SI21883A - Procedure of liquefaction of wood and wood wastes with polyols and acids - Google Patents

Abstract

A procedure is described of liquefaction of wood, waste wood and similar materials like cellulose, cotton, paper or starch. The liquefaction is carried out in a reaction vessel at temperatures between 180 and 250 degrees Celsius and in the presence of reagents and a catalyst. Reagents are polyols, saturated or unsaturated multibasic organic acids and phosphoric (V) acid as catalyst. The reaction lasts for 3 hours and more. Liquefied wood can contain undegraded wood particles, which can be removed by filtration. Liquefied wood prepared according to the procedure described can be used as a raw material for the manufacture of polymeric materials.

Description

The subject of the invention is a process of liquefying wood, wood residues and similar materials using polyols and acids without the use of phenol. In the process described in the invention, finely ground wood is used as the main raw material. In the liquefaction process, wood can be replaced by wood waste and other materials such as cellulose, cotton, paper and starch. An example of wood waste is a chestnut expectorant that is generated as a waste in the tannin extraction process.

In addition to the usual uses of wood as a basic material in construction and for the production of wood products, the use of lower quality wood and wood waste is mainly based on incineration for heat generation or biodegradation in composting processes with other organic waste. Less quality and waste wood is also used in the preparation of wood composites, where ground or chopped wood particles are bonded using various binders or adhesives and molded into compact products or semi-finished products. An example of this kind of processing is the processing of less valuable wood into particle boards. Wood flour and cellulose fibers can be used as a filler for thermoplastic polymers to obtain a thermoplastic mixture suitable for processing on conventional plastic processing devices. Also known is the use of lignin in combination with wood flour as a filler and a natural or artificial polymer acting as a binder (US Pat. 6,706,106). With such a combination, thermoplastic material suitable for injection molding can be obtained.

Wood can also be processed by chemical processes in which the chosen combination of reagents and catalysts results in the partial degradation of natural polymers found in wood, such as lignin, hemicellulose and cellulose. Liquid products are thus obtained which can serve as a raw material for the synthesis of new polymeric materials. The literature has described the chemical processing of wood into a liquid form based on the use of phenol as a liquefaction reagent (JP 97-298983, JP 97-160181). The product was then reacted with formaldehyde to produce the phenol-formaldehyde composite. Polyurethane foams (JP 91-328159) were manufactured in a similar manner.

The invention describes a chemical process for liquefying wood, which differs from the known ones so far in that it uses other reagents and catalysts. Due to the altered reaction mixture, liquefaction by different chemical reactions takes place, which affects the altered nature and usefulness of the products. The object and object of the invention is a process for the chemical processing of wood, wood residues and similar materials into substances that can be used as raw materials in the production of polymeric materials. This gives high added value materials and reduces environmental stresses.

According to the invention, the problem is solved by a chemical process of processing the wood into a liquid form, suitable for further use. The process is based on the reaction of the liquefaction of the wood at elevated temperatures and in the presence of reagents and catalyst. The liquefaction process of wood and wood waste uses polyols, saturated or unsaturated polybasic organic acids, and phosphoric (V) acid as catalysts as reagents. The liquefaction reaction takes place at a temperature between 180 and 250 ° C. The process is carried out in a reactor vessel with a lid made of glass or other inert material and has the ability to mix and condense and return vapors. Wood or waste wood can be replaced by other materials such as cellulose, paper, cotton or starch.

Prior to the process, the wood or wood waste must be ground to a particle size of less than 5 mm. to a size that allows filling into the reactor vessel. The smaller particle size, due to the larger specific surface area suitable for the reaction, enables high yields to be achieved in a shorter time. Grinded wood, wood waste or other material is placed in the reactor vessel. Polyols, saturated and unsaturated polybasic organic acids and phosphoric (V) acid are also grown. With constant stirring, the mixture is heated to the selected temperature in the range of 180 to 250 ° C. The vapors resulting from the mixture in the reflux condense and return to the reactor during the process. A constant stirring of the reaction mixture takes place during the reaction. The liquefaction at said temperature takes place for 3 hours or longer. Under the influence of reagents and elevated temperature, a dense mixture of brown is obtained after a few hours. The liquid reaction product is liquefied wood. A portion of the polyol alcohols which did not react in the reaction may be removed from the reaction mixture before stopping the reaction by distillation. The reaction mixture was then cooled. Depending on the reaction conditions and reaction time, the liquefied wood may contain particles of undamaged wood. Liquid wood can be filtered to remove undamaged wood particles. Liquid wood with or without undegraded particles is suitable for direct use as a multifunctional raw material for the production of polymeric materials.

The present invention improves the liquefaction process of wood, wood waste and similar materials such as cellulose, paper, cotton and starch. The main advantage of the process described is that it allows the production of liquefied wood without the use of phenol, as an environmentally harmful chemical, and using polyols and organic acids. The reagents used for liquefaction give the product suitable properties for further use in the manufacture of polymeric materials. The process is highly efficient and enables efficient and economical use of wood and other materials for the production of polymers based on renewable sources.

Example 1

A 250 ml three-necked glass flask was filled with wipes with 3 g of chestnut seedlings, 20 g of 1,2 propanediol, 2 g of maleic anhydride and 0,5 g of phosphoric (V) acid. The reaction mixture was heated at 190 ° C for 7 hours while stirring. After the reaction, the reaction mixture was cooled and the unreacted chestnut effluent filtered. The filtrate was liquefied wood and unreacted 1,2 propanediol. The reaction yield was 56%.

Example 2

A 250 ml three-necked glass flask was filled with wipes with 3 g of linden wood, 25 g of 1,2 propanediol, 2 g of maleic anhydride and 0,5 g of phosphoric (V) acid. The reaction mixture was heated at 190 ° C for 7 hours while stirring. After the reaction, the reaction mixture was cooled and the unreacted wood filtered. The filtrate was liquefied wood and unreacted 1,2 propanediol. The reaction yield was 56%.

Example 3

A 250 ml three-necked glass flask was filled with wipes with 3 g of alder wood, 30 g of 1,2 propanediol, 2 g of maleic anhydride and 0,5 g of phosphoric (V) acid. The reaction mixture was heated at 190 ° C for 7 hours while stirring. After the reaction, the reaction mixture was cooled and the unreacted wood filtered. The filtrate was liquefied wood and unreacted 1,2 propanediol. The reaction yield was 58%.

Example 4

The 250 g three-necked glass flasks were filled with wipes with 3 g of poplar wood, 30 g of 1,2 propanediol, 2 g of maleic anhydride and 0,5 g of phosphoric (V) acid. The reaction mixture was heated at 190 ° C for 7 hours while stirring. After the reaction, the reaction mixture was cooled and the unreacted wood filtered. The filtrate was liquefied wood and unreacted 1,2 propanediol. The reaction yield was 64%.

The foregoing embodiments of the invention do not limit, but merely explain.

Claims (7)

A method of liquefying wood and wood waste, characterized in that it utilizes polyols, saturated or unsaturated polybasic organic acids, and phosphoric (V) acid as catalyst as reagents. Process according to claim 1, characterized in that the wood or wood waste can be replaced by other materials such as cellulose, paper, cotton or starch. Process according to claim 1, characterized in that it is carried out in a reactor vessel with a lid made of glass or other inert material. Process according to claim 1, characterized in that the liquefaction reaction takes place at a temperature between 180 and 250 ° C. 5. A process according to claim 1, characterized in that the liquefaction reaction takes place for 3 hours or longer. Method according to claim 1, characterized in that the liquefied wood may contain non-degraded wood particles. Method according to claim 1, characterized in that the liquefied wood can be filtered to remove undamaged wood particles.