Method for producing an aqueous solution of 5-hydroxymethylfurfural comprising a liquid-liquid extraction step incorporating or followed by filtration

A process for producing an aqueous solution of hydroxymethylfurfural (5-HMF), said process comprising the following steps:

• a step a) of bringing a feedstock (1) comprising 5-HMF and a polar aprotic synthesis solvent into contact with an aqueous stream (21) so as to obtain at least one aqueous mixture (3);
• a step b) of liquid-liquid extraction of the aqueous mixture (3) obtained on conclusion of step a) in the presence of an extraction solvent (4), so as to produce an aqueous raffinate (5) comprising said polar aprotic synthesis solvent, an organic extract (6), a solid particles fraction, and optionally an intermediate liquid stream (19), said aqueous raffinate (5) and/or said intermediate liquid stream (19) comprising said solid particles fraction;
• then
• a step c) of backwashing the organic extract (6) with an aqueous solvent (7), so as to produce an intermediate aqueous back-extract (9) and an organic raffinate (8) comprising 5-HMF and an organic solvent;
• an optional step d) of concentrating said organic raffinate (8) resulting from step c) by removing at least a portion of the organic solvent, producing a concentrated organic raffinate (10) comprising 5-HMF and residual organic solvent, and producing a first stream (11) comprising organic solvent;
• a hydrodistillation step e) implemented by distilling said organic raffinate (8) resulting from step c) or said concentrated organic raffinate (10) resulting from step d) in the presence of water, to produce an aqueous solution of 5-HMF (12) and a second stream (13) comprising organic solvent;
• a step f) of liquid-solid separation of said solid fraction within said aqueous raffinate (5) resulting from step b) and/or said intermediate liquid stream (19) resulting from step b), producing a stream of solid particles (18) and an aqueous raffinate depleted in solid particles (5′) and/or an intermediate liquid stream depleted in particles (20) which is sent to step b);
• and
• a step g) of treating at least one water-polar aprotic synthesis solvent mixture produced in said process, said mixture consisting of said aqueous raffinate depleted in particles (5′) and resulting from step f) or of said aqueous raffinate (5) not comprising the solid particles fraction and resulting from step b), to produce at least one aqueous effluent (15) that can be recycled into said process.