Energy
Renewable
Sustainable
Waste Management
2.12 billion tons - The amount of waste the world generates in one year today. The bad news is, with the growing global urban population, this number will continue to rise. Annual waste is expected to treble by 2100.
Humans have been treating waste in the same ways for thousands of years by:
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Burying it
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Burning it
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Doing both
With the avalanche of waste coming our way in the following decades, are we able to deal with it effectively, efficiently, and with minimum impact on the environment?
But first, let's take a look at today's methods of dealing with waste!
Burying
Burying waste in landfills is bad for the environment. The problems are toxins, leachate, and greenhouse gases.
Toxins
Many materials in waste contain toxic substances. Over time, these toxins leach into our soil and groundwater, becoming environmental hazards for years.
Leachate
Leachate is the liquid formed when waste breaks down in the landfill and water filters through that waste. This liquid is highly toxic and can pollute the land, ground water, and waterways.
Greenhouse Gases
When organic material such as food scraps and green waste are put in landfills, it is often compacted and covered. This removes oxygen and causes it to break down in an anaerobic process. Eventually, this releases methane, a greenhouse gas. In addition, landfills generate carbon dioxide, ammonia, and sulfides.
21 times - The potency of methane compared to carbon dioxide in the greenhouse gas effect. This will have an enormous implication on global warming and climate change. Methane is also a flammable gas which can become dangerous if it is allowed to build in concentration. Incidents where landfills have exploded due to the presence of flammable methane have occurred.
Burning
2200 - The number of waste incinerators worldwide. These incinerators treat about 255 million tons of waste annually. By 2017, 180 new plants with a capacity of about 52 million tons are scheduled to be built. Growth is particularly strong in Europe due to the ban on landfilling untreated waste. Large numbers of waste incinerators have been built in recent years, with many more under construction.
Below are some challenges faced:
Bottom Ash
Burning waste does not make it totally disappear. There is toxic “bottom ash” which needs to be dealt with. Bottom ash is generally about 15% the weight of the waste burned. That ash must be disposed of, usually in landfills.
Pollution
While incineration could help reduce the demand on landfill, it still presents challenges to the environment. Incinerating waste generates particulates, heavy metal fly ash, sulfur dioxide, hydrochloric acid, and toxin such as dioxins, furans, and mercury. For decades, the incineration industry has tried many different ways to filter out these pollutants. While modern technologies have been able to reduce many pollutants from emissions, the result is still not 100%. There is a reason why the chimney of an incineration plant is typically 150 meters high to ensure the emissions disperse at a higher level and mix with the atmosphere to reduce impact on people.
Greenhouse Gases
Besides pollutants, the other issue is greenhouse gas emissions. For every ton of waste incinerated, it generates at least 1 ton of CO2, not counting the CO2 generated by waste collection trucks transporting waste to the incineration plant.
What should the solution be?
To develop a robust waste management system, we will need a comprehensive strategy:
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To avoid generating waste in the first place
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If the object is discarded and becomes waste, we will try to reuse or recycle it
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If we are unable to do so, we will repurpose the waste such that we can use it in a different way
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As a last resort, the waste will be disposed with minimum impact on the environment
Strategy 1: Reduce, Reuse and Recycle
99% of the things we buy end up as trash within six months. Without a doubt, reduce, reuse, and recycle (3Rs) is the best starting point to manage the runaway growth of the waste phenomenon.
Unfortunately, we still have a long way to go in the 3Rs. Take recycling as an example. Only a few countries like Germany, Austria, Taiwan, and Singapore have attained recycling rates of 60% or more.
However, the majority of countries in the world are far below this standard with sub 30% recycling rates. It is critical to get the 3Rs correct if we truly want to solve the global waste issue.
Strategy 2: Repurpose
If we cannot do the 3Rs, the next best approach will be to repurpose the waste.
This means to convert the waste into a useful form. MURSUN uses gasification technologies to convert all types of wastes into energy. We also use pelletization technologies to convert agricultural, wood, and horticultural wastes into pellets with wide applications ranging from cooking to energy generation.
Strategy 3: Local Repurposing Center
Today, waste management is largely a centralized concept of operations. Typically, waste collection trucks pick up waste from various locations and bring them to a centralized location (usually rural or remote) where they end up in a landfill or incinerator.
Thousands of waste collection trucks powered by diesel engines hit the road everyday, polluting the environment with their emissions. A centralized system depends heavily on this collection network. If a breakdown in the network occurs, the process will come to a halt and waste will be stuck at the place of origin with no alternative.
For practical reasons however, given the massive amount of waste we have to deal with daily, large scale centralized incineration plants are unavoidable.
Even so, we can create pockets of local waste treatment sites like Local Repurposing Centers (LRC) to complement the centralized system. We can position a gasification waste-to-energy system in the LRC to repurpose wastes onsite into energy and channel it back to the local community for their utility.
MURSUN's range of gasification WTE systems will be able to cater for different communities with different waste profiles and energy needs.
