STTR Phase I: Conversion of food waste to biofuels using an anaerobic membrane bioreractor

这项小型企业技术转让（STTR）项目的广泛影响/商业潜力将是一种成本效益高、商业上可行的现场处理食物废物和能源回收的替代方法。在美国，近40%的食物被浪费了，相当于1650亿美元的食物损失加上食品生产中使用的水、能源、化学品和劳动力。处理食物垃圾需要额外的成本，并造成环境污染，例如，垃圾填埋场腐烂的食物垃圾占美国甲烷排放的很大一部分，甲烷是一种强大的温室气体。此外，食物垃圾流中含有大量的化学能，这些化学能在处理过程中也会损失掉。在这个项目中，以生物燃料和化学品的形式回收食物垃圾中的能量，将有效地管理食物垃圾问题，降低食物垃圾的处理成本，同时生产有用的产品。这个STTR一期项目建议开发和演示一种新型的、固定化梭菌膜生物反应器为基础的将食物垃圾转化为丁醇的连续工艺的性能。传统的基于搅拌槽发酵反应器的食物垃圾转化工艺具有丁醇浓度低、生产效率低的特点。提出的工艺将解决传统工艺的技术障碍，通过将梭状芽孢杆菌细胞固定在多孔介质上，以显着增加细胞培养密度，从而提高丁醇产量和转化效率。另外，通过将丁醇从反应介质中分离出来，降低了反应器中回收丁醇的浓度，减轻了丁醇的毒性。生物质分离中的膜污染问题将通过“开放通道”膜模块设计来解决，以分离和回收生物质到生物反应器。通过使用渗透蒸发膜，从稀释反应器流出物中回收丁醇所需的能量将比传统蒸馏减少一个数量级。所提出的努力的目标是在优化单个成分后，展示将食物垃圾转化为丁醇的稳态连续集成过程。

The broader impact/commercial potential of this Small Business Technology Transfer (STTR) project will be a cost-effective, commercially viable, alternative process for on-site treatment of food waste and energy recovery. In the U.S., nearly 40% of food is wasted with $165 billion equivalent loss of food plus associated water, energy, chemicals, and labor used in food production. Disposal of the food waste involves additional costs and causes environmental pollution, e.g. rotting food waste in landfills accounts for a large portion of U.S. methane emissions, a powerful greenhouse gas. Moreover, food waste streams contain a substantial amount of chemical energy that also is lost by its disposal. Recovering energy in food waste in the form of biofuel and chemicals, as proposed in this project, will provide efficient management of food waste problem reducing food waste disposal costs while producing useful products.This STTR Phase I project proposes to develop and demonstrate the performance of a novel, immobilized clostridia cell membrane bioreactor-based continuous process to convert food waste to butanol. The conventional stirred-tank fermentation reactor-based food waste conversion process exhibits low butanol concentration as well as productivity. The proposed process will address the technical barriers of the conventional process by immobilizing the clostridia cells on porous media to dramatically increase cell culture density, and, consequently, butanol productivity and conversion efficiency. In addition, by separating butanol from the reaction media, recycled butanol concentration is minimized in the reactor, which alleviates butanol toxicity. The membrane fouling issues in biomass separation will be addressed by an "open channel" membrane module design to separate and recycle biomass to the bioreactor. The energy requirement for recovery of butanol from dilute reactor effluent will be reduced by an order of magnitude over the conventional distillation by using a pervaporation membrane. The objective of the proposed effort is to demonstrate a steady state continuous integrated process for converting food waste to butanol after optimizing individual components.