Wassenberg André, Esser Tobias, Poller Maximilian J, Albert Jakob
Institute for Technical and Macromolecular Chemistry, University of Hamburg, 20146 Hamburg, Germany.
Materials (Basel). 2023 Apr 4;16(7):2864. doi: 10.3390/ma16072864.
The industrial use of biomass, e.g., for the production of platform chemicals such as levulinic acid, became increasingly important in recent years. However, the efficiency of these processes was reduced by the formation of insoluble solid waste products called humins. Herein, the formation of humins from various carbohydrates was investigated under different process conditions, in order to obtain information about the structure and the formation mechanism. During this process, new potential structural fragments of humins were identified. Subsequently, the produced humins were oxidatively converted to low-molecular-weight carboxylic acids with the use of polyoxometalate catalysts. The experiments showed that the use of sugars in acetic acid and ethanol only lead to the formation of a small amount of humins, which were also structurally most suitable for conversion to carboxylic acids. The main products of the oxidative valorisation of these humins were acetic acid, formic acid, and CO, respectively, and our results indicate that certain functional groups were converted preferentially. These findings will help to improve processes for the valorisation of biomass by enabling an overall more efficient use of thermo-sensitive feedstock such as carbohydrates.
近年来，生物质的工业用途，例如用于生产诸如乙酰丙酸等平台化学品，变得越来越重要。然而，这些过程的效率因形成称为腐殖质的不溶性固体废物产物而降低。在此，研究了在不同工艺条件下各种碳水化合物形成腐殖质的情况，以便获得有关其结构和形成机制的信息。在此过程中，确定了腐殖质新的潜在结构片段。随后，使用多金属氧酸盐催化剂将产生的腐殖质氧化转化为低分子量羧酸。实验表明，在乙酸和乙醇中使用糖类只会导致形成少量腐殖质，这些腐殖质在结构上也最适合转化为羧酸。这些腐殖质氧化增值的主要产物分别是乙酸、甲酸和一氧化碳，我们的结果表明某些官能团被优先转化。这些发现将有助于通过更全面有效地利用诸如碳水化合物等热敏性原料来改进生物质增值工艺。
