A hot alternative to hidden costs of recycling

Some nominally recyclable organic materials, in some specific locations, may be better used as fuel for a waste-to-energy system, even if that system produces some carbon dioxide, for the purpose of replacing a fueled heating system that would produce even more carbon dioxide and reducing waste shipments. La Conner may be one such location.

There are two major reasons to recycle. If you can reuse raw materials that have already been extracted and processed, you’ll reduce the need to extract new resources. And, if you reuse the materials, you’ll save energy, because it takes less energy to convert used (metal, paper, glass, plastic, etc.) to a new product than it does to create the desired product from raw materials.

Most discussions about recycling focus on how much energy it saves to make something from recyclable materials, relative to how much energy it would take to make the same item from conventional feedstocks. Metals have high value and are compact; they are usually recyclable. However, recycling might not be the optimal solution for, say, low-value paper products that may have significant food contamination.

The question of how much energy it takes to collect the recyclable materials, ship them to a sorting facility, sort them, and ship them to the point at which the recycling actually takes place is often ignored. If it takes more energy to ship used materials than is saved by recycling them (including consideration of the fraction of the material that has to be landfilled because it is too contaminated to be recycled), recycling may not be the most environmentally friendly choice, even though it seems like it should be.

The question of how much energy it takes to clean the materials well enough to actually use them as a recycling feedstock is often also ignored. When people put paper containing food residues into a paper recycling stream, the food-bearing paper has to be sorted out. Inadequate sorting can result in the loss of other recyclable materials that are mixed with the contaminated paper, in which case both the contaminated and uncontaminated paper are ultimately landfilled rather than recycled.

In La Conner – and even more so in more remote, but similarly small locations, like Concrete – it’s not necessarily a given that recycling is the optimum solution for all organic waste management. Businesses have to drive tiny loads of cardboard packaging materials – 10 or 20 pounds of waste at a time – to the county recycling collection station, and then drive back. In locations without composting, there’s no easy way to deal with food wastes and food-contaminated paper.

In places like these, it might be desirable to build a small gasifier to process all these waste streams locally. Small gasifiers were originally developed for use on oceangoing ships. Now they are starting to find uses in airports and remote towns. They can safely destroy combined food wastes, paper, cardboard and even some plastics. Unlike an incinerator, a gasifier captures some of the carbon in the feed material in the form of biochar that can be used as a soil additive, instead of releasing it as carbon dioxide.

The remaining carbon does produce carbon dioxide, but the heat this creates can replace heat otherwise produced by gas or propane, while reducing waste shipments and avoiding the contamination of recycle feedstocks.