Separations

Coalbed methane (CBM) is a vital clean energy resource, yet its extraction efficiency is often hindered by rapid production decline and low production rates in medium-shallow reservoirs. This study investigates the potential of CO₂ huff-and-puff technology to enhance CBM recovery and achieve CO₂ storage in low-productivity wells. A comprehensive model, constructed based on the geological conditions of the Qinshui Basin, was developed. Numerical simulations revealed that CO₂ huff-and-puff significantly improves CH₄ production by displacing adsorbed CH₄ and maintaining reservoir pressure. Key findings indicate that higher CO₂ injection volumes yield substantial increases in both peak CH₄ production and cumulative production compared with conventional extraction. Optimal soaking times balance recovery efficiency and operational costs. Sensitivity analysis identified gas diffusion coefficients, initial permeability, and Langmuir volume constants as critical geological parameters influencing the performance. This study preliminarily demonstrates the feasibility of large-scale CO₂ huff-and-puff for enhancing production in low-productivity CBM wells and provides theoretical insights for revitalizing China’s underperforming CBM wells while advancing carbon neutrality goals, although further experimental validation is still required.

An improved multi-module gas purification device is capable of removing micro-particles with an overall efficiency of over 95% at an average velocity of 16 m/s under a flow distribution ratio of 50/50. Its operation is based on the separation and filtration effect, and the multi-module design increases gas flow processing capacity without increasing the size of the device, and ensures good sustainable development as an innovation. The effects of one, dual, and triple-module configurations were experimentally investigated in terms of gas flow and distribution in channels, including pressure drag and separation level. For a comparative analysis of three pilot models of the device, granite micro-dust and wood ash were used as test particles. At an average micro-dust concentration of 4.5 g/m³, a pressure drop of less than 1600 Pa and a separation level of more than 93% were achieved.

The advancement of miniaturized liquid chromatography (M-LC) systems has drawn considerable attention for their ability to enhance sensitivity, expedite analysis, and minimize the environmental impact of chemical usage in various analytical processes. This review explores the fundamental principles and recent innovations in M-LC technology, including diverse pump designs, advanced column techniques, and the reduction in connection devices. Emphasizing the need for components that operate efficiently at the capillary or nanoscale with minimal dead volumes, we also discuss the development of benchtop instruments and mass spectrometry integrations. The review further highlights the growing applications of M-LC in food, environmental, and biological analyses, highlighting its potential as a powerful and emerging tool in separation science. Looking forward, addressing problems such as limited robustness, fabrication complexity, and integration with sensitive detectors will be instrumental to advancing M-LC technology. Modern innovation in microfabrication, materials science, and hyphenated methods holds great promise for allowing real-time, high-throughput, and portable analytical solutions in the near future.