Search results for " reactor"

Hydrothermal liquefaction of municipal sludge in sub- and super- critical water

2020

Hydrothermal liquefaction of municipal sludge was conducted to investigate the effects of sub- and supercritical water and of the fluid dynamic regime on the quality of the products. Preliminary experimental runs were performed at two different temperatures (350°C and 400°C) changing reaction time in order to work at fixed kinetic severity of the process. An improvement of the C content in the solid residues and of the ratio H/C of the biocrude was obtained when a stirred reactor was used both in sub- and supercritical water. A hydrocarbon fraction was separated from biocrude whose maximum yield of 25% w/w was achieved in supercritical conditions. Results showed that the cumulative energy r…

Determination of β-decay ground state feeding of nuclei of importance for reactor applications

2020

In β-decay studies the determination of the decay probability to the ground state (g.s.) of the daughter nucleus often suffers from large systematic errors. The difficulty of the measurement is related to the absence of associated delayed γ-ray emission. In this work we revisit the 4πγ−β method proposed by Greenwood and collaborators in the 1990s, which has the potential to overcome some of the experimental difficulties. Our interest is driven by the need to determine accurately the β-intensity distributions of fission products that contribute significantly to the reactor decay heat and to the antineutrinos emitted by reactors. A number of such decays have large g.s. branches. The method is…

Degradation of Lincomycin in aqueous medium: coupling of solar photocatalysis and membrane separation

2005

Abstract The photocatalytic oxidation of a common antibiotic, the lincomycin was carried out in aqueous suspensions of polycrystalline TiO 2 Degussa P25 irradiated by sunlight. In order to improve the performance of the lincomycin degradation a hybrid system consisting of a solar photoreactor with the photocatalyst in suspension coupled with a membrane module, used to confine both photocatalyst and pollutants in the reaction environment, was tested. A preliminary study was carried out in order to determine some kinetics parameters of the drug photodegradation. The influence of initial substrate concentration on the lincomycin photooxidation rate was investigated. The photooxidation rate fol…

Heterogeneous photocatalytic degradation of pharmaceuticals in water by using polycrystalline TiO2 and a nanofiltration membrane reactor

2006

Abstract A study of the photodegradation of different pharmaceuticals [furosemide, ranitidine (hydrochloride), ofloxacine, phenazone, naproxen, carbamazepine and clofibric acid] in aqueous medium at various pHs by using a batch photoreactor and a photocatalytic membrane reactor working in recirculation regime was carried out. Polycrystalline TiO 2 was used as the photocatalyst, and different membranes (NTR 7410, PAN GKSS HV3/T, N 30 F, NF PES 10) were tested. A different adsorption of the substrates onto the catalyst surface was observed owing to the hydrophilic/hydrophobic character of the catalyst, depending on the pH. The photodegradation of the seven molecules in the batch reactor was s…

Innovative sequential batch reactor solutions for wastewater treatment

2019

Sekwencyjne biologiczne reaktory (SBR) są szeroko wykorzystywane do oczyszczania ścieków, które obecnie stają się zanieczyszczone coraz to nowymi i bardziej złożonymi substancjami. Korzystne zatem staje się włączenie różnego rodzaju rozszerzających się konfiguracji oraz modyfikacji operacyjnych, aby efektywniej oczyszczać ścieki. W pracy przedstawiono podstawowy opis procesu SBR oraz jego modyfikacji, które prowadzą do lepszego usuwania powstających zanieczyszczeń. Scharakteryzowano cykliczny system osadów czynnych (CASS), który jest jednym z najpopularniejszych procesów reaktorów sekwencyjnych (SBR) stosowanych do oczyszczania ścieków komunalnych oraz ścieków z różnych branż, w tym rafiner…

Beta-decay studies for applied and basic nuclear physics

2020

In this review we will present the results of recent beta-decay studies using the total absorption technique that cover topics of interest for applications, nuclear structure and astrophysics. The decays studied were selected primarily because they have a large impact on the prediction of a) the decay heat in reactors, important for the safety of present and future reactors and b) the reactor electron antineutrino spectrum, of interest for particle/nuclear physics and reactor monitoring. For these studies the total absorption technique was chosen, since it is the only method that allows one to obtain beta decay probabilities free from a systematic error called the Pandemonium effect. The me…

Methods to enhance hydrolysis during one and two-stage anaerobic digestion of energy crops and crop residues

2011

The role of fouling mechanisms in a submerged membrane bioreactor during the start-up

2006

Mass transfer and hydrodynamic characteristics of a Long Draft Tube Self-ingesting Reactor (LDTSR) for gas-liquid-solid operations

2011

Gas-liquid stirred vessels are widely employed to carry out chemical reactions involving a gas reagent and a liquid phase. The usual way for introducing the gas stream into the liquid phase is through suitable distributors placed below the impeller. An interesting alternative is that of using “self ingesting” vessels where the headspace gas phase is injected and dispersed into the vessel through suitable surface vortices. In this work the performance of a Long Draft Tube Self-ingesting Reactor dealing with gas-liquid-solid systems, is investigated. Preliminary experimental results on the effectiveness of this contactor for particle suspension and gas-liquid mass transfer performance in pres…

Energy efficient model for biogas production in farm scale

2011

Energy efficient solutions for six farm biogas production was found by calculating mass and energy balance in different scenarios. Raw materials in biogas production were cow manure and grass silage that were produced in these farms. There were calculated mass and energy balances on average for one year biogas prouduction that consisted of grass silage production, raw material transportation and biogas production in the biogas plant. In addition, direct greenhouse gases from biogas production were estimated. The direct mass and energy flows were calculated. It turned out that one input energy unit can produce 5.0 to 5.5 energy units as heat and electricity. Biogas reactor consumed heat from…