【作者】 马浩淼；

【导师】 吴海；

【作者基本信息】 中国计量科学研究院 ， 化学， 2015， 硕士

【摘要】 天然气作为一种低碳清洁能源,在一次能源结构中占重要角色。本文选择天然气中主要的C6~C9烃类组分作为研究对象,按照称量法国家标准GB/T5274-2008,研制了C6~C9烃类气体标准物质,结论如下:(1)建立了原料试剂纯度分析方法:通过GC-MSD定性和GC-FID面积归一方法测定了正己烷、苯等10种试剂中的烃类杂质,利用卡尔费休水分仪测定了试剂中的水含量。通过杂质扣除法获得了各原料试剂的纯度。(2)建立了C6~C9组分的气相色谱分析方法:基于DB-624、VBwax以及Stabilwax三种不同毛细柱分别建立了相应的色谱分析方法,通过比较三种不同方法的分离度、重复性、分析时间,优选采用Stabilwax毛细柱的色谱分析方法,该方法重复性相对标准偏差为0.2%,一天内漂移小于0.4%,单次分析时间8min。(3)建立10组分高沸点有机物的配气技术:通过建立微量转移法和直接注射法制备气体标准物质。研究表明,微量转移技术在转移混合溶液时,蒸汽压较低的组分转移效率偏低,因此制备的气体标准物质量值偏差较大。直接注射法转移混合溶液中各组分的效率一致,直接注射法制备的气体标准物质各组分量值相对偏差小于0.5%。。(4)通过分装试验考察和优选了包装气瓶:并合理评估吸附效应对标准物质定值的不确定度贡献。通过分装法考察了4种常用的国产钢瓶,结果表明普通铝合金气瓶内壁对C6~C9各组分的吸附效应最小,吸附导致标准气体量值偏差不超过1.6%,该偏差作为吸附效应的不确定度贡献。(5)通过放压试验考察了C6~C9气体标准物质的压力均匀性,方差检验结果表明气体标准物质特性量值随压力变化的变动性不显著,可以忽略。(6)研制了C6~C9气体标准物质,采用称量法定值,其特性值为15μmol/mol,相对扩展不确定度为1.5%~3.5%。不确定度考虑了称量法制备过程、钢瓶内壁吸附影响、压力变动性等来源的贡献,未包含长期稳定性的不确定度贡献。研制的气体标准物质可以用于天然气中C6~C9组分的测量,为测量结果建立计量溯源链,保证测量结果的可靠性。从而为天然气烃露点计算、天然气能量计量、油气勘探提供计量支撑。更多还原

【Abstract】 Natural gas is used throughout the world to provide heating and power to homes and industry, and provide fuel to vehicle, as feedstock in industrial processes, and to generate electricity because of high thermal value, safety, large reserves, low pollution.Gas RM can ensure the accuracy and traceability of measurement provide informations for energy measurement, oil and gas exploration, geochemical investigation, hydrocarbon dew point calculation. We prepare C6~C9 gas reference material according to ISO 6142. The research contents are as follows:(1) Purity analysis of parent gases: GC-MSD and GC-FID are used to determinate hydrocarbon impurities, and Karl-Fischer moisture titrator is used to determinate moisture. Purity of parent gases is obtained using deduction method.(2) Establishing laboratory analysis method: compare analysis results from different chromatographic column, and optimize analysis method.(3) Establishing method for the preparation of gas mixtures: injection method is selected through compra injection and micro transfer.(4) Cylinder screening: subpacking experiment is used for examining popular gas cylinders made in China, and result of supacking shows that aluminium alloy gas cylinder after mechanical and chemical polishing has the lowest adsorption effect no more than 1.6%.(5) According to ISO Guide 35 examine gas reference material’s stability as the change of pressure. The result shows that gas reference material has no significant variation as the change of pressure, so the variation is neglected.(6) The concentration of C6~C9 hydrocarbon in gas reference material is 15μmol/mol, the relative expanded uncertainties of concentration are within range from 1.5% to 3.5%.Gas reference material prepared in this research can be used as calibration gas mixtures to measure C6~C9 hydrocarbon in natural gas, and ensure the accuracy and traceability of measurement.更多还原