Thermodynamics and physical properties of an ionic liquid-based metal extraction process

In this study a LLX process for the extraction of cobalt by the IL [P8888][Oleate] is analysed in terms of relevant thermodynamic parameters. The process can be considered a typical example of transition metal extraction by an ionic liquid. Conductivity and chemical (FTIR) analyses indicate that Co2+ complexes with the IL. Three different models are evaluated, all different with respect to the actual Co2+ species that complexes with the IL, as well as the Co2+:IL stoichiometry. Based on simulations we identified CoCl2 as the Co species that enters and complexes with the IL, in a Co2+:IL ratio of 1:2. The complexation reaction between the Co-species and the IL is an endothermic, entropy-driven reaction. The influence of the feed composition on Co2+ extraction is investigated, including the effect of the nature of the accompanying anion as well as the presence of a salting out cation agent. The higher Co2+ extraction from a NO3− medium is due to the stronger interaction between Co(NO3)2 and the IL, reflected by a higher equilibrium constant of Co(NO3)2 compared to CoCl2. Differences in dehydration enthalpy between the ion species involved may contribute as well. Similar effects play a role when comparing uptake rates in solutions containing both Co2+ and Na+, with Co2+ extraction clearly preferred over that of Na+. Observed differences in Co2+ uptake in the presence of a salting-out agent (NaCl, KCl and NH4Cl) can be explained in terms of the hydration energy of the salting out cation, the higher this hydration energy, the higher the Co2+ uptake by the IL.</p

Effects of Vacancies near Substitutional Implants on Trapping and Desorption of Helium - A Simulation

Trapping of He by vacancies and drainage of He from substitutional implants (Ag and Kr in W) to nearby vacancies are investigated using static lattice calculations. The calculations indicate that drainage of He will occur to vacancies within a radius of 2.5 lattice units from the implant. Furthermore the trapping probability of substitutional and interstitial random walkers on a bcc lattice by substitutional traps or vacancies is calculated. When implantation-produced vacancies are present in the vicinity of the observed trap a shielding effect occurs. Trapping constants are calculated with two random walk models for both the unshielded and the shielded defect. For the latter several configurations were taken. The results show that shielding of a defect by one vacancy at a distance of three lattice units leads already to a reduction of He trapping by that defect of 30% to 40%.

Separation technology–Making a difference in biorefineries

In the quest for a sustainable bio-based economy, biorefineries play a central role as they involve the sustainable processing of biomass into marketable products and energy. This paper aims to provide a perspective on applications of separations that can make a great difference in biorefineries, by significantly reducing the costs and thus making the processes competitive without subsidies. A parallel is drawn between bio-refinery and petro-refinery, to highlight the specific separation challenges encountered in biorefineries and point out the impact of separations on the total costs. Existing and foreseen separations in biorefineries are reviewed, and the upcoming challenges in the bio-domain (additional to current fossil) are identified. Relevant industrial examples are provided to illustrate the tremendous eco-efficiency benefits of well-designed separation processes based on process intensification principles (e.g. reactive separations, dividing-wall column, affinity and trigger-enhanced separations). These examples also illustrate the low sustainability of several bio-separations currently practiced, in terms of high relative energy requirements, large amounts of gypsum co-production and/or excess use of caustic

Primary SARS-CoV-2 infection in patients with immune-mediated inflammatory diseases: long-term humoral immune responses and effects on disease activity

Background: Patients with immune-mediated inflammatory diseases (IMIDs) on immunosuppressants (ISPs) may have impaired long-term humoral immune responses and increased disease activity after SARS-CoV-2 infection. We aimed to investigate long-term humoral immune responses against SARS-CoV-2 and increased disease activity after a primary SARS-CoV-2 infection in unvaccinated IMID patients on ISPs. Methods: IMID patients on active treatment with ISPs and controls (i.e. IMID patients not on ISP and healthy controls) with a confirmed SARS-CoV-2 infection before first vaccination were included from an ongoing prospective cohort study (T2B! study). Clinical data on infections and increased disease activity were registered using electronic surveys and health records. A serum sample was collected before first vaccination to measure SARS-CoV-2 anti-receptor-binding domain (RBD) antibodies. Results: In total, 193 IMID patients on ISP and 113 controls were included. Serum samples from 185 participants were available, with a median time of 173 days between infection and sample collection. The rate of seropositive IMID patients on ISPs was 78% compared to 100% in controls (p Pathophysiology and treatment of rheumatic disease

Dehydrogenation of ethylbenzene using CO 2 - A process design study

The design of a dehydrogenation process for ethylbenzene using CO 2 as mild oxidant is put forward, including a technical and economical evaluation. Compared to the conventional process, this one has a more favorable equilibrium and can be operated at a lower temperature and lower energy consumption. The design is based on the data of the most promising catalyst investigated, i.e., Fe/Al/Zn. A single pass conversion of 26% with a selectivity to styrene of 91% for a CO 2/ethylbenzene ratio of 11:1 is observed. The process is designed according to the systematic process synthesis techniques. The low conversion and especially the high CO 2/ethylbenzene ratio leads to an unfeasible recycle flow. It reduces the CO 2/ethylbenzene ratio to 2:1. This is an abstract of a paper presented at the 7th European Congress of Chemical Engineering-7 and 19th International Congress of Chemical and Process Engineering CHISA 2010 (Prague, Czech Republic 8/28/2010-9/1/2010)

A novel method for determining the optimal operating points of reactive distillation processes

Reactive distillation (RD) allows reaction and separation to take place simultaneously in the same unit, thus giving major benefits especially to equilibrium limited reactions. Although the application of RD in chemical industries is attractive, it is considerably challenging. Unlike classic distillation, the optimal configuration of RD from an economical perspective is hardly identified quickly. Usually, any specific reaction system may need extensive studies and rigorous simulations to develop a RD model. This study aims to determine the optimal operating points of a RD application in a quick and reliable way. A novel method is employed for a clear visualization of the RD applicability area (i.e. a plot of reflux ratio vs number of stages). Using this method, an economic analysis can be performed resulting in essential insights into the optimal configurations. The production of amyl acetate by esterification of amyl alcohol and acetic acid is selected as case study, since this reaction sufficiently represents non-ideal behaviours in real systems. The outcome of the analysis reveals that the boundary line of its RD applicability graph consists of the optimal points of RD configurations which generate the lowest total annual cost in the RD operation. Furthermore, it is observed that the additional cost for the reactive section (relative to a separation section) is marginal, which means that the rules of thumb for the optimal configurations in classic distillation could also be applied

Kinetic analysis of an ionic liquid-based metal extraction process using a single droplet extraction column

In this study a liquid-liquid extraction (LLX) process has been investigated based on experimental analysis and kinetic modelling. The purpose of this investigation is (1) to understand the mass transfer behaviour, (2) to determine the rate limiting step via evaluating different mass transfer models, and (3) to estimate the mass transfer and kinetic parameters. This has been discussed in the context of the extraction of Co by the ionic liquid (IL) [P8888][Oleate] as an example of LLX with chemical reaction. Mass transfer models, with and without a chemical reaction, are evaluated based on a statistical cross-validation method. The following operational parameters are included in the analysis: column lengths, droplet diameter, droplet rising velocity and continuous and dispersed phase concentrations on Co uptake. This method reveals that a single parameter representing the external mass transfer resistance can describe the forward extraction of Co (i.e., into the IL) for the whole data set sufficiently accurate (error ±30%) regardless of the studied operational conditions. Back-extraction of Co from pre-loaded IL droplets shows a different transfer mechanism. Now the mass transfer in the dispersed IL phase dominates the process which is attributed to a change of the physical properties of the pre-loaded IL

Recovery of metals from spent lithium-ion batteries using ionic liquid [P8888][Oleate]

A separation method to selectively recover valuable metals (Co, Ni, Mn and Li) from synthetic spent lithium-ion battery cathodes leachate using a fatty-acid-based ionic liquid, tetraoctylphosphonium oleate [P₈₈₈₈][oleate] is demonstrated. The investigated parameters for this selective separation and recovery process include extraction pH, contact time and composition of the regeneration solution. The benefit of using this ionic liquid is that >99% of Co and >99% of the Mn can be separated from the Ni and the Li by a two-stage extraction process. A subsequent single regeneration process separates the Co from the Mn. Finally, Ni and Li are completely separated in an additional regeneration process. An economic potential analysis concludes the paper, revealing that given the current cobalt price, the process outlined here shows a positive zero-order Economic Potential (bases on product sales and raw material cost) when using a 4 M HCl leaching solution and for leachates containing at least 4.5 g Co per liter