Abstract

A research program, lead by CETIOM, in collaboration with ONIDOL (the French Organization for Development of Oilseeds), has been undertaken in order to evaluate the non-food utilization of rapeseed meal. Two strategies were examined : direct utilization of rapeseed meal as fertilizer and combustion material, processing of rapeseed meal for preparation of biodegradable materials. The aims are to find new outlets for rapeseed meal resulting from set aside and to improve energy balance of biodiesel.

Introduction

The main possible non-food applications for proteins are (table 1) traditionally bioplastics, coatings, glue and adhesives, paper, emulsifiers. Two strategies were examined : direct utilization of rapeseed meal as fertilizer and combustion material, processing of rapeseed meal for preparation of biodegradable materials. The aims are to find new outlets for rapeseed meal resulting from set aside and to improve energy balance of biodiesel.

Table 1 : Proteins for non-food applications

1. Rapeseed meal as fertilizer

These uses concern competitive markets with very low value. So there are needs for rapeseed meals with specific properties and slightly higher value than traditional fertilizer. Rapeseed meal is traditionally used as fertilizer in China and was used in Japan some years ago. Furthermore, castor meal is actually used in market gardening.

A few references are actually available (table 2) : the main works have been done by Asano J. (1984), Borcherding A. (1995), Kücke M. (1993).

Asano J., 1984, Effect of manures on quality of vegetables. JARQ, vol. 18 n°1, p. 31-36.

Borcherding A., Luck T., 1995, Evaluation of non-food utilization of by-products of the oil extraction of rapeseed. In : Proceedings of the 21st World congress of the ISF, The Hague.

Kücke M., 1993, Fertilizer value of processed rapeseed meal. In : Proceedings of the 2nd European Symposium on Industrial Crops, Pisa.

Kücke M., 1993, The efficiency of rapeseed oil cake as fertilizer. Agrobiological research, vol. 46, n°3, P. 269-276.

Table 2 : Fertilizer value of processed rapeseed meal - Main references

Field experiments under controlled conditions were carried out by CETIOM for determining kinetics of nitrogen mineralization for rapeseed meal, optimizing application levels and evaluating effects on quality of some vegetable crops.

Four nitrogen levels were brought as rapeseed meal at the time of sowing, without supplementary adding of nitrogen in spring.

The results show a fast mineralization of nitrogen contained in meal (table 3). The result of this could be a too fast growth of rapeseed before winter in case of early seedling and an important risk of leaching during the winter. Possible variations in results could also be due to different granular characteristics of meal.

Table 3 : Rapeseed meal as fertilizer

2 Rapeseed meal as material for combustion

The aim of this research was to evaluate the energetic value of rapeseed meal (RSM). This research was realized at the Compiègne University of Technology where are developed specific procedures for evaluation of wastes incineration. Rapeseed meal in powder or in pellets were tested in a pilot rotating oven, in comparison with sunflower hulls as references.

♦ Calorific power of RSM

The calorific power (main measure for combustion characteristics) of RSM is roughly equal to the ones of anthracite and charcoal.

Table 4 : Upper calorific power (condensed water) of RSM in comparison of other materials

♦ Autoinflammation point

Autoinflammation point of rapeseed meal has a relatively high value (up to 700 °C), much higher than sunflower hulls.

The main thermic characteristics of rapeseed meal allow its utilization as material for combustion. Ash content is relatively low and its calorific power is approximatively equivalent to the ones of charcoal.

Table 5 : Autoinflammation point of RSM in comparison with other materials

3 - Rapeseed meal as biodegradable materials

The technical feasibility of biodegradable materials from rapeseed meal was studied by INRA (Institut National de la Recherche Agronomique - Laboratory for Biochemistry and Technology of Proteins). This program included optimization of extrusion with co-rotative screw applied to non dehulled or dehulled rapeseed meal, with or without additives, with or without other raw material (starch). .

The extrusion of commercial rapeseed meal with formol makes a material with interesting hardness properties which could be used for elaboration of 3D objects. Mechanical properties of these objects can be modified by glycerol. The mechanical properties of the final products were investigated.

Nevertheless, further research are needed, mainly about the influence of process, composition of meal and variability of this composition, the role played by crushing conditions and at least the interactions between proteins and fiber.

Acknowledgements

This study receives a grant of AGRICE (the French Agency for Environment and Energy Management).