Assessing Methane Emission and Economic Viability of Energy Exploitation in a Typical Sicilian Municipal Solid Waste Landfill
Sanitary landfills for municipal solid waste (MSW) represent one of the major anthropogenic source of GHGs emissions and are directly responsible of the climate changes we are facing nowadays. Indeed, the biodegradable organic matter of MSW undergoes anaerobic digestion producing the landfill gas (LFG), whose main components are CH4 and CO2. Therefore, biomethane energy exploitation in MSW landfills will reduce GHGs emission positively affecting the global warming. The aim of the present study was to assess the methane production in a Sicilian landfill by comparing the results from field measurements of methane emission and the estimates achieved by applying different mathematical models. A…
Upgrade of citrus waste as a biofuel via slow pyrolysis
Abstract Slow pyrolysis (200–650 °C) experiments on citrus residues (orange peel waste “OP” and lemon peel waste “LP”) were carried out in lab scale fixed bed batch reactor. Bio-oil and bio-char obtained by thermal degradation are more stable, more homogeneous and higher energy content fuels when compared to the parent feedstock. Thermogravimetric analysis (TGA) showed higher stability of LP waste, which appears related to the higher lignin content . Mass and energy yields of solid and liquid products (i.e., char and oil) were measured to determine the effects of peak temperature on feedstock. A linear correlation between Gross Calorific Value (GCV), peak temperatures and mass loss (ML) all…
Preparation of Pd coated anodic alumina membranes for gas separation media
Different procedures of Pd electroless deposition onto anodic alumina membranes were investigated to form a dense metal layer covering pores. The main difficulty was related to the amorphous nature of anodic alumina membranes, determining low chemical stability in solutions at pH > 9, where Pd plating works more efficiently. As a consequence, it was necessary to find the operative conditions allowing Pd deposition without damaging the membrane: to reduce alumina dissolution, the plating bath was buffered at pH 8.5 by addition of either NaHCO 3 or Na 2 B 4 O 7 ·H 2 O. Acceptable conversion of Pd was found after a deposition time of 3 min. Single and multiple deposition steps (each lasting 3 …
A Novel Lab‐Scale Fixed‐Bed Pyrolysis Reactor for Biofuel Production from Agro‐Waste: Experimental Set‐up and Preliminary Life Cycle Assessment Study
The present study reports the features and set-up of a novel lab-scale fixed bed pyrolysis reactor for the production of solid and liquid bio-fuels from waste biomass. The fixed bed reactor is tested by carrying out pyrolysis experiments using two different waste biomasses. Olive tree trimmings (OT) and olive pulp (OP), olive cultivation and olive mill industries residues respectively, are pyrolyzed, under nitrogen atmosphere, between 200 and 650 °C for a residence time of 0.5 h. The OT and OP pyrolysis chars were characterized in terms of mass yields, high calorific values (HHVs), proximate and elemental analysis. Char mass yields, on a dry basis (d.b.), decreased from 91 to 23 wt% and fro…
Porosity of anodic alumina membranes from electrochemical measurements
A procedure based on the high-field mechanism of the growth of anodic oxides was developed in order to evaluate the morphological features of porous layers. Since the thickness of the barrier film, separating the porous layer from the metal, does not change during the steady-state growth of an anodic porous layer, the rate of displacement of the metal-oxide interface to the metal direction must be equal to the rate of displacement of the pore base to the oxide direction. As a consequence, porosity can be expressed in terms of the ratio i diss/i ion, where i diss is the dissolution current density at the pore base, and i ion is the ionic current density at the metal-oxide interface. Pore dia…
Life Cycle Assessment della pirolisi di biomasse residuali dal settore agro – alimentare
Il presente studio si propone di valutare gli impatti energetico - ambientali connessi al processo di pirolisi di rifiuti agro – alimentari attraverso l’applicazione della metodologia Life Cycle Assessment seguendo un approccio dalla culla al cancello. Il sistema analizzato consiste in un reattore di pirolisi al quarzo a letto fisso realizzato a scala di laboratorio. L’unità funzionale per l’analisi è 1 MJ di energia termica potenzialmente generata dalla combustione del bio-char prodotto dalla pirolisi di residui della potatura di olivi e dei residui della spremitura delle arance a tre diverse temperature (400 °C, 500 °C e 650 °C). Lo studio fornisce un ampio set di indicatori ambientali e …
Assessment of bio-combustibles production via slow pyrolysis of wine industry residues
With the aim of evaluating the potential production of high energy solid and liquid bio-fuels, a laboratory scale fixed bed reactor (FBR) derived from the standard Gray-King (GK) assay test on coal was used to carry out fixed bed pyrolysis experiments on wine industry by-products. The present study provides results on the pyrolysis of grape marc, residual from wine-making process, consisting of 50% by weight of grape seeds and 50% by weight of grape skins, at temperature between 150 and 500 °C, holding time of 30 minutes. Pyrolysis mass yields of solid (char) and liquid (tar) products and their corresponding energy properties, as a function of reaction temperature, are reported and discusse…
Optimized bath for electroless deposition of palladium on amorphous alumina membranes
A new bath for the electroless deposition of palladium on anodic alumina (AA) membranes is proposed. It was found that the optimal conditions for the uniform deposition of palladium, with minimal damage to the AA membranes, were under conditions of pH 8.4 and plating times shorter than 30 min. The deposited Pd layer was detected by X-ray diffraction (XRD) and energy dispersive X-ray (EDX) analysis. The morphology of the AA membrane before and after plating was examined by scanning electron microscopy (SEM). EDX analysis revealed that palladium was deposited only on the surfaces of the membrane and Sn ions, coming from the sensitizing bath, were incorporated into the palladium layer. EDTA in…
Developing a procedure to optimize electroless deposition of thin palladium layer on anodic alumina membranes
In recent years, the increased demand for hydrogen in many industrial applications, like petrochemical and semiconductor processing, and sustainable energy (fuel cells) has led to a renewed interest in methods for separation and purification of hydrogen from gas mixtures. In particular, palladium-based membranes have been the subject of many studies, due to their potential use as hydrogen-selective membranes for gas separation or purification [1,2]. Owing to the high cost of palladium and in order to increase the flow rate of hydrogen, composite membranes, formed by a thin layer of palladium deposited on a porous support, are largely preferred to thick self-standing metal membranes. Differe…
Chemistry of lanthanide–metal carbonyl systems: the ytterbium–chromium carbonyls interaction
Abstract The interaction of the chromium carbonyl hydrides HCr2(CO)10− or HCr(CO)5− with Yb(acac)3·3H2O has been investigated, and the experimental conditions leading to the isolation of ytterbium–chromium carbonyl complex species are reported. Formulation of the coordination compounds produced by such interactions has been proposed on the basis of analytical data and IR spectroscopy.
Metallic lead recovery from lead-acid battery paste by urea acetate dissolution and cementation on iron
Abstract A suitable hydrometallurgical and environmentally friendly process was studied to replace the currently used practices for recycling lead-acid batteries via smelting. Metallic lead was recovered by cementation from industrial lead sludge solutions of urea acetate (200 to 500 g/L) using different types of metallic iron substrates (nails, shaving or powder) as reducing agents. Under specific operating conditions, up to 99.7% of lead acid battery paste, mainly composed of PbSO4, PbO2 and PbO·PbSO4 species, was converted to metallic lead.. The conversion of the metallic lead and rate of the cementation reaction were strictly dependent on the type of iron substrate used as the reductant…
Reactivity of cellulose during hydrothermal carbonization of lignocellulosic biomass
Abstract Hydrothermal carbonization (HTC) of pure cellulose (CE) and birchwood (BW) samples was carried out at temperatures between 160 and 280 °C, 0.5 h residence time and biomass-to-water ratio 1:5, to investigate the reactivity of cellulose in lignocellulosic biomass. Thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FTIR) showed that the CE samples remained unaltered at temperatures up to 220 °C, but were significantly decomposed at 230 °C producing a thermal recalcitrant aromatic and high energy-dense material. FTIR showed that dehydration and aromatization reactions occurred at temperature equal or higher than 230 °C for the CE samples while a similar incre…
Environmental assessment of a waste-to-energy practice: The pyrolysis of agro-industrial biomass residues
Abstract The bio-wastes pyrolysis is a waste to energy strategy that converts bio-wastes into valuable products (bio-char, bio-oil) with wide use in the agri-food sector. However, limited efforts are paid to the investigation of its environmental sustainability: in this context, the study contributes the need towards the assessment of a wide range of environmental impacts for the pyrolysis process of different types of bio-wastes under different operating conditions. The study estimates the potential environmental impacts related to bio-char production from the pyrolysis of several different agro-industrial residues and different temperatures and identifies the process “hot spots”. The anal…
Synthesis and X-ray crystal structure of cationic polynuclear hydroxide acetylacetonate lanthanide(III) clusters with homodinuclear or heterodinuclear decacarbonyl hydrides: [HMo2(CO)10]− and [HCrW(CO)10]−
The synthesis and characterization of new polynuclear lanthanide(III) ionic clusters of general formula [Ln 9 (acac) 16 (OH) 10 ] + [Mo 2 (CO) 10 (μ-H)]- (Ln = Sm, Eu, Gd, Dy, Yb) and [Sm 9 (acac) 16 OH) 10 ] + [CrW(CO) 10 (μ-H)] - is reported. The polynuclear complexes, prepared under pure nitrogen atmosphere by interaction of the hydridic metal carbonyls with the β-dichetonate Ln(acac) 3 ·3H 2 O (Ln=Sm, Eu, Gd, Dy, Yb). The new clusters were characterized by elemental analysis, complexometric titration for Ln, atomic absorption for Cr, W and Mo, gas-volumetric analysis for CO, FTIR spectroscopy and single crystal X-ray structure determination of [Sm 9 (acac) 16 (OH) 10 ][Mo 2 (CO) 10 (μ-H…
Synthesis and Chemical physical characterization of a new series of hydroxil, acetylacetonate lanthanide (III) – ditungsten decacarbonyl hydride complexes
A novel series of the heterometallic lanthanide(III) ionic cluster complexes of general formula Ln 9 (acac) 16 (OH) 10 [W 2 (CO) 10 (μ-H)] with Ln = Sm (la), Eu (1b), Gd (1c), Dy (1d), and Yb (le) was prepared and characterized by FTIR, 1 H NMR spectroscopy and single crystal X-ray analysis. The cluster series was obtained by reaction in ethanol solution of the 2,4-pentanedionate hydrate of lanthanide(III), Ln(acac) 3 .3H 2 O, with the hydridic ditungsten decacarbonyl, [W 2 (CO) 10 (μ-H)] - . X-ray analysis showed that the complexes la-le are isostructural. The complete structural characterization of the Eu derivative (1b) shows, similarly to their chromium derivative analogues, a square an…