Origin of renewable energy sources – Biomass [ctd.]
Waste is not to be wasted
Waste is an unnecessary product in our daily life. We do not generate waste purposely. But we cannot stop generating waste though it is unwanted/ unpleasant.
Waste was commonly considered a waste for centuries.
Of course… Waste generation still remains a big challenge.
We should try our best to reduce waste generation as much as possible since waste leads to many negative impacts on our health, economy, environment and society.
How to reduce waste generation?
The best solution to reduce waste generation is to follow the 5R concept.
- Refuse: Refuse to purchase
- Reduce: Reduce consumption
- Reuse: Reuse the same product over and over
- Recover: Recover usable components for other uses
- Recycle: Recycle any remaining waste
The 5R concept is a proven concept in waste management. However, it is obvious that no single waste management strategy can completely shut off the daily waste generation though some concepts may help reduce the amount of waste to some extent.
What can we do to manage waste?
Waste-to-energy probably would be one of the best solution in waste management.
Waste-to-energy: Waste is not a waste
- Burying waste in landfill and recycling are two common solutions in traditional waste management. Composition of waste varies from country to country, from region to region and even from year to year.
- Organic waste accounts for a significant portion of garbage in an average household. As its name implies, organic waste is a waste which is a challenge and should be properly managed.
However, organic waste is one of the different forms of biomass, as we discussed earlier. Solar energy stored in biomass during photosynthesis can be used to generate electricity or heat.
The technology which uses waste to generate electricity in the form of either electricity or heat is commonly known as waste-to-energy. Several waste-to-energy concepts have already been used to generate electricity. Both thermal techniques such as incineration, pyrolysis and gasification and also non-thermal techniques such as anaerobic digestion are currently being used.
Waste is continually generated by us. So, waste-to-energy is a renewable/ sustainable energy technology. And it does not lead to global warming or climate change since waste (biomass) which is the primary fuel in waste-to-energy plants is carbon neutral.
Goal of waste-to-energy technology
Waste-to-energy plants generate energy from waste which is one of the main challenges in the 21stcentury. In other words, waste to energy technology converts problems into a solution.
Waste-to-energy plants generate electricity or heat from waste. Also, they help alleviate the waste problem. So, waste to energy is a win-win technology.
It has been estimated that an average person in developed countries and developing countries annually generates 521.95–759.2 kg and 109.5–525.6 of waste, respectively . Further, organic waste, paper and plastic accounts for 46%, 16% and 10% of municipal solid waste (Hoornweg & Bhada-Tata 2012). Simply, nearly three quarters of municipal solid waste can be used to generate electricity or heat while greatly reducing the amount of waste.
Anyway, one of the main challenges in waste-to-energy is that they require a continuous supply of combustible waste. Also, most of the waste-to-energy technologies have a lower limit for waste supply. The minimum amount depends on the technology used. This implies not all the regions in the world would be suitable for waste-to-energy plants though waste generation is a common practice in our daily life regardless of the country or region.
Karak, T., Bhagat, R. M., and Bhattacharyya, P. (2012). Municipal solid waste generation, composition, and management: the world scenario. Critical Reviews in Environmental Science and Technology, 42(15), 1509-1630.