in both the conventional and garbage to energy conversion plants. Studies of Columbia University show that .06MWh of power is produced per ton of waste on an average.

In figures per unit cost of conventional power plant is $.17/kWh whereas for waste to energy plant is it only $.15/kWh. This result makes it a win-win scenario for cost of production and for clean environment.

Conclusion

Greenhouse effect of garbage to power conversion is positive for the universe. It reduces greenhouse gases, produces clean energy, saves wastage of land for landfills, and not only removes the amount of trash but also recovers precious metals from wasting into dumps. The resultant of steam is clean water. Residual of flue gases is fly ash which is again raw material for bricks. And the last but not the least per unit cost of energy is much lower than the conventional fuel fired power plants.