9 research outputs found
Opportunities for rail in the transport of carbon dioxide in the United States
The deployment of carbon management strategies like carbon capture and storage (CCS) and carbon dioxide removal (CDR) at scale will require significant investments in transport infrastructure to deliver CO2 to reliable storage. While pipeline transport has dominated the conversation due to economic reasons, there is increasing evidence that other modes may become viable alternatives when considering scale, regional opportunities, and social acceptance. This paper assesses the viability of rail for CO2 transport in the United States using market analysis, techno-economic assessment and geographic information systems mapping. We believe rail presents many advantages, notably in existing infrastructure with established right-of-ways, but also as an instrument to address unwanted effects of our energy transition, particularly in coal communities. We find that the strategic replacement of coal as a freight commodity could translate into 100Â Mt/yr of CO2 movement by rail by 2050, and support up to 60,000 jobs in that industry. Further, we find that while rail pricing is notoriously volatile, there is strong support for rail being the least cost option over pipeline for volumes under 2Â Mt CO2 per year, which aligns well with smaller, more risk-averse, and distributed carbon management projects that are scheduled to deploy over the next decade. Rail can also be an alternative in regions where CO2 pipeline projects have had limited success, like in the Midwest, where CO2 is captured from ethanol plants that are already serviced by rail networks. Likewise, rail can service roughly 25% of point-source CCS opportunities that are not proximal to projected trunk pipeline networks, of which 94% are located 1-mile from railroad. Finally, rail may be an integral part of CDR development in regions that are not coterminous with geologic storage, particularly in the Western and Northern US
Deuterium‑hydrogen inter-diffusion in chlorite
International audienceInteractions between aqueous fluids and rocks occur in a broad range of contexts ranging from hydrothermal alteration veins to regional metamorphism. Tracking these processes and understanding their reaction kinetics require a precise knowledge of the diffusion of water in rocks, and of isotope fractionation in major minerals, such as chlorite. Deuterium‑hydrogen exchange between Mg-rich chlorite and water (D2O) was experimentally investigated using a belt press over the temperature range of 315–650 °C at pressures of 1.5 GPa and 3 GPa. Both chloritite chip and chlorite powder were used. D/(D + H) ratios in chlorite grains were mapped using Raman spectroscopy. Deuterium‑hydrogen exchange proceeded by deuterium‑hydrogen inter-diffusion in chlorite (lattice diffusion). As chlorite is a phyllosilicate, i.e. an anisotropic mineral, diffusion coefficients were determined for crystallographic directions parallel and perpendicular to the silicate layers (perpendicular and parallel to the c* axis, respectively). Arrhenius relations for deuterium‑hydrogen inter-diffusion coefficients were derived from the new dataset. Activation energy (E) is comprised between 215 ± 21 (1σ) kJ/mol (perpendicular to the c* axis) and 194 ± 21 kJ/mol (parallel to the c* axis). Log10(D0) is −2.2 ± 1.3 m2/s for diffusion in the direction perpendicular to the c* axis and −4.5 ± 1.3 m2/s for diffusion parallel to it. The bulk diffusion law derived from a combination of our data with data from Graham et al. (1987) yields E = 176 ± 8 kJ/mol and log10(D0) = −5.1 ± 0.4 m2/s
The cost of direct air capture and storage: the impact of technological learning, regional diversity, and policy.
Direct air capture and storage (DACS) is a carbon dioxide removal technology that is necessary to reach our climate targets. However, huge question marks remain regarding the cost. In contrast to previous studies, we use a costing methodology that is truly consistent with the technology readiness level of DACS to calculate cost trajectories for four example DACS technologies. Our analysis demonstrates the cost of DACS is unlikely to reach the 100-600 t-CO2-1 at the Gt-CO2 year-1 scale. Rational siting and energy source selection will be critical, and importantly, coupling DACS to low capacity factor intermittent renewable electricity is uneconomical. Although, sites with high renewable capacity factors do exist. Furthermore, strong, holistic, technology-catered policy support is needed to aid market creation, scale-up, and long-term cost reductions. The results and conclusions outlined in this work have significant implications for academics, industry, policymakers, and investors alike
The cost of direct air capture and storage can be reduced via strategic deployment but is unlikely to fall below stated cost targets
Epidemiological and clinical characteristics of patients infected with enterovirus D68, France, July to December 2014
Epidemiological and clinical characteristics of patients infected with enterovirus D68, France, July to December 2014
International audienceIn 2014, the United States (US) experienced a nationwide outbreak of enterovirus D68 (EV-D68) infection with 1,152 cases reported mainly in hospitalised children with severe asthma or bronchiolitis. Following the US alert, 11 laboratories of the French enterovirus (EV) surveillance network participated in an EV-D68 survey. A total of 6,229 respiratory samples, collected from 1 July to 31 December 2014, were screened for EV-D68 resulting in 212 EV-D68-positive samples. These 212 samples corresponded to 200 EV-D68 cases. The overall EV-D68 positivity rates among respiratory samples were of 5% (184/3,645) and 1.1% (28/2,584) in hos-pitalised children and adults respectively. The maximum weekly EV-D68 positivity rates were of 16.1% for children (n = 24/149; week 43) and 2.6% for adults (n = 3/115; week 42). Of 173 children with EV-D68 infection alone, the main symptoms were asthma (n = 83; 48.0%) and bronchiolitis (n = 37; 21.4%). One child developed acute flaccid paralysis (AFP) following EV-D68-associated pneumonia. Although there was no significant increase in severe respiratory tract infections reported to the French public health authorities, 10.7% (19/177) of the EV-D68 infected children and 14.3% (3/21) of the EV-D68 infected adults were hos-pitalised in intensive care units. Phylogenetic analysis of the viral protein 1 (VP1) sequences of 179 EV-D68 cases, revealed that 117 sequences (65.4%), including that of the case of AFP, belonged to the B2 variant of clade B viruses. Continuous surveillance of EV-D68 infections is warranted and could benefit from existing influenza-like illness and EV surveillance networks
Sputum versus nasopharyngeal samples for the molecular diagnosis of respiratory viral infection in cystic fibrosis: A pilot study
International audienceViruses are important agents in lung function deterioration in Cystic Fibrosis (CF). To date, no standard operating procedures (SOPs) have been established to determine which sampling method is the most effective for an optimal virological diagnosis of respiratory viral infections in CF. Here we investigated the performances of two sampling sites, sputum samples versus nasopharyngeal (NP) swabs, for thirty participants from three CF centres presenting an acute respiratory infection. Sputum and NP samples were simultaneously collected and multiplex PCR targeting 16 to 18 viruses were performed. Viruses were detected for 18/30 patients (60%). A high concordance between the sputum and NP samples was observed in 25 (83%) paired samples of which 13 tested positive and 12 tested negative. These results highlighted the relevance of sputum sampling for diagnostic of respiratory viruses in CF, which is less invasive and better accepted by CF patients than NP, and allows accurate bacterial detection