New York and the New England states produce about 14 million tons of waste from the construction and demolition (C&D) of buildings. And one of my clients is in the process of building a gasification plant to process with as much that tonnage as he can possibly get his hands on.
He’s latched onto an interesting opportunity to turn lemons into lemonade, as they say. Insofar as a great deal (up to about 30%) of this waste is wood, biomass-to-energy processes can be brought to bear to extract and make use of the chemical energy, while reducing the financial and environmental costs of shipping this material off to landfills.
But, as I’m learning, many of the flavors of waste-to-energy technology are inappropriate here, as the introduction of oxygen to the gasification of wood that has been waterproofed with copper compounds or creosote creates a carcinogenic slag. Also, no matter how you presort the materials, you’ll wind up with a non-negligible amount of the guts of ballasts from fluorescent lights, which contains PBCs.
Some claim they can formulate concrete or aggregate for roads or railway beds with the slag – which is fine, until it decomposes in a decade or two and the cancer-causing agents wind up in the water table. Those with a concern for the health of others (or an aversion for colossal lawsuits) would do well to take note.
Welcome to the world of thermal anaerobic gasification, which introduces no oxygen to the process. Not only does this render the end-products harmless, but most of them have value in themselves, e.g., activated carbon, used in filtration.
I’m lucky enough to have made contact with one of the true masters of this incredible discipline. If anyone wishes to lean more, please let me know, and I’ll put you in touch.