Cryogenic Distillation Process Research Articles

Process design and optimization of membrane-based CO2 capture process with experimental performance data for a steam methane reforming hydrogen plant and a coal-fired power plant

Membrane-based separation is one of the promising next-generation carbon capture technologies. High degrees of freedom in process design for multi-stage membrane networks, make it difficult to fully understand the impact of network configuration on the economics of capture and separation performance. Furthermore, the optimality in process design is heavily influenced by the levels of membrane performance and the characteristics of feed gas. Membrane model utilized for the study is validated and tuned with 183 experimental data measured at various operating conditions, having 2.45 % of overall prediction error. The superstructure-based framework for the optimization of multi-stage membrane networks is used, with which design interactions between network configurations, flue gas characteristics and membrane performance are systematically investigated. Techno-economic analysis is embedded in the optimization framework, which performs rigorous trade-off between capital and operating costs, as well as allows simultaneous determination of optimal process network configuration and operating variables. Flue gas streams emitted from a coal-fired power plant and a steam methane reforming hydrogen production plant are selected as CO2 capture sources for the analysis of flue gas characteristics. Case study shows capture cost ranged from 30.2 $/tCO2 to 79.9 $/tCO2, depending on the network configuration and design specifications, and clearly improves our techno-economic understanding on the network configuration of membrane capture process. In addition, cryogenic-hybridized membrane capture process is examined and the optimal level of enriched CO2 stream concentration between membrane capture and cryogenic distillation processes is determined. Study suggests how network configuration of membrane capture process can impact capture cost.

Biogas Upgrading Technology: Conventional Processes and Emerging Solutions Analysis

The purpose of this research is to investigate a variety of approaches to the conversion of biomass, with a particular emphasis on employing anaerobic digestion and biogas upgrading systems. An analysis of the existing technologies is performed, with a focus on highlighting the benefits and downsides of each alternative. In order to assess the effects of nitrogen and oxygen in the biogas on the cryogenic distillation process, an investigation is being carried out. The findings suggest that the presence of these two chemical species in the biogas necessitates the final condensation of methane in order to separate them from one another. In conclusion, a qualitative economic analysis is carried out in order to ascertain the most cost-effective strategy that can be implemented in a typical Italian installation. According to the assumptions that were used, membrane separation is the solution that offers the most cost-effectiveness.

Relay Adsorption in Metal-Organic Frameworks for One-Step Helium Purification at Ambient Temperature.

One-step He purification from natural gas represents a crucial solution for addressing the global He shortages. The prevailing method to produce high-grade He involves cryogenic distillation and ultralow temperature adsorption processes, which is highly cost- and energy-intensive. Separating and purifying He at ambient temperature is a great challenge because the fundamental limitation lies in the boiling point, polarizability, and kinetic diameters of CH4/N2/He gases. In this study, we seek to implement a relay adsorption strategy using Ni(ina)2 and MIL-100(Cr) metal-organic frameworks (MOFs) to produce high-purity He from ternary mixtures (CH4, N2, and He) at ambient temperature. The CH4/He selectivity in Ni(ina)2 and N2/He selectivity in MIL-100(Cr) both reach record 15.39 and 128.49, respectively, making the relay adsorption for helium purification highly efficient. The breakthrough experiments show that the two MOFs can sequentially adsorb CH4 and N2 in ternary mixtures, producing He with a purity of up to 99.99% in one step. The remarkable separation performance and stability of these MOFs underscore the industrial potential in purifying He at ambient temperature.

Numerical and experimental investigation of cryogenic fluid flow characteristics on corrugated packing surfaces

Cryogenic distillation is a significant method for producing pure oxygen and nitrogen gas. In the past, due to the high cost and difficulty of conducting cryogenic experiments, the structured packings used in cryogenic distillation are mainly developed and designed by referring to the testing results of room-temperature fluids. The real flow characteristics of cryogenic fluids on structured packings, such as flow pattern and wettability which significantly determines the distillation performance, have seldom been revealed. In this study, with the help of a three-dimensional CFD model and a visual experimental setup, the liquid nitrogen (LN2) flow characteristics within the geometric unit of a 45° inclined packing element were revealed detailedly under different liquid loads and crimping angles. Comparison studies were also conducted to show the different film flow characteristics between water and LN2. Additionally, optimization of the crimping angles based on 250Y structured packing was explored. Both simulation and experiment show that the flow pattern and wetting mechanism of the hydraulic test on water are different from those of LN2 in the actual cryogenic distillation. The LN2 has much better film flow performance than water due to its different physical properties. In addition, it is found that the crimping angle has a significant effect on the wetting area ratio. For LN2, the crimping angle of 90° can basically result in a high enough wetting area ratio, while for water, the crimping angle as large as 120° is needed to achieve a high wetting area ratio. It shows that testing and designing the structured packing with water as the main working medium will bring apparent errors in real cryogenic distillation process.

Novel Study on Cryogenic Distillation Process and Application by Using CHEMCAD Simulation.

The purpose of this study was to examine the cryogenic separation process used in air separation plants with the CHEMCAD simulation program. A preliminary analysis was carried out with the literature about the operation of the process. In light of the technical information, the simulation of the cryogenic separation process was utilized with the program. While no changes were analyzed in the basic parts of the process, the filtration of the air and separation from moisture and carbon dioxide were not included in the simulation. The simulation showed the three basic components of air, nitrogen, oxygen, and argon obtained as a product of the desired purity rather than a one-to-one demonstration of the applications in the industry. In addition, the low-temperature separation process of an air separation unit was studied to obtain high-purity products (99.49-99.99%) achieving the expected separation efficiency. As a result, the production of all three substances in desired purity was achieved successfully.

Experimental activities in view of hydrogen- deuterium equilibrium reaction in dielectric barrier discharge reactor: Effects of plasma treatment parameters and reactor design

Cryogenic distillation (CD) is a crucial process for separating and concentrating tritium in the tritium fuel cycle of fusion reactors. The equilibrator plays a vital role in decomposing HD, DT, and HT to improve the separation efficiency of hydrogen isotopes in CD. As the equilibrium reaction temperature decreases, a larger proportion of HD, HT, and DT decomposes into H2, D2, and T2, which enhances the performance of the equilibrator. While Pt/Al2O3 catalyst exhibits high activity at 303 K in the H2-D2 equilibrium reaction, it is almost inactive at 77 K. Non-thermal plasma (NTP) technology offers a promising and attractive alternative to conventional catalytic technology. In this study, H2-D2 equilibrium reaction was carried out without catalysts in a dielectric barrier discharge (DBD) reactor, achieving efficient conversion of HD even at 77 K. In the single-electrode DBD plasma reactor (S-P-Reactor), with an input power of 50 W, the conversion efficiency of HD was found to be 99.5% at 303 K, 99.5% at 273 K, and 99.2% at 77 K. To further optimize the energy efficiency of the S-P-Reactor, the reactor structure was enhanced, leading to the development of a multi-high-voltage DBD reactor (M-P-Reactor). The input power of the M-P-Reactor was reduced by approximately 10 W compared to the S-P-Reactor, while maintaining a conversion efficiency of over 95% for HD. The energy density of the reactor was calculated using the Q-V Lissajous graphic method, demonstrating that the M-P-Reactor exhibited superior energy conversion efficiency compared to the S-P-Reactor. Furthermore, the yield of HD was solely determined by the energy density and temperature. At a specific energy density, the yield of HD remained consistent for the same temperature. However, generating HD at lower temperatures required more energy due to the lower reactant activity. These results illustrate the potential application of NTP technology in improving hydrogen isotope separation performance in the cryogenic distillation process for fusion applications.

Steady-State simulation of cryogenic distillation used for helium isotope separation

Helium-3 (3He) is an invaluable and scarce resource with applications in various scientific and industrial fields. It is typically found mixed with helium- 4(4He) in natural gas and nuclear off-gas, which is industrial source of helium. Therefore, separation of the helium isotope is necessary. Cryogenic distillation is a preferred method of separation due to its higher separation coefficient and processing capacity. In this study, a numerical steady-state simulation of cryogenic distillation column for helium isotope has been conducted using programming. The mathematical model for the equilibrium-state cryogenic distillation process was established and solutions of the thermodynamic formulation was proposed. The simulation provided the distribution of 3He and 4He along each distillation column as well as the profiles of temperature and flow rates along the column, based on the designed specifications including the composition of the feeding mixture, feed flow rate and pressure. The required heat duty of the condenser and reboiler was also calculated, and the column dimensions were estimated. Besides, we have studied the effects of the reflux ratio and feed concentration of 3He on the final isotopic contents of the top and bottom products. The results demonstrated that the distillation simulation could provide crucial theoretical support for the smooth execution of future laboratory experiments.

Techno-economic analysis of carbon molecular sieve membranes to produce oxygen enrichment air

Oxygen Enriched Air (OEA) is essential for medical applications, metal production, chemical production, the petrochemical industry, and energy processes. In this work, carbon molecular sieve membranes (CMSM) and membrane systems are analyzed concerning their technical and economic feasibility to produce OEA for medical, post-combustion, and oxy-combustion applications. Process parameters, such as stage-cut, feed-to-permeate pressure ratio, membrane area, and the number of stages, were studied to assess the technical and economic feasibility of this technology. In this work, it was observed that for each membrane, there is a permeating oxygen concentration that minimizes the specific oxygen cost. The production of 56 tonO2·day−1 for a combustion enhancement process with a concentration of 72 % was obtained in a single-stage with a specific cost of 61.0 €·tonO2−1. A single-stage is also effective for producing OEA for medical applications (required concentration of 82 %) at a minimum separation cost of 45.8 €·tonO2−1. However, a two-stage system is required to produce OEA with a concentration higher than 95 % for oxy-combustion with an OEA production cost of 83.8 €·tonO2−1. These production costs are lower than those obtained with two different commercial membranes and are competitive with medium-scale cryogenic distillation and pressure swing adsorption processes.

Eco-efficiency analysis and intensification of cryogenic extractive distillation process for separating CO2–C2H6 azeotrope through vapor recompression strategy

The cryogenic extractive distillation process for CO2-ethane separation from natural gas involves four distillation columns in series and a rather high amount of energy from boiler and refrigeration compressors. This study proposes the intensification of a real plant located in China using a vapor recompression (VR) strategy to revamp it. The conventional process and the intensification configurations were designed by simulation in UniSim software. A utility plant with cooling water, steam generation, and propane refrigeration sections was also considered for realistic results regarding water consumption, CO2 emissions, and utility costs. Additionally, in order to establish an overall means for performance analysis, such indicators were grouped in a joint evaluation approach using the Comparative Eco-Efficiency Index. Results show that the VR1 scheme applied between the depropanizer condenser and the deethanizer reboiler provides savings of 24.2 % and 24.5 % in energy and water consumption, respectively; therefore, savings of 25.5 % and 21.4 % in CO2 emissions and utility costs were achieved, respectively, which increased the process's eco-efficiency by 41.9 %. As a point of interest, 33 months are necessary to recover the corresponding investment on the compressor and heat exchanger.

Synthesis of green light olefins from direct hydrogenation of CO2. Part II: detailed process design and optimization

BackgroundIn Part II, our objective is to investigate the optimal configuration and operating conditions for each process section of the CO2-based light olefin production process described in Part I. MethodThe main sections (reaction, CO2 capture, and olefin recovery) in the entire process are rigorously designed and optimized. Six alternative reactor configurations were proposed, and optimized by maximizing the productivity. The Trade-offs between cost, indirect CO2 emission, and CO2 capture ratio were analyzed for the CO2 capture section through multi-objective optimization. Three scenarios for olefin recovery were proposed and optimized by minimizing costs. Significant findingsFor the reaction section, the configuration employing two fixed-bed reactors with co-current heat exchange (Scheme R6) results in the highest conversion (75.45 %) and selectivity towards light olefins (82.49 %). Both are significantly higher than the available data in the literature. For the CO2 capture section, the optimal configuration has a 90 % CO2 capture ratio and requires a specific energy of 3.63 GJ/Ton-CO2. For the olefin recovery section, over 50 % of the costs can be reduced if hydrogen is removed before entering the cryogenic distillation process (Scheme O1). These findings support that the entire process presented in Part I of this study is in economical and environmentally-friendly conditions.

New Achievements of H2-HD-D2 Isotopic Separation with the Cryogenic Distillation Experimental Stand from ICSI Cryogenic Laboratory

In the design process of a cryogenic distillation plant for the separation of hydrogen isotopes, two main objectives, often impossible to achieve simultaneously, are taken into account: a high separation factor for different mixtures and isotope concentrations and the reduction of design, manufacturing, and operating costs with increased efficiency and safety. All this should result from the use of a method for calculating the separation efficiency, a method that will generate a conceptual design that must form the basis of the final technical design. Unfortunately, most design methods treat these plants as chemical plants, although in the case of cryogenic plants, it is not possible to readjust the new process operating parameters quickly and with great precision so that the separation efficiency and performance are not affected. There are three causes affecting the separation performance of cryogenic distillation plants, namely, nonideality of the cryogenic process, imperfection of heat exchangers, and heat losses. This paper presents our proposed solutions for increasing the efficiency of the cryogenic distillation process and discusses solutions tested in experimental campaigns with the cryogenic distillation stand developed in the Cryogenic Laboratory at ICSI Rm. Vâlcea.

Process analysis and optimization of high-N2 natural gas liquefaction

The demand for natural gas (NG) is increasing rapidly due to the world energy crisis. Liquefied Natural Gas (LNG) technology is one of the most flexible and reliable supply solutions, which has already been a major research hotpot in energy use. However, NG with high-N2 content lowers the gas calorific value and value of the gas and increases the energy consumption for production and transport. To address this issue, this study established nitrogen removal from the NG process using a single-column cryogenic distillation process based on Aspen HYSYS® in this study. An expanding refrigeration process using N2-CH4 was selected to provide the required cold energy for this plant, and the process power consumption and LNG specific power consumption was used as evaluation indicators. Results from sensitivity analysis showed that by the increase of natural gas feed temperature T1, the distillation column operation pressure Pc, and refrigerant high pressure P3, the LNG specific power consumption also demonstrated an increasing trend. The variables of natural gas inlet pressure P1, the outlet temperature of natural gas from pre-cooler T2, the ratio of return RR, the methane content ZCH4, the temperature of refrigerant after pre-cooler T4 and refrigerant low pressure P5 had a negative impact on the LNG specific power consumption. After conducting an optimization algorithm, the minimum LNG specific power consumption was determined to be 56.17 kJ/mol. Exergy analysis demonstrated that the total exergy destruction was 2076.13 kW. The compressor and expander components accounted for 31.57% and 26.29% of the total exergy losses respectively. This research provides valuable insights into optimizing LNG production processes by mitigating the impact of high nitrogen content, and it contributes to the advancement of LNG technology and energy efficiency in the industry.

Ag+ anchored on sulfonic functionalized mesoporous silica towards efficient liquid phase Olefin-Paraffin separation

Separation of olefin-paraffin gas mixtures has attracted enormous research endeavors as a replacement of the currently used, energy-intensive cryogenic distillation process, while liquid phase olefin-paraffin separation has remained less exploited. The challenge lies in that the difference in physical properties between C6-C8 olefins and paraffins tend to diminish as C = C bond fraction becomes smaller when alkyl chain grows longer. On the other hand, satisfactory adsorption capacity for these bulky molecules requires the use of porous materials beyond microporosity, i.e., mesoporous materials with large pore volume and size, which, nonetheless, lack adsorption selectivity to guarantee satisfactory separation factors. Here, we demonstrate that functionalization of mesoporous silica MCM-41 surface by –COO-, -Ph-SO3- and -SO3- functional groups can be used to immobilize Ag+, which turns the otherwise unselective porous solid into an olefin selective molecular sieving material suitable for liquid phase binary mixture separations. The results underline that ionically anchored Ag+ with intact complexation orbitals outperform coordinatively immobilized Ag+ (on –NH2 or -SH groups), in terms of anti-leaching property, olefin separation factor, as well as recyclability. Small mesopore size can boost olefin adsorption selectivity as accommodated olefins compressed the available space for access of paraffins. Adsorption evaluation for binary C6 to C8 olefin-paraffin mixtures separations discloses that the total adsorption capacity declines, while the separation factor increases, with increasing molecule size.

Highly-selective xenon–krypton separation using hydrate-based technology

Xenon (Xe) and krypton (Kr) are used in many important industries such as lighting, lasers, double glazing for insulation, and medicine. As Xe and Kr are found in extremely low concentrations in the atmosphere, only small quantities of the mixture of these gases are obtained as byproducts from air separation processes. As the further separation of Kr from Xe is achieved via a costly energy-intensive cryogenic distillation method, the development of a new cost-effective approach for Xe–Kr separation is essential. In this study, we demonstrated that clathrate hydrates can be used as a promising Xe trap to separate a Xe–Kr mixture and produce Kr-rich vapors. The Xe and Kr guest distributions in mixed clathrate hydrates were experimentally identified using powder X-ray diffraction, solid-state 129Xe NMR spectroscopy, and gas chromatography. The mixed Xe + Kr hydrates have a Pm3¯n structure, termed structure I (sI), regardless of the concentration of Xe in the feed vapor in the range of 3% to 100%, and the sI hydrate selectively captures Xe from the feed mixture. The phase equilibria of the mixed Xe + Kr hydrates were also investigated, and it was confirmed that the hydrate-based Xe–Kr separation process requires milder temperature conditions than the cryogenic distillation process. Overall, the findings in this work suggest that the hydrate-based Xe–Kr separation process is an excellent alternative to the energy-intensive cryogenic distillation method.

Investigating the Effects of Ag, Cu, and Pd Functionalized Chabazite on the Adsorption Affinities of Noble Gases Xe, Kr, and Ar

Separation of the noble gases from air is typically done through a cryogenic distillation process that is both energy intensive and expensive. Ag-functionalized zeolites and MOFs have a well-documented affinity for Xe and, to a lesser extent, Kr that could serve as an economical alternative to this process on a commercial scale. The mechanism driving the Ag–Xe interaction, however, is still a matter of debate, and the use of other metals in place of Ag is not as thoroughly documented. In this study, Ag, Cu, and Pd functionalized chabazite specimens were prepared, and their affinities for the noble gases Xe, Kr, and Ar were investigated and compared to each other and an unexchanged Na-chabazite. From these analyses, Ag-functionalized chabazite displayed the highest affinity for Xe among these samples, but there was not a similar affinity for Kr or Ar. From the results, a mechanism is proposed such that the strong Ag–Xe interaction contains both an underlying physical and electronic aspect related to the formation of Ag nanoclusters within the chabazite pore geometry that alters the chabazite surface state such that Xe is preferentially adsorbed.

Influence of structured packing geometric parameters on flow and mass transfer performance of liquid nitrogen and oxygen for cryogenic distillation

Normally, the design of the cryogenic structured packings mainly relies on the hydraulic experiments of room temperature fluids such as water due to the difficulties and high cost of conducting cryogenic experiments. This may result in significant performance discrepancies in cryogenic distillation applications since cryogenic fluids have quite different properties. In this work, with the help of the CFD combing VOF method, a three-dimensional structured packing model of counter-current flow was established. The flow characteristics and mass transfer performance of the LN2-O2 system (liquid nitrogen and gaseous oxygen) under different packing parameters including B (base), S (side), H (height), and β (crimping angle) were comprehensively coupled and analyzed. In particular, the flow morphology, and local wetting rate were analyzed to reveal the differences in flow characteristics between the LN2-O2 system and the water–air system. Furthermore, the mass transfer coefficient, mass transfer rate, and pressure drop of the LN2-O2 system were analyzed to obtain a deep understanding of the cryogenic distillation process under different packing geometric parameters. According to the results, the flow of the water–air system and LN2-O2 system is significantly different. As the specific values of base B, side S, and height H decrease, the water remains in rivulet flow, while LN2 changes from film flow to rivulet flow, which indicates the effect of the contact points on the flow of liquid nitrogen is more significant than that of water. With a constant specific surface area, as the crimping angle β increases from 60°to 120°, the wettability of liquid nitrogen on the suspended surface can be significantly improved. The wetting rate of LN2 increases by 9.78%, resulting in the mass transfer rate increasing by 9.02%, and the wet pressure drop decreasing by 9.60%. It shows the structured packing with the higher crimping angle β of 120° has a good application prospect in cryogenic distillation.

Selective separation of propane from the propylene-propane mixture using pure silica zeolites: A molecular dynamic simulation

Purification of propylene from propylene/propane mixtures which almost have a greater percentage of propylene is always a challenging task, because of using the costly cryogenic distillation process. Therefore, finding less-energy intensive, cleaner, and cheaper methods such as the adsorption process is desirable. In this study, with the purpose of separating an industrial feed stream including 90 mol.% propylene and 10 mol.% propane, a high-throughput screening method based on molecular simulation is used to investigate the most proper zeolite framework for this separation. Grand Canonical Monte Carlo (GCMC) and Molecular Dynamic (MD) simulations of the mixture in all 250 pure silica zeolites in the IZA database have been performed. Since a large mole fraction of this mixture is propylene, it is interesting to find an adsorbent that has a greater tendency to adsorb propane, in order to have a product with a higher purity of propylene. It has been found that the AFV-type framework has the highest propane separation potential (greater than 4 mol/L) and propane uptake capacity (0.76 mol/L).In order to choose the appropriate industrial process for the adsorption-desorption cycle between Pressure Swing Adsorption (PSA) and Temperature Swing Adsorption (TSA) processes, the adsorption isotherms and isobars of the mentioned mixture have been obtained. The results showed that the TSA adsorption process is more favorable due to the effect of increasing the temperature on the molar loading than the reduction of pressure in the PSA adsorption process.

High-throughput computational screening of Covalent−Organic framework membranes for helium purification

Currently, helium purification is carried out by the heat-driven cryogenic distillation process, which is prohibitively energy-intensive and capital-intensive. As an alternative, covalent-organic frameworks (COFs)-based membrane separation technology is considered to be cost-efficient and technically feasible. In this study, a high-throughput computational screening strategy was proposed for the rapid determination of high-performing COF membranes for this particular application. A geometric analysis-based prescreening process was carried out on 688 experimentally synthesized COFs, resulting in 665 COF candidates with pore limited diameter (PLD) no less than 3.8 Å. Subsequently, molecular simulations were performed to estimate the henry coefficients and self-diffusion coefficients of N2, H2, and CH4 in each COF. Based on the results, the membrane selectivity and permeability of all the COFs were calculated, from which 23 high-performing COF membranes were identified. Additionally, the performances of these 23 COF membranes for a ternary mixture of He/N2/CH4 were computationally examined, five of which were highly preferable to permeate He over N2 or CH4. The results indicated that a large number of COF membranes exceeded the performance upper limit of polymer membranes owing to their high He permeability. Additionally, the relation between the PLD of COFs and the corresponding separation performances was investigated. Finally, He permeability, as well as He/CH4 and He/N2 selectivity of mixed matrix membranes were estimated by using the Maxwell model. The results revealed that the addition of COFs into pure polymers significantly improved the permeability of He up to 11689 Barrer.

Highly durable ZIF-8 tubular membranes via precursor-assisted processing for propylene/propane separation

ZIF-8 membrane has been considered as a potential alternative to the traditional cryogenic distillation process for propylene/propane (C3H6/C3H8) separation. However, the scale-up preparation and stability of ZIF-8 membranes are limited by the weak binding strength between membrane and tubular support. Herein, we report a precursor-assisted processing method that featured strong binding strength at the interface of ZIF-8 membranes and tubular supports. ZIF-8 tubular membranes are then assembled into a membrane module with an effective membrane area of about 157 cm2 for efficient C3H6/C3H8 separation. Reliable binding strength is achieved and maintained over 10 min sonication which results in remarkable operation stability over 30 days. The C3H6 permeance and separation factor of this membrane module reached 1.08 × 10−8 mol m−2 s−1 Pa−1 and 55 at 60 °C and 0.7 MPa, with purity and productivity of 98.3% and 6.2 × 10−5 mol s−1, respectively. The good repeatability and durability of the ZIF-8 tubular membrane module demonstrate its potential for further scale-up towards practical application.

Superb storage and energy saving separation of hydrocarbon gases in boron nitride nanosheets via a mechanochemical process

Light hydrocarbon olefin and paraffin gas mixtures are produced during natural gas or petrochemical processing. The petrochemical industry separates hydrocarbon gas mixtures by using an energy-intensive cryogenic distillation process, which accounts for 15% of global energy consumption [1]. The development of a new energy-saving separation process is needed to reduce the energy consumption. In this research, we develop a green and low energy mechanochemical separation process in which boron nitride (BN) powders were ball milled at room temperature in the atmosphere of an alkyne or olefin and paraffin mixture gas. BN selectively adsorbs a much greater quantity of alkyne and olefin gas over paraffin gases, and thus the paraffin gas is purified after the ball milling process. The adsorbed olefin gas can be recovered from the BN via a low-temperature heating process. The mechanochemical process produces extremely high uptake capacities of alkyne and olefin gases in the BN (708 cm3/g for acetylene (C2H2) and 1048 cm3/g for ethylene (C2H4)) respectively. To the best of our knowledge, assisted by ball milling, BN nanosheets have achieved the highest uptake capacities for alkyne/olefin gases, which are superior to all other materials reported so far. Chemical analysis reveals that large amounts of olefin gases were quasi-chemically adsorbed on the in-situ formed BN nanosheets via C–N bond formation, whereas small amount of paraffin gases was physically adsorbed on BN nanoparticles. This scalable mechanochemical process has great potential as an industrial separation method and can realize substantial energy savings.