Waste is a resource with vast potential. Harnessing the energy from waste is a must in every modern society. The more value a society can extract from its waste, the better.
How do you convert waste to energy?
Waste that cannot be reduced, reused, or recycled can be used for energy recovery. Modern waste-to-energy plants, also called energy from waste plants, handle a waste problem and produce electricity and heat to nearby cities. The best and most modern systems work with an energy efficiency of nearly 100 percent through advanced technology. The impact of these plants on the local environment is minimal through the advanced use of filters and other technologies to such an extent that they can even be located in the centre of large cities, as is seen in Copenhagen, Denmark.
Global waste management and its impact on greenhouse gas emissions
Currently, only 19% of all waste worldwide is recycled or composted, and 11% is incinerated. The rest is sent to landfills (37%) or openly dumped (33%). According to the Intergovernmental Panel on Climate Change (IPCC) Waste Management report, waste contributes to global greenhouse gas (GHG) emissions. The largest source is landfill methane (CH4), followed by wastewater CH4 and nitrous oxide (N2O). Minor carbon dioxide emissions (CO2) result from the incineration of fossil carbon waste (plastics and synthetic textiles). A landfill is the worst and most common solution.
19%
Recycled / composted
11%
Incinerated
37%
Sent to landfills
33%
Openly dumped
Composition and climate impact of landfill gas (LFG)
Landfill gas (LFG) is a byproduct of decomposing organic landfill material. It is composed of roughly 50% methane, 50% carbon dioxide, and small amounts of non-methane organic compounds. According to the latest IPCC assessment report (AR5), methane is a potent greenhouse gas, 28 to 36 times more effective than CO2 at trapping heat in the atmosphere over 100 years.
Effective waste management practices for reducing GHG emissions
Existing waste-management practices can effectively mitigate GHG emissions. Various mature, environmentally effective technologies can reduce emissions and benefit public health, environmental protection, and sustainable development. These technologies can reduce GHG emissions through landfill gas recovery, improved landfill practices, engineered wastewater management, controlled organic waste composting, expanded sanitation coverage, and advanced incineration.
Benefits and viability of Waste-to-Energy (WtE) technologies
Vestforbraending incineration plant is situated in the suburbs of Copenhagen.
Waste-to-Energy (WtE) technologies, such as incineration and industrial co-combustion, offer significant renewable energy benefits and fossil fuel offsets. Currently, more than 600 plants incinerate over 130 million tons of waste per year. These thermal processes, when coupled with advanced emission controls, are proven technology. While they may be more costly than controlled landfilling with gas recovery, they become increasingly viable as energy prices rise. The potential for renewable energy generation and GHG emission reduction is substantial.
Economic potential of reducing landfill CH4 emissions
The economic benefits of reducing landfill CH4 emissions are not to be overlooked. The total global economic mitigation potential for this in 2030 is estimated to be over 1000 MtCO2-eq (or 70% of estimated emissions) at costs below 100 US$/tCO2-eq/year. This represents a significant opportunity for cost savings and financial gain, making the adoption of waste-to-energy technologies a smart investment.
Waste is a valuable resource for green energy, capable of being converted into biogas or incinerated to produce electricity and district heating (DH).
Videos about WtE technologies around the world
Waste to Energy with Carbon Capture
Waste-to-energy (WtE) with carbon capture is an innovative process that converts waste materials into electricity or heat while capturing carbon dioxide emissions. This technology not only reduces landfill waste but also mitigates greenhouse gas emissions. By integrating carbon capture, WtE plants can sequester CO2, preventing it from entering the atmosphere and contributing to climate change. This combination enhances the sustainability of waste management and energy production, aligning with environmental and energy efficiency goals.
Read about carbon capture in “Carbon Capture – How it is Done at ARC”.
How does energy from waste work?
Energy from waste (EfW), also known as waste-to-energy (WtE), is a process of generating energy in the form of electricity or heat from the primary treatment of waste. It is a form of energy recovery and is achieved through various technologies that transform waste materials into usable energy.
Here is a detailed overview of how energy from waste works:
Collection and Preparation of Waste
The process begins with the collection of municipal solid waste (MSW), industrial waste, or biomass. The waste is then sorted to remove recyclable materials and hazardous substances. The remaining waste is often shredded or prepared to ensure it is suitable for the energy recovery process.
Waste Treatment Technologies
There are several technologies used to convert waste into energy, including:
Energy Utilization
The energy generated from these processes can be used in several ways:
- Electricity Generation: The primary use is to generate electricity that can be fed into the grid.
- District Heating: Heat produced can be used for district heating systems, providing residential and commercial heating.
- Combined Heat and Power (CHP): Some facilities use combined heat and power systems to maximize efficiency by producing electricity and useful heat simultaneously.
Environmental and Economic Benefits
- Waste Reduction: Reduces the amount of waste sent to landfills, mitigating landfill-related issues like leachate and methane emissions.
- Energy Production: Provides a renewable energy source, reducing reliance on fossil fuels.
- Resource Recovery: Metals and other materials can be recovered from the ash produced by incineration.
- Economic Incentives: Creates jobs and can be economically beneficial through the sale of electricity and heat.
Environmental Concerns and Mitigation
- Emissions: EfW plants are equipped with advanced pollution control systems to minimize emissions of harmful pollutants.
- Residual Ash: The ash produced, particularly from incineration, needs proper disposal or can be used in construction materials.
Conclusion
Energy from waste is a versatile and effective means of managing waste while producing energy. It combines waste management with energy recovery, offering environmental and economic benefits. EfW facilities use various technologies to convert waste materials into valuable energy, contributing to sustainable waste management practices and renewable energy production.