Search

The interfacial tensions (IFTs) between hydrocarbon-, water- and CO2-rich phases are important in the processes of carbonated water injection for enhanced oil recovery and carbon geological storage. In this work, the IFTs between decane-rich and water-rich phases, in the presence of the third CO2-rich phase, were measured by the pendant drop method and modelled with the density gradient theory at temperatures from 298.15 K to 353.15 K and at pressures up to the critical point pressure of (CO2 + decane) (maximum 11 MPa at 353 K). The dynamic IFT decreased over time due to CO2 adsorption on the interface and mass transfer into the decane-rich drop until equilibrium was reached. As expected, the equilibrium IFTs were observed to decrease with increasing pressure. At low pressures, the equilibrium IFTs decreased with increasing temperature while, at high pressures, the reverse was observed. By comparing the IFTs of ternary (decane + CO2 + H2O) system with those of binary (decane + H2O) system, it was found that CO2 could reduce system IFT, for example by 15.2 mN/m at T = 333 K and p = 10 MPa. The extent of reduction depends on the solubility of CO2 in the liquid phases and the extent of adsorption at the interface. Furthermore, the equilibrium IFT was found to be linearly dependant on the CO2 concentration in the water-rich phase isothermally, and an empirical relation was developed with an average absolute deviation of 0.3 mN/m. Density gradient theory coupled with the volume translated CPA equation of state was found to provide an accurate description of the IFTs with an average absolute deviation of 0.8 mN/m, proving its capability of predicting IFTs of (alkane + CO2 + water) in the three-phase region. The density profile in the interfacial region is also demonstrated. There is an enrichment of CO2 molecules at the interface and the enrichment is more pronounced with increasing pressure or decreasing temperature.

Biodiesel fuels consist of a mixture of different fatty acid esters. The thermophysical properties of the fatty acid esters are decisive for combustion and storage. Especially density and viscosity influence, e.g., energy density, spray quality and lubrication in a diesel engine. For some of the fatty acid esters, several studies on thermophysical properties can be found in the literature in a wide pressure and a reasonably wide temperature range. However, for several of the esters, data at high pressures as well as low and high temperatures are missing; for some of them, even data at atmospheric pressure are missing. To develop thermophysical property models, comprehensive sets of experimental density and viscosity data are required. Therefore, this work reviews the available experimental data on density and viscosity of fatty acid methyl, fatty acid ethyl and fatty acid butyl esters. Data gaps present in the literature are illuminated. 16 different esters are considered for each of the three ester families. The homologous series of saturated esters from hexanoate (C6:0) to octadecenoate (C18:0) as well as the unsaturated esters oleate (C18:1), linoleate (C18:2), and linolenate (C18:3) are included. In addition, an overview of generalised models for the description of density and viscosity at elevated pressure is given.

For a first-of-a-kind nuclear fusion reactor like ITER, remote maintainability of neutron-activated and contaminated components is one of the key aspects of plant design and operations, hence a fundamental ingredient of its success, as well as of the demonstration of long-term viability of fusion as an energy source. The whole ITER Remote Maintenance System (IRMS) is of unprecedented complexity and includes specifically developed technologies. Its procurement and start of operation will represent a major innovation to maintenance in hostile environments. Europe is a key contributor, with three remote handling (RH) systems, a.k.a. packages, plus a robotic inspection and metrology tool, currently under design. This paper gives an update on the status of design and procurement activities related to the IRMS. It will first introduce some key aspects of the reactor remote maintainability, and then give an overview of the present configuration of the global system. After this, the scope, status and challenges of the European (EU) packages will be illustrated in more detail, together with some key technological developments. Finally, the way all these efforts are coordinated will be presented together with the overall implementation scenario and milestones, and the way they fit with ITER construction and operation.

Direct electrochemical reduction of CO2 to C-2 products such as ethylene is more efficient in alkaline media, but it suffers from parasitic loss of reactants due to (bi)carbonate formation. A two-step process where the CO2 is first electrochemically reduced to CO and subsequently converted to desired C-2 products has the potential to overcome the limitations posed by direct CO2 electroreduction. In this study, we investigated the technical and economic feasibility of the direct and indirect CO2 conversion routes to C-2 products. For the indirect route, CO2 to CO conversion in a high temperature solid oxide electrolysis cell (SOEC) or a low temperature electrolyzer has been considered. The product distribution, conversion, selectivities, current densities, and cell potentials are different for both CO2 conversion routes, which affects the downstream processing and the economics. A detailed process design and techno-economic analysis of both CO2 conversion pathways are presented, which includes CO2 capture, CO2 (and CO) conversion, CO2 (and CO) recycling, and product separation. Our economic analysis shows that both conversion routes are not profitable under the base case scenario, but the economics can be improved significantly by reducing the cell voltage, the capital cost of the electrolyzers, and the electricity price. For both routes, a cell voltage of 2.5 V, a capital cost of $10,000/m(2), and an electricity price of

ELEGANCY was an ERA-Net Cofund ACT project with the aim to help fast-tracking the decarbonization of Europe’s energy system via hydrogen and CCS. This has been achieved by overcoming or highlighting specific scientific, technological and economic/legal barriers and by undertaking five national case studies adapted to the conditions in the partner countries Germany, the Netherlands, Norway, Switzerland and the UK. ELEGANCY had 22 partners from industry and academia/research. This paper gives a brief overview of the project and some main results.

Made available in DSpace on 2021-06-25T10:13:31Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-01 This study analyzed the environmental impacts of nine scenarios for Polyethylene Terephthalate (PET) bottle waste disposal, in the city of Bauru, Brazil. Nine scenarios were considered in this study: (1) current (base) scenario (96.4% of PET waste is sent to landfill, 3.6% is sent to sorting cooperatives); (2) 50% to sorting cooperatives, 50% to landfill; (3) 50% to sorting cooperatives, 50% to incineration; (4) 50% to landfill, 50% to incineration; (5) 100% to sorting cooperatives (keeping the current collection distribution); (6) 100% to landfill; (7) 100% to incineration; (8) and (9) 100% sent to sorting cooperatives, with changes in the collection scheme. Life cycle assessment was implemented to compute the impacts for each scenario and compare their environmental performances. The results have shown that recycling is a better option than incineration across all impact categories analyzed. Landfilling had lower net impacts than incineration in all categories, except for ozone depletion and freshwater eutrophication. All recycling scenarios proposed outperformed the current scenario in all impact categories. Even though recycling presents itself as an environmentally-promising alternative, much work still needs to be done for its successful implementation, such as promoting source-separation at home and improving the management strategies of recycling cooperatives, including additional funding and training to support an increased sorting capacity. Sao Paulo State University – UNESP Department of Production Engineering USF University of South Florida Sao Paulo State University – UNESP Department of Civl and Environmental Engineering Sao Paulo State University – UNESP Department of Production Engineering Sao Paulo State University – UNESP Department of Civl and Environmental Engineering

In this work, measurements were carried out by the Taylor dispersion method [1, 2] to determine the mutual diffusion coefficient for CO2 in water or hydrocarbon at effectively infinite dilution. Measurements were carried out for CO2 in water, hexane, heptane, octane, decane, dodecane, hexadecane, cyclohexane, squalane and toluene at temperatures between 298 K and 423 K with pressures up to 69 MPa. Measurements of CO2 diffusivity in different brines were also carried out by 13C pulsed-field gradient NMR.