Recycling one option for solid waste energy savings

Recycling three typical 12 ounce aluminum beverage cans, to create an aluminum sheet for making a new can, saves about a kilowatt-hour of electricity compared to the electricity it would take to make a sheet from aluminum ore. Glass, steel, plastics, car batteries and paper recycling can also create energy savings. Waste materials that are recycled are not sent to landfills, and thus do not contribute to the use of land for landfills.

Recyclable materials are typically mixed at the initial collection point (recycling bins). It takes capital investment and labor to create and operate a sorting center to separate the materials before sending them to the material production facilities that process materials to make new materials. It takes labor, capital and energy to move waste materials from their point of use to sorting centers and then to raw material production facilities.

In big cities, waste volumes are high and transportation distances to waste processing and manufacturing facilities tend to be low. Recycling is likely to be profitable, or at least to break even when the total costs of recycling vs. landfilling, including energy savings, are considered.

In smaller population centers, such as towns that are not close to larger communities’ recycling infrastructure, the economics of recycling can be more complicated. Paper and plastic products are heavy and bulky. They have value as raw materials for new paper and plastic, but their value is not as high per unit of weight/volume as metals. In a small, remote community, the cost of shipping paper and plastic wastes to a recycling center might be higher than the value of the material as a feedstock, and the energy required to ship them might be more than the energy saved by recycling them.

A new alternative is small-scale waste-to-energy systems. Use of recyclable waste as an energy source can save more energy than recycling, in situations in which shipment and processing energy requirements are high per unit of waste.

Historically, waste-to-energy systems, like those used in Sweden for large-scale electric generation, have been dependent on wastes from large populations. Research and development for specialized waste management conditions, such as ships needing to dispose of waste while at sea, temporary military bases that have no ability to develop long-term infrastructure, and countries that don’t regulate surface dumping has produced a new generation of WTE systems that operate on the scale of the waste produced by towns. These systems are starting to be adopted in the markets for which they were designed.

As with any successful new technology, the costs of WTE systems are falling, and their capabilities are improving. In some small communities in the U.S., choosing a new WTE system over recycling may now be desirable for food and wood product wastes that cannot be disposed of without significant shipping and handling costs.

American waste management regulations reflect a preference for recycling over waste-to-energy processing, especially incineration. The possibility that more energy might be saved by using local wastes, locally, than by using fuel for transporting materials requires fresh exploration. Regulation changes might prove both necessary, and justifiable.