Furfural to Cyclopentanone – a Search for Putative Oligomeric By-products

We report here on the reductive rearrangement of biomass-derived furfural to cyclopentanone, a promising non-fossil feedstock for fuels and chemicals. An underreported aspect of this reaction is the inevitable formation of heavy byproducts. To mitigate its formation, process condition such as, solvent, catalyst, temperature, acidity, and feed concentration were varied to unravel the chemistry and improve the reaction performance. Water medium was confirmed to play a crucial role, as organic solvents were unable to deliver cyclopentanone or heavy by products. Copper-based catalyst showed the highest selectivity for ring-rearrangement, reaching 50 mol % under the conditions investigated. The main factor influencing the yields of cyclopentanone (CPO), and promote oligomer formation, are the feed concentration and the pH, as high feed concentrations and high acidity facilitate the self-polymerization of furfuryl alcohol (FALC). This was confirmed by dedicated experiments using FALC and the hydroxypentenone intermediate as feed. The concentration challenge could be mitigated by slowly dosing the feed, which increased the desired product yields by 4–12 mol %. Nevertheless, most oligomers appeared to fall in the range of common liquid fuels and could be converted to diesel by hydrodeoxygenation.</p

Montmorillonite K10-induced decomposition of methyl N-phenylcarbamate to phenylisocyanate and its prospect for recovering isocyanates from polyurethanes

The significant growth of the production and use of flexible polyurethane (PU) foam causes increased waste accumulation, thereby creating a demand for the recycling of PU. While upgrading PU materials to recycled polyols has been studied in detail, the recovery of diisocyanates is a longstanding challenge. Montmorillonite K10 (MK10) has been proposed as a catalyst to convert carbamates into isocyanates, but its prospects are unclear. Here, the MK10-catalyzed decomposition of methyl phenylcarbamate (MPC) into phenylisocyanate (PI) and the side product N,N’-diphenylurea (DPU) has been studied as a model reaction for the decomposition of PU foam and the potential recovery of PI. The effects of the amount of catalyst, the temperature, and the solvent were investigated by HPLC analyses. Kinetic analysis revealed that the uncatalyzed rate of the MPC decomposition is much lower than the catalyzed rate, indicating that the thermally driven decomposition is negligible. Our results, involving both experimental kinetic studies and models of the kinetics, show that, while MK10 effectively catalyzes the decomposition of MPC, it also causes the formation of aniline, which reacts with PI to form DPU. As a result, large amounts of MK10 favor DPU and prevent the selective formation of PI, and yields of PI &gt;30 % were never observed. Likely, the OH groups of MK10 form covalent bonds with PI, causing a deficiency in the mole balance. Overall, MK10 is unsuited to provide high yields of isocyanates.</p

Kinetics of Furfural Formation from Xylose via a Boronic Ester Intermediate

Previous studies showed that furfural can be made from lignocellulosic biomass with higher selectivity when the xylose is first converted to a boronic ester intermediate. So far, this has only been demonstrated on a laboratory scale with lab-grade reagents. This work aims to lay out the foundations needed for future development of an industrial process. Several parameters have been investigated, such as stirring rate, temperature, and choice of solvent and boronic acid. The reaction has also been validated for use with a real feedstock (i.e., bagasse acid hydrolysate). Additionally, a model has been developed for one combination of reagents, which predicts that at temperatures above 220 °C and a residence time below 400 s, furfural can be made from xylose via this route at more than 70% selectivity on a molar basis and 0.1 t/m3/h.</p

Plastic recycling stripped naked – from circular product to circular industry with recycling cascade

This perspective combines various expertise to develop and analyse the concept of technology cascade for recycling waste plastics with the goal of displacing as much fossil crude oil as possible. It thereby presents archetype recycling technologies with their strengths and weaknesses. It then combines them in various cascades to process a representative plastic mix, and determines how much (fossil) naphtha could be displaced and at which energy consumption. The cascades rely on a limited number of parameters that are fully reported in supplementary information and that were used in a simple and transparent spreadsheet model. The calculated results bust several common myths in plastic recycling, e. g. by prioritizing here recycled volume over recycling efficiency, and prioritizing circular industry over circular products. It unravels the energy cost of solvent-based recycling processes, shows the key role of gasification and the possibility to displace up to 70 % of the fossil feedstock with recycled carbon, a recycling rate that compares well with that aluminium, steel or paper. It suggests that deeper naphtha displacement would require exorbitant amount of energy. It therefore argues for the need to complement recycling with the use of renewable carbon, e. g. based on biomass, to fully defossilise the plastic industry.</p

Connected Digital Twin for incorporating material flow simulation during product development

Changeable production systems do not consider the development and design of a product comprehensively enough. Material flow simulations are useful for considering product changes from a production point of view when used to verify concepts in the planning phase and to check for weak points. While simultaneous engineering is made possible by creating a material flow simulation at an early stage of product development, the creation of simulations is very time consuming and the added value of a simulation is often not fully recognised. In this paper, a concept is presented that helps to reduce the effort of creating and adapting simulation models by relying on the properties of flexibility and easy reconfigurability of adaptive production systems

Influence of blood glucose on heart rate and cardiac autonomic function. The DESIR study.

International audienceOBJECTIVES:   To evaluate in a general population, the relationships between dysglycaemia, insulin resistance and metabolic variables, and heart rate, heart rate recovery and heart rate variability. METHODS:   Four hundred and forty-seven participants in the Data from an Epidemiological Study on the Insulin Resistance syndrome (DESIR) study were classified according to glycaemic status over the preceding 9 years. All were free of self-reported cardiac antecedents and were not taking drugs which alter heart rate. During five consecutive periods: rest, deep breathing, recovery, rest and lying to standing, heart rate and heart rate varability were evaluated and compared by ANCOVA and trend tests across glycaemic classes. Spearman correlation coefficients quantified the relations between cardio-metabolic risk factors, heart rate and heart rate varability. RESULTS:   Heart rate differed between glycaemic groups, except during deep breathing. Between rest and deep-breathing periods, patients with diabetes had a lower increase in heart rate than others (P(trend) < 0.01); between deep breathing and recovery, the heart rate of patients with diabetes continued to increase, for others, heart rate decreased (P(trend) < 0.009). Heart rate was correlated with capillary glucose and triglycerides during the five test periods. Heart rate variability differed according to glycaemic status, especially during the recovery period. After age, sex and BMI adjustment, heart rate variability was correlated with triglycerides at two test periods. Change in heart rate between recovery and deep breathing was negatively correlated with heart rate variability at rest, (r=-0.113, P < 0.05): lower resting heart rate variability was associated with heart rate acceleration. CONCLUSIONS:   Heart rate, but not heart rate variability, was associated with glycaemic status and capillary glucose. After deep breathing, heart rate recovery was altered in patients with known diabetes and was associated with reduced heart rate variability. Being overweight was a major correlate of heart rate variability

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