International Journal of Greenhouse Gas Control 60 (2017) 140–155 Contents lists available at ScienceDirect International Journal of Greenhouse Gas Control journal homepage: www.elsevier.com/locate/ijggc Evaluation of a new technology for carbon dioxide submarine storage in glass capsules Stefano Caserini ∗ , Giovanni Dolci, Arianna Azzellino, Caterina Lanfredi, Lucia Rigamonti, Beatriz Barreto, Mario Grosso Politecnico di Milano, Dipartimento di Ingegneria Civile e Ambientale, Milano, Italy a r t i c l e i n f o Article history: Received 3 October 2016 Received in revised form 3 February 2017 Accepted 8 March 2017 Keywords: CO2 storage Life cycle assessment Emission reduction Carbon sequestration a b s t r a c t The paper describes the energy and environmental evaluation of a new patented process for the storage of liquid carbon dioxide (CO 2 ) in glass capsules on the deep seabed. This technology is proposed as a safe option to store CO 2 captured from flue gas of industrial processes and power plants, as well as directly from the atmosphere, in order to overcome the obstacles that still today limit the commercial deployment of other CO 2 storage techniques, such as the injection in saline aquifers. By keeping the liquid CO 2 separated from the seawater, the technology might be an alternative that presents reduced risk associated with the storage in the marine environment when compared to other alternatives proposed in the past. A Life Cycle Assessment carried out with different combinations of the geographical and technological parameters showed an average impact of 0.10 tCO 2 eq per ton of stored CO 2 . The process with the highest impact was the capsule production, due mainly to the consumption of natural gas and electricity, as well as to calcination taking place during the production of glass. The availability of space in the seabed for submarine CO 2 storage in capsules resulted a minor issue for the development of the technology. Close to most coastal areas where CO 2 emission sources are located, large surfaces of the seabed at a suitable depth (between 1500 and 3000 m) and distance from the coast (<200 km) suitable for this technology are available, and particularly in the Mediterranean and Black seas. A preliminary cost analysis resulted in an average CO 2 levelized cost of US$17 per ton of CO 2 delivered by the external source. © 2017 Elsevier Ltd. All rights reserved. 1. Introduction After the Paris Agreement (UNFCCC, 2015), the interest for the technologies that can assure consistent greenhouse gases (GHGs) emission reductions, or even negative ones in case of the capture of biogenic carbon dioxide (CO 2 ), has continued to grow. Many analyses highlight that the ambitious targets of the cli- mate international policy signed in Paris, to hold “the increase in the global average temperature to well below 2 ◦ C above pre-industrial levels and to pursue efforts to limit the temperature increase to 1.5 ◦ C above pre-industrial levels”, require that carbon dioxide and other GHGs emissions are reduced at very high rates in the coming decades, and that CO 2 is also actively removed from the atmosphere in large quantities. Removal of carbon dioxide can be achieved through a variety of processes, including afforestation, forest management, the combi- ∗ Corresponding author at: Piazza Leonardo da Vinci 32, 20133 Milano, Italy. E-mail address: stefano.caserini@polimi.it (S. Caserini). nation of bioenergy with carbon capture and storage, or through dedicated activities, for example, direct air capture and sequestra- tion, or enhanced weathering of olivine rocks (Keith, 2009). There is a rich literature on the potential obstacles to a large increase of such negative emissions, both for the novelty of many propos- als of atmospheric carbon capture and storage (CCS), and for their geophysical limits, i.e. safe carbon storage capacity (Smith et al., 2015). As noted by Peters (2016), 108 out of the 116 scenarios assessed in the Fifth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC) (Clarke et al., 2014) as consistent with a likely chance of keeping global average temperature below 2 ◦ C, assume the use of large-scale CCS and 101 reach negative emis- sions (below zero) by 2100, by combining bioenergy with CCS. According to these scenarios, the current ramping up of renewable energy technologies, even at high rates, is unlikely to be sufficient to achieve a 1.5–2 ◦ C goal if CCS is not deployed. Although many scenarios defined in the past decades underes- timated the growth of renewable energy technologies, it is possible to identify a consensus in the scientific literature that in the absence http://dx.doi.org/10.1016/j.ijggc.2017.03.007 1750-5836/© 2017 Elsevier Ltd. All rights reserved.