Department of Civil and Environmental Engineering, Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China.
Department of Civil and Environmental Engineering, Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China.
Bioresour Technol. 2017 Aug;237:222-230. doi: 10.1016/j.biortech.2017.01.017. Epub 2017 Jan 12.
This study aimed to maximize the valorization of bread waste, a typical food waste stream, into hydroxymethylfurfural (HMF) by improving our kinetic understanding. The highest HMF yield (30mol%) was achieved using SnCl as catalyst, which offered strong derived Brønsted acidity and moderate Lewis acidity. We evaluated the kinetic balance between these acidities to facilitate faster desirable reactions (i.e., hydrolysis, isomerization, and dehydration) relative to undesirable reactions (i.e., rehydration and polymerization). Such catalyst selectivity of SnCl, AlCl, and FeCl was critical in maximizing HMF yield. Higher temperature made marginal advancement by accelerating the undesirable reactions to a similar extent as the desirable pathways. The polymerization-induced metal-impregnated high-porosity carbon was a possible precursor of biochar-based catalyst, further driving up the economic potential. Preliminary economic analysis indicated a net gain of USD 43-236 per kilogram bread waste considering the thermochemical-conversion cost and chemical-trading revenue.
本研究旨在通过深入了解动力学过程，最大限度地利用面包废弃物（一种典型的食物垃圾）生产羟甲基糠醛（HMF）。研究发现，以 SnCl 为催化剂时可获得最高的 HMF 产率（30mol%），这是因为 SnCl 具有较强的衍生 Brønsted 酸度和适度的 Lewis 酸度。我们评估了这些酸度之间的动力学平衡，以促进更快速的期望反应（即水解、异构化和脱水），同时抑制不期望的反应（即再水合和聚合）。SnCl、AlCl 和 FeCl 的这种催化剂选择性对于最大化 HMF 产率至关重要。较高的温度通过以相似的程度加速不期望的反应，从而仅略微提高 HMF 产率。聚合诱导的金属浸渍高多孔碳可能是基于生物炭的催化剂的前体，进一步提高了经济效益。初步经济分析表明，考虑到热化学转化成本和化学品交易收入，每公斤面包废物可获得 43-236 美元的净收益。
