membrane engineering for green process engineering

Abstract Green process engineering, which is based on the principles of the process intensification strategy, can provide an important contribution toward achieving industrial sustainable development. Green process engineering refers to innovative equipment and process methods that are expected to bring about substantial improvements in chemical and any other manufacturing and processing aspects. It includes decreasing production costs, equipment size, energy consumption, and waste generation, and improving remote control, information fluxes, and process flexibility. Membrane-based technology assists in the pursuit of these principles, and the potential of membrane operations has been widely recognized in the last few years. This work starts by presenting an overview of the membrane operations that are utilized in water treatment and in the production of energy and raw materials. Next, it describes the potential advantages of innovative membrane-based integrated systems. A case study on an integrated membrane system (IMS) for seawater desalination coupled with raw materials production is presented. The aim of this work is to show how membrane systems can contribute to the realization of the goals of zero liquid discharge (ZLD), total raw materials utilization, and low energy consumption

Membrane Condenser: Direct and Indirect Support to CO2 capture

Today membrane technology for gas separation (GS) is a well-consolidated technique, in various cases competing with traditional operations. The separation of air components, H2 from refinery industrial gases, natural gas dehumidification, separation and recovery of CO2 from biogas and natural gas are some examples in which membrane technology is successfully used in industry. Recent constraints and regulations on CO2 emissions from power plants have forced researchers to focus on the separation of CO2 from flue gas streams and to develop specific CO2 capture technologies that can be retrofitted to existing power plants as well designed into new plants with the goal to achieve 90% of CO2 capture limiting the increase in cost of electricity to no more than 35%. Currently, the main strategies for the carbon dioxide capture in a fossil fuel combustion process are: Oxy-fuel combustion, pre-combustion capture and post-combustion capture. The main technical problems are related to the fact that polymeric membranes cannot withstand, however, high temperatures and/or chemically harsh conditions. Refinery gas streams contain impurities such as water vapor, acid gases, olefins, aromatics and other organics. Heavy hydrocarbons can be present in the feed also in petrochemical plants and natural gas treatment, representing a problem, mainly in hollow fiber modules. At relatively low concentrations, these impurities cause membrane plasticization and loss of selectivity, while at higher concentrations they can condense on the membrane surface which could be damaged. Many polymers are swollen or plasticized in presence of hydrocarbons or CO2 at high partial pressure: the result is a significant reduction in their separation performance, or, their damage. Another issue is physical aging which negatively affect the properties of interesting polymers (PTMSP, PIMs, etc.) and limit their applicability. The solution for a successful operation of polymeric modules is a careful selection of feed pre-treatment. In this field, membrane condensers can be considered as a proper solution for pre-treating the flue gas streams that have to be fed to another membrane unit for CO2 separation and whose performances are strongly affected by the presence of such contaminants as SOx, NH3, etc. In a membrane condenser, the waste gaseous stream (e.g. flue gas) from an industrial plant at a certain temperature and, in most cases, water saturated, is fed to the membrane condenser kept at a lower temperature for cooling the gas up to a super-saturation state. The water condenses onto the membrane surface and the hydrophobic nature of the latter prevents the penetration of the liquid into the pores, letting the dehydrated gases pass through the membrane and retaining the liquid water at the retentate side. In comparison with other technologies, the membrane condensers offer higher water recovery and are not affected by desiccant losses, corrosion phenomena typical of traditional condensers or desiccant units. Compared with the dense membrane technology, the latter requires a high pressure difference between the two membrane sides to promote the permeation of water vapor but allows the recovery of a very pure stream. On the contrary, the purity of the water recovered in membrane condensers can be affected by the possible condensation of contaminants – if present in the gaseous stream – but it is sufficient for cooling tower or boiler make up. However, further purifications would be needed to make it drinkable. Moreover, the possibility of controlling, by opportunely tuning the operating conditions, the condensation of contaminants in the liquid water recovered in the retentate side of the membrane condenser could lead to two different options for its use: as a unit for water recovery, minimizing the contaminants content, or, as the pre-treatment stage in post-combustion capture, forcing most of the contaminants to be retained. References Macedonio F., Brunetti A., Barbieri G., Drioli E. Membrane Condenser as a new technology for water recovery from humidified “waste” gaseous streams. Industrial & Engineering Chemistry Research, 2012; 52(3): 1160-1167. Macedonio F., Cersosimo M., Brunetti A., Barbieri G., Drioli E. Water recovery from humidified waste gas streams: Quality control using membrane condenser technology. Chemical Engineering and Processing: Process Intensification, 2014; 86: 196-203

integrated membrane desalination systems with membrane crystallization units for resource recovery a new approach for mining from the sea

The mining industry is facing problems of clean production in terms of mineral processing, pollution, water consumption, and renewable energy. An interesting outlook can be to combine the mining industry with membrane-based desalination in the logic of mining from the sea. In fact, several of the drawbacks found in both mining and desalination can be minimized or overcome, which includes hindering mineral depletion, water production instead of water consumption, smart usage of brine instead of disposal, and low energy consumption, etc. Recently, membrane crystallization (MCr) has been developed to recover minerals from highly concentrated solutions. This study suggests MCr for the treatment of nanofiltration (NF) retentate and reverse osmosis (RO) brine leaving membrane-based desalination system. Thermodynamic modeling has been carried out to predict at which water recovery factor and which amount of minerals can be recovered. Theoretical results deviate only 2.09% from experimental results. Multivalent components such as barium, strontium, and magnesium are easier to recover from NF retentate with respect to RO brine. KCl and NiCl2 might be recovered from both NF retentate and RO brine, whereas lithium can only be recovered from RO brine. Moreover, copper and manganese compounds might also be recovered from desalination brine in perspectives

membrane engineering for environmental protection and sustainable industrial growth options for water and gas treatment

The increasing demand for materials, energy and products drives chemical engineers to propose new solutions everyday able to promote development while supporting sustainable industrial growth. Membrane engineering can offer significant assets to this development. Here, they are identified the most interesting aspects of membrane engineering in strategic industrial sectors such as water treatment, energy production and depletion and reuse of raw materials. The opportunity to integrate membrane units with innovative systems to exploit the potential advantages derived from their synergic uses is also emphasized. The analysis of the potentialities of these new technologies is supported by the introduction of process intensification metrics which provide an alternative and innovative point of view regarding the unit performance, highlighting important aspects characterizing the technology and not identified by the conventional analysis of the unit performance

Membrane condenser as emerging technology for water recovery and gas pre-treatment: current status and perspectives

Abstract The recent roadmap of SPIRE initiative includes the development of "new separation, extraction and pre-treatment technologies" as one of the "key actions" for boosting sustainability, enhancing the availability and quality of existing resources. Membrane condenser is an innovative technology that was recently investigated for the recovery of water vapor for waste gaseous streams, such as flue gas, biogas, cooling tower plumes, etc. Recently, it has been also proposed as pre-treatment unit for the reduction and control of contaminants in waste gaseous streams (SOx and NOx, VOCs, H2S, NH3, siloxanes, halides, particulates, organic pollutants). This perspective article reports recent progresses in the applications of the membrane condenser in the treatment of various gaseous streams for water recovery and contaminant control. After an overview of the operating principle, the membranes used, and the main results achieved, the work also proposes the role of this technology as pre-treatment stage to other separation technologies. The potentialities of the technology are also discussed aspiring to pave the way towards the development of an innovative technology where membrane condenser can cover a key role in redesigning the whole upgrading process

A Novel Approach to Synthesize Helix Wave Hollow Fiber Membranes for Separation Applications

Helix wave hollow fiber membranes are promising candidate to mitigate fouling and polarization effects in membrane operations. Current study describes a novel but simple approach to synthesize hollow fiber membranes with helix wave configuration. Poly(ether sulfone) (PES) based helix-waved hollow fiber membranes have been fabricated by dry-wet phase inversion process by using asymmetric coagulation conditions. Frequencies of the wave cycle have been observed approximately 20 and the wave length 7.1-7.6mm under the specifically required operating conditions defined by dope solution extrudate rate of 1g/min through 4cm of air-gap heights with 8.6m/min of winding speeds. On the other hand, simple hollow fibers are formed when the elongation force exerted by the winder is much higher than the surface tension of the external coagulant. The process can be useful for making polymer fibers for other applications as well

Graphene stimulates the nucleation and growth rate of NaCl crystals from hypersaline solution via membrane crystallization

Advanced graphene engineered membranes designed for sustainable crystallization of high-quality crystals from hypersaline water

The 21 August 2017 Ischia (Italy) Earthquake Source Model Inferred From Seismological, GPS, and DInSAR Measurements

The causative source of the first damaging earthquake instrumentally recorded in the Island of Ischia, occurred on 21 August 2017, has been studied through a multiparametric geophysical approach. In order to investigate the source geometry and kinematics we exploit seismological, Global Positioning System, and Sentinel-1 and COSMO-SkyMed differential interferometric synthetic aperture radar coseismic measurements. Our results indicate that the retrieved solutions from the geodetic data modeling and the seismological data are plausible; in particular, the best fit solution consists of an E-W striking, south dipping normal fault, with its center located at a depth of 800 m. Moreover, the retrieved causative fault is consistent with the rheological stratification of the crust in this zone. This study allows us to improve the knowledge of the volcano-tectonic processes occurring on the Island, which is crucial for a better assessment of the seismic risk in the area.Published2193-22023T. Sorgente sismicaJCR Journa

Campi Flegrei, Vesuvius and Ischia Seismicity in the Context of the Neapolitan Volcanic Area

Studying seismicity in a volcanic environment provides important information on the state of activity of volcanoes. The seismicity of the Neapolitan volcanoes, Campi Flegrei, Vesuvius, and Ischia, shows distinctive characteristics for each volcano, covering a wide range of patterns and types. In this study we relocated some significant volcano-tectonic earthquake swarms that occurred in Campi Flegrei and Vesuvius. Moreover, we compared the earthquake occurrence evolution, the magnitude and the seismic energy release of the three volcanoes. Also, we considered the results of seismic analysis in the light of geochemical and ground deformation data that contribute to defining the state of activity of volcanoes. In Campi Flegrei, which is experiencing a long term unrest, we identified a seismogenic structure at shallow depth in Pisciarelli zone that has been activated repeatedly. The increasing seismicity accompanies an escalation of the hydrothermal activity and a ground uplift phase. At Vesuvius a very shallow seismicity is recorded, which in recent years has shown an increase in terms of the number of events per year. Earthquakes are usually located right beneath the crater axis. They are concentrated in a volume affected by the hydrothermal system. Finally, Ischia generally shows a low level of seismicity, however, in Casamicciola area events with a moderate magnitude can occur and these are potentially capable of causing severe damage to the town and population, due to their small hypocentral depth (typically < 2.5 km). After the seismic crisis of August 21, 2017 (mainshock magnitude M = 4), the seismicity returned to a low level in terms of occurrence rate and magnitude of earthquakes. The seismicity of these three different volcanic areas shows some common aspects that highlight a relevant role of hydrothermal processes in the seismogenesis of volcanic areas. However, while the main swarms in Campi Flegrei and most of the Vesuvian earthquakes are distributed along conduit-like structures, the seismicity of Ischia is mainly located along faults. Furthermore, the temporal evolution of seismicity in Neapolitan volcanic area suggests a concomitant increase in the occurrence of earthquakes both in Campi Flegrei and Vesuvius in recent years

Membrane contactors for water purification and recovery factor increase in desalination plants

Dottorato di Ricerca in: Chemical Engineering and Materials, Ciclo XXI, a.a. 2007-2008Università della Calabri