Assessing Hydrogen Production Potential of Acid-Pretreated Sweet Potato Stillage with Fermentation and Microbially Assisted Electrolysis

Abstract

自18世紀工業革命後，化石燃料已經成為維持人類文明的主要能源，但會造成環境污染及能源匱乏問題。如何找到一個代替化石燃料並且具有低污染及永續性的替代燃料便日益重要。生質能是一種將生質物轉換成能源的一種形式，以作物殘渣產氫是一種生質能的應用方式，可同時達到處理廢棄物並且產生能源的目的。 本研究以迴流污泥粉末植種以暗醱酵及微生物電解電池評估甘藷酒渣經酸處理後的產氫潛能。暗醱酵部份以2%的酸液較3%的酸液在同樣的處理條件下有較大的產能，其中，鹽酸酸前處理其產氫量大於硫酸前處理，最大的產氫值為13.15 mmol H2/g COD。醱酵後的廢液以微生物電解電池持續產氫，在實驗過程中曾發現有產能變低的情形，推測應是交換膜變形所引起。在MEC反應中因產氫量不高，而使能量回收率低。結合暗醱酵與MEC得到的總產氫效率為0.11~0.68 mmole H2/g COD之間， COD移除在13~39%。

Since the 18th century industrial revolution, fossil fuels has become a major energy source to maintain human civilization, but it will cause environmental pollution and energy shortage problems. How to find a place of fossil fuels, and has features such as low pollution, and sustainability of alternative energy increasingly important. Biomass energy is to convert biomass into energy, a form of crop residues to produce hydrogen is a way of biomass energy applications, which can achieve the waste disposal and energy generation. This study is to observe the hydrogen production potential of sweet potato lees after acid treatment. The assessing approach is to integrate dark fermentation and microbial electrolysis cell process. In the part of the fermentation, the hydrogen production potential of 2% acid concentration is higher than the 3% one; among which, the production of hydrogen which is dealt hydrochloric acid pretreated is higher than the one which is sulfuric acid pretreated, and the maximum hydrogen quantity is 13.15 mmole H2/g COD. Treating wastewater which is obtained after fermentation with microbial electrolysis cells and producing hydrogen. In microbial electrolysis cells, it has been found the decline of hydrogen production capacity during the experiment. the reason could be the exchange of membrane deformation. Because the MEC for hydrogen production reaction is not high, that thus results in lower energy recovery. Combining dark fermentation with MEC generates the total hydrogen production efficiency raging from 0.11 to 0.68 mmole H2/G COD, and COD removal rate ranges from 13 to 39 %.