Beef cattle production is a widespread activity in Italy in the agricultural field and determines an important impact on environment and resources consumption. Carbon footprint evaluation is thus ...necessary to evaluate the contributions of the different stages and the possible improvements of the production chain.
In this study, two typical Italian beef production systems, a conventional and an organic one are investigated in order to evaluate the greenhouse gas emissions from “cradle to gate farm” by a Life Cycle Assessment (LCA) approach; the carbon footprint (CF) per 1kg of live weight meat is calculated.
The contributions from feed production, enteric fermentation, and manure management are taken into account, in order to compare the life cycle of the two productions; also the carbon balance in soil is evaluated, in order to verify the impact in a life cycle perspective.
The results of CF calculation of the two farms show that organic system (24.62kgCO2eq/kg live weight) produce more GHG emissions than the conventional one (18.21kgCO2eq/kg live weight) and that the enteric fermentation is the more heavy contribution, with a range of 50–54% of the global CF value. Improvements of the production chain could be realized by accurate feeding strategies, in order to obtain reduction of methane emissions from enteric digestion of cattles.
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•Organic and conventional beef production are compared by carbon footprint.•Conventional system has lower GHG emissions.•The most impacting phase is represented by enteric fermentation in both scenarios.•Sensitivity analysis evaluates the contribution from changes in soil C.
•Kinetic analysis of Coffee Silver Skin pyrolysis is studied through deconvolution.•Activation energy is calculated by Ozawa-Flynn-Wall and Starink kinetic methods.•Reaction mechanisms of ...pseudo-components are evaluated by employing master plots method.•Pyrolysis of pseudo lignin is in two-step reaction process.•Thermodynamic parameters (ΔH, ΔG, ΔS) are also calculated.
Biomass is a fundamental renewable resource to develop sustainable energy conversion systems with low environmental impact. The design of biomass pyrolysis, gasification, and combustion facilities requires a particular attention at kinetic aspects. A coffee production residue such as coffee silver skin, which is the main product of the coffee roasting industry, is very suitable for thermochemical conversion, being already dry and containing compounds like the ochratoxin which does not allow its use in the production of biochemicals. In this work, thermal degradation tests of coffee silver skin are made under inert conditions at various heating rates (5, 7, 10, 15 °C/min) and a proper kinetic model was considered in order to quantify the activation energy (Eα). The variation of Eα with the conversion rate (α) was higher than 30%, showing that the process is kinetically complex and the kinetics cannot be described by a single-step model, according to the International Confederation on Thermal Analysis and Calorimetry. For this reason, a multi-step model and an analytical approach were used. This involves the deconvolution of the individual peaks of each pseudo-component from the overall differential kinetic curves, followed by the application of a model free-isoconversional method to the separated decomposition steps. The determination of the reaction mechanism f(α) of each sub-component (pseudo-cellulose P-CL, pseudo-hemicellulose P-HC, and pseudo-lignin P-LG) was performed by using both the Master-Plots method and the Energy Compensation Effect. The pre-exponential factor, the enthalpy and the Gibbs free energy were also evaluated in order to investigate the pyrolysis characteristics. A second order model mechanism was obtained for P-CL and P-HC, whereas no clear mechanism was found for P-LG when α > 0.5.
Olive pomace is an interesting agro-industrial byproduct that can be a potential raw material for densified biomass products. At first, 2-phase (2 PH) and 3-phase (3 PH) olive pomace pellets were ...analyzed in order to evaluate their quality in terms of the main parameters required by the European Standard EN 17225-6.
The characterization of the pure pellets has shown important problems because of out of limits values of nitrogen, durability and copper in the two olive pomace. To improve the properties of olive pomace pellets, the possibility of manufacturing pellets by mixing olive pomace and olive tree pruning (PR) was investigated.
Several blends at different weight ratios were analyzed in order to verify the effect of mixing on the pellet properties. It can be concluded that the physical properties of all mixtures are in compliance with the requirements of the standard.
In particular, two best blends in terms of physical, chemical and mechanical characteristics were identified as becoming potential fuel for combustion and gasification applications: 75PR252 PH (75% pruning and 25% 2-phase pomace) and 50PR503 PH (50% pruning and 50% 3-phase pomace).
•Olive pomace is a potential raw material for pellet production.•Pure olive pomace pellets not respect requirements for pellet quality.•Pellet blends of olive pomace and olive tree pruning were produced and analyzed.•Physical properties of pellet are improved by mixing olive pomace and pruning.•Two blends have the best performance as physical, chemical and energetic features.
The solid fraction obtained by mechanical separation of digestate from anaerobic digestion plants is an attractive feedstock for the pyrolysis process. Especially in the case of digestate obtained ...from biogas plants fed with energy crops, this can be considered a lignin rich residue. The aim of this study is to investigate the pyrolytic kinetic characteristics of solid digestate. The Starink model-free method has been used for the kinetic analysis of the pyrolysis process. The average Activation Energy value is about 204.1 kJ/mol, with a standard deviation of 25 kJ/mol, which corresponds to the 12% of the average value. The activation energy decreased along with the conversion degree. The variation range of the activation energy is about 99 kJ/mol, this means that the average value cannot be used to statistically represent the whole reaction. The Master-plots method was used for the determination of the kinetic model, obtaining that n-order was the most probable one. On the other hand, the process cannot be modeled with a single-step reaction. For this reason it has been used an independent parallel reactions scheme to model the complete process.
This study explores the hydrothermal carbonization (HTC) process applied to the exhausted chestnut produced by the tannin extraction industry, utilizing process water recirculation to enhance the ...efficiency and sustainability of the conversion process. Tannin extraction from wood typically involves hot water treatment, leaving behind residual wood biomass known as exhausted wood. These by-products maintain their renewable properties because they have only been exposed to hot water under a high pressure, which is unlikely to cause major alterations in their structural components. Hydrothermal treatment was carried out at temperatures of 220 °C and 270 °C for 1 h, with process water being recirculated four times. This investigation focused on analyzing the effects of recirculation on the yield and fuel properties of hydrochar, as well as characterizing the combustion behavior of the obtained hydrochar. The results indicated that recirculation of process water led to improvements in both the mass and energy yields of hydrochar. The mass yield of the hydrochar samples increased by 5–6%, and the ERE of the hydrochar samples increased by 5–8% compared to the HTC reference sample. However, alterations in the combustion characteristics were observed, including decreases in ignition temperature and combustion reactivity. The results indicate that, with PW recirculations, the combustion index decreased by about 14% and 18% for 220 °C and 270 °C, respectively. Overall, this research demonstrates the potential of utilizing HTC on chestnut tannin residue with process water recirculation to produce stable solid fuel and provides insights into the combustion behavior of the resulting hydrochar.
Credit scoring analysis is an important activity, especially nowadays after a huge number of defaults has been one of the main causes of the financial crisis. Among the many different tools used to ...model credit risk, the recent development of rough set models has proved effective. The original development of rough set theory has been widely generalized and combined with other approaches to uncertain reasoning, especially probability and fuzzy set theories. Since coherent conditional probability assessments cope well with the problem of unifying these different approaches, a merging of fuzzy rough set theory with this subjectivist approach is proposed. Specifically, expert partial probabilistic evaluations are encompassed inside a gradual decision rule structure, with coherence of the conclusion as a guideline. In line with Bayesian rough set models, credibility degrees of multiple premises are introduced through conditional probability assessments. Nonetheless, discernibility with this method remains too fine. Therefore, the basic partition is coarsened by equivalence classes based on the arity of positively, negatively and neutrally related criteria. A membership function, which grades the likelihood of default, is introduced by a peculiar choice of t-norms and t-conorms. To build and test the model, real data related to a sample of firms are used.
► We combine rough set theory with other uncertain reasoning approaches. ► This thanks to the generality of conditional coherent probability assessments. ► We soundly incorporate expert opinions in a procedure mainly based on data analysis. ► By a gradual coarsening of information we improve standard classification abilities. ► The study is led through a prototypical credit risk analysis example.
•Solid digestate was used as raw material for microwave-assisted direct liquefaction.•The reaction conditions were optimized by applying response surface methodology.•Bio-oil yield of 59.38%, HHV of ...28.48 MJ/kg were obtained under optimum conditions.
Microwave-assisted direct liquefaction of solid digestate was carried out in polyethylene glycol and glycerol employing sulfuric acid as catalyst, in order to convert it into a biofuel. Response Surface Methodology (RSM) coupled with Box-Behnken Design (BBD) with a total of 15 individual experiments was used to optimize the conditions of three independent variables (temperature, reaction time and solvent-to-biomass ratio) related to the bio-oil yield, the higher heating value (HHV) of bio-oil and the energy use of microwave treatment. Desirability function was employed to determine the optimal reaction conditions of the liquefaction process. The results showed that at the optimal conditions the bio-oil yield, the HHV of bio-oil and energy use were respectively 59.38%, 28.48 MJ/kg, and 115.93 Wh. The predicted responses showed a good compliance to the obtained experimental data. The optimized bio-oil was further characterized using FTIR analysis while the properties of the solid digestate and the liquefaction residue were analyzed by means of SEM analysis.
In this paper, the second generation pathway for bioethanol from hornbeam residues was investigated, in order to define the optimum operative conditions of steam explosion pretreatment and ...subsequently enzymatic hydrolysis maximizing the glucose amount for fermentation process.
The whole experimental procedure was designed and analyzed by Response Surface Methodology, a statistic multivariate model that allows to investigate the effect of different parameters on a process and define the optimum values of these variables to optimize the response.
The glucose yield from enzymatic hydrolysis was maximize as function of three variables: the severity factor of pretreatment (log R0), the total solids (TS%) of the enzymatic hydrolysis and enzyme loading (EL%) in the enzymatic hydrolysis stage.
The Design of Experiment (DoE), based on central composite model, was characterized by 17 tests, varying the variables at five levels, log R0 (3.92, 4.08, 4.31, 4.54, 4.7), TS% (5, 7, 10, 13, 15), EL% (5, 7, 10, 13, 15).
The optimization allows to define the best operative condition that is log R0 = 3.97, TS% = 6, EL% = 15 which leads to an overall fermentable sugars yield of 67.8% respect to the initial sugars content in the raw material that corresponds to a theoretical amount of producible ethanol of 251 L/ton dry raw material.
•Hornbeam residues were investigated as feedstock for cellulosic ethanol production.•Steam explosion pretreatment is a efficient way for hornbeam wastes conversion.•RSM was adopted as methodology for sugars production optimization.•Three variables of pretreatment and saccharification were used in the DoE.
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