www.cheminst.ca September | October 2015
accnCanadian ChemiCal news l'aCtualité Chimique Canadienne
Sweet corn baSiS of nano breakthrough
co2 and waStewater: an unuSual coupling
Art Meets Chemistry
30 September/October 2015 www.cheminst.ca/magazine
Chemical Engineering | Co2 and Wastewater Treatment
It was a summer of extremes, from fires blackening Western Canadian forests to a shrivelling drought in California to heat waves that baked Pakistan
and India. Meteorologists pointed the finger at El Niño, the irregularly occur-ring weather system that causes extreme weather events like droughts, flooding and tropical storms. But some scientists and environmentalists also drew a link between the record-breaking tempera-tures and climate change.
University of British Columbia chemical engineering professor David Wilkinson, FCIC, is cautious about commenting on extreme global weather events. However, in his measured and soft-spoken way, he points out that since the Industrial Revolution beginning in the 18th century, the spewing of carbon dioxide (CO2) along with other greenhouse gases (GHG) into the sky have proven to be agents of atmospheric change. It is dawning on the global community that water shortages and climate change “are two of the biggest challenges we’ll meet in this century, so we definitely have to look for sustainable solutions for the use of water and to reduce CO2 and other GHG emis-sions,” says Wilkinson, a Canada Research Chair. There is some urgency, he adds. “Energy use is expected to double by the middle of this century.”
Wilkinson has been actively working on clean energy for many years. An academic who started his career in industry, Wilkinson once served as vice-president of research and development at Ballard Power Systems in Burnaby, BC. The company’s hydrogen
By Roberta Staley
Power CoupleUniversity of British Columbia chemical engineering professor David Wilkinson is scaling up his innovative clean energy technology — a coupled CO2 and wastewater treatment process that creates high-value chemicals for the fracking and oil and gas industries.
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Chemical Engineering | Co2 and Wastewater Treatment
industries. But until now, they were seen as two separate problems. The idea of treating both together in a coupled process “is unique and new,” says Wilkinson, who holds more than 75 patents in the areas of battery and fuel cell technology, electrochemistry and electrochemical engineering.
The process begins with gas phase CO2, which is fed into an electrochemical cell along with wastewater contaminated by salt or other dissolved solids. An elec-trochemical process then simultaneously converts the CO2 and separates the salts present in the brine. The result is a series of high-value chemicals that can be used on the industrial site, sold or used to create other chemical products. For example, sodium carbonate, sodium bicar-bonate and hydrochloric acid (HCl) are useful chemicals for use in enhanced oil recovery and fracking.
The CO2 stream doesn’t have to be particularly pure. “That’s an advantage of our system: we can take industrial grade CO2 streams and process them,” says Wilkinson. “We don’t have to separate the CO2 like you do in other processes.” This makes the process more efficient and cost effective. As a bonus, other pollutants present in the gas like sulphur oxides (SOx) and nitrogen oxides (NOx) can also be handled.
The key selling point of the technology: the production of high-value products, is attractive to an industry coping with declining oil prices. For many oil companies today, water treatment is seen as a cost and something to be avoided, says Alfred Lam, who was Wilkinson’s first PhD student 10 years ago before becoming a research associate. Wilkinson’s technology, says Lam, who is now the vice-president of Vancouver’s Chrysalix Energy Venture
fuel cells are one of many technologies that aim to offer an efficient alternative to conventional energy use and conversion. Wilkinson’s expertise was sought to help develop and advance the polymer electro-lyte membrane fuel cell (PEMFC) to meet commercial requirements.
Since joining UBC early in 2004, Wilkinson has used his expertise in elec-trochemistry to tackle other clean energy problems. One of his latest projects offers several solutions at once; it helps clean up wastewater left over from industrial processes such as oil extraction or fracking operations, it transforms waste CO2 and it produces valuable chemicals such as acids and carbonate salts. Two years ago, Wilkinson and his team in UBC’s Chemical and Biological Engineering Department: Saad Dara, Arman Bonakdarpour and Alfred Lam, were one of 24 winners out of several hundred international applicants awarded $500,000 in Round 1 of the Climate Change and Emissions Management Corporation (CCEMC) Grand Challenge. The Alberta-based CCEMC is a not-for-profit corporation with the mandate to reduce GHG emissions and adapt to climate change by supporting new technologies. The Wilkinson team’s research has also attracted high levels of funding from Western Diversification Canada and the Pacific Institute for Climate Solutions.
Wastewater treatment — including the removal of salts that build up during the resource extraction process — and the reduction of CO2 emissions have long been a challenge for the oil and gas and fracking
(L-R) University of British Columbia researchers Arman Bonakdarpour and David Wilkinson discuss ex-situ electrochemical measurements with a rotating disk electrode of one of the processes for the coupled water treatment/CO2 technology.
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32 September/October 2015 www.cheminst.ca/magazine
Chemical Engineering | Co2 and Wastewater Treatment
Water retentionWater is key to the fracking and oil and gas in-dustries. Yet both put a huge demand on water resources by drawing from underwater aquifers and surface resources like rivers and lakes. The largest component in fracking fluids is water and, in the United States, the industry uses more than 400 billion litres of water a year. This is more wa-ter than is consumed annually by the cities of Van-couver, Burnaby, Surrey and Richmond combined, says University of British Columbia chemical engi-neering professor David Wilkinson. The Alberta oil sands, which have reduced fresh water consump-tion through recycling efforts, still utilizes at least one barrel of fresh water per barrel of bitumen. This translates to 300,000 barrels of fresh water used ev-ery day in 2013, Wilkinson says.
Warm water is used in mining operations to sepa-rate the bitumen from clay and sand. In drilling op-erations, it generates steam via a process called Steam Assisted Gravity Drainage (SAGD) that heats a reservoir of bitumen, allowing the semi-solid hy-drocarbon product to flow to production wells. Salt is picked up from the sand in the SAGD process, says Wilkinson. Mining operations cannot use saline groundwater because it interferes with the separa-tion process. The salt in tailings ponds also ham-pers reclamation efforts. The technology developed by Wilkinson and his team is able to treat high total dissolved salts (TDS) in industrial wastewater and remove carbon dioxide in a coupled process.
The need for saltwater mitigation is high due to Alberta’s ancient geological history. Millions of years ago, over many different epochs, oceans covered what is now Alberta, leaving behind high-salt aqui-fers and salty soil in addition to the decaying plants and animals that created the province’s vast oil and gas reserves.
Capital, “changes the conversation from being a cost to one that creates value. As a waste-to-value innovation that provides oil field chemicals on site and on demand without complex logistics — that really resonates,” says Lam, who currently advises Wilkinson on the business potential of the project.
Lam also thinks that Wilkinson’s technology will resonate with the general public, which is pushing governments to develop and adopt renewable energy policies. “Some people might say that you’re prolonging the life of oil and gas by making it more cost effective,” says Lam. Experts believe that oil and gas will be in use until the middle of this century. “So how do we reduce that impact? I think this innovation does that,” Lam says.
This fall, Wilkinson and his team are ramping up develop-ment of the technology in a bid to access a CCEMC $3 million grant to support the second phase of the project. During a quick tour of the UBC laboratory in the Clean Energy Research Centre (CERC), Wilkinson points out where bench-scale testing of the process is taking place and where other clean energy research is in progress. The large scale prototyping for treating barrels of indus-trial wastewater will be done in collaboration with Vancouver’s NORAM Engineering and Constructors and be located at the BC Research/Technology Commercialization and Innovation Centre (BCRI). After that comes field testing, the all-important precursor to commercialization. “We have a clear road map through to pilot plant testing roll-out; we’ve demonstrated proof of concept at a reasonable level and carried out parametric analysis and some scal-ability testing,” says Wilkinson, adding that hydraulic fracturing may be a first entry point of commercialization. However, the process is adaptable and will be able to be applied anywhere CO2 or other GHGs are present, Wilkinson says. He anticipates the technology will also be useful in the future for seawater desalination in water-stressed regions where industrial CO2 is available.
Wilkinson says the technology will have positive benefits for the environment. Economic analysis shows that initial adoption of the process in Alberta alone could remove up to several megatonnes of CO2 and treat up to 80 million barrels of water every year. This, says Wilkinson is “significant.” The Canadian oil and gas industry produces 120 megatonnes of CO2 each year, an amount greater than total emissions from all the nation’s vehicles.
New approaches to electrodialysis — the movement of ions through semipermeable membranes aided by an electric field — are one of the keys to the Wilkinson team’s technology. In explaining how the process works, Wilkinson draws upon the example of kidney dialysis. Whether done artificially or within the body, the principles are similar in that waste components are separated out and removed.
Of course the wastewater-CO2 coupling process is slightly more complex. The coupled process treats the CO2 and salts with electrochemical and dialysis processes, producing acids, carbonates and other value-added products. In order to develop
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Chemical Engineering | Co2 and Wastewater Treatment
membranes that can handle the different levels of dissolved salts (TDS) treated by the process, Wilkinson is collaborating with Steven Holdcroft, FCIC, chair of the Simon Fraser University Department of Chemistry. A membrane specialist, Holdcroft focuses on membrane modi-fication and fabrication. The team is also collaborating with Brian Wetton, a professor in the UBC Department of Mathematics, to model some of the processes and components.
Holdcroft has developed a high-performance membrane made from polybenzimidazolium. Chemical modi-fications have transformed the polymer into anion-conducting polymer plas-tics. Initially, Holdcroft and his team designed the membrane to deal with hydroxide, which is highly caustic. “Not many membranes can survive a caustic
environment but these materials can,” he says. (In Wilkinson’s process, other anions such as bromide or chloride take the place of hydroxide but its durability is still a big asset.) Holdcroft’s innovations are some-what similar to established electrodialysis technology used in water purification. The unique nature of his membranes, however make them mechanically superior to commercial materials. These materials being used to make the membrane allows the selective transport of ions so that they become concentrated in some electro-chemical cells while other parts become diluted, thus separating the CO2 from its gaseous or liquid stream.
The membranes, adds Holdcroft, are about 50 microns thin, which is half the thickness of a human hair.
Commercialization is still a few years away and will require some significant
advances in scalability as well as testing at a pilot-scale level with commercial-size cells and stacks, using industrial waste-water. For Alfred Lam, immersed in the world of venture capital, Wilkinson’s technology has the potential to be a game changer. “At this stage, the economic models still have to be proven out but it’s almost the right time for investors to start coming around.” For Holdcroft, seeing the technology achieve commercializa-tion will be the perfect marriage of large and small. “We’re talking massive scales of purification,” he says. “We have to think from the molecular perspective — on the scale of angstroms and nanometres. Yet when we apply it to water purification, we’re talking about materials that have thousands of square metres. It’s huge scales of technology and it’s really exciting to be part of it.”
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The synthesized polymer shown here has been chemically transformed from polybenzimidazolium into mechanically tough anion-conducting material. The complex polybenzimidazolium molecule is pictured on the right.
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