Paolo Spugnoli

Environmental comparison of draught animal and tractor power

The environmental impacts of moving to different traction power sources have not been well studied in either developing countries or modern agriculture. This study assesses the environmental impact of the transition from animal to tractor power and vice versa. Three different scenarios are analyzed: a developing country context where draught animal power (DAP) is actually in use; a similar context where DAP is replaced by mechanical traction; and a developed country scenario where mechanical traction is replaced by DAP. The impact assessment focuses on global warming (GW) and primary energy consumption (PEC). The DAP system refers to an Indonesian case study where Peranakan Ongole cattle are used for work, together with the production of milk and meat, and fed with two forage-supplying alternatives. The mechanical traction system considers the cases of a two-wheel tractor (2WT) and a rear-wheel-drive tractor (4WT). In the first scenario, assessing DAP impacts for plowing through process subdivision and indirect impacts allocation to co-products, DAP has a consistent advantage regarding energy consumption, while for CO2eq emissions, performance is better only in the case of 2WT. In the second scenario, considering product equivalent systems, substituting DAP with tractor power and maintaining the same DAP livestock farming more than doubles the impact; only with the introduction of modern, specialized livestock farming is a reduction achieved. In the third scenario, replacing mechanical traction with DAP results in a greater than three-fold increase in impact for PEC and more than 17 times increase for GW. Further work on the influence of system definition and the socio-economic background would improve the estimates produced in this study.

A Predictive Classification Model for the Management of Virgin Olive Oil Filtration at Industrial Scale

Precoat-bodyfeed filtration of virgin olive oil was investigated on an industrial filter-press plant. Several chemical parameters of the unfiltered oil were measured and the relationship with filtration performances was investigated by Principal Component Analysis. Further, Linear Discriminant Analysis was applied to develop a predictive model for oil filterability. Principal Component Analysis allowed the construction of latent variables which were used to separate oil groups and to select variables for Linear Discriminant Analysis. The developed linear model gave an overall correct recognition of about 88%, good enough for a convenient filterability prediction of oil at industrial scale.

A Condenser to Recover Organic Volatile Compounds during Vinification

Escape of carbon dioxide during grape must fermentation leads to loss of volatile compounds, which ultimately affects the wine’s aroma. An innovative condensation device was designed to trap organic volatile compounds that would otherwise be lost. Trials were performed using Sangiovese and Syrah grapes and involved continuous condensation of vapor (condensed fractions, CFs) that escaped from fermentation tanks. Ethanol content and volatile compound composition of CFs were measured daily since 48 hr after the fermentation began. An average of 1.3 g CF per kg fermenting must was recovered, corresponding to a theoretical yield of ~0.37% of condensed product. Mean ethanol content was ~24% by volume, and the total concentration of organic volatile compounds was ~1200 mg/L. Predominant compounds were alcohols and esters of secondary origin, with four compounds (ethyl octanoate, 1-propanol, ethyl acetate, and 2, 3-butanediol) accounting for more than 88% of the final concentration. The CF volatile profile changed as a function of fermentation time. For sensory evaluation, CFs were added back to their respective wines and were statistically shown to be detectable at a rate of 1‰.

Energy efficiency in the vineyard

The aim of this study was to evaluate efficiency and energy costs of viticulture on farms operating at the same technological level. Process energy analyses have been conducted on five organizations specializing in viticulture and differing both in scale and in management techniques. Process energy was divided into seven categories of inputs, namely, fuel and electrical energy as direct inputs; and machinery, pesticides, fertilizers, buildings and vineyard planting, and various materials as indirect inputs. In calculating indirect inputs particular attention was given to the energy costs of mechanization; the notion of obsolescence was taken into account in determining energy costs. The results of these analyses, based on 3 years of farm reports, were abstracted using a series of indices such as the energy invested, the yield per hectare, the productivity of human labour, machine utilization, the productivity of invested energy (food energy produced per unit of energy consumed) and the inverse index that represents the energy cost of the product (energy consumed per unit of food energy produced). For the farms under consideration, this cost ranged between 0·78 and 2·21 J/J, with an average of 1·13 J/J. Despite the variability, the data shows some trends, e.g. the productivity of invested energy decreased as the energy investment itself increased; the labour was more productive as the degree of mechanization increased and was less productive as the surface area increased; direct inputs increased as the cultivated surface decreased.

Power demand of a flail shredder during the harvest of pineapple fields

espanolSe determino la demanda de potencia de la demolicion de campos de pifia (Ananas comosus) que terminan su ciclo de produccion con una trituradora de mayales, con dos tipos de cuchillas, tres velocidades angulares del organo de corte y tres velocidades del conjunto, utilizando mediciones tensometricas. Los resultados de las investigaciones demuestran la influencia del tipo de cuchilla y el regimen cinematico del organo de corte en la demanda de energia en la demolicion de rastrojos de pifia, y permitieron validar los modelos para la demanda de potencia de la trituradora. EnglishThe power demand of the demolition of pineapple (Ananas comosus) fields, whose production cycle is finished with a flail mower with two different knives, a cutting apparatus with three angular velocities, and a tractor with three translation velocities, was determined using strain gage measures. The results of the investigations demonstrate the influence of the knife type and cinematic regime of the cutting apparatus in the demand of energy in the pineapple demolition. Furthermore, they permitted the validation of models of the power demand of the flail mower.