A test burn last spring at the St. Marys Cement Inc. plant on Water Street left no indication that the company should back off its hopes of one day fueling its kiln with post-recycling shredded plastic. But the road to that reality is a long one, and reaching its end is still not guaranteed.
Following several months analyzing the results from the May 11-25, 2011 test burn, the company hosted an information open house on Wednesday, Nov. 9 at the Town of St. Marys Municipal Operations Centre.
“We are very pleased, in general, with the trials,” said St. Marys Cement Environment Manager Martin Vroegh, in an interview with the Journal Argus.
The plastic, which was actually the shredded remains of bags used to carry compostible materials, performed better than expected from an energy production standpoint, Vroegh said. He believes this is because the shredding process took away more than expected of the residual moisture — which would otherwise have to be evaporated away in the burning process, taking up some of the available energy.
From an environmental standpoint, the fuel — which is normally petroleum coke — makes up only six per cent of what’s fed into the kiln. The rest is limestone for the production of cement. As a result, much of the airborne emissions result from the burning of the limestone, which would not change under the use of alternative fuel.
In addition, the equipment currently in place for feeding fuel into the Cement Plant’s kiln only allowed for a maximum of 23 per cent of the fuel during the test burn to be post-recycled plastic. The rest remained coke.
But even with less than a quarter of the fuel converted to the post-recycled plastic during the test burn, the positive effects on greenhouse gas production were evident. According to Vroegh, petroleum coke consists of as much as 90 per cent carbon, meaning its consumption by burning releases almost solely carbon dioxide — considered a major contributor to the greenhouse effect. The plastic, meanwhile, is a hydrocarbon, meaning some of the emissions are released in the form of hydrogen. This re-forms as water, so its effect in the atmosphere is negligible.
One of the information posters at the Nov. 9 open house summed up these finding succinctly: “No operational or environmental problems were experienced during the course of the demonstration.”
The posters provided brief descriptions of the entire process, ranging from the make-up of the alternative fuel, its delivery to the St. Marys plant from the Orgaworld recycling facility on Wellington Road South in London, and the various levels of testing for both environmental effects and the effects on the cement end product.
“A total of 157.9 tonnes of alternative fuel was delivered to St. Marys Cement, of which 84.9 tonnes . . . was consumed in the cement kiln,” the information explained, adding each of the truckloads was inspected for product quality in London before coming to St. Marys. “The unused alternative fuel was sent back to Orgaworld.”
Orgaworld marketing manager Travis Woollings attended the open house.
“This project is extremely important,” he told the Journal Argus. “It’s taking something that would otherwise be going to landfill, and has energy value, and diverting it from the waste stream.”
Woollings said Orgaworld has had subsequent meetings with St. Marys Cement regarding the logistics of product delivery, and about product quality. He adds they’re ready to do anything that might speed along the process of approval for burning the waste plastic on a permanent basis.
“We’re working very diligently with Martin’s team because, long term, it represents a huge benefit for both companies. We’re willing to invest considerably in our plant to make this work,” Woollings said.
But Vroegh was careful to state his company remains in the very early stages of making alternative fuels a reality in St. Marys.
“You could say that the day we put the application in for our trial (last spring), we were beginning our research stage,” he said. The next step would be a longer-term test burn, but that would again require applications through the Ministry of the Environment, as well as various levels of public consultation.
Still, the company has already invested considerable resources into the process, so it stands to reason that they will continue moving the approvals forward unless some reason arises for them not to. And last spring’s test burn definitely didn’t uncover any such negative feedback.
“This is more sustainable (than burning 100 per cent petroleum coke) because it’s less costly to process,” Vroegh commented. And “if it allows us to be more sustainable . . . if it allows us to be competitive, then it’s something we have to continue to look at from a business perspective.”
Vroegh noted the sluggish US economy has created a situation where, for the first time in memory, American companies are shipping cement into a Canadian market in which there’s still strong demand. Some of those US producers, as well as some in Quebec, are burning alternative fuels in a way that changes their cost structures. So it’s becoming more difficult for St. Marys-made products to remain competitive.
As for the future, though, Vroegh remained non-committal.
“At this point, we just can’t say for sure.”
St. Marys Cement encourages residents who couldn’t attend the open house to call 888-631-3761, email fueldemo@vcsmc. com, or view copies of the project material online at www.stmaryscement.com.