30 research outputs found
Direct route from ethanol to pure hydrogen through autothermal reforming in a membrane reactor: Experimental demonstration, reactor modelling and design
This work reports the integration of thin (∼3–4 μm thick) Pd-based membranes for H2 separation in a fluidized bed catalytic reactor for ethanol auto-thermal reforming. The performance of a fluidized bed membrane reactor has been investigated from an experimental and numerical point of view. The demonstration of the technology has been carried out over 50 h under reactive conditions using 5 thin Pd-based alumina-supported membranes and a 3 wt%Pt-10 wt%Ni catalyst deposited on a mixed CeO2/SiO2 support. The results have confirmed the feasibility of the concept, in particular the capacity to reach a hydrogen recovery factor up to 70%, while the operation at different fluidization regimes, oxygen-to-ethanol and steam-to-ethanol ratios, feed pressures and reactor temperatures have been studied. The most critical part of the system is the sealing of the membranes, where most of the gas leakage was detected. A fluidized bed membrane reactor model for ethanol reforming has been developed and validated with the obtained experimental results. The model has been subsequently used to design a small reactor unit for domestic use, showing that 0.45 m2 membrane area is needed to produce the amount of H2 required for a 5 kWe PEM fuel-cell based micro-CHP system.The presented work is funded within the FluidCELL project as part of the European Union's Seventh Framework Programme (FP7/ 2007-2013) for the Fuel Cells and Hydrogen Joint Technology Initiative under grant agreement nº 621196
Infective endocarditis and diabetes mellitus: Results from a single-center study from 1994 to 2017
Background To evaluate the prognostic impact of diabetes mellitus (DM) in patients with Infective Endocarditis (IE). Methods and results 375 patients with diagnosis of IE referred to our Hospital between 1994-2017 were retrospectively included; diabetes was reported in 129 (34.4%). Diabetic patients were older than non-diabetic (66±1 vs. 57±2 years, p<0.001) and showed a higher prevalence of comorbidities such as hypertension (75 vs. 54%, p<0.001), coronary artery disease (30 vs. 12%, p<0.001) and history of heart failure (HF; 24 vs. 13%, p = 0.021). Echocardiography showed a higher incidence of paravalvular complications (82 vs. 64%, p<0.001) and a lower left ventricular ejection fraction (LVEF; 52±11 vs. 55±10%, p = 0.001) in diabetic than in non-diabetic patients. In-hospital mortality was higher in diabetic patients (83 vs. 74%; p = 0.030). At logistic regression, history of HF (OR = 3.1, 95%CI: 1.87-5.29, p<0.001) resulted an independent predictor of in-hospital death. At long-term follow-up [median 24(7-84) months], the Kaplan-Meier analysis showed a significantly lower survival free from all-cause death in the group with diabetes (Logrank< 0.001). At the propensity score adjusted Cox multivariable analysis, DM (HR = 1.76, 95%CI: 1.18-2.6, p = 0.005), age (HR = 1.03, 95%CI: 1.02-1.05, p<0.001), intravenous drug users (HR = 5.42, 95%CI: 2.55-11.51, p<0.001) and low LVEF (HR = 0.98, 95%CI: 0.96-0.99, p = 0.013) were independently associated to a higher mortality. Conclusion In patients with IE, DM is associated to a higher prevalence of anatomic complications and a more impaired LVEF. Diabetic patients show a significantly lower survival both in hospital and during follow-up compared to the non-diabetic ones