Enhanced oxidation of MgSO3 during desulfurization by a novel spray method in magnesium-based seawater exhaust gas clean system

2017 ◽  
Vol 231 (4) ◽  
pp. 871-876
Author(s):  
Quan Liu ◽  
Meijun Sun ◽  
Tianliang Zhang ◽  
Yimin Zhu
Keyword(s):  
Oxidation Rate ◽  
Oxidation Mechanism ◽  
Aeration Tank ◽  
Exhaust Gas ◽  
Oxidation Method ◽  
Marine Diesel ◽  
Clean System ◽  
Desulfurization Process ◽  
Oxidation Efficiency ◽  
The Cost

The magnesium-based seawater exhaust gas clean system is effective in reducing sulfur dioxide emission from marine diesel engines. Oxidation of the desulfurization by-product, magnesium sulfite (MgSO3), is required for recycling. However, the oxidation efficiency is generally low in the aeration tank after the desulfurization process, making the tank volume too large for practical use on ocean vessels. In this article, we propose a novel spray oxidation method to enhance the oxidation of MgSO3 during the desulfurization process. The effects of MgSO3 content, pH and temperature on the oxidation rate were investigated. The results showed that the spray oxidation rate of MgSO3 was 1.5 order with respect to the MgSO3 concentration under both unsaturated and saturated conditions of MgSO3 solution, which is different from the aeration oxidation researches. The spray oxidation rate decreased with the increase in pH and raised slowly as the temperature increased. The MgSO3 oxidation mechanism of the spray oxidation method was analyzed and discussed in comparison with the traditional bubble aeration method. The novel spray oxidation method is effective in reducing the cost of the subsequent MgSO3 aeration oxidation process and the offprint of aeration tanks, thus is promising to be applied on ocean vessels.

Modeling and prediction for the oxidation efficiency of magnesium sulfite in aeration tank of magnesium-based seawater exhaust gas clean system

2017 ◽  
Vol 233 (1) ◽  
pp. 164-173
Author(s):  
Quan Liu ◽  
Yimin Zhu ◽  
Tie Li ◽  
Xiaojia Tang ◽  
Weifeng Liu ◽  
...  
Keyword(s):  
Flow Field ◽  
Initial Conditions ◽  
Negative Impact ◽  
Fluid Model ◽  
Aeration Tank ◽  
Exhaust Gas ◽  
Clean System ◽  
Physics Modeling ◽  
Set Up ◽  
Oxidation Efficiency

In magnesium-based seawater exhaust gas clean system, the desulfurization by-product, magnesium sulfite (MgSO3), has a negative impact on the ecological environment, which needs to be treated to make harmless. Due to the limited space on board, the aeration oxidation method is used to convert it to magnesium sulfate. Because of the variable size, shape and flow field of aeration tank, it is difficult and expensive to design and verify the oxidation efficiency of the aeration tank by experimental method. In this work, in order to predict the oxidation efficiency accurately, RFlow, a computational fluid dynamics software, was used to analyze the flow field and MgSO3 oxidation reaction in aeration tank. The subdomain technology was adopted for physics modeling and mesh generation of the aeration tank, and the total number of meshes was 285,000. The multi-phase flow field model was set up using the multi-fluid model and dispersive k-ε turbulence model. Under the given initial conditions, the predicted oxidation efficiency was 94.2%. Compared with the results of the actual ship test, the prediction model for MgSO3 oxidation efficiency of the aeration tank is reliable.

A Home-Made Automatic Analyzer to Determine the Dissolved Organic Carbon in Seawater

2011 ◽  
Vol 199-200 ◽  
pp. 1819-1822
Author(s):  
Li Ju Tan ◽  
Jiang Tao Wang ◽  
Yue Li
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Inorganic Carbon ◽  
Visual Basic ◽  
Potassium Persulphate ◽  
Temperature Oxidation ◽  
Oxidation Method ◽  
Automatic Analyzer ◽  
Oxidation Efficiency ◽  
The Cost

A home-made automatic analyzer to determine the dissolved organic carbon (DOC) in seawater was introduced in this paper. This analyzer was based on ultraviolet-potassium persulphate oxidation method. The analyzer has 7 parts, including sampling, purging of inorganic carbon, enter sample, oxidation, cooling, apart of gas/liquid and analysis of CO2. The program was compiled by programming language of Visual Basic as the control system. All of the action of the analyzer is auto controlled. Different samples are separated by worked air and Milli-Q water and enter the system using six-way valve. With the catalysis of ultraviolet radiation, the organic matter in samples can be oxidated to CO2quantitatively by K2SO2O8and analyzed by non-dispersive infrared (NDIR) detector latter. The results showed that the oxidation efficiency, as well as the detect limit and the veracity are satisfying. The home-made analyzer was compared with the high temperature oxidation method, and the results showed that the two methods have little difference. The cost of the instrument is cheaper, and need not expensive catalyst, so the DOC in seawater can be analyzed with much lower prices.

scholarly journals Measurement methods of total organic carbon in seawater

2021 ◽  
Vol 233 ◽  
pp. 01078
Author(s):  
Shuwei Zhang ◽  
Zhaoyu Wang ◽  
Xuejiao Yan ◽  
Jing Wang ◽  
Li Zhang ◽  
...  
Keyword(s):  
High Temperature ◽  
Organic Carbon ◽  
Total Organic Carbon ◽  
Water Oxidation ◽  
Combustion Method ◽  
Oxidation Method ◽  
Persulfate Oxidation ◽  
Temperature Combustion ◽  
Oxidation Efficiency ◽  
High Temperature Combustion

Total organic carbon (TOC) can reflect the total amount of organic matter in water. This paper introduces the common methods of measuring organic carbon, including high temperature combustion method, potassium persulfate oxidation method, spectrometry, ozone oxidation chemiluminescence method, supercritical water oxidation method and so on. At present, high temperature combustion method is the most widely used method for TOC measurement in seawater, because of its high oxidation efficiency. TOC sensor needs to be developed to realize in-situ and long-term monitoring.

Lubricant Flow Optimization of Large Two Stroke Marine Diesel Engine Piston Ring Packs

2016 ◽  
Author(s):  
Matthias Stark ◽  
Richard Mittler
Keyword(s):  
Piston Ring ◽  
Superior Performance ◽  
Exhaust Gas ◽  
Oil Consumption ◽  
Major Step ◽  
Oil Transportation ◽  
Lubrication Performance ◽  
Marine Diesel ◽  
Piston Ring Pack ◽  
Ring Pack

Approaching a characterization of different contributors to the lube oil balance of an engine becomes important when aiming at enhancing lubrication performance and reducing its contribution to exhaust gas emissions. It is essential to quantify relevant data helping to determine lubrication losses related to particular tribosystem components. Recent activities focused on rating distinct tribosystem component effects on their contribution to total lube oil consumption and the possibility to most effectively modify those. This paper thus describes the most effective tribosystem component modifications, consisting of the application of a substantially modified piston ring pack and the introduction of lube oil accumulating grooves in order to considerably enhance lubrication performance. A proper prediction of piston ring pack dynamics and tribodynamic effects on the lube oil film is essential to design a superior piston ring pack in terms of an optimized piston running behaviour and lube oil transportation. One major step designing such a ring pack is based on the consequent application of a novel 3D piston ring pack simulation tool to enhance lube oil transportation characteristics and distribution. Lube oil accumulating grooves are introduced to reduce lubrication losses due to so called ring pack spray. The ring pack spray is a result of accumulated lubricant in the pressurized piston ring pack expanding into the scavenge air receiver during the scavenging phase. Mentioned effect was analysed in detail in order to determine the amount of related lubricant losses. Investigations in this context lead to the application of lube oil accumulating grooves and hence can be considered an important design aspect to reduce total lube oil consumption. Tribosystem performance validation was performed on the basis of the application of an SO2 tracing technology on a full scale engine test in order to determine relevant tribosystem component modifications in real time. The sulphur content of fuel and lube oil considerably influences the formation of particulate matter in the exhaust gas, following chemical reactions of sulphur oxidation. Hence detecting SO2 in the exhaust gas is a direct measure to determine the amount of lubricant in the exhaust gas composition. Finally this report demonstrates measurement results describing the superior performance of the modified tribosystem.

scholarly journals Thermo-economic comparative analysis of gas turbine GT10 integrated with air and steam bottoming cycle

2014 ◽  
Vol 35 (4) ◽  
pp. 83-95 ◽  
Author(s):  
Daniel Czaja ◽  
Tadeusz Chmielnak ◽  
Sebastian Lepszy
Keyword(s):  
Economic Analysis ◽  
Gas Turbine ◽  
Power Plants ◽  
Combined Cycle ◽  
Small Range ◽  
Exhaust Gas ◽  
Thermodynamic Optimization ◽  
Technological Structure ◽  
The Cost ◽  
Selection Of

Abstract A thermodynamic and economic analysis of a GT10 gas turbine integrated with the air bottoming cycle is presented. The results are compared to commercially available combined cycle power plants based on the same gas turbine. The systems under analysis have a better chance of competing with steam bottoming cycle configurations in a small range of the power output capacity. The aim of the calculations is to determine the final cost of electricity generated by the gas turbine air bottoming cycle based on a 25 MW GT10 gas turbine with the exhaust gas mass flow rate of about 80 kg/s. The article shows the results of thermodynamic optimization of the selection of the technological structure of gas turbine air bottoming cycle and of a comparative economic analysis. Quantities are determined that have a decisive impact on the considered units profitability and competitiveness compared to the popular technology based on the steam bottoming cycle. The ultimate quantity that can be compared in the calculations is the cost of 1 MWh of electricity. It should be noted that the systems analyzed herein are power plants where electricity is the only generated product. The performed calculations do not take account of any other (potential) revenues from the sale of energy origin certificates. Keywords: Gas turbine air bottoming cycle, Air bottoming cycle, Gas turbine, GT10

Maintaining Marine Diesel Emissions Using Performance Monitoring

2010 ◽  
Author(s):  
Herbert Roeser ◽  
Dilip Kalyankar
Keyword(s):  
Diesel Engine ◽  
Performance Monitoring ◽  
Fuel Oil ◽  
Exhaust Gas ◽  
Gas Emission ◽  
Heavy Fuel Oil ◽  
Tier Ii ◽  
Technological Advances ◽  
Exhaust Gas Emission ◽  
Marine Diesel

Ships are an integral part of modern commercial transport, leisure travel, and military system. A diesel engine was used for the first time for the propulsion of a ship sometime in the 1910s and has been the choice for propulsion and power generation, ever since. Since the first model used in ship propulsion, the diesel engine has come a long way with several technological advances. A diesel engine has a particularly high thermal efficiency. Added to it, the higher energy density of the diesel fuel compared to gasoline fuel makes it inherently, the most efficient internal combustion engine. The modern diesel engine also has a very unique ability to work with a variety of fuels like diesel, heavy fuel oil, biodiesel, vegetable oils, and several other crude oil distillates which is very important considering the shortage of petroleum fuels that we face today. In spite of being highly efficient and popular and in spite of all the technological advances, the issue of exhaust gas emissions has plagued a diesel engine. This issue has gained a lot of importance since 1990s when IMO, EU, and the EPA came up with the Tier I exhaust gas emission norms for the existing engine in order to reduce the NOx and SOx. Harsher Tier II and Tier III norms were later announced for newer engines. Diesel fuels commonly used in marine engines are a form of residual fuel, also know as Dregs or Heavy Fuel Oil and are essentially the by products of crude oil distillation process used to produce lighter petroleum fuels like marine distillate fuel and gasoline. They are cheaper than marine distillate fuels but are also high in nitrogen, sulfur and ash content. This greatly increases the NOx and SOx in the exhaust gas emission. Ship owners are trapped between the need to use residual fuels, due to cost of the large volume of fuel consumed, in order to keep the operation of their ships to a competitive level on one hand and on the other hand the need to satisfy the stringent pollution norms as established by the pollution control agencies worldwide. Newer marine diesel engines are being designed to meet the Tier II and Tier III norms wherever applicable but the existing diesel engine owners are still operating their engines with the danger of not meeting the applicable pollution norms worldwide. Here we make an effort to look at some of the measure that the existing marine diesel engine owners can take to reduce emissions and achieve at least levels prescribed in Tier I. Proper maintenance and upkeep of the engine components can be effectively used to reduce the exhaust gas emission. We introduced a pilot program on diesel engine performance monitoring in North America about two years ago and it has yielded quite satisfying results for several shipping companies and more and more ship owners are looking at the option of implementing this program on their ships.

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