Humans excel at burning things, and this fixation with fire has led to the combustion of barrels upon barrels of fuel stored in the Earth’s crust—commonly known as fossil fuels. World-o-meter estimates that nearly 35 billion barrels of oil are burned each year. The burning is primarily for energy production. However, this energy production comes at a cost to the environment, as byproducts collect in the atmosphere and oceans. Is there a less damaging and expensive alternative as we shift towards renewable energy sources?
The answer lies in garbage, specifically carbon-based waste materials. Extracting energy from waste not only mitigates the environmental impact of overflowing landfills but also offers an alternative, renewable energy source. In this article, we will explore five remarkable ways in which waste materials are converted into energy, providing a glimpse into the future of sustainable energy production.
1. Biomass:
Source of Waste: Agricultural residues, wood, and organic waste—think of typical yard work leftovers like grass clippings and pruned branches
How Energy is Produced: The Drax Power Station in the United Kingdom serves as an exemplar. It has undergone a transformation by converting from coal to biomass, using compressed wood pellets as fuel sourced sustainably from forests and agricultural residues. Instead of mining coal, this process reduces landfill waste while producing the same crucial energy needs. The burning biomass generates steam, which turns turbines (the key to all electricity production). This renewable energy is then supplied to the grid, reducing the carbon footprint of the area.
2. Tire Recycling:
Source of Waste: End-of-life tires
How Energy is Produced: Waste tire recycling equipment shreds tires into small scraps and removes contaminants like steel and fiber. The resulting tire shreds are packaged and sent to an energy production facility like Genan, a tire recycling company in Denmark. There the shreds become tire-derived fuel (TDF), a substitute for traditional fossil fuels in cement kilns. TDF is popular because it can produce super hot conditions necessary for cement production and helps solve the issue of end-of-life tires in landfills.
3. Landfill Gas:
Source of Waste: Landfills
How Energy is Produced: Decomposing organic matter in landfills releases methane gas—a powerful greenhouse gas and an excellent source of energy production. For example, The Puente Hills Landfill Gas-to-Energy Facility in California captures methane emitted during the decomposition of organic waste in landfills. Methane is then processed and utilized as a fuel source. While methane can be used for various purposes, the majority of the captured methane is combusted in engines to generate electricity. This electricity is integrated into the local power grid, reducing reliance on non-renewable energy sources.
4. Plastic-to-Fuel Conversion:
Source of Waste: Non-recyclable plastic waste
How Energy is Produced: Plastic Energy, a company in Spain, utilizes pyrolysis to break down non-recyclable plastics into synthetic oils. These synthetic oils can then be refined into various fuels, such as diesel or gasoline. The synthetic fuels produced can be used for transportation, thereby reducing the environmental impact of traditional fossil fuels in the automotive sector. Plastic is notoriously difficult to dispose of, and turning plastics into fuel doesn’t completely negate its environmental impact, but it does reduce the need for new oil extraction.
5. Sewage Sludge Conversion:
Source of Waste: Residual sludge from wastewater treatment plants
How Energy is Produced: Anaerobic (without oxygen) digestion of sewage creates methane, similar to that produced in landfills. For example, the Stickney Water Reclamation Plant in Illinois utilizes anaerobic digestion to break down sewage sludge. The generated biogas is used on-site to power the plant’s operations or is upgraded and injected into the natural gas grid. This process reduces dependence on traditional fossil fuels for energy.
Addressing Climate Change:
The transformation of waste into energy plays a crucial role in addressing climate change by offering a two-fold benefit.
- It reduces the reliance on fossil fuels, decreasing greenhouse gas emissions associated with traditional energy production.
- It decreases the release of potent greenhouse gases, such as methane, from decomposing organic matter in landfills.
Embracing waste-to-energy technologies is seldom championed in the media since people don’t love hearing about how their garbage and sewage power their light bulbs, but it remains a key component in the transition to a low-carbon energy future.
As the global community grapples with the challenges of a rapidly changing climate, waste-to-energy technologies stand as one of many technologies holding back the rising seas. By creatively repurposing various forms of waste into valuable energy resources, we not only alleviate the strain on our environment but also move towards a more sustainable and circular economy. As we continue to innovate and invest in these transformative technologies, the path to a greener future becomes more and more within our grasp.