Feasibility Study on the Determination of the Solid Fat Content of Fats Using Temperature‐Modulated Optical Refractometry

The solid fat content (SFC) at different temperatures is an important characteristic of fat phases because it correlates to functionality in product applications. Consequently, this characteristic is also used to specify fat compositions in trade. Of three methods applicable, pulsed nuclear magnetic resonance (pMNR) is predominantly applied. Dilatometry and differential scanning calorimetry (DSC) find much less application. Handling with glass vials and high equipment costs make the search for alternatives to pNMR a useful endeavor. Optical refractometry is evaluated with respect to its potential to determine SFC values. Since refractometry is in the first place not suited for suspensions the positive results found are surprising. Applying temperature modulated optical refractometry (TMOR), isothermal optical refractometry with a superimposed temperature undulation yields repeatable results that are highly comparable to pNMR data. For the system studied (palm oil, coconut oil, partially hydrogenated palm oil), TMOR clearly outperforms DSC when pNMR is considered the method of reference. The key finding that refractive index is suitable to determine properties of suspensions is accompanied by the indications that refractometry has the potential to enable competitive methods within the fat technology. Practical Applications: The observation that refractometry can deliver quantitative data on fat suspensions enables the development of an array of new analytical methods. Next to SFC values and melting point, studies on the characterization of polymorphism can be envisioned. Since the device is robust and affordable, it could be in product development and quality control.     

The Energy Transfer Yield between Carotenoids and Chlorophylls in Peridinin Chlorophyll a Protein Is Robust against Mutations

The energy transfer (ET) from carotenoids (Cars) to chlorophylls (Chls) in photosynthetic complexes occurs with almost unitary efficiency thanks to the synergistic action of multiple finely tuned channels whose photophysics and dynamics are not fully elucidated yet. We investigated the energy flow from the Car peridinin (Per) to Chl a in the peridinin chlorophyll a protein (PCP) from marine algae Amphidinium carterae by using two-dimensional electronic spectroscopy (2DES) with a 10 fs temporal resolution. Recently debated hypotheses regarding the S₂-to-S₁ relaxation of the Car via a conical intersection and the involvement of possible intermediate states in the ET were examined. The comparison with an N89L mutant carrying the Per donor in a lower-polarity environment helped us unveil relevant details on the mechanisms through which excitation was transferred: the ET yield was conserved even when a mutation perturbed the optimization of the system thanks to the coexistence of multiple channels exploited during the process.     

Liquid Flow Visualization in Packed‐Bed Multiphase Reactors: Wire‐Mesh Sensor Design and Data Analysis for Rotating Fixed Beds

Wire‐mesh sensors are increasingly used for flow imaging in packed beds. In this study, a capacitance wire‐mesh sensor is applied to measure the cross‐sectional liquid phase distribution in a rotating fixed‐bed reactor. The liquid filling level is derived as a crucial parameter defining the operational window of the reactor concept. Contrary to the standard sensor configuration, wireless data transfer and autonomous power supply is integrated. Furthermore, appropriate data processing is required to visualize the liquid flow of the three‐phase system (nitrogen, cumene and γ‐Al₂O₃ particles).     

Standortplanung für die Herstellung CO2‐basierter Chemikalien am Beispiel der Olefinproduktion

The use of CO₂ as raw material is increasingly gaining in importance as an option for climate protection and as an alternative raw material feedstock. Both direct electrochemical syntheses and thermochemical processes are associated with a high demand for electrical energy. A contribution to climate protection is only possible in the case of low‐carbon power generation, as can be realized, e.g., by wind power or solar energy. This article presents a methodology for identifying suitable sites for the CO₂‐based production of olefins in Germany.     

Design and Synthesis of Simplified Polyketide Analogs: New Modalities beyond the Rule of 5

Natural products provide important lead structures for development of pharmaceutical agents or present attractive tools for medicinal chemistry. However, structurally complex and thus less accessible metabolites defying conventional drug-like properties, as expressed by Pfizer's rule of five, have received less attention as medicinal leads. Traditionally, research focus has been on realizing total syntheses rather than developing more readily available analogs to resolve the critical supply issue. However, very recent studies with complex myxobacterial polyketides have demonstrated that considerable structural simplification may be realized with retention of biological potencies. The context, underlying rationale and importance of tailored synthetic strategies of three such case studies are presented, which may inspire further related activities and may eventually help exploiting the largely untapped biological potential of complex metabolites in general.     

UV-based advanced oxidation processes for the treatment of odour compounds: Efficiency and by-product formation

The occurrence of the taste and odour compounds geosmin and 2-methyl isoborneol (2-MIB) affects the organoleptic quality of raw waters from drinking water reservoirs worldwide. UV-based oxidation processes for the removal of these substances are an alternative to adsorption and biological processes, since they additionally provide disinfection of the raw water. We could show that the concentration of geosmin and 2-MIB could be reduced by VUV irradiation and the combination of UV irradiation with ozone and hydrogen peroxide in pure water and water from a drinking water reservoir. The figure of merit EE/O is an appropriate tool to compare the AOPs and showed that VUV and UV/O₃ yielded the lowest treatment costs for the odour compounds in pure and raw water, respectively. Additionally, VUV irradiation with addition of ozone, generated by the VUV lamp, was evaluated. The generation of ozone and the irradiation were performed in a single reactor system using the same low-pressure mercury lamp, thereby reducing the energy consumption of the treatment process. The formation of the undesired by-products nitrite and bromate was investigated. The combination of VUV irradiation with ozone produced by a VUV lamp avoided the formation of relevant concentrations of the by-products. The internal generation of ozone is capable to produce ozone concentrations sufficient to reduce EE/O below 1 kWh m⁻³ and without the risk of the formation of nitrite or bromate above the maximum contaminant level.     

Development of a generalized coalescence and breakup closure for the inhomogeneous MUSIG model

In the present study we propose new coalescence and breakup closures for the inhomogeneous MUltiple bubble Size Group (MUSIG) model. The major purpose is to consider bubble coalescence and breakup due to different mechanisms in turbulent gas–liquid mixtures and to develop a generally applicable constitutive model for CFD applications. For bubble coalescence the new model includes coalescence due to turbulence, laminar shear, wake-entrainment and eddy-capture. Bubble breakup mechanisms encompass turbulent fluctuation, laminar shear and interfacial slip velocity. The new model was implemented in the commercial CFD software (CFX-12.0) and applied to the case of turbulent air–water mixtures in a large vertical pipe (DN 200). Simulation results for the evolution of bubble size distributions were compared to the standard closure model of Luo and Svendsen (1996) and Prince and Blanch (1990) as well as the experimental data of TOPFLOW test facility. Better prediction is accomplished by the proposed new model.     

Performance of vapor compression systems with compressor oil flooding and regeneration

Vapor compression refrigeration technology has seen great improvement over the last several decades in terms of cycle efficiency through a concerted effort of manufacturers, regulators, and research engineers. As the standard vapor compression systems approach practical limits, cycle modifications should be investigated to increase system efficiency and capacity. One possible means of increasing cycle efficiency is to flood the compressor with a large quantity of oil to achieve a quasi-isothermal compression process, in addition to using a regenerator to increase refrigerant subcooling.In theory, compressor flooding and regeneration can provide a significant increase in system efficiency over the standard vapor compression system. The effectiveness of compressor flooding and regeneration increases as the temperature lift of the system increases. Therefore, this technology is particularly well suited towards lower evaporating temperatures and high ambient temperatures as seen in supermarket refrigeration applications. While predicted increases in cycle efficiency are over 40% for supermarket refrigeration applications, this technology is still very beneficial for typical air-conditioning applications, for which improvements in cycle efficiency greater than 5% are predicted. It has to be noted though that the beneficial effects of compressor flooding can only be realized if a regenerator is used to exchange heat between the refrigerant vapor exiting the evaporator and the liquid exiting the condenser.     

Location Planning for the Production of CO2-Based Chemicals Using the Example of Olefin Production

A methodology for identifying suitable locations for the CO₂-based production of olefins in Germany is presented. Based on electricity and CO₂ requirements, locations are identified that can provide sufficient CO₂ and renewable energy for the conversion of CO₂ to olefins. In addition, the use of existing infrastructures is taken into account. The regional, technical renewable energy potential in Germany is sufficient to produce ∼ 800 kt of olefins from CO₂-based methanol per year in one plant. But the currently available CO₂ point sources with high CO₂ concentrations of around 100 % are not sufficient to meet the CO₂ requirement of an 800 kt a⁻¹ methanol-to-olefins plant. If existing refineries are preferred due to existing infrastructure services, locations in the north of Cologne, in Lower Saxony, and in Brandenburg are particularly suitable. A full substitution of fossil olefins by CO₂-based olefins is possible in Germany. The challenge is to provide sufficient renewable electricity for the production of H₂ with a low CO₂ intensity.