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Carbon Capture And Storage In Aotearoa – Expert Q+A
The government recently announced decisions on a new framework to incentivise carbon capture, utilisation, and storage by New Zealand companies. How does this technology work and how common is it overseas?
According to the framework, businesses that capture and store carbon dioxide will be rewarded through the Emissions Trading Scheme (ETS). Legislation is expected to be introduced later this year.
The SMC asked local experts to provide background information on the research behind carbon capture, utilisation, and storage (CCUS).
Dr Andrew La Croix, Earth and Environmental Sciences, School of Science, University of Waikato, comments:
Note: Dr La Croix is on the same research team as Prof David Dempsey, who is also quoted below. They note they worked in tandem to provide the following responses.
1. Are carbon capture technologies being actively used right now? If so, how common is it and what countries are using it? In what commercial fields?
“Yes, CCUS is actively used right now, storing approximately 40 Mt / year globally. According to the Global CCS Institute, there are 41 commercial operations around the world including examples in North America (Canada, USA), Europe (Iceland, Norway, Italy, Hungary), Asia (Qatar, Saudi Arabia, UAE, China), and Oceania (Australia). These are commonly associated with coal or gas-fired power stations, liquefied natural gas plants, and petroleum refineries. However, it is also used with ammonium/fertiliser production. A lot of current work is going towards direct air capture for “disposal” of carbon dioxide.”
2. How do the most commonly used forms of carbon capture currently work around the world? Could these be introduced in New Zealand, and if so, where?
“CCUS consists of three main steps. The first step is to separate the CO2 from other gases produced in industrial processes. This can be done in several ways depending on the source of gas, all which are proven and generally effective. The second step is compressing the CO2 into a fluid and transporting it in pipelines to the storage location. Finally, the third step is injecting the fluid CO2 deep underground where it gets permanently trapped in geological formations, most of which have stored fluids for millions of years. This is theoretically possible in Aotearoa too, but work needs to be done by companies to prove that individual locations would be suitable. At the moment, it looks like the Kapuni gas field could be a prime target.”
3. What risks might be associated with this kind of carbon storage in NZ?
“Leakage of CO2 is the main risk of CCUS in New Zealand and around the world. Leakage can be due to a number of factors, but in New Zealand faults and fractures are probably the biggest risk. The main impact of leakage would be its potential effect on groundwater quality. However, with appropriate storage site selection and monitoring, the risk of leakage is very low. If leakage does occur, we need to have robust protocols in place to determine who is responsible and what should be done to fix the problem. A recent leakage at the Decatur plant in the USA resulted in a shutdown, but CO2 hasn’t escaped to the atmosphere or groundwater, with less than 0.2% of the injected volume leaking. In this case, leakage occurred due to corrosion at a monitoring well.”
Conflict of interest statement: “I’m funded through MBIE to undertake research in carbon dioxide removal and associated technologies.”
Associate Professor David Dempsey, Department of Civil and Natural Resources Engineering, University of Canterbury, comments:
Note: Associate Professor Dempsey is on the same research team as Dr La Croix, who is also quoted above. They note they worked in tandem to provide the following responses.
1. What is your team currently studying? What opportunities for carbon storage innovation might there be here in New Zealand?
“Our research team has just started a multi-year project to study something called Carbon Dioxide Removal. This has similarities with CCUS – like the need to safely hold CO2 underground – but its major difference is that it focuses on taking historic emissions out of the atmosphere, rather than preventing new ones from entering it. New Zealand has some good opportunities to innovate here – we do a lot of bioenergy and we have an abundance of a rock known as Dunite – both are key inputs to Carbon Removal. We also have large forestry, agriculture and geothermal sectors that could deploy carbon dioxide removal technologies.”
2. What NZ industries might most readily be able to implement carbon storage?
“Previous studies have suggested the Kapuni gas plant as the obvious first place to trial CCUS in NZ. There’s good reasons to go here. First, they already produce a lot of CO2 that has to be separated off the gas – some of this gets sold for things like beer. Second, they have a pretty good storage site, which is the Kapuni reservoir that has been holding gas in safe storage for millions of years.
“Down the line, other industries that might be good are Methanex, who are a large producer of CO2 emissions and are also located in Taranaki near some depleting gas reservoirs. Huntly power station is another large emitter, although there’s no clear disposal site nearby so CO2 would have to be pumped through pipelines to somewhere else for disposal. If in the future Huntly was converted into a biomass plant, which has been proposed, that would turn the electricity generator into a giant source of negative emissions.”
3. What do we know so far about the social acceptability of carbon storage in NZ?
“The main objection expressed about CCUS has been moral hazard, which is the concern that deployment of CCUS would defer real changes to the energy system to reduce gross emissions. It’s sometimes expressed as a ‘licence to pollute’ although this is a bit of a misnomer since the whole idea of CCUS is to prevent a pollutant entering the atmosphere.
“Other concerns centre on the cost of the technology, although the present government has indicated they wouldn’t be subsidising the technology – I’m not sure the wider public needs to be too worried if a business decides to back the technology using their own resources.”
Conflict of interest statement: “I receive funding from the MBIE to undertake research in carbon dioxide removal and associated technologies.”
Dr Malcolm Arnot, Geological Mapping & Stratigraphy Team Leader, GNS Science, comments:
1. Are CCS technologies being actively used right now? If so, what are the most commonly used forms and where are they being used?
“Yes, CCS technologies are being used around the world right now, and have been for many years. One of the best known and longest running CCS operations is the Sleipner CCS project, offshore Norway, which began in 1996. Sleipner is a Norwegian gas field where the natural gas being produced has a high percentage of CO2 associated with it (similar to the situation at the Kapuni Field in New Zealand). At Sleipner the CO2 is separated from the natural gas and re-injected in to a saline aquifer at between 800-1000m below the seabed. The Sleipner CCS project is also now taking CO2 from adjacent gas fields and injecting that into the geological storage formation.
“In terms of other operational CCS projects, the graphic in this link gives some idea of the number of operation CCS sites around the world.”
2. How do the most commonly used forms of carbon capture currently work around the world? What do they require to be put into place?
“At present the most common forms of carbon capture are probably planting trees, or the capture of natural CO2 in natural gas (e.g., as in the Sleipner project noted above) or the capture of CO2 pre- or post-combustion of coal or natural gas, and also from other large point sources such as cement manufacture or the production of steel. The technologies associated with pre- or post-combustion typically use chemical solvents or chemical sorbents to separate the CO2 from the gas stream. There are membrane technologies that perform the same task.
“Most of these current carbon capture technologies require the right economic drivers and regulations to be in place for them to be viable. The actual engineering side of things are well established, although there is a lot of research going into developing more efficient chemical sorbents, solvent and membranes.”
3. Are there any new CCS innovations or technologies that may be deployed in the near future?
“Yes. There is a lot of research going into a range of new technologies, for the capture and storage of CO2. From direct air capture of CO2 which can then be utilised (made into something) or stored in a geological formation. There is research being undertaken that is looking at whether enhanced weathering of rocks is a viable form of CO2 storage. Similarly, there is research into the potential for injection of CO2 in to reactive rocks, such as basalt, resulting in the mineralisation of CO2 and permanent storage. Globally, there is also a lot of research going into how CO2 can be utilised in products that would store the CO2. For example Murray McCurdy’s Endeavour program looking into the development of a cement that would utilise CO2 in its manufacture and store it in a mineral form. There are also investigations into nature-based solutions for the long-term storage of CO2.”
No conflicts of interest.
Associate Professor Julia Becker, Joint Centre for Disaster Research, Massey University, comments:
“I was involved with carbon capture and storage (CCS) research 15 or so years ago – mostly trying to know whether people understood what CCS was and what kind of support there was for it. We did some surveys and focus groups with public participants and found that people generally had low levels of awareness of CCS. However, when you framed it in terms of a climate conversation or conversations about use of energy they were more likely to see where CCS fitted. Once that conversation was initiated they were generally open to exploring options about it and trying to understand CCS a bit better. Some potentially saw some benefits for CCS helping address climate change.
“People did express some concerns, however, and people’s concerns tended to outweigh the benefits. Concerns centred on the risks surrounding a CO2 leak, the uncertainties associated with new technologies, long term responsibilities for CCS, viability issues and potential flow-on impacts such as the increased use of coal and the development of new mines and industry. In general, most were not immediately opposed to CCS but were unsure if it was necessary for New Zealand, particularly given the abundance of renewable resources available and New Zealand’s unique emissions profile.
“I haven’t done any research since, so I’m unsure whether some of these beliefs have changed over time, but I suspect that many of the same concerns would still be valid.”
No conflicts of interest.
Professor Barry Barton, Faculty of Law, University of Waikato, comments:
“We need access to every possible way of reducing our GHG emissions that we can get, and carbon capture and storage is no exception, even if it only plays a limited part. A range of legal and regulatory changes are needed for CCS, and it is good to see the government moving on them so that the technology is on the table as one of our options.
“There is a lot of international experience now with regulatory frameworks for CCS, and their application to substantial projects, so we can take advantage of the lessons learned. One important dimension is to ensure that the regime is suitable for a range of technologies and practices; a wide range of promising carbon dioxide removal techniques is emerging, such as bioenergy capture, enhanced rock weathering and direct air capture. We need a regime that allows them all to be explored and scaled up wherever possible.”
Conflict of interest statement: “Presently engaged in funded research on carbon dioxide removal.”
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