SBIR Phase I: Closed Loop Solvent Evaporation Ovens

这个小企业创新研究（SBIR）一期项目将开发闭环溶剂蒸发炉。目前，工业过程规模很大。大量的加热空气通过蒸发炉，产生被挥发性有机碳（VOC）化合物污染的气流流出物。这些都造成了环境问题，而且没有机会回收溶剂。所提出的工艺是一个封闭的闭环系统，使用氮气作为再循环气体和膜来回收蒸发的溶剂蒸汽，并去除从泄漏到气体中的空气中产生的氧气和水蒸气。所需的补氮量很小。通过避免处理被挥发性有机化合物污染的稀释气流的成本和回收溶剂的价值，可以证明运营成本是合理的。第一阶段的主要实验任务包括为除氧步骤选择一种透氧、溶剂蒸汽/不透氮的膜。膜必须在高溶剂蒸气压和高原料气温度下保持这些特性。还将设计该系统的原型并估计建造费用。第二阶段将建立一个完整的系统，并在实验室和合作的东道国进行操作，以评估工艺效益和成本。用经济实惠的闭环氮再循环系统取代直接通风的溶剂蒸发炉，将成为可行的，用于片剂涂层和印刷操作，胶带和胶膜的制备，以及工业中常见的表面涂层，清漆和油漆操作。新的烘箱系统将允许溶剂回收和再利用，消除麻烦的蒸汽排放，并提供许多加工优势。基于该技术的价格合理的系统有望得到广泛应用。

This Small Business Innovation Research (SBIR) Phase I project will develop closed-loop solvent evaporation ovens. Currently, industrial processes pass large.volumes of heated air through the evaporation oven, producing an air stream effluent contaminated by volatile organic carbon (VOC) compounds. These present environmental problems and no opportunity for recovery of the solvent. The proposed process is an enclosed, closed-loop system using nitrogen as the recirculating gas and a membrane to recover the evaporated solvent vapors and remove oxygen and water vapor derived from air that leaks into the gas. The amount of make-up nitrogen required will be small. Operating costs would be justified by the avoided costs of treating the dilute VOC-contaminated air stream and by the value of the recovered solvent. The main Phase I experimental task involves a selection of an oxygen-permeable, solvent vapor/nitrogen-impermeable membrane for the oxygen removal step. The membrane must retain these properties at high solvent vapor pressures and high feed gas temperatures. A prototype of the system will also be designed and the construction costs estimated. Phase II will build a complete system and operate it in the laboratory and at cooperating host sites to evaluate process benefits and costs.Replacement of direct-air-vented solvent evaporation ovens with affordable closed-loop nitrogen recirculation systems would become feasible for use in tablet coating and printing operations, preparation of tapes and adhesive films, and surface coating, varnishing, and painting operations common in industry. The new oven systems will allow solvent recovery and reuse, eliminate troublesome vapor emissiona, and offer many processing advantages. Affordable systems based on this technology are expected to be widely used.