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In this study, two-step pyrolysis of biomass-rich municipal solid waste was studied on nickel supported ZSM-5 catalyst. In the first stage of the reactor, constant temperature (T = 550 °C) was applied, and in the second stage, the reactions took place at 500, 700 and 850 °C. Effects of operating parameters (temperature = 500, 700, 850 °C, steam rate = 1, 5 g/h) and catalyst load (0.5, 1.0, 2.0) were studied on yields and compositions, particularly on the hydrogen contents. In order to determine the significance of the operating parameters, response surface methodology was used. Considering the experimental data, the values of hydrogen/carbon monoxide molar ratio, lower heating value and the simulation, it was found that the favourable operating parameters of two-step pyrolysis of biomass-rich municipal solid waste were 850 °C temperature and 1 g/h steam rate (gas yield: 27.1%, hydrogen yield: 9.96 mmol g−1 waste, hydrogen/carbon monoxide molar ratio: 1.8). From the data of response surface methodology, it was also concluded that temperature has a more critical effect on gas yields and composition than steam rate. However, in some cases, the synergistic effect of the two factors can also be significant. Graphical abstract

Hydrogen is one of the key components in renewable energy systems. Its storage and transport, however, are challenging. The Liquid Organic Hydrogen Carrier (LOHC) technology is a possible solution for this issue. With suitable organic components, hydrogen can be stored in a chemically bound form which is safer and has a higher energy density than other solutions. Furthermore, the storage and transport of the LOHC component with high hydrogen content can be provided under normal environmental conditions. The LOHC process cycle involves a catalytic hydrogenation and dehydrogenation step where the LOHC component can be recovered and recycled. The paper reviews a few relevant studies regarding the possible LOHC compound pairs, the potential catalyst systems, and the necessary equipment. Then, the paper discusses a simulation study of three LOHC systems, determining suitable operating conditions and estimating costs. The toluene-methylcyclohexane system was found to be the most promising for LOHC application. Two energy integration opportunities were also examined. The first case study was based on separate hydrogenation and dehydrogenation sites, while the second was based on one site utilization. The results show a lower energy demand in the case of a toluene system, with a reduction of 70% in heating and 45% in cooling. Graphical Abstract

Volatile organic compounds (VOC) are widely used in different industries as solvents or reagents. The removal of excess organic substances is vital from both environmental and economic point of view. The purge columns or silos where the solid particles are discharged continuously and the gas is fed counter currently are examples of operation units where the excess organic substances should be removed. In this study, a previously developed model of a VOC removal silo was used in the investigation of its extended operation. Both economic and environmental concerns were addressed. Response surface methodology (RSM) was applied for a two-factor environmental-economic optimization of the system utilizing temperature and purge gas flow rate as factors, and removal time and energy demand as outcomes. The environmental performance was tested using a simplified life cycle analysis (LCA). Two scenarios were examined and compared, one of them with full and the other one with zero VOC emission case. The main achievement of our study is a new optimization map which includes both environmental and economic aspects. In conclusion, 80 °C temperature and 3 m3/h flow rates resulted as the optimal parameters.

Biomass is of growing interest as a secondary energy source and can be converted to fuels with higher energy density especially by pyrolysis or gasification. Understanding the mechanism and the kinetics of biomass pyrolysis (thermal decomposition) and gasification (conversion of organic material to gases) could be the key to the design of industrial devices capable of processing vast amounts of biomass feedstock. In our work real product components obtained in pyrolysis were took into consideration as well as char and oil as lumped components, and the kinetic constants for a biomass model compound (cellulose) pyrolysis and gasification were identified based on a proposed simplified reaction mechanism within a compartment model structure. A laboratory scale reactor was used for the physical experiments containing consecutive fast pyrolysis and gasification stages using alkali metal (K) containing feedstock, which has a significant effect on the cellulose pyrolysis and gasification. The detailed model was implemented in MATLAB/Simulink environment, and the unknown kinetic parameters were identified based on experimental data. The model was validated based on measurement data, and a good agreement was found. Based on the validated first principle model the optimal parameters were determined as 0.15 mL/min steam flow rate, and 4% K content.

One of the most challenging engineering tasks is the scale-up of a device. The information transfer between the different scales is crucial because similar yields and conversions should be achieved in a pilot and an industrial-scale device, which were obtained in a laboratory-scale unit. To maintain the same performance, the construction and operating parameters are often changed during the scale-up procedures. Traditionally, dimensionless numbers can be used to calculate the proper operating parameters and sizes for the scale unit. However, a validated computational fluid dynamics (CFD) simulator can be an excellent tool to perform scale-up studies with less time and energy consumption. This work reports a scale-up procedure aimed at supporting the building of a pilot plant-scale leaching reactor, used for the dissolution of metals form waste electric and electronic equipment. Particularly, the process deals with the dissolution of copper which has the second highest economic potential after precious metals. The scale-up studies are based on the validated model of the laboratory-scale reactor. Different construction and operating parameters were tested using CFD simulations. The different cases were evaluated based on conversion (leads to economic potential) and environmental assessment. COMSOL multiphysics will be used as CFD software and MATLAB for conversion and utility calculations and also for environmental assessment.

1. Der Quotient Albumin-Globulin schwankt bei Gesunden zwischen 3 und 5,5; der Mittelwert betragt 3,9. Globulinwerte finden sich zwischen 15% und 24%. 2. Aus wiederholt angestellten Bestimmungen ergibt sich, das der Organismus unter physiologischen Umstanden an der Bestandigkeit der Fraktionen konstant festhalt. 3 Bei Lebercirrhose ist in samtlichen Fallen eine bedeutende Vermehrung des Globulins zu Lasten des Albumins zu beobachten. Die Globulinwerte bewegen sich zwischen 33,2% und 64,2%, der Quotient Albumin-Globulin schwankt zwischen 1,8–0,49; der Mittelwert betragt 0,96. 4. Die Diagnose der Lebercirrhose kann beim Fehlen der Globulinvermehrung nicht gestellt werden. 5. Bei nichtcirrhotischen Alkoholikern liegt eine geringfugigere Vermehrung des Globulins auf Kosten des Albumins vor; der Mittelwert des Quotienten Albumin-Globulin betragt 2,01. 6. Die bei Alkoholikern beobachtete Globulinvermehrung ist ein Zeichen der Disposition zur Lebercirrhose. Bei ihrem Vorhandensein ist der weitere Alkoholgenus zu untersagen. 7. In Tier-und Menschenversuchen fuhrt eine einmalige Alkoholdarreichung zu vorubergehender Globulinvermehrung; bei andauernder Zufuhr wird die Globulin vermehrung stabilisiert. 8. Tuberkulose und Lues haben bei langerem Bestand Globulinvermehrung zur Folge. 9. Samtliche in der Atiologie der Lebercirrhose vorkommenden Faktoren fuhren bei entsprechender Anlage zu Globulinvermehrung.

1. Die in das Venensystem gelangte Luft erscheint bald in den Kranzarterien, und zwar auf dem Wege der Capillaren des kleinen Kreislaufs. 2. Die in die Coronarien gelangte Luft erzeugt als Embolus eine vorubergehende Ischamie der betreffenden Herzmuskelgebiete bzw. des Reizleitungssystems, was hinsichtlich der Tatigkeit des Herzmuskels bzw. der Reizleitung mit schweren Folgen einhergeht. 3. Nach der kunstlichen Erweiterung der Kranzarterien durch gefaserweiternde Mittel (Adrenalin, Amylnitrit) bilden nur grosere Luftmengen eine ernste Gefahr, kleinere Luftmengen gelangen rasch durch die Kranzgefase hindurch und erscheinen an verschiedenen Stellen des Korpers. 4. Im Elektrokardiogramm sind Veranderungen, welche auf den Verschlus der Kranzarterien, richtiger auf die Infarzierung des Herzmuskels, weiterhin auf Storungen der Reizleitung hinweisen, zu erkennen. Auf die praktische Frage, was im Falle von Luftembolie als lebensrettender Eingriff vorzunehmen ist, mochten wir auser demKleinschmidtschen Verfahren (Hangenlassen des Kopfes und Hochrichten der Beine) die Anwendung blutdrucksteigernder und kranzgefaserweiternder Mittel empfehlen, da dieselben auf Grund unserer obigen Versuche der gegen das Herz gerichteten unmittelbaren Gefahr der Luftembolie entgegenwirken konnen. Die von mehreren Autoren empfohlene ausgiebige Venensektion kann schon wegen des damit verknupften plotzlichen Sinkens des Blutdruckes und der Steigerung der Anamie nicht als zweckmasig bezeichnet werden.

Die Verfasser beschreiben einen letal ausgehenden Fall des systematischen P-W-Ch-Syndroms, der mit DIC einherging. Die Gerinnungsstorung normalisierte sich nach Heparingabe, das beeinfluste jedoch die Prognose der Krankheit nicht. Eine das Syndrom auslosende Grundkrankheit nachzuweisen, gelang weder im Leben noch bei der Obduktion, sodas sie ihren Fall fur eine sui generis Form halten.