Part 2: Carbon Capture, Utilization and Storage

In Part 1: Living in a Harsh World, I began to frame the challenge facing industrial producers around the world and began to set the table for Alberta having the potential to be a leading home for future investments in an emissions-constrained world.

Today, in Part 2, I look at some of the components of “Clean-tech” that supports this future, their status and where they may be going over the next years and decades.

Carbon dioxide capture

The large-scale CO₂ capture technologies that have been demonstrated around the world on industrial processes and coal-fired power plants have been based on solvent processes. In these capture facilities flue-gas is brought into contact with “lean” solvent that absorbs CO₂. The now-“rich” solvent is then sent to a regeneration stage, where heat is used to drive off the CO₂, after which it is dried and compressed for transportation. The now lean solvent is returned to be re-used.

Canada has punched above its weight in demonstrating large-scale, industrial capture facilities, with three of about 20 global facilities here. Two (Shell Quest and NWR Sturgeon Refinery) are located in the Alberta Industrial Heartland, northeast of Edmonton, and one (SaskPower Boundary Dam) is in Saskatchewan.

There are several parallel tracks where innovation is rapidly advancing in the carbon capture space, from improvements in equipment size, to new solvents and even “dry” processes, using solid sorbents or membranes. The early plants, as first of their kind, were custom engineered using very conservative assumptions. Because of this they were expensive but presented great opportunities to learn.

Some of the benefits spawned from the substantial public and private investments in of these plants, plus the many smaller-scale pilot and demonstration plants that are being built around the world, are the learnings that operators of these plants say will drive down the cost of their next carbon capture projects by 25% to 35%.  At the same time, Canadian and global entrepreneurs and engineering firms are investing in compact, modular designs that, for example, can be pre-fabricated and delivered to site at ever further cost savings.

Deep storage

One of Alberta’s strengths is our geology. The same formations that stored hydrocarbons for millions of years are well suited to store carbon dioxide as well. Alberta has enough storage capacity for about 7,000 years of Canada’s emissions at the current rates in these and other deep formations in Alberta, most of which now store brine (see below for a sidebar on deep storage in brine formations). Rigorous risk analysis has been done to prove that this can be done safely for long periods of time.

In the words of Prof. Stuart Haszeldine of the University of Edinburgh, “Geological storage of CO₂ is about 10,000 times safer than growing trees.”

Utilization: enhanced oil recovery

Carbon dioxide has been used in the U.S., Canada and elsewhere for many years to stimulate production from tired oilfields. Injection of CO₂ for tertiary enhanced oil recovery (EOR) is a proven economic use of CO₂. By injecting CO₂, the formation is pressurized, the flow characteristics of the oil is enhanced and the economic life of the field can be multiplied.

But what about the greenhouse gas impact?

Many climate-activists see CO₂ EOR as a bit of a shell game, asking, “Does this really benefit the environment? Afterall, CO₂ is produced with the oil, and the oil itself produces emissions when it is consumed.”

Operators pay for the CO₂ they inject with the aim of making a profit from the produced oil. They hate to waste an investment and the injected CO₂ is an investment. While CO₂ is produced with the oil, it is separated at the wellhead and circulated for reinjection. About 90 per cent of the CO₂ used in EOR remains in the formation at the end of the project.

It is true that most of the oil produced will be consumed by combustion as fuel. It is also true that oil produced by EOR has a considerably smaller carbon footprint than conventional oil production (assuming the CO₂ used was captured from a man-made source or the atmosphere and not produced from a geological source). Selling this oil into the market offsets higher emitting sources.

Putting a price on CO₂ makes oil production from EOR more profitable, able to compete readily against even the cheapest Saudi crude. At some point, the value of leaving CO₂ in the ground makes it profitable to continue injection even after the oil recovery has ceased. The equipment has long-since been paid for, and the incremental cost of continued injection means the cost per tonne may be quite low. At this point, the quantity of injected CO₂ may even exceed the emissions due to combustion of the oil produced from the field, resulting in a net-zero or -negative footprint for the produced oil.

In a world in which low climate impact opens doors to markets, this approach may tilt the competitive advantage back in Alberta’s favour.

Utilization: CO₂ conversion to valuable products

There has been a great deal said about this type of utilization of CO₂. There is something seductive about the idea of converting what is essentially a waste product into something of value. There are many groups around the world working to address this challenge. And the Carbon XPrize, funded by Canada’s Oil Sands Innovation Alliance (COSIA) and NRG, a major U.S. power utility, has done much to stimulate this work.

The Alberta Carbon Conversion Test Centre, funded by provincial and federal governments and industry, is located adjacent to the ENMAX Shepard Energy Centre. It will begin testing the XPrize finalists’ pilot plants this summer using flue gas from that new natural-gas-fired power station.

What matters in CO₂ utilization is:

• What is the net economic value of the product produced from the CO₂?
• What is the life-cycle emissions associated with it?
• How long does the product hold CO₂ out of the atmosphere? and,
• What is the total potential impact (in tonnes of CO₂ per year)?

Not that any one of these things rules out a technology from being of value, it’s just that all the proposed pathways score differently on these dimensions. A few examples of pathways include:

• Use of CO₂ in curing concrete binds the CO₂ into the cement minerals and produces a stronger concrete (requiring less cement, the source of most of the emissions associated with concrete) – See CarbonCure Technologies.
• Mineralization of CO₂ to produce aggregate for concrete, roadbed material, roofing and many other applications. The potential volumes of CO₂ stored in the built environment is substantial. For example, Blue Planet Ltd.
• Mineralization to produce other industrial products, for example for paper, plastics, paints, adhesives etc. – See Carbon Capture Machine (UK).

Next month: Beyond Projects – A systems approach for Alberta

Next month I’ll discuss how we can build on the existing investments in Alberta, learn from insights gained in initiatives elsewhere in the world, and develop a new Alberta (Carbon) Advantage. Can we develop a solid carbon management infrastructure and attract the next generation of industrial producers to Alberta by addressing their exposure to global climate policy risk?

Sidebar: Deep storage in brine formations

Under much of Alberta there are deep geological formations such as the Basal Cambrian Sands filled with water left over from ancient oceans. These briny, mineral-rich waters fill the pores in rocks that were the sandy sea floor some 540 million years ago. Above these are tight formations that are highly impermeable, consisting of shales, clays and other rocks that are referred to by geologists as “cap rock.”

These and other formations, one, two or more kilometres deep, are under intense pressure. Carbon dioxide compressed to high enough pressures to be injected into these zones enters a state that is neither gas nor liquid. It is more dense than liquid CO₂ and flows easily, like a gas. This “supercritical” fluid is slightly less dense than the brine, collecting under the cap rock, spreading out across the formation and dissolving into the water. Over time a portion of the CO₂ gets locked into ultra-fine pore spaces. The component that dissolves into the water reacts with the surrounding rock, binding the CO₂ into carbonate rock formations.

Over a period of 10,000 years it is as likely as not that 98 per cent of the injected carbon dioxide will still be in place, long after carbon absorbed into trees will have been released back into the atmosphere.

Sidebar: What about scale?

Sometimes I get asked why we can’t achieve the greenhouse gas targets by relying more heavily on variable renewables, such as solar and wind power.

First, that assumes that emissions only have to do with power generation, which is clearly not the case. Industrial emissions, from chemical or fertilizer production or cement, steel production or many other industrial processes cannot simply be replaced by electrification.

Let’s assume you wanted to replace the Shell Quest project (not the largest capture demonstration in the world) at 1 million tonnes CO₂/year captured and stored. Assume we want to use the current generation of 2.75 MW wind turbines, on 120-metre tall towers with 120-metre diameter rotors. Based on the Alberta electricity grid, if all the power produced could be taken, this would require about 235 turbines spread out over an area of approximately 338 square kilometres (about half the size of Edmonton). This one project would produce enough power to supply the city of Red Deer twice over.

This assumes we use the emissions offset factors published by the Alberta government in 2015. But the more renewables get installed, the effective emissions offset by new capacity reduces, so this is an optimistic assumption.

Interestingly, the wind farm would cost about $860 million (not including land acquisition). Given the ‘learning-by-doing’ that has taken place over the past few years, that is not far from the projected cost of the next generation of Shell-Quest-type CCS projects.

We could build many plants of this size in Alberta without making a dent in the geological storage capacity or having visible impact on the landscape.

How many thousands of square kilometres of land can we cover with 120-metre tall wind turbines before we get push-back? And this assumes we have access to premium wind resources and grid capacity and energy storage.

I am by no means opposed to variable renewables. We need to reduce emissions by every means at our disposal. To tackle global, industrial-scale challenges we need to look to industrial-scale solutions.