L'avenir de la capture et de la séquestration du carbone

Le présent essai a pour objectif d’évaluer la pertinence et la viabilité de la capture et de la séquestration du carbone à titre de solution aux changements climatiques. L’approvisionnement mondial en énergie primaire a plus que doublé durant les trente-cinq dernières années. Plus de 80 % de cette énergie provient des combustibles fossiles. Si la tendance se maintient, la consommation d’énergie doublera encore d’ici 2050 et les émissions de gaz à effet de serre suivront la même progression. En l’absence d’efforts supplémentaires visant à stabiliser les concentrations atmosphériques en gaz à effet de serre, l’augmentation de la température moyenne mondiale dépassera les 6°C sur le long terme, entraînant des impacts potentiellement catastrophiques. Les combustibles fossiles constituent une source d’énergie économique largement répandue qui persiste à être subventionnée de façon importante par les gouvernements. Les énergies fossiles occuperont encore longtemps une place importante parmi les autres sources d’énergie. Les solutions visant à minimiser les impacts associés à leur utilisation devraient bénéficier d’un support financier plus important. La capture et la séquestration du carbone est l’une des seules solutions possédant un large potentiel de réduction des émissions de dioxyde de carbone fossile. Selon la International Energy Agency, si la capture et la séquestration du carbone devait être exclue du portfolio de solutions disponibles, les coûts de réductions des émissions provenant du secteur de l’électricité augmenteraient de près de 40 %. En ce sens, la capture et la séquestration du carbone est une solution pertinente aux changements climatiques. La maturité technologique de la capture et de la séquestration du carbone est suffisante pour souscrire à son déploiement à grande échelle dans la mesure où elle est règlementée et contrôlée adéquatement. Il est crucial de continuer à soutenir son développement afin d’encourager des percées techniques qui la rendront plus performante, plus fiable, plus économique et plus accessible. Plusieurs éléments doivent être au rendez-vous afin de rendre la capture et la séquestration du carbone viable : un engagement politique sérieux et déterminé, une entente internationale décisive, un cadre législatif et règlementaire plus sévère, une augmentation de la valeur du dioxyde de carbone sur les marchés, une augmentation du financement des projets de réductions d’émission de gaz à effet de serre et une implication plus large du public en général. À l’échelle internationale, la règlementation actuelle sur le contrôle des émissions de gaz à effet de serre n’est pas suffisante à elle seule pour supporter le déploiement de la capture et de la séquestration du carbone. On s’attend à ce que de nouvelles normes d’émissions soient instaurées cette année aux États-Unis et au Canada, stimulant la création de nouveaux projets de capture et de séquestration du carbone sans toutefois conduire à sa commercialisation généralisée. En Europe, la Commission européenne pourrait imposer la capture et la séquestration du carbone à certains secteurs puisque les efforts soutenant son déploiement, principalement par le biais de subventions, n'ont pas été efficaces. En Chine, plusieurs initiatives régionales de marché du carbone pourraient mener au développement d'une règlementation plus large et à un déploiement plus important de la capture et de la séquestration du carbone. D’ailleurs, la Banque asiatique de développement a annoncé en 2012 son intention de travailler avec la Commission nationale du développement et de la réforme afin de développer une feuille de route pour le déploiement de la capture et de la séquestration du carbone en Chine

Regulation of hepatic EAAT-2 glutamate transporter expression in human liver cholestasis

AIM: To investigate the activity and expression of EAAT2 glutamate transporter in both in vitro and in vivo models of cholestasis. METHODS: This study was conducted on human hepatoblastoma HepG2 cell cultures, the liver of bile duct ligated rats and human specimens from cholestatic patients. EAAT2 glutamate transporter activity and expression were analyzed using a substrate uptake assay, immunofluorescence, reverse transcription-polymerase chain reaction, and immunohistochemistry, respectively. RESULTS: In HepG2 cells, cholestasis was mimicked by treating cells with the protein kinase C activator, phorbol 12-myristate 13-acetate. Under such conditions, EAAT2 transporter activity was decreased both at the level of substrate affinity and maximal transport velocity. The decreased uptake was correlated with intracellular translocation of EAAT2 molecules as demonstrated using immunofluorescence. In the liver of bile duct ligated rats, an increase in EAAT2 transporter protein expression in hepatocytes was demonstrated using immunohistochemistry. The same findings were observed in human liver specimens of cholestasis in which high levels of γ-glutamyl transpeptidase were documented in patients with biliary atresia and progressive familial intrahepatic cholestasis type 3. CONCLUSION: This study demonstrates the alteration in glutamate handling by hepatocytes in liver cholestasis and suggests a potential cross-talk between glutamatergic and bile systems

Severe acute hepatitis and acute liver failure of unknown origin in children:a questionnaire-based study within 34 paediatric liver centres in 22 European countries and Israel, April 2022

To detect potential concern about severe acute hepatitis in children, we conducted a survey among 50 ERN RARE-LIVER centres. By 26 April 2022, 34 centres, including 25 transplant centres, reported an estimated median of 3-5, 0-2 and 3-5 cases in 2021, 2020 and 2019 and a mean of 2 (range: 0-8) cases between January and April 2022 (mean in 10 large liver transplant centres: 3). Twelve centres reported suspicion of an increase, but no rise. Following a report by the United Kingdom (UK) on 5 April 2022 on the occurrence of cases of severe acute hepatitis in children aged 16 years or under, the World Health Organization (WHO) raised concerns about the possibility of an epidemic [1,2]. By 21 April, 169 possible or confirmed cases were reported fulfilling the WHO case definition [3]. The cause of the hepatitis is unknown but a link to a virus infection has been suggested due to the epidemiological pattern of cases [4,5]. The hepatitis can progress to paediatric acute liver failure (pALF) necessitating urgent liver transplantation to avoid multi-organ failure [6]. We intended to assess whether a rise in incidence of severe acute hepatitis or pALF could be observed between 1 January and 26 April 2022 in comparison to previous years, within the European Reference Network on Hepatological Diseases (ERN RARE-LIVER) [7]

Process intensification for post combustion CO₂ capture with chemical absorption: a critical review

The concentration of CO₂ in the atmosphere is increasing rapidly. CO₂ emissions may have an impact on global climate change. Effective CO₂ emission abatement strategies such as carbon capture and storage (CCS) are required to combat this trend. Compared with pre-combustion carbon capture and oxy-fuel carbon capture approaches, post-combustion CO₂ capture (PCC) using solvent process is one of the most mature carbon capture technologies. There are two main barriers for the PCC process using solvent to be commercially deployed: (a) high capital cost; (b) high thermal efficiency penalty due to solvent regeneration. Applying process intensification (PI) technology into PCC with solvent process has the potential to significantly reduce capital costs compared with conventional technology using packed columns. This paper intends to evaluate different PI technologies for their suitability in PCC process. The study shows that rotating packed bed (RPB) absorber/stripper has attracted much interest due to its high mass transfer capability. Currently experimental studies on CO₂ capture using RPB are based on standalone absorber or stripper. Therefore a schematic process flow diagram of intensified PCC process is proposed so as to motivate other researches for possible optimal design, operation and control. To intensify heat transfer in reboiler, spinning disc technology is recommended. To replace cross heat exchanger in conventional PCC (with packed column) process, printed circuit heat exchanger will be preferred. Solvent selection for conventional PCC process has been studied extensively. However, it needs more studies for solvent selection in intensified PCC process. The authors also predicted research challenges in intensified PCC process and potential new breakthrough from different aspects

Current status and future development of solvent-based carbon capture

Solvent-based carbon capture is the most commercially-ready technology for economically and sustainably reaching carbon emission reduction targets in the power sector. Globally, the technology has been deployed to deal with flue gases from large scale power plants and different carbon-intensive industries. The success of the technology is due to significant R&D activities on the process development and decades of industrial experience on acid gas removal processes from gaseous mixtures. In this paper, current status of PCC based on chemical absorption—commercial deployment and demonstration projects, analysis of different solvents and process configurations—is reviewed. Although some successes have been recorded in developing this technology, its commercialization has been generally slow as evidenced in the cancellation of high profile projects across the world. This is partly due to the huge cost burden of the technology and unpredictable government policies. Different research directions, namely new process development involving process intensification, new solvent development and a combination of both, are discussed in this paper as possible pathways for reducing the huge cost of the technology

The Inherent Tracer Fingerprint of Captured CO2.

Carbon capture and storage (CCS) is the only currently available technology that can directly reduce anthropogenic CO2 emissions arising from fossil fuel combustion. Monitoring and verification of CO2 stored in geological reservoirs will be a regulatory requirement and so the development of reliable monitoring techniques is essential. The isotopic and trace gas composition - the inherent fingerprint - of captured CO2 streams is a potentially powerful, low cost geochemical technique for tracking the fate of injected gas in CCS projects; carbon and oxygen isotopes, in particular, have been used as geochemical tracers in a number of pilot CO2 storage sites, and noble gases are known to be powerful tracers of natural CO2 migration. However, the inherent tracer fingerprint in captured CO2 streams has yet to be robustly investigated and documented and key questions remain, including how consistent is the fingerprint, what controls it, and will it be retained en route to and within the storage reservoir? Here we present the first systematic measurements of the carbon and oxygen isotopes and the trace noble gas composition of anthropogenic CO2 captured from combustion power stations and fertiliser plants. The analysed CO2 is derived from coal, biomass and natural gas feedstocks, using amine capture, oxyfuel and gasification processes, from six different CO2 capture plants spanning four different countries. We find that δ13C values are primarily controlled by the δ13C of the feedstock while δ18O values are predominantly similar to atmospheric O2. Noble gases are of low concentration and exhibit relative element abundances different to expected reservoir baselines and air, with isotopic compositions that are similar to air or fractionated air. The use of inherent tracers for monitoring and verification was provisionally assessed by analysing CO2 samples produced from two field storage sites after CO2 injection. These experiments at Otway, Australia, and Aquistore, Canada, highlight the need for reliable baseline data. Noble gas data indicates noble gas stripping of the formation water and entrainment of Kr and Xe from an earlier injection experiment at Otway, and inheritance of a distinctive crustal radiogenic noble gas fingerprint at Aquistore. This fingerprint can be used to identify unplanned migration of the CO2 to the shallow subsurface or surface

Translational biomedical informatics and pharmacometrics approaches in the drug interactions research

Drug interaction is a leading cause of adverse drug events and a major obstacle for current clinical practice. Pharmacovigilance data mining, pharmacokinetic modeling, and text mining are computation and informatic tools on integrating drug interaction knowledge and generating drug interaction hypothesis. We provide a comprehensive overview of these translational biomedical informatics methodologies with related databases. We hope this review illustrates the complementary nature of these informatic approaches and facilitates the translational drug interaction research