Hello everyone. We are going to discuss one of the options for managing our greenhouse gas emissions carbon capture, utilization storage. It's important for us to understand how CCUS fits into the wide range of options we have for reducing and removing CO2 emissions from our atmosphere and how CCUS integrates with the many future energy transition scenarios. This includes fossil fuel related energy production in all its many forms such as heat and electricity. Where CCUS can be an effective tool in reducing emissions, it's also important for us to understand what this means as energy system transitions over the next several decades. And ultimately we will explore the elements of each component of the CCUS value chain capture, utilization and storage. And so what does the CCUS value chain look like? CCUS refers to a suite of technology that involves the capture of CO2, the second C in CCUS from the emissions generated from large point sources. And you will hear this word point sources because CCUS does not generally refer to mobile sources of CO2 that occur in the transportation sector. For instance, where other technologies are being adopted and explored for emissions reduction in those sectors. So these point sources can include power generation facilities such as coal and natural gas-fired power plants or industrial facilities such as cement or steel manufacturing plants. These facilities use either fossil fuels as the primary source or biomass as fuel for their operations. An additional method of capture that is gaining increased intention is direct air capture where CO2 is captured directly from the atmosphere. Air is circulated through specialized particles that absorb and hold onto the CO2. Through all of these methods, once the CO2 is captured using a multitude of processes, it is then transported in a multiple ways. The most common being pipeline transport to a location for use or utilization, the U in CCUS. Or for permanent storage, the S in CCUS by injecting the CO2 into deep geological formations such as saline aquifers or depleted oil and gas reservoirs. So then now that you have a sense of the overall nature of CCUS, it's worth briefly reviewing why CCUS is necessary. Previous modules in this course have highlighted where CCUS is used to manage our emissions from energy and industrial sources. And these figures are a reminder that the challenges large and while progress is being made towards increasingly renewable sources of energy, fossil fuel-based energy remains a significant component of the energy mix over the next several decades. And if that is the case, we need multiple strategies to manage our greenhouse gas emissions. And in order for us to move along that dotted purple line, we need to start now. CCUS provides us with one of those options. And this slide provides a nice summary of a range of those options, including CCUS. As you look at the trend and CO2 emissions beyond 2020 most projections, if we adopt a business as usual approach, we will follow the red line or the current trends line. And what the wedges represent is a whole series of decarbonization options that allow us to move from the red line down to the green sustainable development line by 2050. And you can see that energy efficiency, adoption of renewables fuel switching, CCUS, the topic of today's module and others are all needed to get to that green line. So in other words, we need to walk and chew gum at the same time. And perhaps one more reference to wedges to provide some sense of the size of the decarbonization challenge in the role of CCUS in playing and helping to meet those challenges. In the days of what was called the Climate Change Initiative at Princeton University, Dr. Socolow and Pakula developed the concept of decarbonization wedges. Where each wedge represented an annual reduction of carbon emissions of one gigaton, very large volume. And then given the number of reges, is that was required to get to the green line postulated what types of technologies and at what deployment scale would be needed for each wedge. And if you scan the list and defines each wedge, it is quickly apparent that decarbonization is a major challenge on all fronts. And for CCUS one wedge, the CCUS wedge, it means deploying. It will require being applied to approximately 1,600 natural gas-fired power plants from now until 2057 to remove a gigaton per year of CO2 emissions. This is a big challenge. And so now that we have a sense of what CCUS can indeed play a part in reducing CO2 emissions to the atmosphere. Let's turn our attention to the other three stated objectives of this module, develop a better understanding of carbon capture technologies, understanding the range of CO2 utilization options and what do we mean by the storage of CO2? So CO2 capture involves the separation and purification of CO2 from human-driven processes that generate CO2 emissions, probably the most familiar being fossil fuel combustion. It involves industrial processes that create goods like cement and steel and chemicals, and capture can happen directly from the atmosphere as we just chatted. There are three basic types of CO2 capture pre-combustion, post-combustion and oxyfuel combustion. Pre-combustion processes convert fuel into a gaseous mixture of hydrogen and CO2. The hydrogen is separated and can be burnt without producing any CO2, the CO2 can then be compressed for transport and storage. Post-combustion processes separate CO2 from combustion exhaust gases. CO2 can be captured using a liquid solvent or some other separation method, but the use of solvents is by far the most widely used method today and is widely used to capture CO2 for use in the food and beverage industry. Ox fuel combustion processes use oxygen rather than air for the combustion of fuel. This produces exhaust gas that is mainly water vapor and CO2 that can easily be separated to produce a high purity CO2 stream. Direct air capture or DAC technologies capture and removes CO2 directly from the atmosphere by pulling air directly into the bank of fans like you see in the picture in the bottom right. And uses a special chemical to capture or hold onto the CO2. One of the things to note about DAC is that it represents something called negative emissions. Which means it's pulling existing CO2 emissions out of the atmosphere and it can help offset ongoing emissions that are difficult to avoid or capture or to offset historical emissions. From the utilization perspective, the U in CCUS, CO2 uses vary considerably across a wide range of applications. In this figure, if you follow the utilization or the orange text pathway, you can see that we have options to convert CO2 into useful products or for direct use primarily in enhanced recovery of fossil fuels. There is also an option to utilize CO2 given its quite unique properties as a working fluid for geothermal applications. CO2 enhanced oil recovery is a technique for increasing the recovery hard carbons from an oil field. A CO2 EOR project is designed as a closed loop system where some of the injected CO2 is produced back with the oil and then separated from the oil and reinjected back into the reservoir. It is not released into the atmosphere. The other volume of CO2 that is not produced back with the oil remains trapped in the subsurface and is treated as stored CO2. CO2 EOR as been practiced successfully for several decades and is a major element of the utilization pathway. But the conversion of CO2 into useful products has received significant attention as we explore all of our energy transition options. Conversion to fuels chemicals and building materials provide potential value added options for CO2 emissions. And for the last letter in CCUS, the S or storage component, there are three general forms that have been explored. Terrestrial or land storage, mineralogical storage which takes advantage of reactions between minerals and CO2, and geological storage which involves the injection of CO2 into deep underground formations. Now for terrestrial storage of CO2, and most of you will likely recall that biological CO2 conversion, that process we call photosynthesis is fundamental to all life on earth. While terrestrial carbon storage then is the process through which CO2 from the atmosphere is absorbed by trees and plants through photosynthesis and stored as carbon in soils and biomass. With optimized and improved land management practices, the amount of carbon stored in soils and plants can be increased. There are a variety of options for terrestrial storage including restoring mine lands, afforestation, reforestation, range land improvement, improved tillage practices and wetlands restoration. Mineralogical storage of CO2 takes advantage of those reactions we just spoke about between CO2 and a particular family of minerals. CO2 can be converted to a solid carbonate mineral. An example of one of those possible reactions is shown in the formula in the slide. So the conversion of CO2 into a solid form assists us with greatly improving storage security. And for rocks such as basalt which is a volcanic rock which highly reactive to CO2 provides a significant global storage potential. And the geological storage of CO2 or the S in CCUS involves the injection of captured CO2 into a deep underground geological reservoir. Porous rock overlaying by an impermeable layer of rocks which seals the reservoir and prevents the upward migration of CO2 and escape into the atmosphere. And by ensuring the permanence of this storage, we are permanently removing these emissions from the atmosphere. Fortunately there are many geological systems throughout the world capable of retaining centuries worth of CO2 captured from our industrial and fuel-based industries. This slide summarizes the several types of subsurface reservoirs that are suitable for geological storage of CO2. And while a number of options do exist, it really is deep saline aquifers reservoirs and depleted oil and gas reservoirs that have the greatest capacity to store CO2. And I had mentioned previously about the special properties of CO2, and while a complicated topic, these two graphs can help us understand a few fundamental principles of how CO2 behaves. The graph on the left shows the variation of CP2 density with depth. And so on this axis we have depth and here we have an increase in density. And what the cubes represent is the relative volume of CO2 that the CO2 occupies at different depths. So if I start with the volume of CO2 at the surface say just after capturing it, that's of 100 units. By the time I've taken this and injected it down to say 1, 000 meters, one kilometer, that same volume has been compressed down. Its density has increased. It's been compressed down to about 3.2 units or where this little orange dot lies. And so by injecting CO2 at depths at or below a kilometer, we can store 100 units of CO2 in only three units of pore space which provides for a very efficient use of our geological formations. Now, if I know that at this 1, 000 meters, one kilometer, the density is 600, and if I look at this figure on the right and I look at 600. This orange dot provides me a position that tells me at what state the CO2 will be in at that depth. And what this shows is that the CO2 will be in what's called the supercritical region, where the CO2 will have the density of a liquid but the viscosity of a gas. And we can take advantage of those special properties when injecting CO2 into deep geological formations. And for geological storage of CO2 to be successful, it is important that we demonstrate three requirements. One, we need to have enough injectivity to be able to place the CO2 into the formation at the rate it's being supplied from the CO2 capture facility. Two, we need to have the seals, the low permeability geological horizons above those reservoirs sufficient to ensure containment for a very long time. We don't want the injected CO2 coming back to the surface. And three, we need to have sufficient capacity or the pore space volume within the subsurface reservoir to be able to store the total volume of CO2 that we need over the lifetime of a project. And based on decades of research and operational experience on subsurface injection, multiple regulations and standards exist that provide recommendations for the safe and effective storage of CO2 through all phases of a project. Now to provide a sense of what a CO2 injection project looks like and the kinds of measurements that are taken to demonstrate that safe, effective storage is occurring. Let's take a quick look at The Aquistore Project which is the CO2 storage component of Sask Power's Boundary Dam CO2 Capture Project in Southeastern Saskatchewan. Aquistore is a project examining the injection of CO2 into a very deep saline formation. It started in 2015, involved the drilling of one injection well and one observation well and has now injected in excess of 450,000 tons of CO2 at an average injection rate of about 800 to 1,000 tons per day. The project involved the application of measurement, monitoring and verification or what's called MMV technologies to ensure the CO2 is being permanently stored. The project is in the Southeast corner of Saskatchewan Canada, a couple hours away from Regina. These pictures give you a sense of the land surrounding the project and you can see the power plant, this as power boundary dam power plant off in the distance. And this modest building is called the metering building at the injection well site where the CO2 to arrive from the catch-up plant and is redirected into the injection well. And to give you a sense of the configuration of the whole site, you can see in this plan view site, the position of the boundary dam plant. You can see it here in this upper right-hand picture and off to the side is the capture plant. The capture facility that takes the emission streams off one of the combustion facilities here and puts it into a pipeline which is shown here by the red line. The CO2 moves along this pipeline off to the west, moving to the Weyburn CO2 EOR operation which is an example of a utilization application for CO2. But there is also a small section of the pipeline that comes off in this direction towards the Aquistore site when the CO2 is not required for the CO2 operations. So the deep saline aquifer is quite unique. It's a package of sands, the Deadwood and Winnipeg formation sands that lie right above the Canadian shield, the Precambrian rocks or granites. It's quite deep, about 3,300 m and the sand stones are overlaying by shales that serve as the primary seals. And even above that there is a salt horizon, the prairie evaporate that act as a secondary seal to prevent CO2 from migrating to the surface. And the CO2 injection behavior can be quite complex. Injection occurs at different rates. These blue lines, you can see the fluctuations in the blue lines. This is the rate here versus time. This is 2016 and 2017. And this results in variations in bottom hole pressure, which is the red line. You can see the bottom hole pressure, red line data is here. And the colorful plot below shows how the temperature of the CO2 to varies along the depth of the injection well as injection starts and stops. And the figure on the right shows how the cumulative volume of CO2 injected has varied within the project. One of the measurements we need to consider is the conformance. Do we know where the CO2 is going in the subsurface and can we monitor it? So the image on the left shows a series of colored lines that is the interpretation of the CO2 plume movement at about 3,300 meters depth using seismic technology, a common MMV technique. And the image on the right compares those seismic measurements with the results from numerical simulations of CO2 movement. And these comparisons provide improved confidence in our ability to predict the future behavior of CO2 in the subsurface. And so in this module we took a quick look at the role CCUS can play in our energy transition future. And we also looked at describing the overall process of CCUS and reviewed an ongoing CCUS project in Canada. Thank you. And I hope this module on carbon capture, utilization and storage helps you better understand how it can play a role in our 21st energy transition. [MUSIC]
