References of "Meyer, Laurence"
     in
Bookmark and Share    
Full Text
See detailEffect of steam explosion pre-treatment on enzymatic saccharification of lignocellulosic material
Meyer, Laurence ULg; Jacquet, Nicolas ULg; Vanderghem, Caroline ULg et al

Poster (2011, September 08)

Taking into account the sharp rise in prices and the depletion of resources of petroleum, an alternative to fossil resources is needed. A probable alternative is the use of lignocellulosic raw material to ... [more ▼]

Taking into account the sharp rise in prices and the depletion of resources of petroleum, an alternative to fossil resources is needed. A probable alternative is the use of lignocellulosic raw material to produce biofuels. The “first generation” biofuels are highly controversial because of the use of food plant material. The aim of the “second generation” biofuels is to take lignocellulosic non-food plant material as raw material. Lignocellulosic biomass has a very complex structure made of linkages between lignins, cellulose and hemicelluloses. The saccharification of these lignocellulosic materials requires the fractionation of its constituents. Research has lead to many lignocellulosic biomass fractionation pre-treatments. This study particularly focuses on the steam explosion pretreatment followed by an enzymatic saccharification. Steam explosion is a thermomechanical process which allows the breakdown of the lignocellulosic material structure by the combined action of steam heating, hydrolysis induced by the organic acids formed during the process and shear stress resulting from the pressure rough drop. This treatment leads to modification of the physical parameters such as water retention capacity, cristallinity rate of the cellulosic fraction, hydrolysis of the hemicellulosic fraction and rearrangement in the lignin structure. Such modifications are supposed to make cellulose enzymatic hydrolysis from complex lignocellulosic material easier. In order to verify this hypothesis, different lignocellulosic raw materials have been pre-treated by steam explosion. These materials were sugar beet pulp, corn straw and miscanthus. In order to check the effect of steam explosion pre-treatment on cellulose, a microcrystalline cellulose was also treated. Steam explosion was performed at a vapor pressure of 18 bars and with a retention time of 2 minutes. The steam exploded lignocellulosic materials and the untreated one were submitted to a hydrolysis with a mixture of enzymes composed of cellulases and cellobiase activities during 24 hours. The quantification of glucose in the hydrolysates at different times was performed by HPAEC-PAD. Rate of cellulose converted into glucose were better with steam exploded raw material showing that steam explosion allows improvement of lignocellulosic material for enzymatic saccharification. [less ▲]

Detailed reference viewed: 72 (21 ULg)
Full Text
See detailProduction of Biopolymers from Sugar Beet Pulp
Meyer, Laurence ULg; Paquot, Michel ULg; Dubois, Philippe

Poster (2009, May)

Sugar beet pulp is an important by-product of the sugar industry. In order to make the most of this waste, pectin extraction can constitute an economical solution. Pectin is commonly used in food industry ... [more ▼]

Sugar beet pulp is an important by-product of the sugar industry. In order to make the most of this waste, pectin extraction can constitute an economical solution. Pectin is commonly used in food industry as a gelling agent. However, in the present study another use of pectin is considered: its potential embedding into biodegradable polymer films which can further be used in plastic industry. At first, different pectin extraction methods have been developed on sugar beet pulp in order to obtain four different types of pectins characterized at the same time by their molecular weight degree of esterification. Acidic extraction leads to pectin of high molecular weight and high degree of esterification. From this pectin, a de-esterification and a de-polymerization allow us to obtain, respectively, a pectin of high molecular weight and low degree of esterification and a pectin of low molecular weight and high degree of esterification. On the other hand, a basic extraction leads to pectin of low molecular weight and degree of esterification. Preliminary, tests have been conducted on mixes comprising 5, 10, 15, 20 % of commercial pectin and PLA (polylactic acid) or PBAT (Polybutylen-adipate terephtalate). In all cases, the products were not stable and therefore the use of a compatibilizing agent was required. Glycerol and D-Sorbitol were thus studied for that purpose, in mixing ratios between 40-80 % with commercial pectin. The best mechanical properties (Young modulus; yield stress and yield strain) were obtained with the pectin/sorbitol 50/50 mix. This proportion was then used with our different sugar beet pulp extracted pectins to produce PLA/pectin/Sorbitol 50/25/25 formulations. The best mechanical properties were reached with the low molecular weight end degree of esterification pectin. Indeed, the relative small size of this pectin with the lack of esterified groups enables interactions between pectin chains plastified by sorbitol and PLA. These interactions lead to a better cohesion of the high pectic content biomaterial. [less ▲]

Detailed reference viewed: 143 (10 ULg)