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ObjectiveAir-independent propulsion (AIP) submarines carry huge quantities of liquid oxygen. However, in the liquid oxygen combustion process, the cold energy is not usually recovered, and there are criticisms concerning CO2 removal in the confined space of a submarine. Aiming at the two major pain points that have long plagued AIP submarines, this paper proposes an integrated solution that organically combines the recovery and utilization of cold energy from liquid oxygen with the removal of CO2 . Method Liquid oxygen can be used as a cold energy source to process the cabin air. According to the different phase transition temperature characteristics of each air component, the CO2 in the air is frozen (condensed) and separated under normal pressure. ResultsThis study uses quantitative data analysis to show that the energy stored in liquid oxygen can basically meet the cold energy demand for freezing the CO2 produced by the crew's respiratory metabolism within the self-sustaining capacity of the submarine, and proposes a three-level workflow and implementation plan. ConclusionThe technical solution proposed in this paper can recycle 5% of cold energy from liquid oxygen, which conforms to the idea of the comprehensive integration of energy saving and noise reduction, and the full integration of overall resources. As such, it can be used for air purification and CO2 removal in confined spaces such as submarines, submersibles and deep-sea space stations powered by AIP systems.

bjective Taking the coal chemical process of a company in Hami, Xinjiang as the research object, the problem of high energy consumption in the low temperature separation and liquefaction system of coal chemical syngas was solved. Methods Aspen HYSYS software was used to simulate the separation liquefaction process of the single mixed refrigerant synthetic natural gas. The distribution ratio of the component in mixed refrigerant and the first and second stage compression pressure of the mixed refrigerant cycle were optimized by using BOX algorithm, with the minimum specific power consumption of the system as the objective function and the minimum heat transfer temperature difference of the cold box as the constraint condition of 3 ℃. Results The results show that the cold-heat composite curve of the optimized cold box is closer and smoother and the heat exchange effects are optimized, while keeping the production of LNG and methanol raw gas unchanged, with overall power consumption of the system decreased by 16.59%, exergy efficiency increased from 37.96% to 43.04%, significantly increasing the energy utilization rate. Conclusions The optimization of mixed refrigerant ratio and compression pressure by BOX algorithm has a significant effect on reducing energy consumption of syngas liquefaction process and increasing exergy efficiency, which has reference significance for the research of low temperature separation and liquefaction process of syngas in coal chemical industry. [ABSTRACT FROM AUTHOR]

The relevance. In recent years, due to the severe depletion of oil and gas fields, there is an urgent need to create new highly efficient technologies to increase oil and gas production both in oil and gas fields. Most of these fields are at the last stages of development, which are characterized by falling reservoir pressure, high water cut, a large amount of mechanical impurities and moisture in the produced hydrocarbon feedstock. As a result, there is an urgent need to develop new processes and improve technologies for field preparation of natural gas. Purpose: analysis of modern industrial processes of natural gas preparation: absorption and adsorption purification of natural gas from water, low-temperature separation, supersonic gas separation technology; choice of the most cost-effective and reliable process and technology for natural gas deep purification from water impurities in the conditions of industrial operation of gas and oil fields of the Russian Federation based on the analysis of technologies. Results. The analysis of industrial processes and methods of drying natural gas: absorption and adsorption drying, low-temperature separation and technology of supersonic separation of gas from moisture content and mechanical impurities, is carried out. The features of these processes, their properties, technological schemes, solutions, as well as advantages and disadvantages are analyzed. It was established that the use of natural gas absorption drying from water impurities makes it possible to obtain dried gas to a water dew point temperature of up to –20 °C. The introduction of the technology of natural gas adsorption drying from water impurities makes it possible to dry gas to a water dew point temperature in the range from –38 to –99 °C.

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Hydrogen deuterium exchange mass spectrometry (HDX MS) reports on the conformational landscape of proteins by monitoring the exchange between backbone amide hydrogen atoms and deuterium in the solvent. To maintain the label for analysis, quench conditions of low temperature and pH are required during the chromatography step performed after protease digestion but before mass spectrometry. Separation at 0 °C is often chosen as this is the temperature where the most deuterium can be recovered without freezing of the typical water and acetonitrile mobile phases. Several recent reports of separations at subzero Celsius emphasize the promise for retaining more deuterium and using a much longer chromatographic gradient or direct infusion time. Here we present the construction and validation of a modified Waters nanoACQUITY HDX manager with a third temperature-controlled zone for peptide separations at subzero temperatures. A new Peltier-cooled door replaces the door of a traditional main cooling chamber and the separations and trapping column are routed through the door housing. To prevent freezing, 35% methanol is introduced post online digestion. No new pumps are required and online digestion is performed as in the past. Subzero separations, using conventional HPLC column geometry of 3 μ m particles in a 1 × 50 mm column, did not result in major changes to chromatographic efficiency when lowering the temperature from 0 to −20 °C. There were significant increases in deuterium recovery for both model peptides and biologically relevant protein systems. Given the higher levels of deuterium recovery, expanded gradient programs can be used to allow for higher chromatographic peak capacity and therefore the analysis of larger and more complex proteins and systems. [ABSTRACT FROM AUTHOR]

During the process of trial operation, a large number of solid blockages were formed in the low temperature separator of the natural gas processing plant of a high temperature and high pressure gas field in West China, which caused the blocking of the processing device. Based on the analysis, it was concluded that the major components of solid phase deposition materials were C12 - C14. When the operating pressure of the device was 6.85 MPa> the temperature of the device was reduced to - 9.5 °C, the solid crystal was directly precipitated in the gas phase, and the low temperature separator was blocked. The results of field test showed that the temperature of the low temperature separator could be increased appropriately to reduce the formation of solid phase deposition materials to a certain extent, but still couldn't solve the blockage problem of solid phase deposition completely. Combined with the injection of light hydrocarbons, the solid phase deposition could be effectively removed. [ABSTRACT FROM AUTHOR]

• Chromatographic systems with higher back pressure limits improve HDX MS. • Faster flow rate at 0 °C means more back pressure but better peak capacity. • At higher flow rate, separation time can be reduced without sacrificing performance. • Higher flow rate and shorter separation reduce back exchange in HDX MS. Reversed-phase peptide separation in hydrogen deuterium exchange (HDX) mass spectrometry (MS) must be done with conditions where the back exchange is the slowest possible, the so-called quench conditions of low pH and low temperature. To retain maximum deuterium, separation must also be done as quickly as possible. The low temperature (0 °C) of quench conditions complicates the separation and leads primarily to a reduction in separation quality and an increase in chromatographic backpressure. To improve the separation in HDX MS, one could use a longer gradient, smaller particles, a different separation mechanism (for example, capillary electrophoresis), or multi-dimensional separations such as combining ion mobility separation with reversed-phase separation. Another way to improve separations under HDX MS quench conditions is to use a higher flow rate where separation efficiency at 0 °C is more ideal. Higher flow rates, however, require chromatographic systems (both pumps and fittings) with higher backpressure limits. We tested what improvements could be realized with a commercial UPLC/UHPLC system capable of ∼20,000 psi backpressure. We found that a maximum flow rate of 225 µL/min (using a 1 × 50 mm column packed with 1.8 µm particles) was possible and that higher flow rate clearly led to higher peak capacity. HDX MS analysis of both simple and particularly complex samples improved, permitting both shorter separation time, if desired, and providing more deuterium recovery. [ABSTRACT FROM AUTHOR]

This paper describes the status of various carbon capture technologies investigated and outlines challenges and opportunities of carbon capture in gas turbine power generation for enhanced oil recovery (EOR). Technical achievements, maturity, drivers, barriers and gaps in knowledge are described for four technologies: novel chemical solvents and processes, low temperature separation, membranes and exhaust gas recirculation (EGR) in gas turbines. As a near-term application, carbon capture in gas turbine power generation for enhanced oil recovery (EOR) is analyzed and drivers, requirements and challenges are outlined. The paper is structured as follows: the first section describes the current global status of carbon capture and storage (CCS), second section explains the approach followed in the paper, third section presents a literature review, fourth section provides a technical analysis of the focus technologies, fifth section describes challenges and opportunities of carbon capture from gas turbines for CO 2 -EOR applications and finally sixth section provides conclusions. [ABSTRACT FROM AUTHOR]