A review of developments in carbon dioxide storage

Carbon capture and storage (CCS) has been identified as an urgent, strategic and essential approach to reduce anthropogenic CO2 emissions, and mitigate the severe consequences of climate change. CO2 storage is the last step in the CCS chain and can be implemented mainly through oceanic and underground geological sequestration, and mineral carbonation. This review paper aims to provide state-of-the-art developments in CO2 storage. The review initially discussed the potential options for CO2 storage by highlighting the present status, current challenges and uncertainties associated with further deployment of established approaches (such as storage in saline aquifers and depleted oil and gas reservoirs) and feasibility demonstration of relatively newer storage concepts (such as hydrate storage and CO2-based enhanced geothermal systems). The second part of the review outlined the critical criteria that are necessary for storage site selection, including geological, geothermal, geohazards, hydrodynamic, basin maturity, and economic, societal and environmental factors. In the third section, the focus was on identification of CO2 behaviour within the reservoir during and after injection, namely injection-induced seismicity, potential leakage pathways, and long-term containment complexities associated with CO2-brine-rock interaction. In addition, a detailed review on storage capacity estimation methods based on different geological media and trapping mechanisms was provided. Finally, an overview of major CO2 storage projects, including their overall outcomes, were outlined. This review indicates that although CO2 storage is a technically proven strategy, the discussed challenges need to be addressed in order to accelerate the deployment of the technology. In addition, beside the necessity of techno-economic aspects, public acceptance of CO2 storage plays a central role in technology deployment, and the current ethical mechanisms need to be further improved

Experimental Investigation of Flow Condensation in Microgravity

Future manned missions to Mars are expected to greatly increase the space vehicle's size, weight, and heat dissipation requirements. An effective means to reducing both size and weight is to replace single-phase thermal management systems with two-phase counterparts that capitalize upon both latent and sensible heat of the coolant rather than sensible heat alone. This shift is expected to yield orders of magnitude enhancements in flow boiling and condensation heat transfer coefficients. A major challenge to this shift is a lack of reliable tools for accurate prediction of two-phase pressure drop and heat transfer coefficient in reduced gravity. Developing such tools will require a sophisticated experimental facility to enable investigators to perform both flow boiling and condensation experiments in microgravity in pursuit of reliable databases. This study will discuss the development of the Flow Boiling and Condensation Experiment (FBCE) for the International Space Station (ISS), which was initiated in 2012 in collaboration between Purdue University and NASA Glenn Research Center. This facility was recently tested in parabolic flight to acquire condensation data for FC-72 in microgravity, aided by high-speed video analysis of interfacial structure of the condensation film. The condensation is achieved by rejecting heat to a counter flow of water, and experiments were performed at different mass velocities of FC-72 and water and different FC-72 inlet qualities. It is shown that the film flow varies from smooth-laminar to wavy-laminar and ultimately turbulent with increasing FC-72 mass velocity. The heat transfer coefficient is highest near the inlet of the condensation tube, where the film is thinnest, and decreases monotonically along the tube, except for high FC-72 mass velocities, where the heat transfer coefficient is enhanced downstream. This enhancement is attributed to both turbulence and increased interfacial waviness. One-ge correlations are shown to predict the average condensation heat transfer coefficient with varying degrees of success, and a recent correlation is identified for its superior predictive capability, evidenced by a mean absolute error of 21.7%

Medicinal herb use among asthmatic patients attending a specialty care facility in Trinidad

BACKGROUND: There is an increasing prevalence of asthma in the Caribbean and patients remain non-compliant to therapy despite the development of guidelines for management and prevention. Some patients may self-medicate with medicinal herbs for symptomatic relief, as there is a long tradition of use for a variety of ailments. The study assessed the prevalence of use and the factors affecting the decision to use herbs in asthmatic patients attending a public specialty care clinic in Trinidad. METHODS: A descriptive, cross-sectional study was conducted at the Chest Clinic in Trinidad using a de novo, pilot-tested, researcher-administered questionnaire between June and July 2003. RESULTS: Fifty-eight out of 191 patients (30.4%) reported using herbal remedies for symptomatic relief. Gender, age, ethnicity, and asthma severity did not influence the decision to use herbs; however, 62.5% of patients with tertiary level schooling used herbs, p = 0.025. Thirty-four of these 58 patients (58.6%) obtained herbs from their backyards or the supermarket; only 14 patients (24.1%) obtained herbs from an herbalist, herbal shop or pharmacy. Relatives and friends were the sole source of information for most patients (70.7%), and only 10.3% consulted an herbalist. Ginger, garlic, aloes, shandileer, wild onion, pepper and black sage were the most commonly used herbs. CONCLUSIONS: Among patients attending the Chest Clinic in Trinidad the use of herbal remedies in asthma is relatively common on the advice of relatives and friends. It is therefore becoming imperative for healthcare providers to become more knowledgeable on this modality and to keep abreast with the latest developments

Comparative energy and environmental performance of 40% and 30% monoethanolamine at PACT pilot plant

Post combustion CO2 capture using amines is one of the most well understood processes. The most widely used and studied solvent for this purpose is 30% Monoethanolamine (MEA). The main issue with the process is the use of energy for stripping CO2 out of the solvent. It is anticipated that higher concentrations of MEA can capture a higher amount of CO2 and thus reduce energy consumption but may also result in a worsening of the environmental emissions due to potential increase in corrosion and solvent degradation. In order to study the impact of 40% MEA (as opposed to 30% MEA) on the capture plant performance, a test campaign was carried out at the Pilot Scale Advanced Capture Technology (PACT) facilities of the UK Carbon Capture and Storage Research Centre (UKCCSRC) using 30% and 40% MEA. The absorber (9 m height x 0.3 m dia.) is packed with 28 sections (6.5 m) of Mellapak CC3 structured packing. The absorption column temperature profile is measured by 10 RTDs installed around 48 cm apart along the column length. The performance of the capture plant in terms of reboiler duty, capture efficiency, loading capacity and liquid to gas ratio is evaluated at different operating conditions. It has been found that specific reboiler duty using 40% MEA drops by up to 14% as compared to that with 30% MEA under similar test conditions. It has also been observed that the process is very sensitive to reboiler temperature and slight changes in reboiler temperature can have a significant impact on the plant performance. Moreover, similar energy and capture performance can be achieved at different reboiler temperatures with right combination of temperature and pressure in the reboiler/stripper. Corrosion rate was found to be higher with 40% MEA than 30% MEA. Solvent degradation rate and solvent carry over has also indicated slightly higher levels for 40%. Water wash was shown to be effective in recovering most of the MEA from the flue gas

results from the World Mental Health Survey Initiative

Purpose: Understanding the effects of war on mental disorders is important for developing effective post-conflict recovery policies and programs. The current study uses cross-sectional, retrospectively reported data collected as part of the World Mental Health (WMH) Survey Initiative to examine the associations of being a civilian in a war zone/region of terror in World War II with a range of DSM-IV mental disorders. Methods: Adults (n = 3370) who lived in countries directly involved in World War II in Europe and Japan were administered structured diagnostic interviews of lifetime DSM-IV mental disorders. The associations of war-related traumas with subsequent disorder onset-persistence were assessed with discrete-time survival analysis (lifetime prevalence) and conditional logistic regression (12-month prevalence). Results: Respondents who were civilians in a war zone/region of terror had higher lifetime risks than other respondents of major depressive disorder (MDD; OR 1.5, 95% CI 1.1, 1.9) and anxiety disorder (OR 1.5, 95% CI 1.1, 2.0). The association of war exposure with MDD was strongest in the early years after the war, whereas the association with anxiety disorders increased over time. Among lifetime cases, war exposure was associated with lower past year risk of anxiety disorders (OR 0.4, 95% CI 0.2, 0.7). Conclusions: Exposure to war in World War II was associated with higher lifetime risk of some mental disorders. Whether comparable patterns will be found among civilians living through more recent wars remains to be seen, but should be recognized as a possibility by those projecting future needs for treatment of mental disorders.publishersversionpublishe

Application of Raman spectroscopy to real-time monitoring of CO2 capture at PACT pilot plant; Part 1: Plant operational data

Process analyzers for in-situ monitoring give advantages over the traditional analytical methods such as their fast response, multi-chemical information from a single measurement unit, minimal errors in sample handing and ability to use for process control. This study discusses the suitability of Raman spectroscopy as a process analytical tool for in-situ monitoring of CO2 capture using aqueous monoethanolamine (MEA) solution by presenting its performance during a 3-day test campaign at PACT pilot plant in Sheffield, UK. Two Raman immersion probes were installed on lean and rich streams for real time measurements. A multivariate regression model was used to determine the CO2 loading. The plant performance is described in detail by comparing the CO2 loading in each solvent stream at different process conditions. The study shows that the predicted CO2 loading recorded an acceptable agreement with the offline measurements. The findings from this study suggest that Raman Spectroscopy has the capability to follow changes in process variables and can be employed for real time monitoring and control of the CO2 capture process. In addition, these predictions can be used to optimize process parameters; to generate data to use as inputs for thermodynamic models, plant design and scale-up scenarios

Comparing Characteristics of Endometrial Cancer in Women of South Asian and White Ethnicity in England

Differences in patient demographic and tumour characteristics between patients of South Asian and White ethnicity diagnosed with an endometrial cancer (EC) and currently living in England are not well described. We undertook a retrospective study of EC cases diagnosed at the University Hospitals of Leicester, UK. A total of 1884 cases were included, with 13% of the patients being of South Asian ethnicity. South Asian women were diagnosed at a significantly younger age (mean age of 60.3 years) compared to women of White ethnicity (mean age of 66.9 years) with a mean difference of 6.6 years (95% CI 5.1 to 8.1, p < 0.001). Rising body mass index (BMI) in the White patient group was significantly correlated with younger age at diagnosis (p < 0.001); however, this association was not seen in South Asian patients. A linear regression that adjusted for diabetes status, BMI, and the interaction terms of diabetes status with BMI and ethnicity with BMI, highlighted a younger age of diagnosis in South Asian patients with a BMI less than 45 kg/m2. The difference was greatest at lower BMIs for both non-diabetics and diabetics. Further investigation is needed to explain these differences and to determine their impact on suspected cancer referral criteria

Comparing Characteristics of Endometrial Cancer in Women of South Asian and White Ethnicity in England

Differences in patient demographic and tumour characteristics between patients of South Asian and White ethnicity diagnosed with an endometrial cancer (EC) and currently living in England are not well described. We undertook a retrospective study of EC cases diagnosed at the University Hospitals of Leicester, UK. A total of 1884 cases were included, with 13% of the patients being of South Asian ethnicity. South Asian women were diagnosed at a significantly younger age (mean age of 60.3 years) compared to women of White ethnicity (mean age of 66.9 years) with a mean difference of 6.6 years (95% CI 5.1 to 8.1, p < 0.001). Rising body mass index (BMI) in the White patient group was significantly correlated with younger age at diagnosis (p < 0.001); however, this association was not seen in South Asian patients. A linear regression that adjusted for diabetes status, BMI, and the interaction terms of diabetes status with BMI and ethnicity with BMI, highlighted a younger age of diagnosis in South Asian patients with a BMI less than 45 kg/m2. The difference was greatest at lower BMIs for both non-diabetics and diabetics. Further investigation is needed to explain these differences and to determine their impact on suspected cancer referral criteria.</p