Garbage has become a huge social and environmental problem to almost all the people in the modern world. Every day, millions of tons of garbage is stockpiled throughout the world, and strategies for its utilization had been laid down, in the sense according to economic principles of how to make profit with as small expenditure as possible. Current waste management and treatment practices only target reduction of garbage, often at a high cost but doesn’t solve the problem for good, with no added economic benefits. Such options are no longer the best ones in this time of economic hardship.
When I say garbage, I refer to the sort that consists of a variety of heterogeneous materials such as metals, glass, plastic, rubber, cement and organic waste materials such as lumber, and agricultural waste, human and animal manure, etc. Pyrolysis, is the best technology that can process this kind of garbage economically and turn it into usable energy. However, garbage can not be fed directly into a pyrolysis reactor unit because of the impurities in it. Processing it would need a lot of preparation to produce high value products. Only after heterogeneous materials are separated from organic materials, can garbage input be feed into the pyrolysis reactor.
Products generated by the pyrolysis process include charcoal, bio oil and syn-gas. Charcoal with a calorific value between 4000-4500 kcal / kg will be made into briquettes and can be used as a clean substitute for coal to fuel boilers and turbines to generate electricity. It can also be used as BIO-CHAR as a soil amendment. Studies have been made on charcoal briquettes processed from garbage and some have been made on a commercial scale. Bio oil can be used as a fuel as well. This can be obtained from further processing and refining the excess syn-gas (synthetic gases) and can be used to fuel big power plants. Generally, there are still a lot of big cities in the world that experience shortages electricity today. Pyrolysis technology has been proven to be a practical, safe and reliable alternative energy source that could benefit such cities.
Millions of tons of city garbage is stockpiled throughout the world everyday. Problem or Opportunity? It depends on how you look at it…