Superior Sorbents for Desulfurization of Gas and Liquid Fuels by Adsorption

目前，液体运输燃料的脱硫是通过高温和高压催化工艺来实现的，而天然气的脱硫是通过使用胺的溶剂萃取来进行的。这些都是昂贵且能源密集的过程。吸附脱硫是一个简单、低能耗的过程。由于缺乏良好的吸附剂，它没有被使用。在我们的实验室中已经发现了一类与所有先前已知的吸附剂相比具有更高的硫选择性和更高的硫容量的π络合吸附剂，并且π络合吸附剂是完全可再生的。天然气和运输燃料的脱硫都是这种情况。在我们的实验室中，只有非常有限数量的阳离子能够与硫分子形成π-络合键。此外，只有非常有限数量的大孔基板已被研究作为支持π-络合吸附剂。我们最近的研究表明，对于气体和液体燃料脱硫，孔扩散导致固定床吸附中硫容量的严重限制。在这个建议中，最有前途的介孔，大孔，π络合吸附剂的气体和液体燃料脱硫的系统研究概述。最有前途的d区金属阳离子的盐和氧化物将以单层形式分布在这些大孔基底上。这些吸附剂将具有最高的硫选择性和容量。它们也将是最稳定和完全可再生的。它们将具有大孔，以使扩散阻力最小化，从而提供最高的固定床硫吸附容量。平衡等温线和孔扩散系数（扩散时间常数）的纯组分和含硫分子的混合物将测量这些π-络合吸附剂。通过分子轨道理论计算和光谱研究，对各种π络合吸附剂的吸附物种和键合有了基本的了解。将通过研究金属分散和稳定性来检查使用分散剂用于在高表面积基底上铺展单层π络合盐的可能益处。将在各种新型吸附剂上测量气体和液体燃料的固定床吸附器穿透曲线。将获得对硫容量的扩散限制的理解。该项目将涉及各种研究生和本科生的积极参与，特别是少数民族学生和女生。学生们将在国家会议上和通过出版物积极传播研究结果和发现。这项研究将导致气体和液体燃料脱硫的全新技术，从而以更低的成本生产更清洁的燃料。硫含量较低的清洁燃料将减少向大气中的硫排放。在这项工作中开发的吸附剂可以很容易地转移到工业应用。此外，对含硫分子与d区金属（即，π-络合键）。

0852129YangDesulfurization of liquid transportation fuels is currently accomplished by high temperature and high pressure catalytic processes, while desulfurization of natural gas is performed by solvent extraction using amines. These are costly and energy intensive processes. Desulfurization by adsorption would be a simple and low-energy process. It is not being used because of the lack of good sorbents. A class of pi-complexation sorbents has been discovered in our laboratory that has higher sulfur selectivities and higher sulfur capacities compared to all previously known sorbents, and the pi-complexation sorbents are fully regenerable. This is the case for desulfurization of both natural gas and transportation fuels. Only a very limited number of cations that are capable of forming pi-complexation bonds with sulfur molecules have been explored in our laboratory. Also, only a very limited number of large pore substrates have been studied as supports for pi-complexation sorbents. Our most recent studies showed that for both gas and liquid fuel desulfurization, pore diffusion causes severe limitation on the sulfur capacity in fixed-bed adsorption. In this proposal, a systematic study of the most promising mesoporous, largepore, pi-complexation sorbents for desulfurization of both gaseous and liquid fuels is outlined. Salts and oxides of the most promising d-block metal cations will be spread in monolayer form on these large-pore substrates. These sorbents will have the highest sulfur selectivities and capacities. They will also be most stable and fully regenerable. They will have large pores in order to minimize diffusion resistance and consequently provide the highest fixed-bed adsorption capacities for sulfur. Equilibrium isotherms and pore diffusivities (in terms of diffusion time constants) for both pure-component and mixtures of sulfur-containing molecules will be measured for these pi- complexation sorbents. A basic understanding of the adsorbed species and bonding on various pi-complexation sorbents will be obtained through molecular orbital theory calculations as well as spectroscopic studies. The possible benefit of using a dispersant for spreading monolayer pi- complexation salts on high-surface-area substrates will be examined by studying the metal dispersion and stability. Fixed-bed adsorber breakthrough curves will be measured for both gas and liquid fuels on various new sorbents. An understanding of the diffusion limitation on sulfur capacity will be obtained. This project will involve active participation of a diversity of graduate as well as undergraduate students, particularly the minority and female students. The students will be active in disseminating the findings and discoveries at national meetings and through publications. The research will lead to entirely new technologies for desulfurization of both gaseous and liquid fuels, which will result in cleaner fuels at lower costs. Cleaner fuels with lower sulfur contents will reduce sulfur emission into the atmosphere. The sorbents developed in this work can be readily transferred to industrial applications. In addition, a basic understanding on the bonding between sulfur containing molecules and d-block metals (i.e., pi- complexation bonds) will be obtained.