Three step process for obtaining liquid biofuels consisting mainly of isomers of methylpyran and methyl tetrahydropyran from cellulose, hemicelluloses or starch, using in a first step N alkyl imidazol chloride containing a slight excess of hydrochloric acid 37%. This mixture acts as a solvent and catalyst for dissolution and hydrolysis of cellulose and dehydration of glucose to isomers of hydroxymethyl pyranone (HMP).
In a second step the reaction mixture is mixed with a water solution of sodium chloride to increase the ionic strength, and to make possible an extraction with butanol, which otherwise is miscible with the ionic liquid reaction mixture. Butanol was found to be the best solvent for HMP under these conditions.
In a third step, the butanol extract is concentrated by distillation, and the concentrate is submitted to hydrogenation with gaseous hydrogen using palladium or platin catalysts on carbon or alumina.
The final mixture is separated from butanol by distillation.
By GCMS only one relevant product was obtained representing about 90% of final products. It was identified by NMR as 2-methyl pyran.
从
纤维素、半
纤维素或淀粉中获取主要由甲基
吡喃和甲基
四氢吡喃异构体组成的液体
生物燃料的三个步骤过程。在第一步中,使用含有轻微过量37%
盐酸的N烷基
咪唑氯化物作为溶剂和催化剂,用于溶解和
水解
纤维素以及
葡萄糖脱
水成为羟甲基
吡喃酮(HMP)的异构体。在第二步中,将反应混合物与
氯化钠水溶液混合以增加离子强度,并使
丁醇可以进行提取,否则
丁醇会与
离子液体反应混合物相互溶解。在这些条件下,
丁醇被发现是HMP的最佳溶剂。在第三步中,通过蒸馏浓缩
丁醇提取物,然后使用碳或氧化铝上的
钯或
铂催化剂进行氢化。最终混合物通过蒸馏与
丁醇分离。通过GCMS仅得到一个相关产品,代表最终产品的约90%。通过NMR鉴定为2-甲基
吡喃。