TPAD of whole and thin bioethanol residues

酒糟干谷物可溶物（DDGS）的市场已经饱和，过量的蒸馏对生物乙醇工业来说是一个浪费问题。蒸馏处理是玉米乙醇工艺的主要限制之一，因为DDGS干燥和蒸馏蒸发分别约占整个工艺能耗的30.3%和16.5%。每升乙醇可产生高达20L的沉淀物，总化学需氧量（TCOD 100-200 g/L），稀沉淀物蒸发器冷凝水是最大的废水贡献者。尽管与好氧生物降解相比，厌氧消化（AD）具有较低的碱度和营养需求，并且在减少沉淀物的有机污染和生产甲烷作为生物乙醇工厂的燃料方面具有很大的潜力，但它尚未得到广泛的应用。迄今为止的研究主要集中在稀沉淀物的消化上，而大部分沉淀物的甲烷潜力未经处理。然而，如果可以在实际固体反应时间（SRT）下直接在AD中处理整个沉淀物（浓度比稀沉淀物高3-5倍），而不需要蒸发和干燥，就可以使现有和新的生物乙醇设施实现能源独立，同时解决主要的瓶颈和浪费问题。这项技术的建立也将为加拿大工业打开国际市场。本研究的主要目的是研究在嗜热、中温和温度阶段消化（TPAD）（热/中温或中温/热；T/M VS M/T）条件下，分批和连续流AD对整个和薄层蒸馏液的生物降解性能和动力学[沼气产量、TCOD、总固体（TS）和挥发性固体（VS）去除效率]。

The market for Distillers Dried Grains with Solubles (DDGS) is saturated and excess stillage is a waste problem to the bioethanol industry. Stillage handling is one of the major limitations of the corn to ethanol process, since DDGS drying and stillage evaporation account for approximately 30.3 and 16.5% of total process energy consumption, respectively. Each litre of ethanol can generate up to 20L of stillage with total chemical oxygen demand of (TCOD 100-200 g/L), and thin stillage evaporator condensate is the largest wastewater contributor. Although anaerobic digestion (AD) has lower alkalinity and nutrient requirements compared to aerobic biodegradation and has great potential to reduce the organic pollution of stillage and produce methane as fuel for the bioethanol plant, it has not been applied with the magnitude possible. Studies to date focus on digestion of thin stillage, leaving the majority of the methane potential of the stillage untreated. However, if whole stillage (3-5 times more concentrated than thin stillage) can be treated directly in AD at practical solid reaction times (SRT) bypassing evaporation and drying it could make existing and new bioethanol facilities energy-independent while solving a major bottle neck and waste problem. Establishment of this technology would also open international markets for Canadian industry. The main objective of this research is to study the biodegradation performance and kinetics [biogas production, TCOD, total solid (TS) and volatile solids (VS) removal efficiencies] of whole and thin stillage using batch and continuous-flow AD under both thermophilic, mesophilic and temperature phased digestion (TPAD) (thermophilic/mesophilic or mesophilic/thermophilic;T/M vs M/T) conditions.