水合物法分离CO_2与N_2混合气的实验

An experimental study on the separation of mixed CO_2 and N_2 by the hydrate method

与传统的分离方法相比,水合物法分离气体混合物技术具有可降低制冷能耗、简化工艺流程、节省投资成本等优势,但目前该技术还不成熟,尚未形成统一的成套技术。为研究各种因素对分离效果的影响并给出一定配比混合气的最佳分离条件,以摩尔分数59%CO2＋41%N2混合气为例,利用自行设计的实验装置,系统地进行了温度、初始压力及含水量对分离效果的单值影响实验。分析处理实验数据,得到混合气在温度1.4~5.6℃、初始压力4.2~6.8 MPa及含水量160~300 mL范围内的分离效果。实验结果显示：降低温度,升高初始压力都可以提高分离率,但同时也会增大损失率;增加含水量会提高分离率,降低损失率,但含水量超过一定值,对分离率的影响便不再明显。综合考虑,对于一定配比的CO2＋N2混合气,在允许的损失率及最小气液比下,可以先增大含水量,然后降低温度,最后提高初始压力,以此来达到最佳的分离效果。

In comparison with the traditional methods to separate the mixed gas,the hydrate method may have the advantages of lower refrigeration energy consumption,simplified technological process,and less cost of investment.However,this new technique is still immature and has no necessary supporting techniques available now.In order to study the influences of various factors on separating effect and determine the optimal conditions for separating mixed gas with certain formulation,we systematically performed experiments on the mixed gas with mol fractions of 59 %CO2+41 %N2 to define the influences of temperature,initial pressure and water content on separation effects.The experimental data were processed to determine the separation effects with temperature 1.4-5.6 ℃,initial pressure 4.2-6.8 MPa,and water content 160-300 mL.Both lowering temperature and increasing initial pressure can raise the separation rate,but they increase loss factor at the same time.Increasing water content can raise separation rate and lower loss factor,but its influence on separation rate is no longer significant when water content is higher than a given value.As to the CO2+N2 mixed gas with certain mol fractions,under an allowable loss factor and the minimum gas fluid ratio,an optimal separation effect can be achieved through first increasing water content,then lowering temperature,and finally increasing initial pressure.