Abstract: A continuous process for producing levulinic acid from carbohydrate-containing materials in high yields is described. According to the process, a carbohydrate-containing material is supplied continuously to a first reactor and hydrolyzed at between 210.degree. C. and 230.degree. C. for between 13 seconds and 25 seconds in the presence of between 1% and 5% by weight mineral acid. The hydrolysis produces hydroxymethylfurfural, which is removed continuously from the first reactor and supplied continuously to a second reactor. In the second reactor, the hydroxymethylfurfural is hydrolyzed further at between 195.degree. C. and 215.degree. C. for between 15 minutes and 30 minutes to produce levulinic acid, which is continuously removed from the second reactor. The levulinic acid preferably is produced in at least 60%, and more preferably at least 70%, of the theoretical yield based on the hexose content of the carbohydrate-containing material.
Abstract: A process for producing furfural and levulinic acid from lignocellulose includes subjecting a sample of lignocellulose to acid degradation at an elevated temperature for a minute or less, during which time at least fifty percent of the furfural that theoretically can be derived from the sample is generated. The resulting mixture is then subjected to a second acid degradation at an elevated temperature to produce levulinic acid. During the second acid degradation, furfural vapors are continuously collected from the mixture.