EAGER: COMPUTER AIDED MOLECULAR DESIGN (CAMD) FOR NEW ADSORBENTS FOR NORM REMOVAL FROM NATURAL GAS FRACKING PRODUCED WATER

1434964 DiwekarVishwamitra研究所为了生产大量新发现的非常规天然气，威尔斯的水力压裂通常在页岩气和煤层气开采的盆地中进行。在油气（O G）勘探期间，威尔斯的水力压裂消耗大量的淡水并产生大量的污染废水。大约15-25%的水在水力压裂后30天内作为回流水返回到地面。采出水在井的使用寿命期间继续流动。除了高盐度和硬度外，水还可能含有大量天然放射性物质（NORM）。从这些沃茨中选择性去除NORM是非常困难的，本工作将研究新的和新颖的模型吸附剂。 研究人员将与天然气技术研究所（GTI）合作，确定一个高性能吸附剂预期功能的简化列表，并将该列表与常见的吸附剂相关联。PI将使用计算机辅助分子设计（CAMD）方法开发新的环境友好型吸附剂，用于NORM去除。CAMD通常是基团贡献法（GCM）的反向使用，其用于产生具有期望性质的分子。GCM已被用于预测状态属性，如选择性，相对挥发度，表面张力，密度，粘度和反应性。PI将开发新的基团贡献方法，用于基于热力学的吸附剂的重要性质。利用气相色谱法研究物理吸附已取得初步结果。 PI建议研究化学吸附和朗缪尔等温线。大气环流模式将确定对环境无害的吸附剂类别。这些基团将被独特地设计成通过探索所有可能的组合来产生所有可能的分子。每个基团的性质和/或基团之间的相互作用参数可以理论计算、实验获得或统计回归。从这组基团中，可以通过基团组合产生所需的分子。可以施加来自物理和化学性质的约束，以及来自监管限制的约束，因此可以减少组合的数量。然而，这是第一次提出这种方法来产生用于NORM分离的吸附剂。PI将从CAMD获得的新吸附剂列表中选择前30名进行进一步研究。为了识别潜在的所需化学品，使用各种解决方案算法。这些方法包括启发式计算、知识库方法、具有代数方程的分子性质簇和基于优化的方法。PI将使用优化方法进行此项工作。CAMD方法已经应用于许多领域，例如萃取溶剂、聚合物设计、结晶溶剂、毯式洗涤溶剂、吸收溶剂、制冷剂设计、蒸馏溶剂、反应溶剂、催化剂、增值产品、结晶溶剂和发泡剂。该研究对天然气压裂行业具有重要的理论和实践意义。建议的调查涉及开发新的和强大的工具，用于识别天然气压裂中NORM去除的新型吸附剂。除水力压裂外，吸附剂还用于许多应用中。因此，这项工作中开发的框架具有更广泛的商业和社会影响。该团队计划与来自行业和国家实验室的研究人员合作，以他们之前在其他项目上的互动为基础。

1434964DiwekarVishwamitra Reserach InstituteTo produce large volumes of newly discovered unconventional gas, hydraulic fracturing of wells is commonly practiced in basins where shale gas and coal bed methane are extracted. Hydraulic fracturing of wells during oil and gas (O&G) exploration consumes large volumes of fresh water and generates larger volumes of contaminated wastewater. About 15-25% of this water returns to the surface as flowback water within 30 days of hydraulic fracturing. Produced water continues to flow for the life of the well. In addition to high salinity and hardness, the water may also contain significant levels of natural occurring radioactive materials (NORM). It is very difficult to selectively remove NORM from these waters.New and novel model adsorbents will be researched in this work. The reserachers will collaborate of the Gas Tecnology Institute (GTI)to identify a simplified list of functions expected from high performance adsorbents and to correlate that list with the adsorbents commonly found. The PI will use computer aided molecular design (CAMD) methods for developing new environmentally benign adsorbents for NORM removal. CAMD is generally the reverse use of the group contribution method (GCM) that is used to generate molecules having desirable properties. GCM has been used to predict state properties like selectivity, relative volatility, surface tension, density, viscosity, and reactivity. The PI will develop new group contribution methods for important properties of adsorbents based on thermodynamics. Preliminary results have been obtained using GCM for physical adsorption. The PI proposes to study chemical adsorption and the Langmuir isotherm. GCM will identify the groups for environmentally benign adsorbents. These groups will be uniquely designed to generate all possible molecules by exploring all possible combinations. The properties of each group and/or the interaction parameters between groups can be theoretically calculated, experimentally obtained, or statistically regressed. From this set of groups, desired molecules can be generated by group combinations. Constraints from physical and chemical properties, as well as those from regulatory restrictions, may be imposed, and hence the number of combinations can be reduced. However, this is the first time such an approach is proposed for generation of adsorbents for NORM separation. The PI will select top 30 from the list of new adsorbents obtained by CAMD for further study. In order to identify potentially desirable chemicals various solution algorithms are used. These include heuristic numeration, knowledge-base approaches, molecular property clusters with algebraic equations and optimization-based methods. The PI will use optimization approach for this work. CAMD methods have been applied to many areas, such as extraction solvents, polymer designs, degreasing solvents, blanket wash solvents, absorption solvents, refrigerant design, distillation solvents, reaction solvents, catalysts, value added products, crystallization solvents and foaming agents. The proposed research is of considerable fundamental and practical significance to natural gas fracking industries. Proposed investigations concern the development of novel and powerfultools for identifying novel adsorbents for NORM removal in natural gas fracking. Adsorbents are used in numerous applications apart from hydraulic fracturing. Therefore, the framework developed in this work has a broader commercial and societal impact. The team is planning to collaborate with researchers from industries and national laboratories, building upon their prior interactions on other previous programs.