Glycerin for New Biodiesel Formulation

Biofuels are an important way of progress for limiting greenhouse gas emissions, improving air quality and finding new energetic resources. For diesel engines, FAE (Fatty Acid Ester), coming from transesterification of vegetable oils, have shown their potentials as fuel substitutes. Nevertheless, this transesterification induces the production of glycerin (or glycerol) as fatal co-product. Finding an outlet to this glycerol is fundamental for the FAE network. In the same time, oxygenated compounds have been shown to have great potential for the reduction of diesel particulate emissions. Transforming glycerol into new oxygenated compounds, which could be formulated with diesel fuel, would be a very promising way. Different oxygenates derived from glycerol, such as acetals, ethers and carbonates, have been synthesized and evaluated as blending components for Diesel fuel. Our objective was to evaluate their potential, compared with RME (Rapseed Methyl Ester) blends in term of pollutant emissions with different new engine technologies and to select the most promising of them. GTBE (Glycerol Ter Butyl Ether) was the most interesting compound and it was formulated with biodiesel with the respect of the physicochemical criteria required by EN14214 standard. This new biofuel (92.5% RME + 7.5% GTBE + 1000 ppm pro cetane) was incorporated in diesel fuel (5% vol.) and compared with a mixture containing 5% RME. After various tests carried out on vehicle and engine, focusing on pollutant emissions and possible fouling problems, it is possible to conclude that this new biodiesel does not present any technical disadvantage. The decision to use this glycerol derivatives in diesel fuel formulation will thus be controlled by economical criteria

Adsorption of Polyisobutenylsuccinimide Derivatives at a Solid-Hydrocarbon Interface †

International audienceThe adsorption of polymer dispersants of the polyisobutenylsuccinimide series has been studied at the solid/xylene interface. Carbon black was studied as a model solid. Adsorption isotherms were determined, the enthalpy of adsorption was measured by calorimetry, and the thickness of the adsorbed layer was obtained from small-angle neutron scattering. The paper emphasizes the structure-properties relationships with the help of a series of polyisobutenylsuccinimides having different polyamine groups and different polymer architectures, simple diblock (PIBSI) and comblike structure (polyPIBSI). The polyamine part ensured a strong adsorption on the solid surface, which increased in strength with the number of amine groups. In the same way, changing the diblock structure for a comblike one led to an enhanced affinity of the polymer for the solid surface. The adsorption was enthalpic but the Gibbs free energy of adsorption remained moderate because of a large entropy loss during adsorption. There was an enthalpy-entropy compensation phenomenon. Below a concentration of 70 mmol/m 3 , the polymers adsorbed as a 30 Å thick monolayer and the adsorption phenomenon was irreversible, due to the polymeric nature of the polar part. A drastic increase of adsorbed amount took place for higher concentrations. The formation of reverse hemimicelles was assumed as the origin of this phenomenon. The supplementary adsorption was reversible, showing that the polymer-polymer interactions were weaker than the polymer-surface interactions

Amine degradation in CO₂ capture. 3. New degradation products of MEA in liquid phase: Amides and nitrogenous heterocycles

International audienceTo reduce greenhouse gas emissions from fossil fuel power plants, post combustion CO2 capture with amine-based solvent is the most mature technology. Ethanolamine (MEA), the benchmark amine, is the most studied amine but some degradation products are still unknown and for an environmental acceptance, it is important to identify them. In this work eleven amides and nitrogenous heterocycles were identified in a pilot plant liquid sample. Among them seven molecules were never reported in literature. Different analytical methods were developed especially HS-SPME coupled to GC/MS. Mechanisms of formation were proposed for each molecule and were validated in most cases