柔性孔径可变MOFs材料对通风瓦斯的吸附特性及其甲烷提浓研究

In China, the annual loss of coal seam gas resources is about 20 billion cubic meters. The concentration and utilization of the ventilation gas, which has been directly discharged into the atmosphere, is still in the initial stage. With high-pressure isothermal adsorption as the basic research means, in this proposal, we will study the adsorption and desorption performances of nitrogen and methane, and then design composite sorbents and fluid-bed adsorption and concentration device, so as to achieve ideal enrichment effect of ventilation gas. Firstly, metal-organic frameworks (MOFs) material will be designed with pore size between the molecular dynamics diameter of nitrogen and methane at some certain temperature, using the "molecular gate" effect of an mesh-adjustable molecular sieve, which can preferentially adsorb nitrogen, and composite sorbent will be assembled combining carbon molecular sieve, which is cheap and with high surface area. Then we will design the adsorption and concentration device based on fluid-bed reactor. The concentrated gas can be collected after multiple adsorption, with the sorbent regenerated at the same time. Thus gradient enrichment of mine ventilation methane would be achieved, contributing to emission reduction and mine safety.

在我国，每年损失煤层气资源约200亿立方米，其中，矿井通风瓦斯中的甲烷浓度通常低于0.75%，一直以来都是直接排放到大气中，对其利用尚处于起步阶段。本项目以高压等温吸附测试为基本的研究手段，针对通风瓦斯中主要气体氮气和甲烷的吸附解吸特性，设计合成复合吸附剂及流化床式吸附浓缩装置，对通风瓦斯中的甲烷进行浓缩。首先，利用新型柔性金属-有机骨架材料（Metal Organic Frameworks, MOFs）的“分子门”效应，设计合成孔径可变的MOFs结构，使其在一定温度下孔径尺寸介于氮气与甲烷分子动力学直径之间从而可以优先吸附氮气，并结合具有较大比表面积的廉价碳分子筛，组装成复合吸附剂。然后，以流化床式反应器为模型，设计吸附浓缩装置，收集经过多次吸附后的流出气体，即浓缩气，同时吸附剂自身通过脱附段进行循环再生。本项目的研究成果可用于矿井通风甲烷的连续性浓缩，有助于节能减排及保障矿井安全。

在我国，每年损失煤层气资源约200亿立方米，其中，矿井通风瓦斯中的甲烷浓度通常低于0.75%，一直以来都是直接排放到大气中，对其利用尚处于起步阶段。本研究以高压等温吸附测试为基本的研究手段，针对通风瓦斯中主要气体氮气和甲烷的吸附解吸特性，设计合成孔径可变的新型金属-有机骨架材料，使其在一定条件下具有较好的选择吸附性能，并结合具有较大比表面积的介孔分子筛材料，组装成复合吸附剂。设计了穿透曲线和变压吸附实验装置，通过穿透曲线测试，考察吸附剂的脱氧性能，判断吸附剂对甲烷和氮气两种气体的分离能力以及确定变压吸附的基本条件，并测试变压吸附效果。另外，设计吸附浓缩装置，对矿井低浓度瓦斯进行收集、浓缩。本项目的研究成果可用于矿井通风甲烷的连续性浓缩，有助于节能减排及保障矿井安全。