Catalytic Dehydration of Carbohydrates in Near- and Supercritical Polar Solvents

生物过程可以产生大量的乙醇， 异丙醇、乳酸和1-丁醇， 生物资源。 酸催化脱水这些 超临界水中的生物产品可以导致高产量的 重要的高价值石油化学品乙烯、丙烯、丙烯酸 和1-丁烯在超过22 MPa的压力下。 因此，这些工业 重要的单体可以由稀水相溶液制备 生物基质的压力适合于直接 聚合物塑料如聚乙烯的合成， 聚丙烯. 类似地，糠醛和5-羟甲基糠醛可 可以从戊糖和己糖以高产率获得。 这些 糠醛在工业上用于合成树脂。 不幸的是，寄生反应竞相消耗 生物底物，降低高价值单体的产率。 的 这项研究的目的是确定机制， 这些竞争反应的动力学，以确定条件 和优化双键形成的产率的催化剂 脱水反应 这项工作的关键要素是它的重点 近临界水作为反应介质。 夏威夷和许多发展中的热带国家（如泰国 和菲律宾）可以享受其农业复苏， 如果发酵使用更高的价值， 蔗糖的产物被鉴定。 同样，内布拉斯加州， 堪萨斯、爱荷华州和其他中西部州将受益于 乙醇、乳酸的替代性高价值用途， 玉米制品工业的其他发酵产品。 的 塑料、树脂和石化中间体的生产 也许是最有前途的选择， 改善以糖和玉米为基础的农业经济 经济体 先前的工作已经揭示了催化剂的前景， 超临界水作为生产石油化工产品的新方法， 生物材料 这项研究将为 开发这种新的化学反应。

Biological processes can produce large quantities of ethanol, i-propanol, lactic acid, and 1-Butanol at moderate cost from renewable biological resources. The acid catalyzed dehydration of these bioproducts in supercritical water can result in high yields of the important high value petrochemicals ethylene, propylene, acrylicacid, and 1-Butene at pressures exceeding 22 MPa. Thus these industrially important monomers can be produced from dilute aqueous phase solutions of the biological substrate at pressures appropriate for the direct synthesis of polymeric plastics, such as polyethylene and polypropylene. Similarly, furfural and 5-hydroxymethyl furfural can be obtained from pentoses and hexoses in high yields. These furaldehydes are used industrially to synthesize resins. Unfortunately, parasitic reactions compete to consume the bio-substrate and reduce the yield of the high-value monomer. The objectives of this research are to identify the mechanisms and kinetics of these competing reactions in order to determine conditions and catalysts which optimize yields of the double bond forming dehydration reactions. The key element of this work is its emphasis of near and supercritical water as a reaction medium. Hawaii and many of the developing tropical countries (such as Thailand and the Philippines) could enjoy a resurgence of their agricultural economies if higher value uses for the fermentation products of sucrose were identified. Similarly, Nebraska, Kansas, Iowa, and other mid-western states would benefit from alternative, higher value uses for ethanol, lactic acid, and other fermentation products of the corn products industry. The production of plastics, resins, and petrochemical intermediates from bio-materials is perhaps the most promising option for improving the economics of sugar- and corn-based agricultural economies. Prior work has revealed the promise of catalysis in supercritical water as a new method for producing petrochemicals from bio-materials. This research will lay the foundation for industry to exploit this new reaction chemistry.