Showing papers by "Pierre-Yves Pontalier published in 2012"

Life cycle assessment (LCA) applied to the process industry: a review

Abstract: Life cycle assessment (LCA) methodology is a well-established analytical method to quantify environmental impacts, which has been mainly applied to products. However, recent literature would suggest that it has also the potential as an analysis and design tool for processes, and stresses that one of the biggest challenges of this decade in the field of process systems engineering (PSE) is the development of tools for environmental considerations. This article attempts to give an overview of the integration of LCA methodology in the context of industrial ecology, and focuses on the use of this methodology for environmental considerations concerning process design and optimization. The review identifies that LCA is often used as a multi-objective optimization of processes: practitioners use LCA to obtain the inventory and inject the results into the optimization model. It also shows that most of the LCA studies undertaken on process analysis consider the unit processes as black boxes and build the inventory analysis on fixed operating conditions. The article highlights the interest to better assimilate PSE tools with LCA methodology, in order to produce a more detailed analysis. This will allow optimizing the influence of process operating conditions on environmental impacts and including detailed environmental results into process industry.

Thermo-pressing of cake meal from sunflower whole plant, one only operation for two actions : expression of residual oil and molding of biodegradable agromaterials

Abstract: The starting material used in this study was a cake generated during thermo-mechanical fractionation of sunflower (Helianthus annuus L.) whole plant in a Clextral BC 45 (France) twin-screw extruder. It was slightly deoiled (17.6% dry matter for residual oil content), leading to an oil extraction yield of 46.1% (yield based on the residual oil content in cake). As it was a mixture of fibers and proteins, it could be considered as a natural composite that was processed successfully into fiberboards by thermo-pressing. This study aimed to evaluate the influence of thermo-pressing conditions on oil expression yield during molding and on flexural properties of fiberboards manufactured from this cake. An experimental design with three variables was realized: from 250 to 500 kgf/cm² for pressure applied (in 5 levels), from 60 to 300 s for molding time (in 7 levels), and from 600 to 1200 mg/cm² for cake quantity (in 3 levels). Temperature of the aluminium mold positioned between the two plates of the heated hydraulic press (PEI, France) with 400 tons capacity was 200°C. All fiberboards were cohesive. As an internal binder, proteins ensured the agromaterial cohesion, and fibers entanglement also acted like reinforcement. Thermo-pressing was not only a molding operation. It also consisted in increasing the oil extraction efficiency. Oil expression yield during molding increased with the increase of pressure applied, and especially with the increase of molding time. At the same time, it was not so much influenced by the modification of cake quantity. Highest oil expression yield was 58.8% in proportion to the oil that the cake contained, leading to a total oil yield (oil extracted by water in twin-screw extruder, and oil expressed during molding) of 77.8% in proportion to the oil that the sunflower whole plant contained. It was associated with the next thermo-pressing conditions: 469 kgf/cm² for pressure applied, 300 s for molding time, and 697 mg/cm² for cake quantity. Flexural properties of the corresponding fiberboard were 8.1 MPa for flexural strength at break, and 1778 MPa for elastic modulus. Its thickness was 5.40 mm, leading to a mean apparent density of 1.25. Such flexural strength at break was a bit lower (-25%) than the one of the most resistant fiberboard (10.8 MPa), manufactured from the next thermo-pressing conditions: 250 kgf/cm² for pressure applied, 300 s for molding time, and 807 mg/cm² for cake quantity. For such conditions, oil expression yield was 48.0% in proportion to the oil that the cake contained, leading to a total oil yield close (-8%) to the highest yield obtained (71.9% in proportion to the oil that the sunflower whole plant contained instead of 77.8%). Thermo-pressing of cake from sunflower whole plant led to two actions in a single step: the expression of part of residual oil in cake that contributed to the improvement of the oil extraction efficiency, and the molding of biodegradable fiberboards. Their flexural properties were promising. Moreover, because residual oil content in fiberboards was at least 8.0% dry matter, they were not too water-sensitive (i.e. more durable than other thermo-pressed agromaterials). Such fiberboards were value-added agromaterials that may have direct industrial applications. Indeed, they would be potentially usable as inter-layer sheets for pallets, for the manufacturing of biodegradable containers (composters, crates for vegetable gardening), or for their heat insulation properties in building trade.

Multi-response optimization of aqueous oil extraction from five varieties of cameroon-grown avocados

Abstract: Production of avocado oil could be a way of reducing avocado post-harvest losses in Cameroon. The optimization of extraction of oil from five varieties of avocado was conducted using the Response Surface Methodology (RSM). The five varieties were Booth 7, Booth 8, Collinson, Hickson and Lula. The extraction efficiency (EE) was investigated with respect to four variables: temperature (T), time (t), pH and water-to-pulp ratio (WPR). A two-level full factorial design was used to develop regression models for the responses, and the desirability function of the multiple response surface methodology to determine the optimal conditions of extraction of the five cultivars. The results showed that the extraction efficiency was linearly affected by the variables depending on the variety. The optimal conditions were found to be 45 C, 180 min, 4.5 and 6 respectively for the temperature, time, pH and water-to-pulp ratio with the extraction efficiencies ranging from 7.86 to 31.42% of fresh, mature and ripe sample.

Method for manufacturing a solid material from an oleaginous plant, and resulting solid material

Abstract: The invention relates to a method for manufacturing a solid material from an oleaginous plant composition, wherein: said oleaginous plant composition is first subjected to a so-called thermo-mechano-chemical treatment, wherein trituration of said oleaginous plant composition is carried out in water so as to form: a liquid composition including a stable emulsion of at least one fat from the oleaginous plant composition in the water; and a so-called "oleaginous plant oilcake" solid having fat content less than that of the oleaginous plant composition; subsequently, the oleaginous plant oilcake is subjected to a step of heat compression at a predetermined temperature and pressure; wherein said method is characterized in that the predetermined pressure and predetermined temperature are maintained for a duration greater than 1 minute and less than 10 minutes so as to form the solid material.