Laboratory-scale liquefiers for natural gas: A design and assessment study

Exact knowledge of natural gas composition is essential in custody transfer to determine the energy content of the delivery. However, for liquefied natural gas (LNG), a reliable composition determination is difficult. Here, we describe the design of a laboratory-scale reference liquefier that enables the validation and calibration of optical spectroscopy sensors by providing them with a sample of metrologically traceable composition. Hence, it is crucial to avoid fractionation of the sample during liquefaction. This is realized by supercritical liquefaction of a reference gas mixture in conjunction with a special vapor–liquid-equilibrium (VLE) cell. As this is a demanding high-pressure application, low-pressure condensation as liquefaction method was also assessed. Through experimental investigations and VLE calculations, preservation of the composition of the produced liquid sample during condensation was studied. We conclude that under optimized conditions, validation, and calibration measurements of optical sensors can be performed on condensed liquids, which, however, needs further confirmation.     

On higher structures

In this paper, we discuss various philosophical aspects of the hyperstructure concept extending networks and higher categories. By this discussion, we hope to pave the way for applications and further developments of the mathematical theory of hyperstructures.     

Enhancement in crystallinity of poly(3-hexylthiophene) thin films prepared by low-temperature drop casting

Low-temperature casting of high molecular weight (HMW > 40 kDa) regioregular poly(3-hexylthiophene) (P3HT) is demonstrated to yield highly crystalline P3HT thin films with well defined and preferentially edge-on oriented [(100) contact plane] nanocrystallites on the pure and silanized Si/SiO₂ substrates. Transmission electron microscopy and X-ray diffraction provide evidence for the increase in preferential edge-on orientation of P3HT-conjugated backbone while decreasing the film preparation temperature below room temperature. The optimum growth temperature is about −12°C for the given concentration (2 mg/mL in CHCl₃). The reduced evaporation rate of the solvent results in a better selection of the thermodynamically stable orientation of nanocrystallites onto the substrate. The degree of preferential orientation and size of the crystallites can be further increased on n-octadecyltrichlorosilane-treated SiO₂ substrates as well as by annealing the films at 200°C for 1 h. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Eumelanin for nature‐inspired UV‐absorption enhancement of plastics

In the human body, the black‐brown biopigment eumelanin blocks harmful ultraviolet (UV) radiation. In the plastics industry, additives are often added to polymers to increase their UV‐absorption properties. We herein report an assessment of the biopigment eumelanin as a nature‐inspired additive for plastics to enhance their UV absorption. Since eumelanin is produced by natural sources and is nontoxic, it is an interesting candidate in the field of sustainable plastic additives. In this work, the eumelanin‐containing films of commercial ethylene–vinyl acetate copolymer, a plastic used for packaging applications, were obtained by melt compounding and compression molding. The biopigment dispersion in the films was improved by means of the melanin free acid treatment. It was observed that eumelanin amounts as low as 0.8 wt% caused an increase of the UV absorption, up to one order of magnitude in the UVA range. We also evaluated the effect of eumelanin on the thermal stability and photostability of the films: the biopigment proved to be double‐edged, working both as UV‐absorption enhancer and photo‐prooxidant, as thermogravimetric analysis and infrared spectroscopy revealed. © 2019 Society of Chemical Industry     

Aufbau einer Versuchsanlage zur katalytischen Spaltung des 9,10‐Dihydroxystearinsäuremethylesters mit Luftsauerstoff

The development of new catalysts for the oxidation of chemical compounds with oxygen as cheap and environmentally oxidant is an important topic of the current research. Due to the risk of the formation of potentially explosive gas mixtures aerobic oxidation reactions have to be performed with consideration of the explosion prevention. A safety concept for aerobic oxidation reactions and the construction of an experimental plant is presented. The oxidative cleavage of methyl 9,10‐dihydroxystearate to azelaic acid methyl ester and pelargonic acid was investigated as a model reaction.     

Production and Use of Sustainable C2-C4 Alcohols – An Industrial Perspective

In the recent past, society has become increasingly aware of the environmental impact of political and corporate action. Hence, several industrial sectors are currently undergoing a transition to more sustainable products and processes. Sustainable production processes for C2-C4 alcohols can help to decrease the environmental impacts of large downstream markets such as fuels and polymers. However, a reliable and consistent framework is needed for companies to further develop and commercialize these processes. Furthermore, standardized procedures for determining the sustainability of a process are essential in evaluating the environmental benefits.     

Value creation for tenants in environmentally certified buildings

Previous research suggests that environmental certification (EC) affects rental rates in non-residential buildings, but there is still little understanding of how tenants differentiate such buildings from those without EC. This paper examines whether and how tenants perceive value creation in EC premises in Sweden. The findings (based on 29 questionnaire responses and 14 interviews with tenants in EC buildings) inform landlords and tenants on the development of EC strategies for improved organizational outcomes. EC creates value for tenants principally as support for their environmental management and reporting (e.g., low energy demand). EC is important for tenants internally, raising employee environmental awareness and improving employee attraction and retention. Tenants are generally positive about employee morale, indoor environmental quality (IEQ) and rental costs. However, it is not clear if such perceptions are dependent on features of modern premises in general, such as new fixtures, fittings and furnishings, and space-efficiency or from some EC-related feature. Tenants do not identify health or productivity increase in their EC premises. Findings suggest that the research focus should be shifted from investigating health and productivity increases through IEQ improvement to understanding the motivational improvement through value alignment with employees through EC.