Top Vapor Research Articles

A novel heat integrated double extractive divided-wall column avoiding vapor recompression system in water purification from petrochemical

The chemical plant produces wastewater with tetrahydrofuran (THF), methanol, and water, which form two energy-intensive binary azeotropes. With this aim, this research introduces a novel extractive divided-wall column (DWC) to efficiently separate water from the THF-methanol mixture. The study utilizes a combination of a solvent and steam, leading to the creation of a double extractive DWC (DEDWC) as the foundational model. A key innovation of this study is the recovery and reuse of waste heat from the column's top vapor through vapor recompression, which is used for further separation. While this method requires a significant initial compression ratio and, by extension, a considerable capital investment, the study introduces a heat integration system to mitigate these costs. This system raises the vapor temperature by combining it with the heated solvent (bottom product) and strategically employing intermediate steam-driven reboilers. This inventive method, known as the heat-integrated DEDWC (HiDEDWC), notably increases the vapor temperature by 15 K beyond the reboiler liquid. Impressively, HiDEDWC demonstrates a remarkable improvement in energy and cost efficiency over the standard DEDWC and the version with vapor recompression. Specifically, HiDEDWC achieves an impressive energy saving of 52.81% and reduces the total annual cost by 52.11% compared to DEDWC.

Vientos—A New Satellite Mission Concept for 3D Wind Measurements by Combining Passive Water Vapor Sounders with Doppler Wind Lidar

Abstract It is challenging to accurately characterize the three-dimensional distribution of horizontal wind vectors (known as 3D winds). Feature-matching satellite cloud top or water vapor fields have been used for decades to retrieve atmospheric motion vectors, but this approach is mostly limited to a single and uncertain pressure level at a given time. Satellite wind lidar measurements are expected to provide more accurate data and capture the line-of-sight wind for clear skies, within cirrus clouds, and above thick clouds, but only along a curtain parallel to the satellite track. Here we propose Vientos—a new satellite mission concept that combines two or more passive water vapor sounders with Doppler wind lidar to measure 3D winds. The need for 3D wind observations is highlighted by inconsistencies in reanalysis estimates, particularly under precipitating conditions. Recent studies have shown that 3D winds can be retrieved using water vapor observations from two polar-orbiting satellites separated by 50 min, with the help of advanced optical flow algorithms. These winds can be improved through the incorporation of a small number of collocated higher-accuracy measurements via machine learning. The Vientos concept would enable simultaneous measurements of 3D winds, temperature, and humidity, and is expected to have a significant impact on scientific research, weather prediction, and other applications. For example, it can help better understand and predict the preconditions for organized convection. This article summarizes recent results, presents the Vientos mission architecture, and discusses implementation scenarios for a 3D wind mission under current budget constraints.

Experimental study on continuous spill fire of liquid fuel on porous bed

ABSTRACT As a traditional fossil fuel, petroleum fuel is prone to spills and fire accidents during storage, transportation, and use, which poses a great threat to the safe utilization of energy. This work aims to study the effect of porous media on the combustion characteristics of continuous spill fires. The transformer oil spill fire experiment is carried out on a porous bed with a length of 120 cm, a width of 15 cm, and a depth of 5 cm. The effects of sand diameter (0.75 mm, 1.5 mm, 3 mm, and 6 mm) and discharge rates (25 ml/min, 50 ml/min, and 75 ml/min) on the development of spill fires are analyzed. The results show that the spill fire fuel transport mechanism mainly includes gas phase diffusion caused by fuel consumption on the surface of a porous bed and liquid phase convection caused by capillary flow. Thus, three zones are formed from top to bottom: (i) the top vapor zone; (ii) the middle gas–liquid two-phase zone; and (iii) the bottom liquid phase zone. The presence of sand reduces the efficiency of the heat and mass. And it makes the spill fire stable combustion area increase compared with the smooth substrate. The stable combustion area has a positive correlation with the mass discharge rate and a negative correlation with the sand size. The stable combustion area of 1.5 mm, 3 mm, and 6 mm sand is 87.1%, 81.9%, and 77.5% of that of the 0.75 mm sand. In contrast to transformer oil pool fires and spill fires on smooth substrates, the burning rate is negatively related to the equivalent burning diameter. Meanwhile, the burning rate of spill fire on porous beds is significantly reduced compared with the first two. Based on the analysis of heat and mass transfer, a model for the burning rate of spill fire in porous media is formed and its correctness is verified. The experimental results are of great significance to the safe utilization of liquid energy.

Intra-Lid Multi-Core Vapor Chamber Architecture for Heterogeneous Electronic Packages: Technology Concept to Prototype Evaluation

Thermal management of future heterogeneous electronic packages with extreme heat fluxes relies on effective spreading of heat in the package lid. Intra-lid integration of vapor chambers is a promising strategy for simultaneous dissipation of large total heat loads and localized high-flux hot spots. However, conventional vapor chambers comprising a single vapor core require relatively thick evaporator wicks to prevent dry out at high total heat loads, thereby imposing a large temperature drop across the wick at the hot spot location. We recently proposed a cascaded multi-core vapor chamber (CMVC) architecture comprising a single-core vapor chamber stacked on an array of smaller footprint vapor cores having relatively thinner wicks. The multi-core array is designed to spread heat from arbitrarily distributed high-flux hot spots before they enter the top vapor chamber having a thicker wick. Then, the top vapor chamber spreads the high total heat loads to the base of the mounted heat sink. To evaluate the proposed CMVC technology, we make a weighted decision to identify an appropriate minimum viable prototype for subsequent design and testing. A reduced-order model is used to determine the dimensions and properties of the wick and vapor core that minimize the temperature drop across the down-selected multi-core vapor chamber architecture for a given power map, considering manufacturing process constraints. Finite element analysis (FEA) simulations are employed to decide a condenser wall thickness that avoids permanent deformation in the vapor chamber architecture under a mechanical load. A prototype is manufactured by a commercial vendor following these parameters and manufacturing constraints. As predicted by the thermal model, experimental characterization of this first-reported multi-core vapor chamber array prototype offers a notable reduction in temperature drop relative to a benchmark solid copper spreader, owing to attenuation of hot spots at a low temperature difference.

Application of dividing wall column in azeotropic distillation with intermediate boiling-point heteroazeotrope: Simulation and optimization

Dividing wall column (DWC), as a proven process intensification technology, has been used widely in separation of ideal multi-components, and some azeotrope systems. For heterogeneous azeotrope with the potential possibility of crossing distillation boundary by liquid-liquid splitting, it is advantageous to integrate liquid-liquid decanter with distillation column, especially with DWC to further simplify flowsheets and reduce energy consumption. In this work, existing heterogeneous azeotrope separation processes are described, and an innovative DWC-based process (MHADWC) is proposed for intermediate boiling-point heteroazeotropic systems. Then an industrial case of MIPK system, is used to evaluate mentioned configurations by rigorous simulation and optimization. These configurations are compared and analyzed in detail on energy consumption, exergy analysis and equipment invest. The results show that, from the perspective of process energy consumption, MHADWC process has the most advantages, because it saves 37% of energy consumption; if both equipment costs and exergy recovery are taken into account, HADWC2 has a higher thermodynamic efficiency (43.5%) at its TAC and can be used as a preferred target. And in this work, purification of an intermediate boiling-point heteroazeotrope is the main difference of these processes compared with the well-known heterogeneous azeotropic distillation process where the top vapor product is the lowest boiling point of the ternary system.

Optimizing the Assimilation of the GOES-16/-17 Atmospheric Motion Vectors in the Hurricane Weather Forecasting (HWRF) Model

Hourly and 15 min GOES-16 and -17 atmospheric motion vectors (AMVs) are evaluated using the 2020 version of the operational HWRF to assess their impact on tropical cyclone forecasting. The evaluation includes infrared (IR), visible (VIS), shortwave (SWIR), clear air, and cloud top water vapor (CAWV and CTWV) AMVs derived from the ABI imagery. Several changes are made to optimize the assimilation of these winds. The observational error profile is inflated to avoid overweighting of the AMVs. The range of allowable AMV wind speeds entering the assimilation system is increased to include larger wind speeds observed in tropical cyclones. Two data quality checks, commonly used for rejecting AMVs, namely QI and PCT1, have been removed. These changes resulted in a 20–40% increase in the number of AMVs assimilated. One additional change, specific to infrared AMVs, is narrowing the atmospheric layer where IR AMVs are rejected from 400–800 hPa to 400–600 hPa. The AMVs’ impact on forecast skill is assessed using storms from the North Atlantic and the Eastern Pacific, respectively. Overall, GOES-16 and -17 AMVs are beneficial for improving tropical cyclone forecasting. Positive analysis and forecast impact are obtained for track error, intensity error, minimum central pressure error, and storm size.

Modeling of two-phase refrigerant distribution in brazed plate heat exchangers

This paper presents a mechanistic model that predicts two-phase refrigerant distribution in brazed plate heat exchangers. The modeling of two-phase distribution is based on the flow visualization in the inlet header, in which the flow regime is identified to be periodic and one cycle includes two or three flow stages, given a fully developed stratified/stratified-wavy flow is present at the heat exchanger entrance. To predict the vapor refrigerant distribution, this model considers two different flow stages in the inlet header: for the top corner vapor flow, the vapor refrigerant distribution is predicted by the balance between the suction force (radial pressure gradient) and the axial momentum of each phase; for the vapor jet flow, the vapor refrigerant is assumed to be distributed evenly among the channels. The time ratio of the two flow stages is estimated by assuming the irregular large-amplitude rolling waves in the feeding tube, which lead to the vapor jet flow in the header, to have the most dangerous wavelength and their traveling time can be related to the liquid slug frequency. The apparent vapor refrigerant distribution is the time average of the vapor distributions at the two stages. For the liquid refrigerant distribution, it is predicted by imposing an equal total pressure drop for each flow path. The proposed model is validated against the experimental results: quantified two-phase refrigerant distribution, heat exchanger capacities, pressure profiles in the headers, and surface temperature of the sidewalls.

Visualization of two-phase refrigerant flow in the inlet header of brazed plate heat exchangers and its effect on distribution

• Two-phase flow visualization is achieved by a clear window on the inlet header. • Flow regime in the inlet header is periodic and one cycle has two or three stages. • Flow regime in the inlet header significantly affects the two-phase distribution. • Effects of mass flux, inlet vapor quality, and the number of plates are examined. This paper presents an experimental study of two-phase R134a flow in the inlet header of brazed plate heat exchangers and its effect on flow distribution among the channels. Visualization of the two-phase flow is accomplished through a 3-D printed transparent window on the inlet header of the heat exchangers. The two-phase flow distribution among channels is quantified based on infrared images of the heat exchanger sidewalls. At the test conditions, the observed flow regimes in the inlet header are periodic and two or three stages are identified in one cycle: top corner vapor flow, vapor jet flow, and (conditional) liquid blockage flow. Among them, the top corner vapor flow affects the distribution most, in which the vapor refrigerant is mainly present at the top corner of the header and branches out through the first several channels, leaving the liquid refrigerant to occupy the rest flow area of the inlet header and present a single-phase like distribution profile. When the inlet vapor quality increases, the distribution of the liquid refrigerant is improved since the vapor refrigerant can reach more downstream channels to help balance the total pressure drop. With the mass flux increases, the maldistribution caused by the header induced pressure drop is more significant, which compromises the benefit brought by the higher vapor momentum. When the number of plates is increased, the liquid refrigerant distribution is worse due to an increased pressure drop in the headers.

Sequential two-column batch distillation processes for separation of ternary mixture containing three binary minimum boiling point homoazeotropes

Based on the continuous two columns distillation technology, it is difficult to separate the ternary mixture of n-hexane/ethanol/butanone, which contains three binary minimum boiling point homoazeotropes. Through analyzing characteristics of batch distillation and the phase behavior, it is feasible to achieve high purity separation of this kind of complex mixture by two-column batch distillation. Three sequential two-column batch distillation processes including Process A (Double columns with series operation), Process B (Double columns with parallel-then series operation) and Process C (Single column-then double columns process) were designed and analyzed in this work. The processes were evaluated and optimized from the aspects of economy and environment. In terms of economy, environment impacts and operating time, Process B is prior to Process A and Process C. Based on the thermodynamic analysis of the column, the heat integration problem of Process B is considered, which includes a self-preheating scheme at first step, and a heat exchange scheme in which high-pressure column top vapor provide part of the heat to low-pressure column bottom at second step. Compared with the unimproved Process B, the operating cost of the improved Process B can be reduced by 28% and TAC can be reduced by 3% at step 1. The operating cost of the improved Process B can be reduced by 30% at step 2.

Improved design of separation system for the recovery of benzene and isopropanol from wastewater

In order to recover valuable benzene and isopropanol from wastewater, development of energy-efficient design flowsheet of this separation system is a relevant design problem in industry and worthy of investigation. The available separation methods in open literature were to either use a triple-column pressure swing distillation or by combining heterogeneous azeotropic distillation and pressure-swing distillation. Although the above two separation methods having the favorable feature of not introducing any foreign component into the system, the economics and energy consumption of the above separation design flowsheets can still be significantly improved. The purpose of this paper is to develop an improved design flowsheet for this separation task, not ever seen in open literature, making use of natural liquid–liquid splitting in a decanter and arranging the distillation sequence so that one of the preceding column to be designed as a stripper to preserve latent heat of this column’s top vapor stream. Further energy-saving schemes of this separation system were also thoroughly investigated. It is found that the economics of our proposed heat-integrated separation system can significantly cut 75.1% and 66.2% in total operating cost and total annual cost, respectively, as compared to that of the best separation system recently proposed in open literature.

Enhancement of a R-410A Reclamation Process Using Various Heat-Pump-Assisted Distillation Configurations

Distillation for R-410A reclamation from a waste refrigerant is an energy-intensive process. Thus, various heat pump configurations were proposed to enhance the energy efficiency of existing conventional distillation columns for separating R-410A and R-22. One new heat pump configuration combining a vapor compression (VC) heat pump with cold water and hot water cycles was suggested for easy operation and control. Both advantages and disadvantages of each heat pump configuration were also evaluated. The results showed that the mechanical vapor recompression heat pump with top vapor superheating saved up to 29.5%, 100.0%, and 10.5% of the energy required in the condenser duty, reboiler duty, and operating cost, respectively, compared to a classical heat pump system, and 85.2%, 100.0%, and 60.8%, respectively, compared to the existing conventional column. In addition, this work demonstrated that the operating pressure of a VC heat pump could be lower than that of the existing distillation column, allowing for an increase in capacity of up to 20%. In addition, replacing the throttle valve with a hydraulic turbine showed isentropic expansion can decrease the operating cost by up to 20.9% as compared to the new heat pump configuration without a hydraulic turbine. Furthermore, the reduction in carbon dioxide emission was investigated to assess the environmental impact of all proposed sequences.

A novel cryogenic vapor-recompression air separation unit integrated to oxyfuel combined-cycle gas-to-wire plant with carbon dioxide enhanced oil recovery: Energy and economic assessments

Abstract Oxyfuel carbon capture is both power and capital intensive due to oxygen demand. Consequently, oxyfuel requires the development of more efficient air separation units. This work proposes an alternative cryogenic distillation process for large-scale gaseous oxygen supply. Instead of using different pressure columns, the new air separation unit couples top vapor recompression to a single atmospheric cryogenic air distillation double-reboiler column, whose nitrogen-rich top vapor is compressed to heat the intermediate column reboiler, while the bottom reboiler is heated with compressed saturated air. Several processes for low-pressure oxygen gas supply were simulated and optimized. The power requirement of the new air separation unit producing atmospheric oxygen at 95%mol attained the best value of 139.0 kWh/t (oxygen basis). A sensitivity analysis for oxygen purity was performed showing that, even for higher purities, the new developed process achieves the lowest specific power for low-pressure gaseous oxygen production. The economic leverage of the new air separation unit is proven via successful supply of low-pressure oxygen to oxyfuel natural gas combined-cycle Gas-To-Wire plant. Assuming carbon dioxide destination to enhanced oil recovery, even with an investment about 100% higher than the counterpart of a conventional air-fed combined-cycle Gas-To-Wire plant and despite net efficiency penalty of 6.88%, the oxyfuel combined-cycle Gas-To-Wire solution coupled to the new air separation unit was capable of achieving comparatively superior profitability under carbon taxation above 13.5 USD/t.

Design optimization and operating pressure effects in the separation of acetonitrile/methanol/water mixture by ternary extractive distillation

Ternary extractive distillation is a green and sustainable separation process for the treatment of pharmaceutical wastewater containing methanol/acetonitrile and acetonitrile/water azeotropes that achieves the recovery of the acetonitrile and methanol solvents. A novel sequential iterative optimization methodology is proposed and the isovolatility curves of systems at different pressures are analyzed in this work to investigate the effect of the operating pressure on the ternary extractive distillation process. Four optimization procedures with different conditions of pressure and limits for the use of cold utilities were carried out. The optimization results showed that the optimal pressures of the first column and the third column are related to the top vapor that can be condensed by chiller water and cooling water, respectively, and the pressure of the second column is related to the effect of preheating on the third column. The ternary extractive distillation process with optimal operating pressure shows 60.1% energy cost savings and 47.0% total annual cost savings compared with the optimal process operating at atmospheric pressure. The proposed optimization method has the advantages of automatic optimization with a smaller number of simulator runs, providing a new solution for the simulator-based process optimization. The investigation of the operating pressure effect provides additional insight for the design and optimization of ternary extractive distillation.

Optimum Performance Analysis of a Hybrid Cascade Refrigeration System Using Alternative Refrigerants

This research article deals with a Hybrid cascade refrigeration system (HCRS) comprising of vapor absorption refrigeration system (VARS) at the top or high temperature stage and vapor compression refrigeration system (VCRS) at the bottom or low temperature stage in a two-stage cascade refrigeration system using a mathematical model for energy and exergy analysis. The theoretical analysis is carried out taking H2O-LiBr solution in VARS and R134a, R32, R1234yf in VCRS as refrigerants. The three refrigerants (R134a, R32 and R1234yf) in this study are selected because these refrigerants have been recommended as future alternative refrigerants due to their zero ODP and low GWP properties. It has been found that the optimum generator temperature of HCRS is same for all the three eco-friendly refrigerants at which maximum coefficient of performance (COP) and maximum exergetic efficiency occurs. Further it is observed that the performance of the system considered in the study is better with R134a in comparison to R32 and R1234yf as refrigerants in the VCRS and R32 exhibits better result when compared with R1234yf.

Performance investigation of vapour recompressed batch distillation for separating ternary wide boiling constituents

The vapour recompression scheme (VRC) has been very effective in continuous distillation for energy intensification. The applicability of this scheme for the separation of multicomponent wide boiling con- stituents in batch distillation is a major challenge, because of the unsteady nature of the batch. In this study, the vapour recompression scheme has been implemented for the separation of multicomponent wide boiling constituents in the batch distillation. For the optimal usage of energy from compressed vapours manipulation of top tray vapour or external energy is done. A comparative study of the vapour recompressed batch distillation having a variable speed single compressor (SVRBD) and double stage compressor (DVRBD) with conventional batch distillation in terms of energy savings and total annual- ized cost is done. The VRC schemes achieve an energy savings of 50% and 10.03% total annualized cost (TAC) for SVRBD and DVRBD achieve 52% energy savings and 12.21% TAC with a payback period of 10 years.

Utilizing heat sinks for further energy efficiency improvement in multiple heat integrated five-column methanol distillation scheme

Although the potential of energy efficiency improvement of methanol distillation is largely reduced, heats are still in lack of recovery for discharging along with liquid products at embarrassing temperatures. Instead of routinely elevating certain stream temperatures to make a heat source at the cost of other energies. This work suggests an opposite strategy to utilize heat sinks to obtain temperature differences enough for heat recovery. In our former publication, compositions of lower boiling points are observed at the medium pressure column and the atmospheric column, whence make heat sinks available. This facilitates process adjustments for higher heat efficiency: (1) transit the medium column into a preceding atmospheric column, (2) pressured column top vapor distributes heat for thermal integration between bottoms of the light ends column and the preceding atmospheric column, (3) steam condensate from all the reboilers take over 90% heat supply to the former atmospheric column. Compared with the prototype, these changes knock down 31.85% specific stream consumption from 0.919 to 0.697kg (steam)/kg (methanol). Exemplified by the evolution of five-column methanol distillations, the heat sinks strategy adds another train of thought to create heat transfer drive when utilizing low temperature heat for thermal coupling within chemical plant installations.

Performance investigation of vapour recompressed batch distillation for separating ternary wide boiling constituents

Abstract The vapour recompression scheme (VRC) has been very effective in continuous distillation for energy intensification. The applicability of this scheme for the separation of multicomponent wide boiling constituents in batch distillation is a major challenge, because of the unsteady nature of the batch. In this study, the vapour recompression scheme has been implemented for the separation of multicomponent wide boiling constituents in the batch distillation. For the optimal usage of energy from compressed vapours manipulation of top tray vapour or external energy is done. A comparative study of the vapour recompressed batch distillation having a variable speed single compressor (SVRBD) and double stage compressor (DVRBD) with conventional batch distillation in terms of energy savings and total annualized cost is done. The VRC schemes achieve an energy savings of 50% and 10.03% total annualized cost (TAC) for SVRBD and DVRBD achieve 52% energy savings and 12.21% TAC with a payback period of 10 years.

Development of a unique modular distillation column using 3D printing

3D printing is recently used in many fields of technology, from medical science to aerospace and food products. In some cases, this technique is faster and increases the design flexibility in comparison with conventional machining. In this article, the design and manufacturing of a modular distillation column are presented using 3D printing. The flexibility and freedom in 3D model designs and the challenges for developing a small scale distillation column are demonstrated. The column was designed in a coil shape with modular structure to overcome the printing area limitation of the used 3D printer. The chemical compatibility of the printed polymer with several common solvents was examined. A 3D printable packing, and a commercially available stainless steel spring packing were used in the distillation. The column was used to distill a binary mixture of hexane+cyclohexane in full reflux and continuous mode. The heat loss of the column was also measured at the boiling points of hexane and cyclohexane. The composition of reflux and boilup streams were analyzed online using a gas chromatograph equipped with two sampling valves. The temperature of the vapor phase was measured at the top (vapor outlet) and bottom (boilup) of the column.

Energy Saving for Batch Distillation with Mechanical Heat Pumps

Operational and economic feasibility of different heat-pump systems with mechanical compression integrated to real batch distillation columns are investigated. This study is focused to the reduction of the external energy demand of the batch distillation. The separation of a low relative volatility mixture (nheptane-toluene) is studied by rigorous simulation performed with a professional dynamic flow-sheet simulator. The distillation column has AE-1000 reactor-reboiler of DIN standard type. The methods studied are vapour recompression, vapour compression and vapour recompression with the application of an external heat exchanger. Operational, heat transfer and economic issues are discussed. We stated that for the VRC in the minimal pay-pack period point the operation time of the batch process is significantly higher (the production capacity is much lower) than that of the conventional batch distillation. For boosting the overall performance of the VC system, we suggested to complete it with an external heat exchanger (VRCE) where the heat of the compressed top vapour is transferred to the usual heating medium (water). The original VRC system was not economical (payback period much above 10 y). However the payback period of the new VRC-E system was significantly shorter (less than 10 y). Distillation is one of the most widely used separation methods in the chemical industry in spite of its very high energy demand. The highest heat duties are required by creating the vapour flow in the reboiler (heating) and condensation of the top vapour in the condenser (cooling). The different methods of energy saving which is achieved by means of internal and external heat integrations were widely studied for the continuous distillation process and summarised by Bruinsma and Spoelstra (2010). Kiss et al. (2012) a practical selection scheme of energy efficient distillation technologies is proposed, with a special focus on heat pumps. The advantages of batch distillation (BD) over the continuous one are well-known. The energy saving methods for batch distillation have been much less studied than for the continuous one. Recently Jana and his co-workers (2011, 2012) investigated the feasibility and efficiency of the vapour recompression system for batch distillation. They proposed the application of variable compression ratio and pointed out the great economical potential of the vapour recompression systems for batch distillation. However they did not study in details the issues of the heat transfer in the reboiler. The goals of this paper -to study for batch distillation different heat pump (HP) systems with mechanical vapour compression (vapour recompression, vapour recompression with an external heat exchanger), -the rigorous simulation of the operation (including the heat transfer conditions) of these HP systems integrated to real batch distillation columns, -to estimate the costs and payback times of these systems and to compare them with those of the conventional batch distillation system. The calculations are performed with a professional dynamic flow-sheet simulator (CCDCOLUMN, Chemstation, 2007) for the separation of a low relative volatility (n-heptane-toluene) mixture. The reboiler of the systems is of DIN standard types (AE series). For the vapour compression system n-pentane was selected, as working fluid.

Optimum design and exergy analysis of a novel cryogenic air separation process with LNG (liquefied natural gas) cold energy utilization

A novel cryogenic air separation process with LNG (liquefied natural gas) cold energy utilization that produces liquid nitrogen and oxygen is proposed and analyzed. Air separation process problems such as process configuration complexity, extreme operating conditions and high operating costs are covered. In this process heat from the top vapor stream of the column is recovered and exchanged with heat in the bottom liquid and feed streams. It is noted that column operating pressure can be decreased compared with the high pressure portion of the air separation systems. In fact, the high and low pressure columns are combined here to exchange nitrogen latent heat with oxygen latent heat. This significantly reduces the energy input to the main compressor located before the column. Also, to completely utilize the cold energy of the LNG and to offset some of the consumed power, a power generation cycle is integrated with the process. This cycle utilizes pure oxygen from the air separation unit. The cryogenic air separation process is simulated and the main parameters are analyzed. It is shown that the energy consumption for the proposed air separation process with LNG cold recovery is about 38.5% lower compared for a convectional cryogenic air separation process. The energy and exergy efficiencies increase by 59.4% and 67.1%, respectively.