Ammonia is a highly liquid product that is used for the production of mineral fertilizers, explosives and polymers, nitric acid and other chemical products. The discovery of the reaction of its synthesis and commercial production using Haber-Bosch process became an outstanding achievement of the chemical science and industry at the beginning of the 20th century. At present, ammonia production technologies, while continuing to develop, have practically reached their perfection. Various technologies of ammonia production are considered in the paper; their characteristics are given. Megammonia technology, developed by the company «Casale» in conjunction with the company «Lurgi» is the most promising one. It allows building large-capacity ammonia aggregates in one technological line with a capacity of 5000 tons/day and above. Advantages of Megammonia technology make it possible to create units with low energy consumption, reaching 6,4 Gcal / ton of ammonia. As a result, the cost of production of ammonia can be reduced by 40 % compared to traditional technologies.

Front-end purification units (FEPUs) are a part of modern air separation units (ASUs). The quality of air purification from impurities significantly affects both the performance of ASUs and the provision of their safe operation. FEPUs are being constantly improved as new and more effective adsorbents are being used. Implementation of technological regulations of the process of adsorbent regeneration can significantly prolong its service life. However, there comes a time when you need to replace the existing adsorbents. Processes of adsorption of water and carbon dioxide using various adsorbents are considered in the paper; factors reducing their adsorption capacity are mentioned; characteristics of new types of adsorbents are presented. By analyzing the characteristics of the adsorbents used for air drying and its purification from CO2, we have selected the most efficient zeolite 13X APG-III, manufactured by «Honeywell UOP». The adsorbent is a molecular sieve with the adsorption capacity for CO2 1.7 times higher than the standard zeolite 13X. This allows its use to replace the exhausted adsorbent while achieving a number of advantages.

Intensification of large-capacity carbamide (urea) production is a vital task now. One of the factors restraining the increase in the production of carbamide (urea) is the insufficient flow rate capacity of the granulation tower. In the tower, outside air is supplied from below to cool free falling droplets of carbamide( urea) melt. At high temperatures of the environment, during the summer period, there is a decrease in urea production in the tower. The influence of air drying and cooling on the increase in carbamide (urea) yield and its quality improvement has been studied. The system of cooling and drying of external air, supplied to the tower, in a hollow water jet nozzle has been developed.The calculations show that the proposed system can, firstly, ensure the stable operation of the tower whereby the annual production of carbamide (urea) increases by 40 thousand tons, and secondly, it will allow creating new high-performance granulation towers based on the same axial blow fan K-664 A.

To use efficient technology «Carbon Capture and Storage» the issue of incorporating cryogenic air separation plants that produce oxygen into the large thermal power plants is considered in the paper. New projects provide for the use of «Oxyfuel Combustion Capture» technology to produce clean energy, followed by the preparation of carbon dioxide for deposition or for the manufacture of products based on it. As a result, energy production is always accompanied by the acquisition and use of air separation products. In the process of implementing «Cryogenic Energy Storage» technology, oxygen is used both to keep up the fuel combustion process and to store energy in the form of a cryogenic fluid. This makes it possible to solve complex problems related to the provision of peak energy consumption during the day, while reducing the specific energy consumption to produce oxygen and increasing the efficiency of the steam turbine. Cryogenic technologies are also used in plants for the effective CO2 removal from flue gases. The paper examines main circuit and technological solutions used in the development and implementation of such projects.

The efficiency of a large-capacity ammonia refrigeration plant (ARP) with an air condenser depends on many factors. Changes in some of them in the condenser with a collector circuit lead to additional hydraulic resistances within the system. They are caused by ambient temperature changes, the accumulation of non-condensable gases in the system, the design features of the condenser and the uneven distribution of ammonia in the condenser coils. All this causes a pressure increase in the condenser and, consequently, excess demand energy, which is explained by the presence of non-condensable gases (NCG) in the system. The latter, in its turn, leads to the unnecessary more frequent opening of NCG relief valves, which results in a significant loss of ammonia. The reasons for the emergence of additional hydraulic resistances on the example of large-capacity ARP have been researched. The basic reasons for changing the operating parameters of the refrigeration unit, indicating the presence of NCG or the occurrence of resistance in the hydraulic system, worsening the drain of liquid ammonia from the condenser to the receiver have been determined. In order to stabilize the operation of ARP with an air cooled condenser and to reduce the resulting hydraulic resistance, as well as ammonia losses, we have developed and explained new algorithms of gas flaring and operating modes of air cooling fans that reduce the loss of ammonia by 10 times and the hydraulic resistance in the air condenser by 30 kPa.

The efficiency of an ammonia refrigeration unit (ARU) depends on many factors. Changes of some of them result in thermal hydraulic oscillations arising within the system. They are caused by changes in ambient temperature, the performance of the compressor and condenser. All this leads to the pressure increase in the condenser and, consequently, to the excessive energy consumption, which is perceived as the presence of non-condensable gases (NCG) in the system. This brings about more frequent opening of NCG relief valves, resulting in a substantial loss of ammonia. Causes of the appearance and self-destruction of thermal hydraulic oscillations on the example of a large-capacity ARU are researched. To reduce these oscillations are developed and justified the new algorithms and modes of operation of the fan air cooling, which reduce the amplitude of the pressure fluctuations in the air condenser at 30 kPa (0,3 bar).

The efficiency of an ammonia refrigeration unit (ARU) depends on many factors. Changes of some of them result in thermal-hydraulic oscillations arising within the system. They are caused by changes in ambient temperature, the performance of the compressor and condenser. All this leads to the pressure increase in the condenser and, consequently, to the excessive energy consumption, which is perceived as the presence of non-condensable gases (NCG) in the system. This brings about more frequent opening of NCG relief valves, resulting in a substantial loss of ammonia. To eliminate these fluctuations frequency and duration of opening/closing the NCG relief valves on the torch from high pressure receivers are developed. New algorithms and modes of operation of the NCG discharge valves on the torch which allow reducing the frequency of oscillation phenomena and the loss of ammonia by 10 times are developed and validated.

In the near future it is expected increasing a demand for liquefied natural gas (LNG) as the universal gas fuel for motor transport and agricultural machinery. Its efficient production can be organized on the basis of an automobile gas filling compressor station (AGFCS). To do this a station should be reconstructed to include in its composition of a natural gas liquefier (NGL). In NGL some equipment can use of the station as own operating time ratio is sometimes less than 40 %. However, the automobile filling stations can be created and based on independent NGS. At these stations, motor vehicles will be refueled or compressed NG (CNG) or LNG at presence of cryogenic fuel tanks. Several technological schemes of NGL with the work of their cycles by medium or high pressure have been considered. The analysis of the characteristics of NGL of medium pressure showed that for NGL regasification of obtained LNG for refueling of a natural gas of the motor cars specific costs in NGL will be 1,3 kWh/kg. NGL efficiency can be greatly improved with the organization of its work on a cycle of high pressure. In it the work of the turbo expander is used in a compressor stage of the unit for compressing the entire return flow of gas liquefier to the pressure of its absorption of 1,0 MPa in the high-pressure compressor. The specific costs in NGL of a high pressure can be reduced by two times, that is to 0,65 kWh/kg.The advantage of such NGL is the absence in their schemes of refrigerating machines.

Currently, in the process of manufacturing electric power at large thermal power plants, CCS (Carbon Capture and Storage) technology is used, which reduces carbon dioxide emissions into the atmosphere by 90 % in the process of burning different fuels. We considered three major CCS-technologies: «Post-combustion capture»; «Pre-combustion capture» and «Oxyfuel combustion capture». Decrease of CO2 emissions occurs due to the removal of carbon dioxide from combustion gases by means of chemical processes of absorption / desorption. We analyzed new efficient technologies of CO2 extraction from combustion gases, such as «Advanced Amines Process» and «Сhilled Ammonia Process». It was concluded that «Oxyfuel combustion capture», based on the combustion of fuel in pure oxygen with the simultaneous use of «Сhilled Ammonia Process» is the most advanced technology. It is possible to ensure a higher efficiency of large steam turbine plants by using thermochemical regeneration of heat of initial fuel with the simultaneous use of oxygen. This will allow manufacturing high-efficiency steam turbine plants (STP) with a complete CO2 capture, implementing the technology «Oxyfuel combustion» Absolute thermal efficiency of such STPs which equals 57,6 %, practically reaches the level of combined-cycle plants. In addition, oxygen required capacity of air separation plants will be from 3840 to 5600 t / day.

Air cooling units are widely used in the chemical industry for condensation of ammonia. Generally they are manufactured as per a special design. Air-condenser design features of a large-capacity ammonia refrigerating system and the actual performance of its work are considered. The effect of different modes of operation of fans on the efficiency of the condenser are established. Two algorithms of putting cooling air fans into operation are proposed. The first one involves their consequent putting into operation. First, all odd fans located first along the path of ammonia, and then the even ones. The second algorithm is characterized by first putting into operation even fans located second along the path of ammonia and then the odd ones. Fans are put into operation symmetrically from the center of the condenser. Analysis showed that the second algorithm of using fans is preferable. The practical application of the new algorithm will allow the fans to adjust the condenser heat load, to stabilize its performance and reduce power consumption for fan drive.

Currently, in order to reduce emissions of greenhouse gases into the environment in large thermal power plants use CCS-technology (Carbon Capture and Storage and Carbon Capture and Sequestration). This allows to reduce the growth rate of CO2 concentration in the atmosphere at a continuous increase in electricity production. In order to solve global problems need to be developed and widely adopted and other promising CCS-technology, but intended for direct removal of CO2 from the air. In this connection considered several innovative projects. The schemes, characteristics and description of the settings, realizing CCS-technology direct removal of CO2 from the air.

There is a growing interest in the problems of methane hydrates. Increased attention to them is caused by the abundant occurrence of hydrate containing reserves in seas and permafrost. High specific concentration of methane in hydrates (150 ... 180 volumes of methane per volume of water) and their shallow formation under the seabed starting from the depths of 300 ... 500 m allow us to consider natural hydrates as a real alternative to now mined various hydrocarbons. Despite a great number of discovered hydrate reserves, their industrial development has not been carried out yet. In the future, these resources will certainly be used. So far, only the first steps in the study of the geology of gas hydrate deposits have been made. Currently, however, there is a lot of interest in several developed advanced gas hydrate technologies. Transportation and storage of natural gas in a hydrate state are considered. Foreign experience shows that it allows a 25 % reduction in operating costs as compared with the delivery of natural gas in a liquefied form. Work on organizing methane extraction by means of its replacement by using CO2 is extremely relevant. In addition, the problem of a reliable disposal of carbon dioxide can be solved. Implementation of combined processes such as gas transportation from offshore fields to the mainland and delivery of CO2 gas hydrates for their burial at sea in the opposite direction has a great potential.

Indicators of ammonia refrigeration plant (ARP) depend on the efficiency of the condenser. The most affect the ARP with air condenser ammonia. They are designed with completely definite specified parameters that characterize his work in design mode. Created methodology for calculating the main indicators of a large condenser ARP when using it in the design conditions. It is allowed to analyze the characteristics of ARP when the ambient temperature changes. The results of calculations of a number of characteristics of the ammonia refrigeration plant showed good convergence with experimental data.

Спрос на электроэнергию является неравномерным. В связи с этим разрабатываются и применяются технологии, позволяющие создавать различные системы аккумулирования энергии. Цель таких систем — улучшение распределения и потребления электрической энергии в различные периоды времени. Рассматриваются основные технологии хранения энергии в виде воды (PSHE), компримированного воздуха (CAES) и криогенной жидкости (CES). Показано, что системы хранения энергии в виде жидкого воздуха LAES находят широкое применение и имеют относительно высокий коэффициент преобразования энергии, равный 60…70 %. С помощью CES-технологии можно создавать виртуальную криогенную трубу для резервирования энергии и её потребления в короткий промежуток времени.

На показатели работы аммиачной холодильной установки влияет наличие инертов — неконденсируемых газов, которые накапливаются в конденсаторе и ресивере. Увеличение их концентрации приводит к снижению коэффициента теплопередачи конденсатора в 3…5 раз, повышению давления конденсации аммиака на 1…3 бара и перерасходу потребляемой энергии на 7 %. Удаление инертов позволяет снизить энергопотребление холодильной установки, но при этом теряется часть аммиака. Рассмотрены различные системы удаления неконденсируемых газов, а также места их скопления и установки продувочных вентилей. Приведены примеры подключения автоматических отделителей инертов. Отмечена целесообразность проведения многоточечного автоматического удаления инертов.

The performance of the ammonia refrigeration installation is influenced by the presence of inerts — non-condensable gases that are accumulated in the condenser and the receiver. The increase in the gases concentration leads to an increase in the pressure of ammonia condensation by 0,1-0,3 MPa and to excessive energy consumption by 7%. The inerts removal using deaeration systems reduces energy consumption of the refrigeration installation, but at the same time some ammonia is lost. Various deaeration systems of ammonia refrigeration installations have been considered. It is shown that constant flowage of the condensers and receivers of the installation can be ensured with full return of ammonia in liquid form to the receiver.

Atmospheric air and water are effective and accessible agents which allow to provide heat removal from the technological equipment into the surrounding environment. For many installations, which operate practically all the year round, the summer period is critical due to a rise in temperature in the surrounding environment. To stabilize the operation of the heat exchange equipment during this period the temperature of the return water should be kept at the level not higher than 28 °C. Various processes of water and air cooling in the contact devices — mechanical draft cooling towers have been considered. The analysis of changes in the parameters of atmospheric air which should be kept in the cooling tower to cool a circulating water has been made. It has been shown that the limiting temperature of water cooling and the temperature differences are determined by the preliminary way of water cooling and the atmospheric air parameters. The most efficient way of water cooling is a combined indirect evaporative air cooling before feeding it into the cooling tower. It allows to cool the circulating water of the recirculation system up to the temperatures close to the dew point temperature of 17...22 °C.

В состав производств технических газов входит теплообменное оборудование, нуждающее в регулярной очистке от различных видов загрязнений. Загрязнения существенно влияют на эффективность работы теплообменного оборудования. Увеличение слоя накипи на 0,1…0,3 мм приводит к снижению коэффициента теплопередачи в 2,5 раза. При этом относительная эффективность работы теплообменника составляет 60…70 %. Для восстановления экономичной работы теплообменников необходимо периодически выполнять очистку поверхностей теплообмена от загрязнений. Рассмотрен комплекс технологий и методов по борьбе с отложениями различного характера и происхождения. Описаны основные этапы выполнения работ и даны рекомендации по выбору химических реагентов и технологическому режиму их применения.

В настоящее время развивается технология «Carbon Capture and Storage», для осуществления которой необходимо включать криогенные воздухоразделительные установки, производящие кислород, в состав крупных теплоэлектростанций. В новых проектах предусматривают использование технологии «Oxyfuel combustion» для производства чистой энергии с последующей подготовкой диоксида углерода к депонированию. В результате производство энергии обязательно сопровождается получением продуктов разделения воздуха. Кислород используется как для поддержания процесса горения топлива, так и для аккумулирования энергии в виде криогенной жидкости. Это позволяет решать комплекс задач, связанных с обеспечением пикового потребления энергии в дневное время с одновременным снижением удельных энергозатрат на производство кислорода. Криогенные технологии также используются в установках для эффективного извлечения СО2 из дымовых газов. В работе рассматриваются основные схемные и технологические решения, применяемые при разработке и реализации таких проектов.

Carbon dioxide is a marketable product. Large quantities of the product are used for carbamide production. The designs of two installations for obtaining liquid low-temperature СO2 in the cycle of medium pressure with subsequent feeding it into the units of carbamide synthesis are considered. In the first one for СО2 condensation the use of the liquid ammonia cold has been suggested; in the second one - the cold of an absorptive ammonia-water refrigerating unit has been proposed. Liquid carbon dioxide from these installations is moved by the pump to the carbamide production unit. The specific power inputs for carbon dioxide liquefaction and feeding with the pressure level of 15 MPa in both installations were lower by 25 % than in the compressor lines used nowadays.