The aim of this programme is to develop the methyl esters of vegetable oils, and glycerol, for new industrial applications, according to innovative and environmentally friendly means.
The choice of the participants was directed by the interest in the industrial applications, to the sights of the expertise of 2 industrial partners and of 2 specialized technical centres. Participants are accustomed moreover to working together or in sub-groups.
Tasks envisaged can be gathered in 3 topics of a general nature:
- New products, new uses, through the production of agromaterial by cross esterification on wooden sawdusts, through the use of derivatives of rough glycerin in polyurethanes.
- Obtaining new synthons through the analysis of epoxy rapeseed oil.
- Search for new derivatives for traditional applications listed under the generic term of surface-active chemicals, with a variable and controlled "HLB" balance.
- The accent is put on the new conditions and functions of the derivatives. These issues are important because they are connected with the expansion of the development of non food uses of oils in Europe, in particular within the framework of the industrial set-aside reforms.
Theme 1: New compounds for new applications
Fatty esters of lignocellulose
The first area investigated concerns the production of thermoplastic materials from fatty esters (or acids) combined with lignocellulosic wastes. Two separate approaches have been adopted (chemical and enzymatic) to test basic principles using pure cellulose and short chain saturated fatty acids (C4: O and C8: O). Treatments required to increase the reactivity of hydroxyl groups have been investigated together with the use of acetic anhydride, which has been shown to increase esterification yields providing a mixture of cellulose esters is obtained in the form of acetate and caprylate. The enzymatic route has been investigated using various hydrolases in several organic solvents. In the initial work, cellulose structural units (glucose, cellobiose) were selected as substrates to enable precise reaction conditions to be defined. In particular, it was shown that the esterification of glucose and cellobiose by butyric acid or caprylic acid methyl ester takes place in the presence of a hydrolase in pyridine. The application of these techniques was then extended to the more complex substrate such as cellulose. The most promising results were obtained with b cellulose.
Glycerol derivatives in polyurethane foams
The objective of this work is the formulation of polyurethanes which can be swollen by water instead of the CFCs known to contribute to the hole in the ozone layer. So far, fourteen polyester resins have been prepared and their properties determined in terms of suitability for formulation. Two of them appeared promising and will be investigated during the formulation stage which is taking place during 1996.
Theme 2: New chemical intermediates
Catalytic epoxydation of fatty esters and acids
These fatty epoxides are used as plasticisers and stabilisers (PVC), as components of resins or as oleochemical intermediates. Epoxydation of oleic methyl ester (OME) has been studied in various solvents in presence of several catalysts such as zeolites. Using these it was possible to obtain diols in a single step.
Chemical opening of epoxydised fatty acids and esters
The opening of oleic methyl ester epoxide with various nucleophiles has been studied in detail since transformation could lead to several kinds of lubricants and plastisers. The epoxides used were derived from either rapeseed or sunflower methylesters. The nucleophiles tested included alcohols, carboxylic acids and amines. Various products have been made, but are still under evaluation.
Theme 3: New compounds for established applications
Preparation of fatty unsaturated alcohols
Unsaturated fatty alcohols are known for their good lubricating properties under pressure and as detergents after slight modifications. A pilot development has been started using a heterogenous catalyst which gave a yield of oleyl alcohol of around 80 %. The catalytic system is being improved to increase this.
Reductive amination of fatty acids and esters
Fatty amines are one of the major classes of derivatives used in oleochemistry. They have many applications reflecting their particular surfactant properties. It is especially true for the dialkylmethylamines. It has been found that fatty amine methylation is both faster and more selective when a methylating agent is used instead of methanol. Formation of final products depends on temperature.
Esteramides and polyesteramides
The synthesis of these products, used as temporary coatings for the protection of iron sheets, has been evaluated and formulations which give effective protection of iron sheets stored in the open. Addition of acid was found to increase protection in many cases, while the effectiveness of amines depended on their structure.
Estolides are polyesters of fatty hydroxyacids which are prepared by autocondensation of the carboxylic function on the double bond of unsaturated fatty acids. So far authentic samples of estolides have been prepared from ricinoleic acid using perchloric acid as catalyst.
Selective esterification of glycerol
Methods of obtaining pure monoglycerides, in one step avoiding any purification, has been investigated using a number of lipases for the selective synthesis of monoglycerides from oleic, palmitic and ricinoleic acid. Under the best conditions, yields with oleic acid are around 80%. This compares with chemical methods which gave a 70% yield with palmitic acid. Two reactions were studied in the presence of heterogeneous catalysts in emulsions. Using resins as catalyst the yield of glycerol 1 mono-oleate was over 95%. Zeolites were also investigated using oleic acid or rapeseed oil as raw material.
Aluminium silicate gave 75 % of conversion with 60 % glycerol mono oleate. Magnesium oxide based catalysts gave complete conversion with a high selectivity.
The fatty derivatives required have been prepared at the laboratory scale and the reactions investigated have worked well. Promising catalysts have been prepared and one of them (for use with unsaturated fatty alcohols) has been prepared in quantity for pilot scale development. Catalysts for epoxidation have been prepared and will be investigated further. Epoxide opening with several nucleophiles has been demonstrated, this will be scaled up to produce material for future application testing. Derivatives have been prepared for polyurethane foams and temporary coatings. These have yet to be evaluated. Laboratory scale production of fatty amines (ESIP) enables assessment with stability testing of the catalyst and design of a continuous device part of the continuing activity. Monoglycerides preparations are promising at the laboratory scale and samples are available for the first evaluations.
The aim of this programme is to develop methyl esters of vegetable oils and glycerol for new industrial applications. The overall approach covers three related topics. Objectives include identification of new products and new uses for materials produced from biological raw material, such as cross esterification of lignocellulosic wastes (eg, sawdust) or the use of derivatives of low grade glycerin in polyurethanes. Another approach focuses on epoxy derivatives of rapeseed oil and a third covers new derivatives for traditional applications under the generic term of surface active chemicals. The emphasis is placed on new processes and functions which can be associated with expansion of non-food uses of vegetable oils in Europe, in particular within the framework of the industrial set aside reforms. The results achieved so far are presented in terms of these three distinct themes.
Funding SchemeCSC - Cost-sharing contracts
8755 Castellbisbal (Barcelone)