It may or may not taste better than cement, but one thing's for sure - St. Marys Cement's newest product is safe enough to eat.
Last fall, the plant began testing a world's-first process that converts polluting carbon dioxide from its emissions stack into algae, the green, goopy plant that naturally coats river rocks and neglected swimming pools.
The fact that the concentrated algae resembles cake batter is of little consequence - in the small shed at the south end of the Water Street plant, this goo could go on to change the world. Instead of using fossil fuels such as coal and petroleum coke, many industries could look to using - and making - algae as a green, renewable source of fuel, without the dangerous greenhouse emissions.
The test has been running for about half of the time since the equipment was installed in October 2009, says Martin Vroegh, St. Marys Cement's (SMC) environmental manager.
“We're very excited,” says Vroegh. “As can be expected with a world's first, we're learning, but the results are very promising so far… we're very close to having the ability to go full-scale.”
SMC and its parent company, Brazilian-based Votorantim Cimentos, have been working with Pond Biofuels of Scarborough, on the algae test for the past three years - as a private company, Votorantim did not have to consult with shareholders, speeding up the approval process. The St. Marys site also helped get the test off the ground; without knowing exactly how much land would be needed for the test, the few hundred acres of SMC-owned land to the south of the plant could have proved convenient.  
The process basically mimics what happened on the Earth millions of years ago; volcanoes spewed gases from the Earth's core (mainly carbon dioxide, but a few trace elements as well, such as sulphur dioxide) which algae then converted, using photosynthesis, into more algae, as well as oxygen and nitrogen, which are naturally present in the Earth's atmosphere.
The resulting algae, with its naturally high carbon content, has been successfully used as biodiesel fuel in laboratory. Vroegh says a timeline for using the SMC-produced algae is hinged to when the process moves from test to reality, as not enough algae is currently being made to fuel the plant or its fleet of trucks.
As for the more contentious test -- burning waste plastic instead of fossil fuels -- while SMC did receive approval from the Ministry of the Environment in the spring to conduct a test burn of waste plastic, Vroegh says that the project is “currently on hold” as Orgaworld is sorting out odour issues at the London plant which would be supplying the test.
The Journal Argus was the first in the world to report on the groundbreaking algae test in June 2009, and Vroegh says that thanks to the Internet, he's received calls of interest from around the world based on the story, as well as a story that appeared in the Toronto Star this March.
Pond Biofuels recently secured intellectual property rights on the process. And, without fears of the technology being usurped by other firms, more people can participate in the research - and not have to replicate any missteps that have already been made in St. Marys.
This means an industrial steering committee will be created, in order to attract researchers from the private and education sectors to perfect the process so that all of the plant's emissions can be used, instead of the one per cent of the emissions currently being tested.
“We're using SMC engineers now, but (with the creation of the steering committee) we'll be able to get university researchers who eat, live and breathe algae production,” says Vroegh.
He adds that there's been extensive interest from universities in the region to participate in the test and rollout of the full-scale system.
Considering that a full-scale algae system would cost millions of dollars, Vroegh says, “we have to make sure risk is minimized when we go to a full-scale facility.”
Aside from perfecting the process to allow for a full-scale rollout, Vroegh says researchers will be especially interested in the micro ecology of the process. Since the process essentially replicates what a natural pond does, it is essential that the process mimic a healthy pond, instead of creating something completely different than nature.
“It's a question of how to manage an existing system instead of creating our own ecosystem, so that the algae species interact naturally,” notes Vroegh.
The test already has two aspects working in its favour. First, the process of using carbon dioxide gas as algae food is working in the real world, outside of the sterile confines of a laboratory. Second, SMC and Pond Biofuels are using strains of algae already found in this area, from the Thames River, a mere few hundred metres away. (Some research firms in the United States are exploring a genetically engineered algae to create biofuels in different settings, raising concerns that a so-called “super algae” could become an invasive species if it escapes a controlled setting, acccording to  a New York Times article on its website, www.nytimes.com, from July 26.)
But replicating nature isn't as easy as one might think. From a point about 70 feet up the SMC's main exhaust stack, 1,000 feet of stainless steel piping runs into the unassuming, insulated shed where the magic happens.
In the shed are three large tanks, as well as a myriad of computer equipment monitoring the test. On the day of the Journal Argus' visit, two tanks are running different versions of algae production. In the first tank, water and stack gas are being conditioned prior to algae being added. The pH levels are being calibrated, the nutrient content determined and enough time is passing to ensure the carbon dioxide is properly dissolved within the water. As for other trace compounds found in the exhaust, including sulphur and nitrous oxide, they are involved in the process as a “fertilizer” for the algae, says Vroegh.
Once the water is ready, algae is implanted into the tank, and artificial light is used to mimic the sun, so that photosynthesis can take place in the algae and it can absorb carbon dioxide while releasing oxygen.
It's not a run-of-the-mill bulb powering the photosynthesis, but rather a highly efficient light that is proprietory to Pond Biofuels. The system allows the test to run 24-hours a day, without having to worry about weather conditions. Vroegh points out that they have also been testing a system that uses a parabolic reflector to harness light from the sun to also be used in the tank, similar to how a solar panel captures the sun's energy.
Over in the second tank, there is a murky, mucky mix of water and algae growing that’s bubbling away as it grows, due to the oxygen and nitrogen that's found in the atmosphere (and the stack gasses) coming to the surface.
This tank has been running for about two-and-a-half weeks, and was “harvested” two days prior. Ideally, says Vroegh, harvesting would take place at the exact rate of the algae's growth - and the team was able to make it this happen for one straight week.
“A lot of the hiccups are from the plant shutting down,” whether it is from a power outage or a work stoppage, such as holiday shutdowns, says Vroegh.
At harvest time, the water and algae eventually reaches a level that surpasses a drainage point (like a bathtub's emergency drain near the tub’s top) and it runs off into a harvest tank that draws the algae-water mix into a centrifuge.
“It's cheaper than using filters that have to be regularly cleaned and replaced,” says Vroegh. “We looked to apple juice manufacturers and sewage treatment plants to see how they separated solids from liquids.”
It only takes a half-gram of algae per litre of water to seed the tanks. Vroegh says they are a trying out a variety of  local algae strains to best replicate what would happen in nature. The entire test is computer-monitored, and nce the system becomes full-scale, Vroegh says it will be likely be linked to the plant's main operating computer.
The steering team will also be looking at balancing the end products with the system itself; for example, if coal-fired power plants can use algae as a fuel, different strains or photosynthesis techniques will be used to maximize this potential so that there is a financial bonus to production.
“In the future, it's very possible that the cement industry will be mining limestone as a source of carbon dioxide, instead of letting it out of the stack, use it to make biofuels,” says Vroegh.
Theoretically, the next stage would be to increase the scale of the test to one-third of the stack gases, instead of the current one per cent. The study would continue, and then when it proves itself, move up to a full-stage system.
“This is the future of energy,” he says of the prehistoric algae. “And now we can put research into it, finding out what makes it tick.”