Conversion of Lignocellulosic Biomass in Biobutanol by a Novel Thermal Process

This work aims at demonstrating the possibility of producing 2-butanol from lignocellulosic biomass through a new thermochemical approach. The production of biobutanol was carried out using different lignocellulosic feedstock through a 3-step process: first the whole lignocellulosic biomass is hydrolyzed under acid catalyst to produce levulinates, then the levulinates go through decarboxylation to produce 2-butanone which is, in a final step, reduced to produce of 2-butanol. The experimental conditions for the first two steps of the process were optimized using the response surface methodology (RSM). The latter could represent an opportunity for the production of economical second-generation butanol without having to go through the classical pathway requiring the production of sugar prior to microbial conversion.The authors are grateful for the financial support to MITACS (Grant number ITO3931) and for the grant to the Natural Sciences and Engineering Research Council of Canada (NSERC, Grant number EGP 487206-15)

Robust superhydrophobic cellulose nanofiber aerogel for multifunctional environmental applications

The fabrication of superadsorbent for dye adsorption is a hot research area at present. However, the development of low-cost and highly efficient superadsorbents against toxic textile dyes is still a big challenge. Here, we fabricated hydrophobic cellulose nanofiber aerogels from cellulose nanofibers through an eco-friendly silanization reaction in liquid phase, which is an extremely efficient, rapid, cheap, and environmentally friendly procedure. Moreover, the demonstrated eco-friendly silanization technique is easy to commercialize at the industrial level. Most of the works that have reported on the hydrophobic cellulose nanofiber aerogels explored their use for the elimination of oil from water. The key novelty of the present work is that the demonstrated hydrophobic cellulose nanofibers aerogels could serve as superadsorbents against toxic textile dyes such as crystal violet dye from water and insulating materials for building applications. Here, we make use of the possible hydrophobic interactions between silane-modified cellulose nanofiber aerogel and crystal violet dye for the removal of the crystal violet dye from water. With a 10 mg/L of crystal violet (CV) aqueous solution, the silane-modified cellulose nanofiber aerogel showed a high adsorption capacity value of 150 mg/g of the aerogel. The reason for this adsorption value was due to the short-range hydrophobic interaction between the silane-modified cellulose nanofiber aerogel and the hydrophobic domains in crystal violet dye molecules. Additionally, the fabricated silane-modified cellulose nanofiber hydrophobic aerogels exhibited a lower thermal conductivity value of 0.037 W\ub7m -1 K -1 , which was comparable to and lower than the commercial insulators such as mineral wools (0.040 W\ub7m -1 K -1 ) and polystyrene foams (0.035 W\ub7m -1 K -1 ). We firmly believe that the demonstrated silane-modified cellulose nanofiber aerogel could yield an eco-friendly adsorbent that is agreeable to adsorbing toxic crystal violet dyes from water as well as active building thermal insulators

Potential applications of nanotechnology in thermochemical conversion of microalgal biomass

The rapid decrease in fossil reserves has significantly increased the demand of renewable and sustainable energy fuel resources. Fluctuating fuel prices and significant greenhouse gas (GHG) emission levels have been key impediments associated with the production and utilization of nonrenewable fossil fuels. This has resulted in escalating interests to develop new and improve inexpensive carbon neutral energy technologies to meet future demands. Various process options to produce a variety of biofuels including biodiesel, bioethanol, biohydrogen, bio-oil, and biogas have been explored as an alternative to fossil fuels. The renewable, biodegradable, and nontoxic nature of biofuels make them appealing as alternative fuels. Biofuels can be produced from various renewable resources. Among these renewable resources, algae appear to be promising in delivering sustainable energy options. Algae have a high carbon dioxide (CO2) capturing efficiency, rapid growth rate, high biomass productivity, and the ability to grow in non-potable water. For algal biomass, the two main conversion pathways used to produce biofuel include biochemical and thermochemical conversions. Algal biofuel production is, however, challenged with process scalability for high conversion rates and high energy demands for biomass harvesting. This affects the viable achievement of industrial-scale bioprocess conversion under optimum economy. Although algal biofuels have the potential to provide a sustainable fuel for future, active research aimed at improving upstream and downstream technologies is critical. New technologies and improved systems focused on photobioreactor design, cultivation optimization, culture dewatering, and biofuel production are required to minimize the drawbacks associated with existing methods. Nanotechnology has the potential to address some of the upstream and downstream challenges associated with the development of algal biofuels. It can be applied to improve system design, cultivation, dewatering, biomass characterization, and biofuel conversion. This chapter discusses thermochemical conversion of microalgal biomass with recent advances in the application of nanotechnology to enhance the development of biofuels from algae. Nanotechnology has proven to improve the performance of existing technologies used in thermochemical treatment and conversion of biomass. The different bioprocess aspects, such as reactor design and operation, analytical techniques, and experimental validation of kinetic studies, to provide insights into the application of nanotechnology for enhanced algal biofuel production are addressed

The formation of aerosols during the co-combustion of coal and biomass

The global drive to lessen the emission of greenhouse gases in the power industry has seen an increase in the co-combustion of coal with various types of biomass. The practice “represent possibly the best (cheapest and lowest risk) renewable energy option for many power producers”. Most reviews of the practice cite environmental benefits coupled with satisfactory technological performance. One environmental aspect which has been virtually ignored is the formation and release of ultra-fine aerosol particles, which have a damaging effect on the respiratory system. The emission of respirable aerosols during the combustion of both coal and biomass has received considerable attention, but there is little information available for the combustion of their mixture. The available evidence, reviewed here, indicates that the extent of their formation is increased by co-combustion, due to the high ash and sulphur content of coals, and the high alkali metal content of biomass

Valorisation de sédiments fluviaux pollués traités en assises de chaussée

Le dragage des sédiments est nécessaire pour maintenir le transport fluvial mais les sédiments extraits sont souvent pollués. La société Solvay a mis au point un procédé pour les traiter et permettre ainsi d’envisager une valorisation : le procédé Novosol®. Celui-ci permet de fixer les métaux lourds mais aussi de détruire la matière organique. Les principales caractéristiques d’un sédiment traité et sa valorisation en techniques routières sont présentées dans cet article. D’un point de vue mécanique, les mélanges réalisés avec les sédiments sont conformes aux normes routières. Les tests environnementaux sur les matériaux incorporant les sédiments traités montrent que le relargage est similaire à celui sur matériaux témoins. L’ensemble de ces résultats permet d’envisager l’utilisation des sédiments traités Novosol® en techniques routières

La polymérisation acrylique sur prothèse en métal

International audienc

Characterization of chars from regular and supercritical water gasification

International audienc

Activated and deactivated sintering of hydroxyapatite adsorbent using metallic additives

This work is part of a series of studies dealing with the evaluation of the effects of major elements of solid waste, especially metallic oxides, nitrates, sulfates and chlorides on the sintering and the densification of calcium hydroxyapatite Ca(PO) (OH) ,(Ca-HA) adsorbent. Ca-HA is a promising compound for adsorption and immobilisation of heavy metals from soils, incinerator fly ashes and hazardous industrial wastes. The immobilisation of heavy metals by Ca-HA increases significantly by calcination at temperatures ranging from 650°C to 900°C. The effects of chloride salts of potassium (KCI) and zinc (ZnCl ) as well as lead oxide (PbO) and lead nitrate [Pb(NO)] on sintering and densification of Ca-HA were studied using specific surface area changes, and dynamics measurements methods such as Thermomechanical Analyser (for shrinkage studies) and Environmental Scanning Electron Microscopy (ESEM). The addition of KCI, PbO and Pb(NO) (2% w/w) activated the sintering process by bringing a swift reduction in surface area, and lowering the densification temperature. However, a low final densification was achieved. On the other hand, the addition of 2% of ZnCl deactivated the sintering process by slowing down the densification process and raising the densification temperature. However, the reduction of surface area was comparable to that of Ca-HA