Industrial Emissions: Algae that Eat Pollution

Any system that cuts down industrial pollution is a bonus – but if the method can use natural organisms rather than chemicals or energy-intensive industrial processes, then that’s even better. By Jeremy Torr and ASLA’s Phil Stamper.

Philadelphia, United States, 21 October 2013. According to Taimur Burki, Global Green Building Program Manager for Intel Corporation, the possibility of using algae to cut industry pollutants is a real one. At a session at the 2013 Greenbuild in Philadelphia, he noted that during the certification of severa wafer fabrication plants for Intel, he was able to achieve LEED NC and LEED EBOM certification, even though the process at the plants involved highly complex chemical and water-intensive processes.

“We managed to achieve those while driving the world's largest semiconductor company to a 90% solid waste recycling goal - and improving the green building footprint via a multiplicity of efforts,” he said.

Together with Joshua Wray, a graduate Research Assistant (PhD) at Arizona State University, Burki looked at the possibility of using algae as an industrial emissions control strategy. Their team analysed the results of an experiment between ASU and Intel to measure algae’s impact on the industrial sector.

Wray, a self-professed algae farmer, has been involved in many bioremediation projects in the past that involved capturing nutrients from waste streams, but, in this case, the algae was intended to draw carbon and nitrogen from flue gases produced in an industrial process.

After identifying the many alternate uses of algae—biofuels, pharmaceuticals, even in food—researchers found that some strains are very adaptable. Picking and choosing the best strains for this experiment was incredibly important, says Wray. “With full development and implementation of this technology, industries could better manage their greenhouse gas emissions making it easier to meet ever-tightening air quality standards while making their operations more sustainable,” he said. The main problem is that only specific strands of algae will feed on carbon dioxide and help reduce emissions; identifying which ones is key to the success of the technology.

The Arizona desert, used as a test site, was perfect for many reasons, said Wray. The dry places offer a lot of sun (which is key to photosynthesis, and important part of the process), heat, access to wastewater and it is made up of non-arable land so does not displace any other valuable agricultural activities.

And at ASU, the number of world-renowned algae scientists is higher than normal – so the location virtually chose itself. ASU worked with Intel to erect flat panel bioreactors on the roof of one of their fabrication buildings to capture boiler emissions and convert the otherwise waste pollutants into biofuel. The reactors were filled with algae grown from ponds or other bioreactors. “CO2 and greenhouse gas emissions are newly regulated at many industrial sources. Control technologies for these gases are not readily available yet, so it is important to understand which technologies may be viable either currently or in the future,” said Tim Higgs, Corporate Environmental Engineer for Air Quality at Intel and another contributor to the project.

Higgs also noted that working with agencies in developing countries such as China to help them learn from their experiences how to implement pollution control and sustainability in their home countries. Researchers studied the roof-mounted bioreactors to see if they could grow algae, whether any CO2 was filtered out and if this process could be used to create clean-burning processes.

Intel’s project leader Brad Biddle said the outcome was already giving “some pretty exciting results” but admitted there is still much research to be done and many follow-up experiments on the system are required, but noted they had great success in growing algae and filtering carbon and nitrogen oxides out of the flue gas.

Though the desert light and heat are best for the experimental work and for the algae farmers, similar work is going on at several other research establishments. In the US, Duke Energy and the University of Kentucky have a partnership that will soon start using algae to convert flue gas emissions into biofuel. And in India, the country’s largest generation utility has launched a project to use algae to minimise CO2 output from power generation plants.

As Biddle says, it’s still a process that researchers are learning about every day, but its potential is outstanding. A key to sustainable building is to reduce carbon emissions, and if something as small and plentiful as microalgae can help bring plants to near-zero emissions, that’s exciting possibilities for the future. “The big question is scalability,” he admits, “but we found a really important answer to the question. Can you grow algae in a flue stack? And the answer is yes.”