Carbon capture and storage update Boot-Handford, Matthew E; Abanades, Juan C; Anthony, Edward J ...
Energy & environmental science,
01/2014, Letnik:
7, Številka:
1
Journal Article
Recenzirano
In recent years, Carbon Capture and Storage (Sequestration) (CCS) has been proposed as a potential method to allow the continued use of fossil-fuelled power stations whilst preventing emissions of CO
...2
from reaching the atmosphere. Gas, coal (and biomass)-fired power stations can respond to changes in demand more readily than many other sources of electricity production, hence the importance of retaining them as an option in the energy mix. Here, we review the leading CO
2
capture technologies, available in the short and long term, and their technological maturity, before discussing CO
2
transport and storage. Current pilot plants and demonstrations are highlighted, as is the importance of optimising the CCS system as a whole. Other topics briefly discussed include the viability of both the capture of CO
2
from the air and CO
2
reutilisation as climate change mitigation strategies. Finally, we discuss the economic and legal aspects of CCS.
A comprehensive discussion of CCS technologies, deployment and prospects across the world.
Power plants are prime candidates to apply CO2 capture for final storage as a mitigation option for climate change. Many CO2 capture concepts make use of a sorption−desorption cycle to separate CO2 ...from flue gas or O2 from air. These include commercial absorption processes, as well as processes using new sorbent formulations, adsorption, and high-temperature chemical looping cycles for CO2 and O2. All of these new processes must confront the large scale of carbon flows typical in a power plant. In this work, a common mass balance for all of these processes is used to define a parameter that highlights the minimum sorbent performance required to keep sorbent makeup costs at an acceptable level. A well-established reference system for which reliable commercial data exist (absorption with monoethanolamine, MEA) is used as a technoeconomic baseline to show that some of the sorbents being proposed in the open literature might need to be tested under laboratory conditions for tens of thousands of sorption−desorption cycles before they can be further considered as viable options for CO2 capture from power plants.
A novel concept is presented to capture CO2 from a large-scale (>100 MWe) dedicated biomass-fired power plant by using CaO as the CO2 sorbent. Biomass is burnt in a circulating fluidized bed at ...sufficiently low temperature to allow in situ CO2 capture at atmospheric pressure. The product, CaCO3, is then calcined in an interconnected oxy-fuel combustor, or calciner, that delivers CO2 ready for subsequent purification, compression, and permanent geological storage. A detailed process analysis using Honeywell’s UniSim R400 is carried out to reveal process performance and economics of the proposed power plant which is compared against biomass-air-fired and biomass-oxy-fired power plants. A heat exchanger network is designed using a pinch analysis aimed at the recovery of the maximum amount of excess heat from high temperature gas and solid streams in the plant, while the recovered heat is transferred into a subcritical steam cycle for power generation. The entire process simulation also includes a CO2 purification and compression unit that allows reaching more than 95 mol % CO2 purity. The close similarity of the system with commercial coal based CFB power plants enables us to evaluate costs of electricity and CO2 avoided in detail. This process is capable of achieving 84% overall CO2 capture efficiency with additional cost of 43 €/ton CO2 avoided excluding green certificate and European Trading Scheme (ETS) CO2 incentives. If current typical values for these subsidies are included, the avoided cost can even take negative values. The biomass-air-fired plant becomes the most attractive option when only green certificates are introduced. The biomass-oxy-fired and in situ calcium looping plants largely improve their economics when ETS price for CO2 credits increases. The in situ calcium looping option becomes slightly more economical and more flexible to adapt to different market conditions affecting the economic incentives to use biomass for power generation when the biomass plant is colocated with an oxy-fired coal power plant.
ObjectivesTo validate the diagnoses of acute myocardial infarction (AMI) and stroke recorded in electronic medical records (EMR) and to estimate the population prevalence of both diseases in people ...aged ≥18 years.DesignCross-sectional validation study.Setting45 primary care centres.ParticipantsSimple random sampling of diagnoses of AMI and stroke (International Classification of Primary Care-2 codes K75 and K90, respectively) registered by 55 physicians and random age-matched and sex-matched sampling of the records that included in primary care EMRs in Madrid (Spain).Primary and secondary outcome measuresSensitivity, specificity, positive and negative predictive values and overall agreement were calculated using the kappa statistic. Applied gold standards were ECGs, brain imaging studies, hospital discharge reports, cardiology reports and neurology reports. In the case of AMI, the ESC/ACCF/AHA/WHF Expert Consensus Document was also used. Secondary outcomes were the estimated prevalence of both diseases considering the sensitivity and specificity obtained (true prevalence).ResultsThe sensitivity of a diagnosis of AMI was 98.11% (95% CI, 96.29 to 99.03), and the specificity was 97.42% (95% CI, 95.44 to 98.55). The sensitivity of a diagnosis of stroke was 97.56% (95% CI, 95.56 to 98.68), and the specificity was 94.51% (95% CI, 91.96 to 96.28). No differences in the results were found after stratification by age and sex (both diseases). The prevalence of AMI and stroke was 1.38% and 1.27%, respectively.ConclusionThe validation results show that diagnoses of AMI and stroke in primary care EMRs constitute a helpful tool in epidemiological studies. The prevalence of AMI and stroke was lower than 2% in the population aged over 18 years.
Individual health education is considered to be essential in the overall care of patients with type 2 diabetes (DM2), although there is some uncertainty regarding its metabolic control benefits. ...There have been very few randomized studies on the effects of individual education on normal care in DM2 patients with a control group, and none of these have assessed the long-term results. Therefore, this study aims to use this design to assess the effectiveness of the PRECEDE (Predisposing, Reinforcing, Enabling, Causes in Educational Diagnosis, and Evaluation) education model in the metabolic control and the reduction of cardiovascular risk factors, in patients with type 2 diabetes.
An open community effectiveness study was carried out in 8 urban community health centers in the North-East Madrid Urban Area (Spain). Six hundred patients with DM2 were randomized in two groups: PRECEDE or conventional model for health promotion education. The main outcome measures were glycated hemoglobin A1c, body mass index (BMI), blood pressure, lipids and control criteria during the 2-year follow-up period.
Glycated hemoglobin A1c and systolic blood pressure (SBP) levels decreased significantly in the PRECEDE group (multivariate analysis of covariance, with baseline glycated hemoglobin A1c, SBP, and variables showing statistically significant differences between groups at baseline visits). The decrease levels in diastolic blood pressure (DBP), triglycerides and LDL cholesterol were nonsignificant. PRECEDE increased compliance in all control criteria, except for LDL cholesterol. BMI did not change during the study in either of the two models analyzed.
PRECEDE health education model is a useful method in the overall treatment in patients with type 2 diabetes, which contributes to decrease glycated hemoglobin A1c and SBP levels and increase the compliance in all the control criteria, except for LDL cholesterol.
ClinicalTrials.gov NCT01316367.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Background
Adherence to the therapeutic plan is one of the most important health issues in terms of treatment efficacy, healthcare costs and patient safety. Unfortunately, homebound elderly patients ...are especially vulnerable to nonadherence because they have higher morbidity rates combined with cognitive and social problems that hinder their correct use of drugs. The level of therapeutic adherence in homebound elderly people has not been adequately studied.
Objective
To estimate the prevalence of therapeutic adherence, using the Morisky-Green test, in homebound elderly patients taking polypharmacy (defined as use of four or more drugs), and to study the factors associated with adherence.
Methods
This was a descriptive, cross-sectional, multicentre study. A total of 327 patients were selected by random start systematic sampling from the total number of homebound patients taking four or more drugs in Healthcare Area 4 of the Madrid Autonomous Region, Spain. Through an in-home survey of patients and their caregivers, information was gathered on sociodemographic data, co-morbidities, number of hospital admissions, responsibility for purchasing and preparation of the medication, level of cognitive impairment (Pfeiffer questionnaire), functional dependence in activities of daily living (Katz Index), knowledge of the disease (Batalla test), adherence to treatment (Morisky-Green test), visual and auditory perception, and caregiver burden (Zarit interview).
Results
Of the homebound patients, 65.7% (95% CI 60.6, 70.9) had good adherence to treatment. The variables most negatively associated with therapeutic adherence, after adjustment for age, sex, number of drugs, knowledge of the disease, and cognitive function, were a large caregiver burden (odds ratio OR 3.09; 95% CI 1.75, 5.48) and impaired hearing (OR 2.00; 95% CI 1.17, 3.40). There was also a trend toward a positive association between nonadherence and patients aged >85 years (OR 1.57; 95% CI 0.93, 2.65) and patients who had nine or more drug prescriptions (OR 1.59; 95% CI 0.96, 2.65).
Conclusions
Poor therapeutic adherence in homebound elderly patients receiving polypharmacy is a serious problem affecting one of every three individuals concerned, and is directly related to caregiver burden, regardless of age, sex, cognitive status or number of drugs administered.
In patients with type 2 diabetes, the prevalence of hypertension is higher than in non-diabetic subjects. Despite the high cardiovascular risk involving hypertension in these patients, its prevalence ...and control are not well known. The aims of this study were: to estimate the hypertension prevalence, awareness, treatment and control in Spanish adults with type 2 diabetes attended in Primary Care; and to analyse its time trend from 2003 to 2009. A serial cross-sectional study from 2003 to 2009 was performed in 21 Primary Care Centres in Madrid. The study population comprised all patients with diagnosed type 2 diabetes in their computerised medical history. Overall annual prevalence during the period 2003-2009 was calculated from and according to sex and age groups. Linear trend tests, regression lines and coefficients of determination were used. In 2003 89.78% (CI 87.92-91.64) of patients with type 2 diabetes suffered hypertension and 94.76% (CI: 92.85-96.67) in 2009. This percentage was greater for women and for patients over 65 years old. 30% of patients suffered previously undiagnosed hypertension in 2003 and 23.1% in 2009. 97% of diagnosed patients received pharmacological treatment and 28.79% reached the blood pressure objective in 2009. The average number of antihypertensive drugs taken was 2.72 in 2003 and 3.27 in 2009. Only 5.2% of patients with type 2 diabetes show blood pressure levels below 130/80 mmHg. Although significant improvements have been achieved in the diagnosis and control of hypertension in people with type 2 diabetes, these continue to remain far from optimum.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Computerized Clinical Records, which are incorporated in primary health care practice, have great potential for research. In order to use this information, data quality and reliability must be ...assessed to prevent compromising the validity of the results.The aim of this study is to validate the diagnosis of hypertension and diabetes mellitus in the computerized clinical records of primary health care, taking the diagnosis criteria established in the most prominently used clinical guidelines as the gold standard against which what measure the sensitivity, specificity, and determine the predictive values.The gold standard for diabetes mellitus was the diagnostic criteria established in 2003 American Diabetes Association Consensus Statement for diabetic subjects. The gold standard for hypertension was the diagnostic criteria established in the Joint National Committee published in 2003.
A cross-sectional multicentre validation study of diabetes mellitus and hypertension diagnoses in computerized clinical records of primary health care was carried out. Diagnostic criteria from the most prominently clinical practice guidelines were considered for standard reference.Sensitivity, specificity, positive and negative predictive values, and global agreement (with kappa index), were calculated. Results were shown overall and stratified by sex and age groups.
The agreement for diabetes mellitus with the reference standard as determined by the guideline was almost perfect (κ=0.990), with a sensitivity of 99.53%, a specificity of 99.49%, a positive predictive value of 91.23% and a negative predictive value of 99.98%.Hypertension diagnosis showed substantial agreement with the reference standard as determined by the guideline (κ=0.778), the sensitivity was 85.22%, the specificity 96.95%, the positive predictive value 85.24%, and the negative predictive value was 96.95%. Sensitivity results were worse in patients who also had diabetes and in those aged 70 years or over.
Our results substantiate the validity of using diagnoses of diabetes and hypertension found within the computerized clinical records for epidemiologic studies.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Implementation of a standardized language in Nursing Care Plans (SNCP) allows for increased efficiency in nursing data management. However, the potential relationship with patientś health outcomes ...remains uncertain. The aim of this study was to evaluate the effectiveness of SNCP implementation, based on North American Nursing Diagnosis Association (NANDA) and Nursing Interventions Classification (NIC), in the improvement of metabolic, weight, and blood pressure control of Type 2 Diabetes Mellitus (T2DM) patients.
A two-year prospective follow-up study, in routine clinical practice conditions. 31 primary health care centers (Spain) participated with 24,124 T2DM outpatients. Data was collected from Computerized Clinical Records; SNCP were identified using NANDA and NIC taxonomies. Descriptive and ANCOVA analyses were conducted.
18,320 patients were identified in the Usual Nursing Care (UNC) group and 5,168 in the SNCP group. At the two-year follow-up, the SNCP group improved all parameters except LDL cholesterol and diastolic blood pressure. We analyzed data adjustming by the baseline value for these variables and variables with statistically significant differences between groups at baseline visit. Results indicated a lowering of all parameters except HbA1c, but a statistically significant reduction was only observed with diastolic blood pressure results. However, the adjusted reduction of diastolic blood pressure is of little clinical relevance. Greater differences of control values for diastolic blood pressure, HbA1c, LDL-cholesterol and Body Mass Index were found in the SNCP group, but only reached statistical significance for HbA1c. A greater proportion of patients with baseline HbA1c ≥7 decreased to <7% at the two-year follow-up in the SNCP group than in the UNC group (16.9% vs. 15%; respectively; p = 0.01).
Utilization of SNCP was helpful in achieving glycemic control targets in poorly controlled patients with T2DM (HbA1c ≥7%). Diastolic blood pressure results were slightly improved in the SNCP group compared to the UNC group.
ClinicalTrials.gov NCT01482481.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
PDF
