Cement company Lafarge Canada Inc. will try once again to gain permission to burn tires as fuel at its Brookfield Cement Plant in Nova Scotia. A similar proposal in 2007 was shot down by Nova Scotia in the face of public objection and a report that argued that there were better ways to deal with the province’s end-of-life tires.
But perhaps there aren’t.
The option chosen in 2007 was based on a demand for shredded tires as an additive to asphalt, and as aggregate and fill. However, the market never materialized at a scale that would take up the roughly one million tires that Nova Scotians dispose of each year. Currently, Nova Scotia’s recycling agency Divert NS (formerly the Resource Recovery Fund Board) has the equivalent of more than 600,000 tires in storage.
Lafarge has submitted an environmental assessment of a proposal that would make short work of that surplus inventory, burning up to 6,000 tonnes of tires per year at the Brookfield Cement Plant’s kiln #2. At an average weight of 10 kg per tire, the kiln could take up Nova Scotia’s entire backlog in its first year of operation.
Lafarge is also positioning the proposal as one adopting a “lower carbon fuel” option. This claim is based on three years of research at Dalhousie University that found that tires emit 30% less carbon than the coal currently burned in the kiln, and cut nitrogen oxides (NOx) emissions by between 10% and 15%.
Lafarge also has its eye on the looming price on carbon. Nova Scotia will be imposing a cap-and-trade system on large emitters beginning in 2018, and though the cap is not expected to be onerous at first, it will be cut annually, placing pressure on emitters like Lafarge.
Lafarge notes that the fuel mix at its Brookfield Cement Plant is already 35% lower carbon (shredded non-recyclable plastics and asphalt shingles) — the maximum based on global experience. According to its submission, “[i]n order to move from 35% to 50% fossil fuel replacement with lower carbon fuels, the goal of this project, the only proven technology for this kiln design is to use mid-kiln injection scrap tire systems which are in use throughout North America.”