膜-变压吸附耦合工艺掺氢天然气提纯氢气的实验研究OA

Due to the low density of hydrogen,transportation via high-pressure tube trailers is economically inefficient.Blending hydrogen into natural gas pipelines is considered one of the effective approaches for long-distance,large-scale hydrogen transport.An experimental study was conducted on the coupled membrane-pressure swing adsorption(PSA)process for hydrogen separation from natural gas with hydrogen blending ratios of 5.0%to 20.0%(volume fraction,the same below).The main factors affecting hydrogen separation efficiency,such as the natural gas hydrogen blending ratio,pressure,flow rate,and carbon dioxide content,etc.,were analyzed.The results show that the hydrogen blending ratio in natural gas has the most significant impact on hydrogen separation efficiency,with higher blending ratios leading to lower hydrogen separation costs.Higher pressure of hydrogen-enriched natural gas results in a higher hydrogen recovery rate.However,an increase in flow rate leads to a decrease in the hydrogen recovery rate.Carbon dioxide and hydrogen exhibit strong permeation competition when passing through the polymer membrane,and carbon dioxide significantly affects hydrogen separation efficiency.Under natural gas pressure of 4.0 MPa and hydrogen blending ratios of 5.0%to 20.0%,high-purity hydrogen with a purity of 99.999%(volume fraction)can be efficiently separated from hydrogen-enriched natural gas,achieving a total hydrogen recovery rate of 90%and a theoretical energy consumption of 0.5 kWh/m3 to 1.0 kWh/m3(based on hydrogen).