SBIR Phase I: Carbon Nanotube Enhanced Membrane Distillation for Sea and Brackish Water Desalination, and the Treatment of Saline Waste Water

这个小型企业创新研究第一阶段项目的更广泛的影响/商业潜力是从海水和微咸水中产生廉价清洁水的可能性。 随着世界人口的迅速增长，饮用水将成为本世纪最重要的技术挑战之一。有没有独特的？一个尺寸适合所有人？接近脱盐。许多因素，如盐作为盐的浓度、特定离子的存在、能量成本、预处理要求和资本投资是选择要实施的脱盐技术的重要考虑因素。本文提出的碳纳米管强化膜蒸馏是一种相对低温的过程，其中工业废热和太阳能加热可用于脱盐。小型热水器，如家庭中使用的天然气加热器，可以用来产生高质量的饮用水沿着什么是家庭消费所需的。这项技术的另一个主要应用是石油和天然气钻探。水力压裂或压裂是一个水密集型过程。一个典型的压裂井在其使用寿命中使用数百万加仑的水，并产生高盐度？产水？ 由于其处理高盐浓度的能力，所提出的方法是处理这种废物的可行替代方案。 该项目的技术目标是利用碳纳米管（CNT）创造突破性的膜性能，用于通过膜蒸馏（MD）进行海水淡化。在MD中，疏水多孔膜分离热盐水进料和冷渗透物流。 当加热的盐水通过膜时，部分转化为水蒸气。膜的疏水性防止水溶液进入孔。然而，脱离氢键的水蒸气通过并冷凝在膜的渗透侧上。碳纳米管固定化膜（CNIM）将通过将碳纳米管固定到膜孔中来开发，在膜孔中它们将充当分子转运体和吸附剂，从而为水蒸气传输提供额外的途径。CNIM的另一个主要优点是它比传统膜更不易结垢。该提案的关键创新包括CNT的功能化，以最大限度地提高水蒸气传输，同时最大限度地减少污垢。 其他目的包括研究一些商业上重要的水样，如海水，发电厂废水和采出水的结垢行为。最后，将开发一个工艺优化工具来优化CNIM-MD设计。

The broader impact/commercial potential of this small business Innovative Research Phase 1 project is the possibility of inexpensive clean water generation from sea and brackish water. With rapidly increasing world population, portable water will be one of the most important technological challenges of this century. There is no unique ?one size fits all? approach to desalination. Many factors such as salt concentration, the presence of specific ions, energy cost, pretreatment requirements and capital investments are important considerations in selecting the desalination technology to be implemented. The carbon nanotube enhanced membrane distillation proposed here is a relatively low temperature process where industrial waste heat and solar heating can be used for desalination. Small water heaters such as the natural gas heaters used in homes can be used to generate high quality drinking water along with what is needed for domestic consumption. Another major application of this technology is in oil and gas drilling. Hydraulic fracturing or fracking is a water-intensive process. A typical frack well uses several million gallons of water over its lifetime and generates a highly saline ?produced water?. With its ability to handle high salt concentrations, the proposed approach is a viable alternative for treating this waste. The technical objectives in this project are to utilize carbon nanotubes (CNTs) to create breakthrough membrane properties for desalination via membrane distillation (MD). In MD, a hydrophobic porous membrane separates a hot salt water feed and a cold permeate stream. As the heated brine passes on the membrane and is partially transformed to water vapor. The hydrophobicity of the membrane prevents the aqueous solution from entering the pores. However, freed from hydrogen bonding the water vapor passes through and is condensed on the permeate side of the membrane. The novel membranes referred to as carbon nanotube immobilized membranes (CNIM) will be developed by immobilizing CNTs into membrane pores where they will serve as molecular transporters and sorbents, thus providing additional pathways for water vapor transport. The other major advantage of CNIM is that it is less prone to fouling than conventional membranes. Key innovations of the proposal include the functionalization of CNTs for maximization of water vapor transport while minimizing fouling. Additional objectives include the study of fouling behavior of some commercially important water samples such as sea water, power plant effluents and produced water. Finally, a process optimization tool will be developed to optimize CNIM-MD design.