| abstract |
A method for producing an alcohol or carboxylic acid from a carbohydrate containing material, wherein the chemical energy efficiency of the method is greater than the chemical energy efficiency of a solely biological conversion process, and is greater than a process in which all the material is initially subjected to a thermochemical conversion step. The method comprises the steps: (I) Converting a material that has less than 75 percent by weight of the carbon containing material as carbohydrate into two intermediates. One intermediate is produced by a biological fermentation, and the other intermediate is produced by a thermochemical conversion process selected from gasification, pyrolysis, reforming and partial oxidation; and (II) Reacting the two intermediates to form an alcohol, carboxylic acid, salt or ester of a carboxylic acid. The microorganism used in the biological conversion can be a homofermentative microorganism |