Innovations in new technology enable us to recycle municipal solid waste and even convert non-recyclable waste into energy — which is good because landfills just keep growing.

Municipal solid waste (MSW) consists of everyday garbage like food scraps, metals, paper, textiles, glass, and wood. The United States generates the largest amount of MSW worldwide with 258 million tons per year.

The EPA estimates that of this waste: 30% is recycled or composted, 10% is sent to waste-to-energy facilities, and the rest makes its way to landfills. Worldwide population growth and increasing consumer demand will lead to even greater waste generation in the future.

At the rate the U.S. is generating waste, landfill space will eventually run out, according to RoadRunner Smarter Recycling, which means we desperately need new solutions to reduce the size of our landfills. Recycling and waste-to-energy technologies have been utilized to combat MSW accumulation over the past several decades, giving waste a new purpose.

Recycling significantly reduces landfill waste and carbon dioxide

Recycling is preferred to energy recovery methods, according to the EPA’s hierarchy of strategies for disposing of MSW. By recycling solid waste, materials once considered trash can become of use again due to new technology.

While recycling gained some attention from environmentalists in the 1960s, it wasn’t popularized until landfills began filling up in the 1970s. Now recycling has become a common residential practice with almost 75% of single-family households having access to some sort of recycling service.

In addition to reducing the size of landfills, recycling MSW has the power to substantially cut down annual carbon dioxide emissions. By recycling MSW 186 million metric tons worth of carbon dioxide was reduced in 2013 – the equivalent to taking 39 million cars off the streets for the whole year.

Recycling technologies

Low technology, such as manual sorting, is still used in many material recycling facilities today. Materials that require less attention, such as glass, paper, and plastic, may be sorted at curbs — a process known as source separation.

Higher technology has recently been incorporated into several low-tech MRFs:

Dual-stream recycling separates the waste into two streams — fiber and containers — by using both manual sorting and automated equipment.
Single stream recycling is similar to dual-stream except the recyclables don’t come separated, so higher technology is required to separate them at the beginning of the process.
Mixed waste recycling separates recyclable materials from waste and then continues separating the recyclables, making it the most tech-oriented method of these options.

Recycling companies, like MSW Sorting, believe utilizing cutting edge technology will advance their recycling abilities. MSW Sorting has invested in sorting robots that can identify different kinds of waste and sort them into their proper category. This investment limits the need for manual sorting, a time-consuming technology.

How effective is recycling?

Waste can be a renewable energy source

While recycling is the preferred method of waste management, non-recyclable MSW can be converted to energy through methods like combustion, pyrolysis, and gasification. Because energy can be recovered from MSW, many researchers consider the waste itself to be a renewable energy source.

Waste has been burned for the past several decades in an effort to create space in landfills, but it wasn’t until the 1970s when waste-to-energy recovery became more common.

The U.S. converted 25 million tons of combustible MSW into an estimated 13 billion kilowatt-hours of electricity in 2019 — enough electricity to power over a million homes in the US for a whole year.

Waste-to-energy plants can reduce the volume of waste up to 87%, so many countries with limited space take advantage of this technology. In 2017, 74% of Japan’s MSW was converted to energy compared to the United States’ mere 12%.

Methods of conversion can be separated into two broad types:

Aerobic oxidation, mainly done through composting food scraps.
Anaerobic digestion, the most commonly used method. Organic matter is broken down without the presence of oxygen to create biogas and biofuel.

Thermal treatment types

Thermal treatment uses anaerobic digestion to modify both the physical and chemical structure of the waste so it’s able to be converted into energy. It can be divided into three subcategories: gasification, pyrolysis, and combustion in excess air.

Gasification is the complex process of converting household waste into substances rich in carbon, like char and synthetic gas. This process requires a high level of maintenance to be performed correctly and efficiently. On the other hand, it requires little to no fuel demand and emits little air pollution, making it an attractive option.
Combustion, also known as mass burning, is the process of burning MSW in a combustion chamber with the presence of excess air. This process is the most common waste-to-energy method used partly due to its low maintenance requirements. Incinerators are often used to combust waste, but this technology can produce toxic chemicals, such as carbon monoxide, that pollute the air.
Pyrolysis is the process of exposing waste to extremely high temperatures in order to create biofuel. While this process may sound similar to incineration, pyrolysis is performed in the absence of air and generates less dioxins, making it a cleaner method. But pyrolysis does have some downfalls — particularly the fact that MSW technology is still limited.

Van Dyk Recycling Solutions utilizes several technologies they believe allow them to have the most advanced sorting equipment to recover energy from non-recycled MSW. The company uses 3D technology to estimate the size of the waste and prevent any jamming that may occur. Their newest technology can convert some MSW into sellable compost.

A New Hope

Technological innovation in general often leads to resource depletion, deforestation, and other environmental harm. Countless examples of this exist, including the industrial revolution, improvements in agriculture, and fossil fuel extraction.

By investing in technology dedicated to waste management, we can leverage human innovation to reverse the effects of climate change rather than exacerbating them.

+12 Resources

Advancing Sustainable Materials Management: Facts and Figures 2013: Assessing Trends in Material Generation, Recycling and Disposal in the United States. EPA. (2015, June). https://www.epa.gov/sites/default/files/2015-09/documents/2013_advncng_smm_rpt.pdf.
Al-Ghouti, M. A., Khan, M., Nasser, M. S., Al-Saad, K., & Heng, O. E. (2020, November 24). Recent advances and applications of municipal solid wastes bottom and fly ashes: Insights into sustainable management and conservation of resources. Environmental Technology & Innovation. https://www.sciencedirect.com/science/article/pii/S2352186420315674.
ASCE. (n.d.). 2017 Infrastructure Report Card. https://www.infrastructurereportcard.org/wp-content/uploads/2017/01/Solid-Waste-Final.pdf.
Deer, R. (n.d.). Landfills: We're running out of space. RoadRunner Recycling. https://www.roadrunnerwm.com/blog/landfills-were-running-out-of-space.
Eldred, S. (2020, April 14). When did americans start recycling? History.com. https://www.history.com/news/recycling-history-america
Lane, T. (2016, May 31). Municipal Solid Waste (MSW) Value-Recovery Technology Assessment. Solid Waste Authority of Central Ohio. https://www.swaco.org/DocumentCenter/View/132/Solid-Waste-Value-Recovery-Technology-Report-PDF?bidId=.
Mouw, S. (2020, February 13). State of Curbside Recycling Report. Recycling Partnership. https://recyclingpartnership.org/wp-content/uploads/dlm_uploads/2020/02/2020-State-of-Curbside-Recycling.pdf.
Municipal Solid Waste Generation, Recycling, and Disposal in the United States: Facts and Figures 2012. U.S. Environmental Protection Agency. (2014, February). https://www.epa.gov/sites/default/files/2015-09/documents/2012_msw_fs.pdf.
Municipal solid waste (msw) sorting & recycling systems - Vdrs. Van Dyk Recycling Solutions. (2020, September 25). https://vdrs.com/msw-processing/.
MSWsorting. (n.d.). MSW sorting. MSWsorting. https://www.mswsorting.com/.
U.S. energy Information administration - eia - independent statistics and analysis. Waste-to-energy (MSW) - U.S. Energy Information Administration (EIA). (n.d.). https://www.eia.gov/energyexplained/biomass/waste-to-energy.php.
Sustainable Materials Management: Non-Hazardous Materials and Waste Management Hierarchy. (n.d.). U.S. Environmental Protection Agency. https://www.epa.gov/smm/sustainable-materials-management-non-hazardous-materials-and-waste-management-hierarchy

Cleanup News is an all-volunteer organization dedicated to bringing individuals and organizations together with the shared mission to encourage a clean outdoors. We’re growing because of giving individuals that recognize the positive aspects of our mission. CleanUp News is your source for news about the industry.

Technologies that Divert Waste from Landfills