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影响/商业潜力是有可能从海水和咸淡水中生产廉价的清洁水。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。有没有独特之处？一刀切？脱盐方法。盐浓度、特定离子的存在、能源成本、预处理要求和资本投资等许多因素是选择要实施的海水淡化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工艺，可以利用工业废热和太阳能加热进行海水淡化。家庭中使用的小型热水器，如天然气加热器，可以用来生产高质量的饮用水以及家庭消费所需的水。该技术的另一个主要应用是石油和天然气钻井。水力压裂法是一个耗水量很大的过程。一口典型的轨道井在其生命周期中使用数百万加仑的水，并产生高含盐量的水。生产水吗?。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（CNTs）为通过膜蒸馏（MD）脱盐创造突破性的膜特性。在MD中，疏水性多孔膜将热盐水饲料和冷渗透流分开。当加热的盐水通过膜时，部分转化为水蒸气。膜的疏水性阻止了水溶液进入毛孔。然而，从氢键中释放出来的水蒸气通过并在膜的渗透侧凝结。新型膜被称为碳纳米管固定化膜（CNIM），通过将碳纳米管固定在膜孔中，它们将作为分子转运体和吸附剂，从而为水蒸气输送提供额外的途径。CNIM的另一个主要优点是它比传统膜更不容易被污染。该提案的关键创新包括碳纳米管的功能化，以最大限度地提高水蒸气输送，同时最大限度地减少污染。其他目标包括研究一些商业上重要的水样的污染行为，如海水、发电厂废水和采出水。最后，开发了一种工艺优化工具来优化cims - 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.