scholarly journals COMPRESSOR PUMP UNIT FOR CO2 LIQUIDATION AND SUPPLY IT FOR CARBAMIDE SYNTHESIS

2020 ◽  
pp. 41-49
Author(s):  
G.K. Lavrenchenko ◽  
B.H. Hrudka
Keyword(s):  
Carbon Dioxide ◽  
Energy Consumption ◽  
Specific Energy ◽  
Large Scale ◽  
Liquid Ammonia ◽  
Specific Energy Consumption ◽  
Urea Synthesis ◽  
Compressor Unit ◽  
Synthesis Column ◽  
Cold Liquid

Carbon dioxide, as well as ammonia, are widely used in large-scale chemistry for the production of urea. Currently, the most common technology for producing carmabide is according to which liquid NH3 is pumped into the synthesis column by a pump at a pressure of 15 MPa, and gaseous CO2 is supplied by a compressor with the same pressure as ammonia. Gaseous CO2 is compressed in a multi-stage compressor to a pressure of 15 MPa before it enters the urea synthesis unit, in which it reacts with ammonia. The specific energy consumption for compressing carbon dioxide in a compressor unit is 0.13 kWh/kg. Reducing energy for producing CO2 and also urea can be achieved when it is possible to supply carbon dioxide in liquid form under a pressure of 15 MPa to the urea synthesis column. The analysis showed that to solve this problem it is necessary to implement two processes: compression to 1.8–3.0 MPa, and then cooling and liquefaction of gaseous CO2 due to the cold of liquid ammonia. Liquefied CO2 can then be pumped to the urea column. In order to introduce carbamide into production, a new carbon dioxide compressor and pumping unit has been created. The installation scheme for compressing CO2 to a pressure of 15 MPa and its subsequent supply to the production of urea is given. A cold liquid ammonia stream with an initial temperature of –30 °C is used as a source of cold in the installation. The performance and power consumption of the compressor unit depend on the compression pressure of CO2. After the CO2 is compressed to 1.8 MPa, it is possible to cool 2.3 t/h of carbon dioxide with cold liquid ammonia and then direct it to the synthesis of urea using a pump under a pressure of 15 MPa. The specific energy consumption in the installation will be 0.1 kWh/kg. When CO2 is compressed up to 3 MPa, the plant capacity is 8.78 t/h, and the unit costs are 0,108 kWh/kg. Urea production in this case may increase from 1400 to 1680 t/day. Ref. 5, Fig. 3, Tab. 3.

scholarly journals INCREASING THE EFFICIENCY OF THE SYSTEMS OF COMPRESSOR-PUMPING AND REFRIGERATION UNITS SUPPLYING LIQUID CO2 AND NH3 TO THE UNIT FOR CARBAMIDE SYNTHESIS

2021 ◽  
pp. 23-32
Author(s):  
G.K. Lavrenchenko ◽  
B.H. Hrudka
Keyword(s):  
Carbon Dioxide ◽  
Energy Consumption ◽  
Specific Energy ◽  
Specific Energy Consumption ◽  
Stable Operation ◽  
Urea Synthesis ◽  
Daily Production ◽  
Additional Absorption ◽  
Liquid Co2 ◽  
Refrigeration Machine

Carbon dioxide is used in large volumes to produce urea, a highly efficient nitrogen fertilizer. It is compressed in a multistage compressor to a pressure of 15 MPa and fed to the urea synthesis unit. The specific energy consumption for the compression of carbon dioxide by a compressor reaches 0.16 kWh/kg. It may be more profitable to use in the system of compressor-pumping and refrigeration units. They can be used to liquefy carbon dioxide and compress it to pressure 15 MPa before feeding it to the synthesis of urea. In the simplest scheme, an ammonia compression refrigeration machine (ACRM) is included in the system to improve efficiency. The specific energy consumption in such a system for the liquefaction and compression of CO2 is 0.118 kWh/kg. In case of replacement of the ACRM with an absorption refrigeration machine, unit costs can be reduced to 0.09 kWh/kg. These two systems can be used to increase urea production or to ensure stable operation of the units during the summer period of their operation. The analysis showed that further improvement of the technological scheme of the entire system will completely abandon the use of the compressor method of compression of CO2 to pressure 15 MPa before its supply to the urea synthesis unit. To do this, you need to include an additional absorption lithium bromide refrigeration machine in the system. In this scheme, the compressor-pumping unit will provide the simultaneous supply of liquid carbon dioxide and ammonia for the synthesis of urea with a pressure of 15 MPa. To increase the daily production of urea from 1400 to 2000 tons, it is necessary to increase the feed liquid CO2 in the amount of 62 t/hour and liquid NH3 — 47.5 t/hour. Bibl. 14, Fig. 3.

Determination of grinding parameters of fenugreek seed

1970 ◽  
Vol 26 (1) ◽  
pp. 16 ◽  
Author(s):  
S Balasubramanian ◽  
Rajkumar Rajkumar ◽  
K K Singh
Keyword(s):  
Particle Size ◽  
Energy Consumption ◽  
Moisture Content ◽  
Specific Energy ◽  
Feed Rate ◽  
Average Particle Size ◽  
Specific Energy Consumption ◽  
Average Particle ◽  
Fenugreek Seeds ◽  
Fenugreek Seed

Experiment to identify ambient grinding conditions and energy consumed was conducted for fenugreek. Fenugreek seeds at three moisture content (5.1%, 11.5% and 17.3%, d.b.) were ground using a micro pulverizer hammer mill with different grinding screen openings (0.5, 1.0 and 1.5 mm) and feed rate (8, 16 and 24 kg h-1) at 3000 rpm. Physical properties of fenugreek seeds were also determined. Specific energy consumptions were found to decrease from 204.67 to 23.09 kJ kg-1 for increasing levels of feed rate and grinder screen openings. On the other hand specific energy consumption increased with increasing moisture content. The highest specific energy consumption was recorded for 17.3% moisture content and 8 kg h-1 feed rate with 0.5 mm screen opening. Average particle size decreased from 1.06 to 0.39 mm with increase of moisture content and grinder screen opening. It has been observed that the average particle size was minimum at 0.5 mm screen opening and 8 kg h-1 feed rate at lower moisture content. Bond’s work index and Kick’s constant were found to increase from 8.97 to 950.92 kWh kg-1 and 0.932 to 78.851 kWh kg-1 with the increase of moisture content, feed rate and grinder screen opening, respectively. Size reduction ratio and grinding effectiveness of fenugreek seed were found to decrease from 4.11 to 1.61 and 0.0118 to 0.0018 with the increase of moisture content, feed rate and grinder screen opening, respectively. The loose and compact bulk densities varied from 219.2 to 719.4 kg m-3 and 137.3 to 736.2 kg m-3, respectively.  

scholarly journals Bibliometric Analysis of Specific Energy Consumption (SEC) in Machining Operations: A Sustainable Response

2021 ◽  
Vol 13 (10) ◽  
pp. 5617
Author(s):  
Raman Kumar ◽  
Sehijpal Singh ◽  
Ardamanbir Singh Sidhu ◽  
Catalin I. Pruncu
Keyword(s):  
Energy Consumption ◽  
Bibliometric Analysis ◽  
Specific Energy ◽  
Specific Energy Consumption ◽  
Primary Data ◽  
Data Content ◽  
Author Keywords ◽  
Link Strength ◽  
Inclusive Analysis ◽  
Machining Operations

This paper’s persistence is to make an inclusive analysis of 268 documents about specific energy consumption (SEC) in machining operations from 2001 to 2020 in the Scopus database. A systematic approach collects information on SEC documents’ primary data; their types, publications, citations, and predictions are presented. The VOSviewer 1.1.16 and Biblioshiny 2.0 software are used for visualization analysis to show the progress standing of SEC publications. The selection criteria of documents are set for citation analysis. The ranks are assigned to the most prolific and dominant authors, sources, articles, countries, and organizations based on the total citations, number of documents, average total citation, and total link strength. The author-keywords, index-keywords, and text data content analysis has been conducted to find the hotspots and progress trend in SEC in machining operations. The most prolific and dominant article, source, author, organization, and country are Anderson et al. “Laser-assisted machining of Inconel 718 with an economic analysis”, the Int J Mach Tools Manuf, Shin Y.C., form Purdue University Singapore, and United States, respectively, based on total citations as per defined criteria. The author keywords “specific cutting energy” and “surface roughness” dominate the machining operations SEC. SEC’s implication in machining operations review and bibliometric analysis is to deliver an inclusive perception for the scholars working in this field. It is the primary paper that utilizes bibliometric research to analyze the SEC in machining operations publications expansively. It is valuable for scholars to grasp the hotspots in this field in time and help the researchers in the SEC exploration arena rapidly comprehend the expansion status and trend.

scholarly journals Batch Reverse Osmosis Desalination Modeling under a Time-Dependent Pressure Profile

Membranes ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 173
Author(s):  
Abdeljalil Chougradi ◽  
François Zaviska ◽  
Ahmed Abed ◽  
Jérôme Harmand ◽  
Jamal-Eddine Jellal ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Reverse Osmosis ◽  
Specific Energy ◽  
Energy Demand ◽  
Specific Energy Consumption ◽  
Pressure Profile ◽  
Recovery Ratio ◽  
Feed Concentration ◽  
Energetic Performance ◽  
Feed Volume

As world demand for clean water increases, reverse osmosis (RO) desalination has emerged as an attractive solution. Continuous RO is the most used desalination technology today. However, a new generation of configurations, working in unsteady-state feed concentration and pressure, have gained more attention recently, including the batch RO process. Our work presents a mathematical modeling for batch RO that offers the possibility of monitoring all variables of the process, including specific energy consumption, as a function of time and the recovery ratio. Validation is achieved by comparison with data from the experimental set-up and an existing model in the literature. Energetic comparison with continuous RO processes confirms that batch RO can be more energy efficient than can continuous RO, especially at a higher recovery ratio. It used, at recovery, 31% less energy for seawater and 19% less energy for brackish water. Modeling also proves that the batch RO process does not have to function under constant flux to deliver good energetic performance. In fact, under a linear pressure profile, batch RO can still deliver better energetic performance than can a continuous configuration. The parameters analysis shows that salinity, pump and energy recovery devices efficiencies are directly linked to the energy demand. While increasing feed volume has a limited effect after a certain volume due to dilution, it also shows, interestingly, a recovery ratio interval in which feed volume does not affect specific energy consumption.

scholarly journals Kinetics of Microcystin-LR Removal in a Real Lake Water by UV/H2O2 Treatment and Analysis of Specific Energy Consumption

Toxins ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 810
Author(s):  
Sabrina Sorlini ◽  
Carlo Collivignarelli ◽  
Marco Carnevale Miino ◽  
Francesca Maria Caccamo ◽  
Maria Cristina Collivignarelli
Keyword(s):  
Energy Consumption ◽  
Specific Energy ◽  
Lake Water ◽  
Harmful Effect ◽  
Specific Energy Consumption ◽  
World Health ◽  
Oh Radicals ◽  
H2o2 Treatment ◽  
Initial Concentration ◽  
Kinetics Of

The hepatotoxin microcystin-LR (MC-LR) represents one of the most toxic cyanotoxins for human health. Considering its harmful effect, the World Health Organization recommended a limit in drinking water (DW) of 1 µg L−1. Due to the ineffectiveness of conventional treatments present in DW treatment plants against MC-LR, advanced oxidation processes (AOPs) are gaining interest due to the high redox potential of the OH• radicals. In this work UV/H2O2 was applied to a real lake water to remove MC-LR. The kinetics of the UV/H2O2 were compared with those of UV and H2O2 showing the following result: UV/H2O2 > UV > H2O2. Within the range of H2O2 tested (0–0.9 mM), the results showed that H2O2 concentration and the removal kinetics followed an increasing quadratic relation. By increasing the initial concentration of H2O2, the consumption of oxidant also increased but, in terms of MC-LR degraded for H2O2 dosed, the removal efficiency decreased. As the initial MC-LR initial concentration increased, the removal kinetics increased up to a limit concentration (80 µg L−1) in which the presence of high amounts of the toxin slowed down the process. Operating with UV fluence lower than 950 mJ cm−2, UV alone minimized the specific energy consumption required. UV/H2O2 (0.3 mM) and UV/H2O2 (0.9 mM) were the most advantageous combination when operating with UV fluence of 950–1400 mJ cm−2 and higher than 1400 mJ cm−2, respectively.

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