掺氢天然气分离工艺方案及经济性分析

目的天然气管道掺氢输送被认为是氢能大规模、低成本、长距离运输的重要途径之一。为了获得高纯度氢气,需要在终端将掺氢天然气进行分离。目前,单一的氢气分离手段难以直接适用于低含量氢的掺氢天然气分离。 方法对比了几种常见的氢气分离技术的原理、工艺参数、优缺点等,结合掺氢天然气的特点,选定了“膜分离+变压吸附”耦合工艺路线,并针对掺氢比(摩尔分数,下同)分别为10%、15%、20%的掺氢天然气分离工艺方案进行了经济性分析,获得了各分离方案的成本。 结果 掺氢比为10%、15%、20%的综合分离成本分别为0.846 7 元/m³氢气、0.519 7 元/m³氢气、0.382 6 元/m³氢气。 结论较低含量的掺氢天然气分离成本较高,大规模推广应用仍面临经济性制约和诸多挑战。 

Scheme and economic analysis of hydrogen-blended natural gas separation

ObjectiveHydrogen-blended natural gas pipeline is regarded as one of the important ways to transport hydrogen energy in large scale, low cost and long distance. In order to obtain high purity hydrogen, hydrogen-blended natural gas needs to be separated at the terminal. At present, the common hydrogen separation methods are not directly applicable to the separation of hydrogen-blended natural gas with low hydrogen concentration. Methods This paper introduces the principle, process parameters, advantages and disadvantages of the common hydrogen separation technology. Combined with the characteristics of hydrogen-blended natural gas, the coupling process route of "membrane separation + pressure swing adsorption" is determined, and the economic analysis is made on the separation process scheme of hydrogen-blended natural gas with hydrogen blending ratio of 10 mol%, 15 mol% and 20 mol%. The separation cost of each separation scheme is specified. ResultsThe comprehensive separation cost of 10% hydrogen blending ratio is 0.846 7 yuan/m³ hydrogen, the comprehensive separation cost of 15% hydrogen blending ratio is 0.519 7 yuan /m³ hydrogen, and the comprehensive separation cost of 20% hydrogen blending ratio is 0.382 6 yuan/m³ hydrogen. ConclusionsThe separation cost of hydrogen-blended natural gas with low concentration is high, and its large-scale application still faces economic constraints and challenges.