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Institute Feature: CIRCC Italy
No full textThe CIRCC, Interuniversity Consortium on Chemical Reactivity and Catalysis, includes 17 universities and over 75 research units in Italy, with the aim to develop new chemical reactions, new catalytic systems, and their possible industrial applications. This Guest Editorial presents the consortium to EurJIC readers and summarizes the scientific articles that are showcased in the Institute Feature dedicated to CIRCC
Merging the Green-H2 production with Carbon Recycling for stepping towards the Carbon Cyclic Economy
Full text linkHydrogen Economy and Cyclic Economy are advocated, together with the use of perennial (solar, wind, hydro, geo-power, SWHG) and renewable (biomass) energy sources, for defossilizing anthropic activities and mitigating climate change. Each option has intrinsic limits that prevent a stand-alone success in reaching the target. Humans have recycled goods (metals, water, paper, and now plastics) to a different extent since very long time. Recycling carbon (which is already performed at the industrial level in the form of CO2 utilization and with recycling paper and plastics) is a key point for the future. The conversion of CO2 into chemicals and materials is carried out since the late 1800s (Solvay process) and is today performed at scale of 230 Mt/y. It is time to implement on a scale of several Gt/y the conversion of CO2 into energy products, possibly mimicking Nature which does not use hydrogen. In the short term, a few conditions must be met to make operative on a large scale the production of fuels from recycled-C, namely the availability of low-cost: i. abundant, pure concentrated streams of CO2, ii. non-fossil primary energy sources, and iii. non-fossil-hydrogen. The large-scale production of hydrogen by Methane Steam Reforming with CO2 capture (Blue-H2) seems to be a realistic and sustainable solution. Green-H2 could in principle be produced on a large scale through the electrolysis of water powered by perennial primary sources, but hurdles such as the availability of materials for the construction of long-living, robust electrochemical cells (membranes, electrodes) must be abated for a substantial scale-up with respect to existing capacity. The actual political situation makes difficult to rely on external supplies. Supposed that cheap hydrogen will be available, its direct use in energy production can be confronted with the indirect use that implies the hydrogenation of CO2 into fuels (E-fuels), an almost ready technology. The two strategies have both pros and cons and can be integrated. E-Fuels can also represent an option for storing the energy of intermittent sources. In the medium-long term, the direct co-processing of CO2 and water via co-electrolysis may avoid the production/transport/ use of hydrogen. In the long term, coprocessing of CO2 and H2O to fuels via photochemical or photoelectrochemical processes can become a strategic technology
Atmospheric CO2 mitigation technologies: carbon capture utilization and storage
Full text linkRecently, the utilization of carbon dioxide has gained in consideration as it may contribute to improve the economics of CO2 capture process by producing added value goods and is now considered a valid alternative to geological CO2 storage. Nowadays, the scientific community considers the integrated carbon capture, utilization and storage an important mitigation technology that involves the carbon dioxide sequestration from fuel combustion or industrial processes, its transport (via ship or pipeline) and conversion into valuable products or its permanent storage deep underground in geological formations. Noteworthy, CCS is functional to a linear economy, whereas utilization of carbon dioxide is at the hearth of a circular economy and its strategic role will grow in the future. In this mini review, the current state of the art in the field of capture, disposal, and reuse of CO2 as technologies for its overall reduction in the atmosphere will be discussed
Carbon Recycling Through CO2-Conversion for Stepping Toward a Cyclic-C Economy. A Perspective
No full textThe conversion of CO2 into added value chemicals, materials and fuels is a case of transition from the linear to the cyclic-C economy, a necessary change for stopping the putative negative effect of CO2 on climate and the environment. Several strategies can be implemented for CO2 conversion and their potential and timeframe is discussed in this perspective paper. The overall amount of avoided CO2 is evaluated in the short-, medium-, and long-term. The distinct contribution of Catalysis, Solar Chemistry and integrated Chemocatalysis-Biosystems is discussed
Carboxylation Reaction Based on the Direct and Indirect Uses of CO2: Sustainable Syntheses of C—CO2, O—CO2, and N—CO2Bonds
No full textCarboxylation represents an important route to afford C-C bonds useful to make building block molecules for polymer chemistry. This chapter will focus on recent advances in the field of direct carboxylation reactions based on CO2. The use of urea and inorganic carbonate will be also discussed. Different kinds of synthetic approaches (electrochemical, photochemical, catalytic, and enzymatic) will be considered mainly as future perspectives from the point of view of possible industrial applications, focusing attention on the energy and atom economy. The use of heterogeneous catalytic species will be described, also with mechanistic considerations
Industrial utilization of carbon dioxide (CO2)
No full textThe chapter presents the various aspects of the utilization of CO2 (technological, chemical, biotechnological) together with an analysis of the benefits derived from such practice. Conditions for correct use of CO2 are defined, and the potential of each technology is highlighted in terms of reducing emission into the atmosphere and lowering energy and/or material consumption, either directly (recycling of carbon) or indirectly, e.g. when the use of CO2 reduces the emission of products having a much higher climate change power (CCP) than CO2 itself. The potential utilization of CO2 as a tool to store excess or intermittent energies is also discussed, and the production of chemicals or energy products is presented, highlighting existing barriers to a full exploitation. The potential of enhanced fixation into aquatic biomass as a means of recyling CO2 and replacing fossil carbon in the production of chemicals or fuels for the transport sector is discussed. Emphasis is placed on the requirement for research into the potential for CO2 utilization to contribute to the reduction of its accumulation in the atmosphere. © 2010 Woodhead Publishing Limited All rights reserved
Valorization of C5 polyols by direct carboxylation to FDCA: Synthesis and characterization of a key intermediate and role of carbon dioxide
No full textReplacing fossil-C based plastics with those derived from renewable-C is one of the goals of the modern polymer industry. 2,5-Furan dicarboxylic acid (2,5-FDCA) is a candidate to substitute terephthalic acid as comonomer for polyesters. 2,5-FDCA is usually produced from C6 sugars. Carboxylation of 2-furancarboxylic acid (2-FCA) to 2,5-FDCA is an alternative synthetic approach to such monomer for polyethene furoate (PEF) preparation. In this work, several inorganic carbonates have been tested in the 2-FCA carboxylation in presence and absence of CO 2 . A key copper intermediate has been synthesized and fully characterized that is able to increase the acidity and, thus, the reactivity of 5-H towards a carbonate species. Carboxylation occurs at 93% yield in absence of CO 2 . The role of metal salts and CO 2 were investigated. The conversion yield of 2-FCA into the dicarboxylic acid is related to the charge density on the metal cation, increasing with lower charge-density
The Future of Carbon Dioxide Chemistry
No full textThe utilization of carbon dioxide as building block for chemicals or source of carbon for energy products has been explored for over 40 years now, with varying allure. In correspondence with oil-crises, the use of CO2 has come into the spotlight, soon set aside when the crisis was over due to the low price of fossil carbon and the convenience of using established technologies. Nowadays, there is a continuous shift from fossil-C-based to perennial (solar, wind, geothermal, hydro-power) energy-driven processes that will also have a great potential to convert large amounts of carbon dioxide. The integration of biotechnology and catalysis will be a key player towards the utilization of CO2 in several different applications, reducing both the extraction of fossil carbon and the carbon transfer to the atmosphere
L’allattamento artificiale di agnelli di razza-popolazione “Altamurana” macellati a 56 giorni di età: sua validità tecnica ed economica
No full textPitfalls in Photochemical and Photoelectrochemical Reduction of CO2 to Energy Products
Full text linkThe photochemical and photoelectrochemical reduction of CO2 is a promising approach for converting carbon dioxide into valuable chemicals (materials) and fuels. A key issue is ensuring the accuracy of experimental results in CO2 reduction reactions (CO2RRs) because of potential sources of false positives. This paper reports the results of investigations on various factors that may contribute to erroneous attribution of reduced-carbon species, including degradation of carbon species contained in photocatalysts, residual contaminants from synthetic procedures, laboratory glassware, environmental exposure, and the operator. The importance of rigorous experimental protocols, including the use of labeled 13CO2 and blank tests, to identify true CO2 reduction products (CO2RPs) accurately is highlighted. Our experimental data (eventually complemented with or compared to literature data) underline the possible sources of errors and, whenever possible, quantify the false positives with respect to the effective conversion of CO2 in clean conditions. This paper clarifies that the incidence of false positives is higher in the preliminary phase of photo-material development when CO2RPs are in the range of a few 10s of μg gcat−1 h−1, reducing its importance when significant conversions of CO2 are performed reaching 10s of mol gcat−1 h−1. This paper suggests procedures for improving the reliability and reproducibility of CO2RR experiments, thus validating such technologies
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