Search results for " Chemical engineering"
showing 10 items of 2965 documents
Antiviral and antioxidant properties of active alginate edible films containing phenolic extracts
2018
In this work, novel active edible films having antiviral activity were developed through the solvent casting method. Emulsified edible films were prepared by adding lipids into alginate films in order to improve their water vapour permeability. In addition, two natural extracts rich in phenolic compounds, specifically a green tea extract (GTE) and a grape seed extract (GSE) were used as active agents. Interestingly, incorporating GTE or GSE within the biopolymer matrix, the films exhibited significant antiviral activity against murine norovirus (MNV) and hepatitis A virus (HAV) since ∼2 log reduction were recorded for the 0.75 g extract/g alginate in the film, being GTE more efficient than …
Corrosion in alkanolamine used for acid gas removal: From natural gas processing to CO2 capture
2010
The aim of this paper is to review some of the parameters influencing the corrosivity of alkanolamine solvents used for natural gas purification or for CO2 capture. In the light of literature data and of new experimental results, the influences of temperature and of acid gas loading are discussed. These two parameters appear to have a strong impact on corrosion rates of carbon steel, with extrapolated corrosion rates of several tens of mm/year for the highest temperature and acid gas loading condition.
Analysis of optimal temperature, pressure and binder quantity for the production of biocarbon pellet to be used as a substitute for coke
2019
In order to contribute to the decarbonization of the economy, efficient alternatives to coal and coke should be found not only in the power sector but also in the industrial sectors (like steel, silicon and manganese production) in which coal and coke are used as a reductant and for steel production also as a fuel. To this aim many research works have been focused on the development of a coke substitute based on woody biomass and known as “biocarbon”. There are still barriers to overcome, among them: the biocarbon low density, poor mechanical strength and high reactivity. In this paper a new biocarbon production methodology is proposed, based on: pyrolysis at 600 °C, densification (using py…
Sewage sludge as cheap alternative to microalgae as feedstock of catalytic hydrothermal liquefaction processes
2019
Abstract Production of biocrude through hydrothermal liquefaction (HTL) of sewage sludge (SS) and Chlorella vulgaris was investigated. NiMo/Al2O3 (KF 851), CoMo/Al2O3 (KF 1022) and activated carbon felt, tested as catalysts at 598 K for 30 min, did not change the biocrude yield but significantly improved its quality. Quantitative sulfur removal and lower oxygen content were found in biocrude when KF 851 and KF 1022 were used with C. vulgaris. The same catalysts decreased O/C and S/C ratio of the biocrude from SS. The highest HHV (38.19 MJ/kg) and H/C ratio (1.65) and the lowest O/C (0.11) of the biocrude from SS were obtained with the cheaper activated carbon felt. A new product phase, prob…
Metal distribution in the process of lignocellulosic ethanol production from heavy metal contaminated sorghum biomass
2016
Effect of torrefaction on properties of pellets produced from woody biomass
2020
Torrefaction has been recognized as a promising strategy to improve handling and storage properties of wood-based pellets, thus producing a uniform-quality commodity with high energy density and hydrophobicity. In this work, pellets produced from spruce stem wood, bark, and forest residues were torrefied in a bench-scale tubular reactor at 225 and 275 °C with two residence times (30 and 60 min). The effects of torrefaction on general properties, grindability, mechanical properties, hydrophobicity, and microstructure of the studied pellets were investigated. The increase of torrefaction severity reduced mass yields, but the heating values and the fixed carbon content of the torrefied pellets…
Specifications for carbonate content quantification in recent marine sediments using Rock-Eval pyrolysis
2019
11 pages; International audience; The amount of CaCO3 in sediments and/or sedimentary rocks is usually measured by calcimetry while the nature of the carbonates is determined by X-ray diffraction. Recently, a carbonate recognition method based on the results of Rock-Eval pyrolysis was proposed in 2014 by Pillot et al. [1]. Rock-Eval pyrolysis is also widely used for the characterization of recent sediments. However, later in 2015 Baudin et al. [2] noticed that some of the characteristics of recent sediments tended to produce different results from those of more classical Rock-Eval analyses, causing bias in interpretations.In this study, the thermal stability of fossil and recent marine carb…
Modeling the natural gas supply chain for sustainable growth policy
2020
Abstract Natural gas has been used globally as a transitional fuel for supporting a green-energy-supply strategy, which has been questioned for the intermittence and lack of reliability of renewables. This paper proposes a System Dynamics model for assessing alternative security of supply policy along the natural gas value chain. The model incorporates demand, transport, production and reserves of natural gas variables according to a systemic perspective. It also includes a module for evaluating the effect of natural gas price on the demand and supply levels, respectively. Alternative supply policies are evaluated under different scenarios. The chosen case-study focuses on the Colombian nat…
Energy and economic analysis of air-to-air heat pumps as an alternative to domestic gas boiler heating systems in the South of Italy
2019
Abstract According to the electricity tariff recently issued by the Italian government for the domestic heating systems fed with heat pumps (HP), an energy and economic analysis was carried out with the aim of investigating the effectiveness of the air-to-air heat pump systems (HPS) as an alternative to the traditional heating using domestic gas boilers systems (GBS). For the purpose of this study, the apartments of three residential buildings were examined. The hourly heating loads were calculated with the ASHRAE radiant time series and the coefficient of performance (COP) of the HPs was evaluated for each operating condition. The costs for the heating system installation and electricity a…
Characterization of renewable reductants and charcoal-based pellets for the use in ferroalloy industries
2018
This study investigates the effect of high-temperature pyrolysis and post-treatment processes on spruce and oak charcoal yields and CO2 reactivity in a slow pyrolysis reactor. Post-treatment processes such as co-pyrolysis of biomass and recirculated tar mixture with that to the distillation of the charcoal-tar blend gave similar increase in charcoal yields. From a technological standpoint, co-pyrolysis of charcoal and tar mixture decreased the CO2 reactivity of the charcoal approaching that of fossil-based coke. This emphasize the importance of tar addition and high temperature treatment on charcoal properties. Moreover, the findings of this work show the potential use of the tar organic fr…