SBIR Phase I: Closed Loop Solvent Evaporation Ovens

这个小型企业创新研究(SBIR)第一阶段项目将开发闭环式溶剂蒸发炉。目前，工业过程中，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。这些都是环境问题，没有回收溶剂的机会。拟议的工艺是一个封闭的闭环系统，使用氮气作为循环气体，并用一层膜回收蒸发的溶剂蒸气，并去除泄漏到气体中的空气中产生的氧气和水蒸气。所需的补充氮量将很少。处理被挥发性有机化合物污染的稀薄气流所避免的费用和回收的溶剂的价值将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透氧膜、溶剂蒸气/不透氮膜。膜必须在高溶剂蒸汽压和高进气温度下保持这些特性。还将设计该系统的原型，并估计建造成本。第二阶段将建立一个完整的系统，并在实验室和合作的主办地点运行，以评估工艺效益和成本。用负担得起的闭环氮气再循环系统取代直接通风式溶剂挥发炉，将可用于片剂涂布和印刷作业、胶带和胶粘剂薄膜的制备，以及工业中常见的表面涂布、上光和涂漆作业。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。基于这项技术的负担得起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.