Luca Turchetti

Development of a Solar-Powered, Fuel-Flexible Compact Steam Reformer: The CoMETHy Project

bProcessi Innovativi Srl. (Italy); c Acktar Ltd. (Israel); d Technion - Israel Institute of Technology (Israel); e Fraunhofer Institute for Ceramic Technologies and Systems (Germany); f University of Salerno (Italy); g Centre for

Hydrogen production by the solar-powered hybrid sulfur process: Analysis of the integration of the CSP and chemical plants in selected scenarios

The Hybrid Sulfur (HyS) is a water splitting process for hydrogen production powered with high temperature nuclear heat and electric power; among the numerous thermo-chemical and thermo-electro-chemical cycles proposed in the literature, such cycle is considered to have a particularly high potential also if powered by renewable energy. SOL2HY2 (Solar to Hydrogen Hybrid Cycles) is a 3 year research project, co-funded by the Fuel Cells and Hydrogen Joint Undertaking (FCH JU). A significant part of the project activities are devoted to the analysis and optimization of the integration of the solar power plant with the chemical, hydrogen production plant. This work reports a part of the results obtained in such research activity. The analysis presented in this work builds on previous process simulations used to determine the energy requirements of the hydrogen production plant in terms of electric power, medium ( 550°C) temperature heat. For the supply of medium temperature (MT) heat, a parab...

Carbon-free Production of Hydrogen via the Solar Powered Hybrid Sulfur Cycle: the Sol2hy2 Project

This paper presents an overview of the activities carried out during the first half of the SOL2HY2 project. In particular, this paper is focused on the activities carried out by ENEA within the consortium, namely: elaboration of general plant concepts, integration of the hydrogen production plant with a concentrated solar power (CSP) plant, development of the catalyst for SO3 decomposition and selection and design of balance of plant (BoP) units.

Integration of photovoltaic and concentrated solar thermal technologies for H2 production by the hybrid sulfur cycle

It is widely agreed that hydrogen used as energy carrier and/or storage media may significantly contribute in the reduction of emissions, especially if produced by renewable energy sources. The Hybrid Sulfur (HyS) cycle is considered as one of the most promising processes to produce hydrogen through the water-splitting process. The FP7 project SOL2HY2 (Solar to Hydrogen Hybrid Cycles) investigates innovative material and process solutions for the use of solar heat and power in the HyS process. A significant part of the SOL2HY2 project is devoted to the analysis and optimization of the integration of the solar and chemical (hydrogen production) plants. In this context, this work investigates the possibility to integrate different solar technologies, namely photovoltaic, solar central receiver and solar troughs, to optimize their use in the HyS cycle for a green hydrogen production, both in the open and closed process configurations. The analysis carried out accounts for different combinations of geographical location and plant sizing criteria. The use of a sulfur burner, which can serve both as thermal backup and SO2 source for the open cycle, is also considered.It is widely agreed that hydrogen used as energy carrier and/or storage media may significantly contribute in the reduction of emissions, especially if produced by renewable energy sources. The Hybrid Sulfur (HyS) cycle is considered as one of the most promising processes to produce hydrogen through the water-splitting process. The FP7 project SOL2HY2 (Solar to Hydrogen Hybrid Cycles) investigates innovative material and process solutions for the use of solar heat and power in the HyS process. A significant part of the SOL2HY2 project is devoted to the analysis and optimization of the integration of the solar and chemical (hydrogen production) plants. In this context, this work investigates the possibility to integrate different solar technologies, namely photovoltaic, solar central receiver and solar troughs, to optimize their use in the HyS cycle for a green hydrogen production, both in the open and closed process configurations. The analysis carried out accounts for different combinations of geographic...

Blood Oxygenators and Artificial Lungs

This chapter is aimed at discussing the main engineering aspects involved in the design of artificial lungs, defining the limits of the currently available devices and understanding the challenges for further developments. To that end, the first part of the chapter provides a short overview of the functions of the respiratory system, that allows defining the medical requirements for the artificial devices and the goals that must be achieved in their design; information on the historical development of the artificial lungs is also included. Subsequently, the physical and chemical fundamentals of gas solubility in blood and gas transport through the membranes widely used in artificial lungs are presented. These fundamentals provide the basis for the engineering analysis of the artificial lung and assessment of its performance. The chapter is concluded with a survey of the state of the art of the clinically used devices with indications for possible further improvements.

Time-on-stream stability of new catalysts for low-temperature steam reforming of biogas

Time-on-stream stability of six different steam reforming catalysts has been tested at 500 °C under a simulated biogas feed. The catalysts are based on different combinations of Ni, Pt and Rh as active species, and CeO₂, ZrO₂ and La₂O₃ as support. In order to perform a conservative analysis, biogas was simulated with a 50 % v/v CO2-CH4 mixture; furthermore a steam to methane ratio as low as 2.5 has also been used. All the samples containing CeO₂ in the support proved fairly stable up to 50 h on stream. Therefore, these catalysts are worth being further investigated to assess their activity and determine appropriate reaction rate expressions.

Conceptual study of the coupling of a biorefinery process for hydrothermal liquefaction of microalgae with a concentrating solar power plant

A conceptual analysis of the coupling of a concentrating solar power plant with a chemical process for hydrothermal liquefaction (HTL) of microalgae to biocrude was performed. The two plants were considered coupled by molten salt recirculation that granted energetic supply to the chemical process. Preliminary estimations have been done considering a solar field constituted by 3 linear parabolic solar collectors rows, each 200 m long, using a ternary molten salts mixture as heat transfer fluid, and a chemical plant sized to process 10 kT/y of microalgae. Under adopted conditions, we have estimated a minimum selling prize of the biocrude that is similar to that achieved in non-solar HTL processes.

Artificial and Bio-Artificial Liver

This chapter is focused on the design of artificial liver support devices (LSD). After a short overview of liver functions and pathologies, aimed at defining the minimum requirements for artificial devices, a survey of the different artificial liver support devices developed and used in clinical practice is reported. Subsequently, starting from a description of the physicochemical phenomena that characterize each unit operation used in the detoxification process (albumin dialysis and toxin adsorption), mathematical models of dialysis and adsorption units are developed and combined into an LSD model. A proposal for a first approach to a patient-device model is also considered to predict the evolution in time of toxin levels in patient blood and to evaluate the effectiveness of the treatment. The chapter ends with a survey on the bio-artificial liver devices.

Mass Transfer Coefficient

Blood oxygenation or detoxification is a typical example of the processe that artificial organs are required to carry out when replacing the functions of a failing natural organ. All of these processes are based on interphase mass transfer and the rate at which they occur directly affects the performance of the supporting devices. Mass transfer coefficients are the fundamental parameters required estimating the mass transfer rate in a given condition; this chapter presents a very short overview of mass transfer coefficients, starting from their definition and describing the methods for their estimation.

Modeling of mechanical blood damage: a discussion of current approaches and alternative proposals

In artificial organs such as vascular prostheses and detoxification devices, blood is exposed to mechanical stresses that can damage red blood cells, possibly leading to membrane lysis. In this work a theoretical analysis of mechanical hemolysis in artificial organs is presented, by firstly considering the main features of the current modeling approaches in literature. Two alternative modeling approaches, based on a physical description of the hemolysis process, are then presented, discussed and compared with experimental data.