Carbon Capture and Storage(CCS) has been on the agenda for a while now. More recently, the “Utilisation” term is also added to consider the process in a broader sense. By risking being oversimplified, I want to share a necessary thought process about one of the possible routes for CCUS. Ignorant speculation, a bet, so to speak.
First thought, harness the natural processes as much as we can so we don’t have to do it ourselves. Any solution to Climate Change has to be cost-effective and also scalable if it is going to have a significant contribution. A smart and sustainable way to achieve this goal is to make use of large scale natural processes that occur with slight adjustments like putting fans in front of the naturally flowing stuff to turn (wind turbines, tidal energy) or further even controlling that flow to some extent (hydroelectricity). Imagine if we had to spin all those turbines with muscle, suppose it wouldn’t be much useful.
Secondly, accepting our limits. There are some limitations to what can or can’t be done. These are usually engraved to the fabric of reality, like limits on material properties or evolutional behavior patterns. In other words, if we are to lower CO2 concentrations, it won’t be by people suddenly becoming more thoughtful and aware nor by a super laser-shooting the nucleus of CO2 atoms to eradicate them. Yet still, we have to capture the CO2 gas somehow, and somehow store it somewhere. There are numerous methods suggested for each of the capturing, utilizing, and storing parts. Among those pathways, one of the ways that make sense to me is to capturing and storing it in solid form, and by solid, I refer to a specific kind of solid named CO2 hydrate.
CO2 Hydrate is a solid form of CO2 forming under specific conditions (simply cold and pressurized). Now comes the part of harnessing nature. Making something cold against nature’s will is quite an energy-intensive job, additionally pressurizing it seems far from efficient. Thankfully we got oceans providing this service for us for free. Well, not exactly free. Unfortunately, the stored CO2 seems not to be stable enough and only stays in the deep ocean for a few hundred years, slowly contributing to Ocean Acidification and posing a threat to the marine biota. Moreover, oceans might be providing free storage, but putting the lot down there is a costly thing, bringing us to the transportation issue.
Although it is within our capability to do so, being able to inject something deep ocean is far from cheap. We can even supply energy to the seafloor by using waves if required. However, if something is to be transported anyway, it might be better to transport it in a solid phase since it takes a lot less space for the same amount of matter. IEA’s 2004 report on the issue points out that it will probably be much cheaper to transport captured CO2 in hydrate form.
Furthermore, the capturing part, hydrates are considered as an alternative, especially when it comes to industrial flue gas. Since CO2 has the lowest hydrate forming requirements within the mixture, it is possible to capture it by hydrate forming. Yet we also have to note that the hydrate capturing method is slightly negative in terms of energy balance when only the capturing part of CCUS is considered. Nevertheless, if we are to accept our limits for now and focus mainly on capturing from industrial zones rather than directly from the air, then hydrates are an option on the table.
Last but not least, there is another kind of hydrate named methane hydrates, which are potential energy sources for the future, in which the Black Sea has great potential. And hopefully, in days to come, the Black Sea will prove also to have great potential for oil. Minister Fatih Dönmez has announced that the drillship Fatih will probably start drilling in the Black Sea in July. It has been concluded by the source rock-oil analysis carried out by OMV(Austrian O&G Company), parts of the Western Black Sea are good candidates for such an exploration (Mayer et al., 2018). Let’s cross our fingers, for now, wish luck and hope for the best.