The present invention provides a process for preparing furfural and furfural derivatives using a furfural-derived solvent.

The present invention provides a process for preparing furfural and furfural derivatives using a furfural-derived solvent.

Methods and processes for the production of valuable organic products and alcohols from biomass material using a closed-loop process having numerous advantages over prior production methods are described. In the process, the biomass is subjected to acid-catalyzed digestion, followed by a separation of the digestion product stream into a solid product stream and a liquid product stream, the liquid product stream thereafter undergoing acid-catalyzed dehydration in the presence of an organic solvent, and thereafter separating the organic products in the organic layer from the aqueous layer. During the process, aqueous and organic fluid streams are fed back into various portions of the production process to increase the concentration of active portions and maximize product recovery.

Methods and processes for the production of valuable organic products and alcohols from biomass material using a closed-loop process having numerous advantages over prior production methods are described. In the process, the biomass is subjected to acid-catalyzed digestion, followed by a separation of the digestion product stream into a solid product stream and a liquid product stream, the liquid product stream thereafter undergoing acid-catalyzed dehydration in the presence of an organic solvent, and thereafter separating the organic products in the organic layer from the aqueous layer. During the process, aqueous and organic fluid streams are fed back into various portions of the production process to increase the concentration of active portions and maximize product recovery.

Furfural is produced from biomass material containing pentosan, in high yields, in a production process comprising treating the biomass with a solution containing at least one α-hydroxysulfonic acid thereby hydrolyzing the biomass to produce a product stream containing at least one C.sub.5-carbohydrate compound in monomeric and/or oligomeric form, and dehydrating the C.sub.5-carbohydrate compound in the presence of a heterogeneous solid acid catalyst, in a biphasic reaction medium comprising an aqueous phase and a water-immiscible organic phase, at a temperature in the range of from about 100° C. to about 250° C. to produce a dehydration product stream containing furfural. An aqueous stream is separated from the dehydration product, which can be optionally recycled to the hydrolysis step.

Furfural is produced from biomass material containing pentosan, in high yields, in a production process comprising treating the biomass with a solution containing at least one α-hydroxysulfonic acid thereby hydrolyzing the biomass to produce a product stream containing at least one C.sub.5-carbohydrate compound in monomeric and/or oligomeric form, and dehydrating the C.sub.5-carbohydrate compound in the presence of a heterogeneous solid acid catalyst, in a biphasic reaction medium comprising an aqueous phase and a water-immiscible organic phase, at a temperature in the range of from about 100° C. to about 250° C. to produce a dehydration product stream containing furfural. An aqueous stream is separated from the dehydration product, which can be optionally recycled to the hydrolysis step.

A process to produce an aqueous solution of carbohydrates that contains C6-sugar-containing oligomers, C6 sugar monomers, C5-sugar-containing oligomers, C5 sugar monomers, or any combination thereof is presented. The process includes the steps of reacting biomass or a biomass-derived reactant with a solvent system including a lactone and water, and an acid catalyst. The reaction yields a product mixture containing water-soluble C6-sugar-containing oligomers, C6-sugar monomers, C5-sugar-containing oligomers, C5-sugar monomers, or any combination thereof. A solute is added to the product mixture to cause partitioning of the product mixture into an aqueous layer containing the carbohydrates and a substantially immiscible organic layer containing the lactone.

A process to produce an aqueous solution of carbohydrates that contains C6-sugar-containing oligomers, C6 sugar monomers, C5-sugar-containing oligomers, C5 sugar monomers, or any combination thereof is presented. The process includes the steps of reacting biomass or a biomass-derived reactant with a solvent system including a lactone and water, and an acid catalyst. The reaction yields a product mixture containing water-soluble C6-sugar-containing oligomers, C6-sugar monomers, C5-sugar-containing oligomers, C5-sugar monomers, or any combination thereof. A solute is added to the product mixture to cause partitioning of the product mixture into an aqueous layer containing the carbohydrates and a substantially immiscible organic layer containing the lactone.

This invention relates to a method for the conversion of lignocellulosic biomass into ethyl esters of carboxylic acids. Said method consists of treating the biomass material with an oxidizing agent that is incorporated in an solution comprising one or more acids, one or more alcohols and water, and subsequently performing a catalytic reaction at a higher temperature using the same acidic solution into which a larger volume of alcohol is added, in such a way that the catalytic conversion occurs in a medium with a much higher concentration of alcohol, i.e. with a much higher alcohol-to-water wt ratio. Such a method results in relatively high yields of ethyl esters, such as ethyl esters of formic, acetic, and levulinic acids, while producing a low yield of dialkyl ethers, which are unwanted by-products. The concentration of the oxidizing agent in the pre-treatment step is preferably higher than 6.0 wt %. The oxidizing agent is preferably a Fenton or Fenton-type reagent, and most preferably hydrogen peroxide activated by Fe (II), and/or Ti (IV) ions. The alcohol is preferably ethanol, and when ethanol is used, diethyl ether is formed as the unwanted dialkyl ether by-product. Preferably, the biomass material is pelleted before treatment.

An object of the present invention is to provide a method for suppressing the corrosion of a reactor and reducing waste in the production of 2-furaldehyde from a sugar raw material containing a hexose as a constituent component, and another object of the invention is to provide an industrially advantageous method for producing 2-furaldehyde, which suppresses a decrease in the activity of a catalyst in a case of using an acid catalyst and provides a higher yield. The present invention relates to a method for producing 2-furaldehyde comprising heating a sugar raw material containing a hexose as a constituent component in an aprotic polar solvent in the presence of a solid acid catalyst.