Beetroot pulp: from an agricultural by-product to a strategic industrial compound

5-Hydroxymethylfurfural (5-HMF) is one of the most sought-after molecules in the chemical industry. Versatile and offering high added value, it lies at the heart of green chemistry’s ambitions. The problem is that it is still mainly produced from fructose and glucose derived from food crops, which are often imported from abroad. Supported by Carnot MICA, the BIOVAL project has brought together researchers from the ICPEES laboratory and the private research centre RITTMO to turn the tide: to produce this strategic molecule from beet pulp, a by-product of the sugar industry that usually ends up in livestock feed.

Beet pulp at the heart of an innovative process

Millions of tonnes. That is the annual volume of beet pulp produced in Europe; a by-product of sugar extraction that is currently under-utilised. Yet this waste could become an opportunity that no one had really seized upon until now.

This is where BIOVAL comes in. By developing a catalyst capable of converting this pulp into 5-HMF, researchers at ICPEES have opened up an unexpected avenue. Better still: whereas the conventional process requires 1½ hours at 140°C and an organic solvent, microwaves do the same job in 10 minutes, without a solvent, in water. The initial results are in, and they were achieved without even optimising the parameters. There is enormous scope for further improvement. As for the residues from the reaction, they have been tested for return to the soil: no harmful effects were detected on microorganisms, but further testing is required for a comprehensive study of their ecotoxicity.

From beetroot pulp to 5-HMF: the BIOVAL process

ICPEES

Solid acid catalyst

5-HMF

Organic phase

Fraction analysed by the ICPEES

RITTMO

Beet pulp

Cellulose
Fructose
Glucose

 

Microwave

10 mins · solvent-free · in water

 

Aqueous phase

Recovery & ecotoxicity

Solid residue

Return to soil

A process designed for industry

BIOVAL did not stop at the production of 5-HMF. From the outset, the project took into account the issue of reaction residues, which were studied with a view to returning them to the soil. The reaction waste becomes an agricultural resource. The model is thus designed to be sustainable from start to finish:

• A local, abundant raw material that does not compete with food supplies
• Electrified processes (microwave, induction) that reduce energy consumption
• Recyclable residues with no environmental impact
• Technology that can be adapted to other cellulosic sources, including textile waste

The range of applications for 5-HMF

Versatile and bio-based, the 5-HMF molecule opens up concrete opportunities in numerous industrial sectors.

Promising prospects

The proof of concept has been validated. The next steps are to improve yields, test other substrates and confirm the safety of the residues on a larger scale.