A feasibility study to optimise extraction of bio-based materials following fermentation of distillery waste

麦芽酒是威士忌工业的主要副产品，生产量很大，每升制造的威士忌产生8.5 - 10升麦芽酒。处理技术在很大程度上局限于对麦芽酒加热以产生糖蜜型糖浆或通过AD提取能量以产生热和电。一份零废物苏格兰报告表明，多达20亿升的酒糟可用于生物精炼。实验室研究表明，二次发酵过程能够产生一类被称为“挥发性脂肪酸”（VFA）的有价值的化合物。其中最主要的是己酸，这是一种C6短链酸，在食品、制药、化妆品和塑料等众多行业中有着广泛的用途。世界上己酸的供应主要来自棕榈油，而棕榈油主要生长在东南亚。世界己酸生产的碳足迹估计超过3700万吨/二氧化碳当量。目前正在与生物可再生能源开发中心合作，从阿尔茨海默氏病样本中鉴定产己酸细菌。现在的任务是扩展这项研究，并进行可行性研究，以确定如何最好地提取和储存发酵混合物中的VFA。然后，这些结果将在整个过程中确定这一要素的费用概况。这是确定流程优化和通知财务决策以向全尺寸工厂投入大量资金的重要一步。

Pot-ale is the principal effluent co-product of the whisky industry and is produced in copious quantities with between 8.5 -10 litres of pot-ale being created for each litre of manufactured whisky. Treatment technologies have largely been restricted to applying heat to pot-ale to create a molasses type syrup or energy extraction via AD to create heat and electricity. A Zero Waste Scotland report suggested that up to 2 billion litres of pot-ale could be available for bio-refining.Laboratory research has demonstrated that a secondary fermentation process is capable of producing a valuable class of compounds known as 'volatile fatty acids'(VFAs). Chief amongst these is hexanoic acid, a C6 short-chain acid which has numerous uses across a wide range of industries, including food, pharma, cosmetics and plastics. World supplies of hexanoic acid are largely derived from palm oil which is predominantly grown in South-East Asia. The carbon footprint for world hexanoic acid production is estimated to be in excess of 37M tonnes/CO2eq. per annum.Work undertaken with the Bio-Renewables Development Centre (BDC) is currently in the process of identifying hexanoic acid producing bacteria from samples of AD digestate. The task is now to extend this research and undertake a feasibility study to determine how to best extract and store VFAs from the fermentation mixture. The results will then establish the cost profile for this element within the overall process. This is an important step in determining process optimisation and informing the financial decision to commit substantial funds to full sized plant.