Ship Exhaust Gas Research Articles

Simultaneous measurement of SO2 and CO2 for sulfur content detection in marine diesel fuel using QCL absorption spectroscopy

Simultaneous measurement of CO2 and SO2 in ship exhaust gases is a common method for assessing compliance with sulfur emission standards. This study develops a new ship exhaust gas analyzer using time-division multiplexing of two quantum cascade lasers for simultaneous detection of the two gas species. A digital circuit integrated with a dual-channel waveform generator and a lock-in amplifier is developed to implement wavelength modulation spectroscopy (WMS) scheme. To enhance the measurement accuracy of SO2 with broadband absorption feature, a novel WMS approach that combines first-harmonic and normalized second-harmonic detection is introduced. A Kalman filter algorithm is employed to further refine the measurement precision. Experimental results show a 30.76% increase in detection accuracy. With a 1 s time resolution, the sensitivities of 13.4 ppb for SO2 and 9.81 ppm for CO2 are achieved. The effectiveness of the prototype for sulfur content detection is demonstrated, aiding emission management of water transport emissions.

Capture of Sulfur Dioxide in Ship Exhaust Gas by Tertiary Amine Absorbents

AbstractSulfur dioxide (SO2) emissions from ship exhausts pose serious health and environmental concerns. Herein, the SO2 absorption and desorption characteristics of tertiary amines with different functional groups were explored under simulated ship exhaust gas conditions. Tertiary amines with electron‐donating groups had superior absorption performance to those with electron‐withdrawing groups, and highly polar absorbents exhibited enhanced SO2 absorption loading. Dimethylaniline (DMA) showed excellent desorption performance, outperforming other absorbents (amino acids, ionic liquids, and deep eutectic solvents) in terms of cyclic capacity. Thus, tertiary amines, especially DMA, can be potentially used for the prevention of SO2 emissions from ship exhausts and other desulfurization applications.

Toxic effects of ship exhaust gas closed-loop scrubber wash water.

To meet the strict requirements of reducing sulfur emissions, an increasing number of commercial ships have installed exhaust gas cleaning systems (EGCSs). However, wash water produced during the cleaning process is discharged back to the marine environment. We investigated the effects of closed-loop scrubber (natrium-alkali method) wash water on three trophic species. Severe toxic effects were found when Dunaliella salina, Mysidopsis bahia, and Mugilogobius chulae were exposed to 0.63-6.25, 0.63-10, and 1.25-20% concentrations of wash water, respectively. The 50% effective concentration in 96h (EC50-96h) for D. salina was 2.48%, and the corresponding total polycyclic aromatic hydrocarbons (PAHs) and heavy metals were 22.81 and 23.67μg L-1. The 50% lethal concentration in 7d (LC50-7d) values for M. bahia and M. chulae were 3.57% and 20.50%, respectively. The lowest observed effect concentration (LOEC) values for M. bahia and M. chulae were 1.25% and 2.5%, respectively, and the corresponding total PAHs and heavy metals were 11.50 and 11.93 and 22.99 and 23.86μg L-1. M. bahia's body weight was negatively correlated with the amount of wash water. Low concentrations of wash water (0-5%) had no significant effect on the reproduction of M. bahia. Although concentrations of 16 PAHs and 8 heavy metals are known, different compounds might react with each other and form more unknown toxic substances, and the measured toxicity comes from synergistic effects between various pollutants. Therefore, future work is needed to clarify other more toxic contaminants in wash water. We highly recommend that wash water be treated before being discharged to the marine environment.

A new absorbent system for reducing chlorine gas escape and enhancing pollutants removal during ship exhaust wet scrubbing

Using chlorine-containing oxidants to remove pollutants in the exhaust gas of ships is normally accompanied by Cl2 escape, which poses a significant threat to the environment and the health of the crew. This paper proposes a method to solve the problem of Cl2 escape in a single NaClO solution system using BAD (a new amide absorbent, C12H25NO). The electrostatic potential (ESP) theoretical calculations, FT-IR and UV–vis spectra tests showed that the strong field effect interaction between BAD and Cl2, which can form a stable symmetrical structure similar to a “sandwich”, results in a strong binding ability of BAD to Cl2. The effects of the initial pH, the concentration of NaClO solution, aeration time, and some operating parameters on the loss of active chlorine (AC) components were studied. Under the same conditions, a two-phase composite absorbent system with the addition of BAD can reduce the loss of AC components by 32.67% on average and up to 56.12%. It also can effectively capture the Cl2 escaping with the gas flow and keep it in the system, which enhances the oxidation of NO by Cl2 at the gas–liquid interface. It also has a strong ability to remove pollutants for a long period, as the removal efficiencies of SO2, NO, and NOx within 20 mins were 97.84%, 77.98%, and 76.01%, respectively. The results show that the BAD-NaClO two-phase composite absorbent system can effectively reduce Cl2 escape, and it is a sustainable wet treatment scheme for ship exhaust gas with great application prospects.

The application of two-phase composite absorbent systems consisting of BAD and seawater resources in the wet treatment of ship exhaust gas

The impact of ship emissions on the environment cannot be ignored and should be controlled. The possibility of applying seawater electrolysis technology and a novel amide absorbent (BAD, C12H25NO) to the simultaneous desulfurization and denitrification of ship exhaust gas is entirely confirmed by using various seawater resources. Concentrated seawater (CSW) with high salinity can effectively reduce the heat generated during electrolysis and the escape of chlorine. The initial pH of the absorbent can greatly affect the NO removal capacity of the system, and the BAD could keep the pH range suitable for NO oxidation in the system for a long time. The use of fresh seawater (FSW) to dilute the electrolysis of concentrated seawater (ECSW) to make an aqueous oxidant is a more reasonable scheme; the average removal efficiencies of SO2, NO, and NOx were 97.10%, 75.41%, and 74.28%, respectively. The synergistic effect of HCO3 -/CO3 2- and BAD was shown to further restrict NO2 escape.

Diffusion and Superposition of Ship Exhaust Gas in Port Area Based on Gaussian Puff Model: A Case Study on Shenzhen Port

Ship exhaust gas has become an essential source of air pollution in recent years. To assess the impact of ship exhaust gas on the atmospheric environment and human health, this paper studies the problem of ship exhaust gas diffusion in the port area. According to automatic identification system (AIS) data, ship exhaust gas is estimated based on the bottom-up method, and the result of emission calculation is entered into a Gaussian puff model to calculate the superposition of the diffusion of gaseous pollutants from multiple ships. In addition, the results of a case study of the diffusion of ship exhaust gas in the western area of Shenzhen Port in China show that the distribution of the NO2 concentration in the studied area is not stable, the diffusion of exhaust gas from multiple ships mainly affects some areas near large ship berths at night, and there is a small impact on the whole study area. This lays a foundation for monitoring and treating the atmospheric environment in the port area.

Innovation of Thermoelectric Conversion Stirling Device for Recovering Heat from Ship Exhaust Gas

With the implementation of the national carbon neutralization and carbon peak strategy, the technology of shipping energy conservation and emission reduction has also been concerned by the public. As there are high-power engines and generator sets in the engine room of the ship, the waste heat temperature of waste gas generated during equipment operation is extremely high, which can be as high as thousands of degrees Celsius. The device first converts waste gas waste heat into mechanical energy through Stirling machine, and then converts it into electrical energy through external generator. The whole working process produces electric energy while reducing the ambient temperature, and improves the utilization efficiency of waste heat. According to the preliminary experiment, about 3.3v electric energy can be generated when the temperature is 433°C. The device has simple structure, no complex mechanical structure, high safety and strong reliability. If multiple equipment can be used in the marine engine room at the same time, it will have a positive help to achieve the goals of carbon neutralization and carbon peak.

Particulate Matter (PM1, 2.5, 10) Concentration Prediction in Ship Exhaust Gas Plume through an Artificial Neural Network

In the last decade the reduction of carbon dioxide emissions in the transport sector, including the marine sector, has become the direction of its strategic development. Increased air pollution in the air is one of the main reasons for premature deaths around the globe. It was determined that while many methods provide adequate information about pollution levels, improvements could be made to avoid major errors. The traditional methods are either expensive or require a lot of data and human resources to correctly evaluate those data arrays. To avoid these problems, artificial neural networks (ANN) and other machine learning methods are widely used nowadays. Many ANN models for ship pollution evaluation in ports either included the whole port area or went even further and included cities near port areas. These studies show that ANNs can be effectively used to evaluate air pollution in a wide area. However, there is a lack of research on ANN usage for individual ship pollution or ship plume evaluation. This study attempts to fill this gap by developing an ANN model to evaluate an individual ship’s plumes by combining several data sources such as AIS data, meteorological data, and measured the ship’s plume pollutants concentration. Results show good correlation; however, additional limitations have to be overcome regarding data filtering and the overall accuracy of the model.

A Ship Exhaust Gas Monitoring Equipment based on NBIoT

Because of the severe problem of ship exhaust pollutant emission and the high cost, high power consumption of relevant ship exhaust monitoring schemes in the market, a ship exhaust monitoring equipment based on NBIoT (Narrow Band Internet of Things) is designed in this study. This equipment includes four parts: the power management unit, the minimum system unit, the communication circuit unit and the ship exhaust gas monitoring circuit unit. The overall process of the equipment is that the power management unit supplies power for the whole system; the minimum system unit starts the processing program and NBIoT communication program of ship exhaust gas monitoring; after receiving the power supply, the minimum system unit uploads the ship exhaust gas parameters measured by the ship exhaust gas monitoring circuit unit to the CVM(Cloud Virtual Machine) through the communication circuit unit. In this study, the ship exhaust monitoring equipment is installed at a fixed point in Gezhouba, and the coordinate position of the equipment is manually input to the cloud to conduct real-time monitoring of the exhaust emission of vessels passing through the lock. The results show that the equipment integrates ultra-low power consumption and low cost, is easy to set up, and can operate stably. It realizes real-time monitoring of SO2, CO2, NO2, and NO pollutants from ship exhaust.

Primary Factors Affecting the Efficiency of Thermoelectric Power Generation Sheets for Waste-Heat Recovery from the Ship’s Exhaust Gas

In order to investigate the effect of different influencing factors on the application of temperature differential power generation in the ship exhaust gas and to explore the potential of waste heat recovery and the utilization of exhaust gas during ship travel, an experimental system based on the temperature differential power generation of ship exhaust gas in the marine environment was established. The maximum output power and the maximum efficiency of each temperature-difference power generation module were theoretically calculated. The results showed that the insulation material and the salt water (seawater) had little effect on the efficiency of the temperature differential power generation modules. Conversely, the installation pressure, the heat transfer oil, the cooling water temperature (seawater temperature), and the heat source temperature (exhaust gas pipe temperature) had a great influence on the open-circuit voltage and the maximum output power. The thermally conductive silicone grease and the cooling water temperature of 10 °C increased the open-circuit voltage by 31.54% and 18.95%, respectively, and increased the maximum output power by 82.05% and 51.79%, respectively. The maximum output of a single temperature differential power generator reached 63.5% when using an installation pressure of 3 bar, a cooling water temperature of 20 °C, double-layer aluminum insulation, and thermally conductive silicone grease. Finally, this study provides relevant data support for using temperature differential power generation devices for ship exhaust gas.

2020年船舶燃料油硫黄分規制強化による大気質改善効果の評価 - 船舶排ガスを対象とした大気汚染インベントリ構築および陸域影響の観測的評価

2020年船舶燃料油硫黄分規制強化による大気質改善効果の評価 - 船舶排ガスを対象とした大気汚染インベントリ構築および陸域影響の観測的評価

2020年船舶燃料油硫黄分規制強化による大気質改善効果の評価 - 船舶排ガスを対象とした大気汚染の数値シミュレーションに基づく評価

2020年船舶燃料油硫黄分規制強化による大気質改善効果の評価 - 船舶排ガスを対象とした大気汚染の数値シミュレーションに基づく評価

An improved method for optimizing detection bands of marine exhaust SO2 concentration in ultraviolet dual-band measurements based on signal-to-noise ratio

SO2 emitted from ship exhaust can cause serious air pollution. Ultraviolet (UV) imaging detection technology is considered to be a simple and effective technique for detecting SO2 concentration in ship exhaust gas. To predict the concentration of SO2 emitted by ships more accurately, in this paper, a simulation and analysis model of UV dual-band imaging detection of ship exhaust gas is established by considering different types and concentrations of ship exhaust gas, natural background radiation intensity, transmittance of the filter used, and quantum efficiency of the detector. The results of wavelength optimization show that for zenith angles 10°, 20°, 30°, 40°, 50°, 60°, 70°, and 80°, the corresponding optimal dual band positions are (301, 303), (305, 307), (302, 307), (307, 309), (312, 315), (316, 317), (321, 323), and (331, 332) nm, respectively. The sulfur–carbon ratio was calculated based on the SO2 concentration obtained and CO2 concentration collected and from these measurements the sulfur content in the marine oil used was calculated. The results show that the sulfur content can be accurately estimated on the basis of the sulfur–carbon ratio in favorable background radiation conditions.

Performance Analysis of Ship Exhaust Gas Temperature Differential Power Generation

In addition to the use of waste heat from the vessel’s exhaust gas to save energy onboard, reduce the carbon emissions of the ship, and combine the characteristics of ship waste heat, mathematical modeling and testing of ship waste heat temperature difference power generation were carried out in this study. Finally, an experimental platform for temperature differential power generation was established to assess the impact of influencing agents on the efficiency of temperature differential power generation. The results show that the effect of different thermally conductive greases on the efficiency of temperature differential power generation tablets is basically the same. In addition, the rate of flow of cooling water, the cooling plate area, and the heat source temperature have more significant effects on the open-circuit voltage and maximum output power. The results show that the maximum power output growth rate increases with increasing cooling water flow, reaching 8.26% at 4 L/min. Likewise, increasing the heat source temperature enhances the maximum output power growth rate by 15.25% at 220 °C. Conversely, the maximum output power of the temperature difference power generation device decreases as the cooling plate area increases, and the maximum output power reduction rate is 15.25% when the cooling plate area is 80 × 200 mm2 compared to the case of using a cooling plate area of 80 × 80 mm2. Moreover, the maximum output power of the temperature differential power generation device reaches 13.6 W under optimal conditions. Assuming that the temperature difference power generation plate is evenly distributed on the tailpipe of the 6260ZCD marine booster diesel engine, it could save approximately 5.44 kW·h electric power per hour and achieve a reduction in CO2 emissions of 0.3435 kg per hour.

Study on AgCl/Al2O3 Catalyst Coating on Metal Workpiece Surface by Electrophoretic Deposition and Its Overall Catalytic Performance

This paper is a study of the coating technique of AgCl/Al2O3 catalyst on metal-based surfaces. In order to remove nitrogen oxides from the exhaust of marine diesel engines, this paper proposes a method of electrophoretic deposition and designs an electrophoretic deposition apparatus according to the coating conditions. An in-house developed catalyst was coated on a specific stainless-steel workpiece by the electrophoretic deposition method under the conditions of appropriate voltage and catalyst solution concentration. The surface and cross section of AgCl/Al2O3 coating on stainless steel were observed by scanning electron microscope, and the thickness of catalyst coating after coating was determined. In this study, an exhaust gas evaluation system was built, and a removal test of nitrogen oxides from diesel exhaust gas was conducted under the environment of temperature cyclic change, and repeated experiments proved that the coated workpiece could still effectively remove harmful nitrogen oxides from the exhaust gas. Converting them to N2 provides a new idea for ship exhaust gas purification.

Experimental and mechanism research on the NOx removal by a novel liquid electrode dielectric barrier discharge reactor

Metal electrode corrosion and poor discharge uniformity are the key factors that restrict the discharge lifetime and de-NOx efficiency of a dielectric barrier discharge (DBD) reactor. In order to solve this problem, a novel DBD reactor with homothermic sodium chloride (NaCl) solution as grounded electrode was designed in this paper. The effects of NaCl solution conductivity on the electrical parameters, the de-NOx performance and the optical emission spectrum characteristics of DBD were studied experimentally. The pathways and mechanism of de-NOx in the whole discharge phase were revealed by numerical simulation, electron impact mechanism and chemical reactions sensitivity analysis. The results showed that the best discharge intensity, uniformity, energy consumption and de-NOx performance were achieved at 32mS/cm of NaCl solution conductivity. The removal efficiency of NO, NO2 and NOx reached close to 100%, 97.4% and 83.9% respectively. The numerical simulation showed that the de-NOx process of DBD could be divided into 3 phases, including the rapid removal phase of NO (0–0.05 s), the removal phase of NO and NO2 (0.05–0.7 s), and the stabilization phase of NOx (0.7–1 s). In terms of de-NOx mechanism, the active particles of N atoms, N(2D) atoms and O atoms dissociated from exhaust gas played key roles in the de-NOx process. The N atoms mainly reduced NO to pure N2, and the selectivity of N2 could reach up to 13.6%. The N(2D) atoms were the only radicals that formed extra NO. The O atoms contributed greatly with NO2 re-conversion to NO. This work is of great significance to promote the removal of NOx from ship exhaust gas by the DBD with liquid electrode.

Research on Machine Vision Detection Method of Ship Sulfur Emission Based on Convolutional Neural Network

The traditional method of ship exhaust gas detection has the shortcomings of poor timeliness, blindness and hysteresis, which cannot meet the needs of marine supervision departments for comprehensive, efficient and real-time supervision of ship sulfur emissions. To solve this problem, a convolution neural network(CNN) based machine vision detection method for ship sulfur emission is introduced, and the plume characteristics of heavy sulfur black smoke ship exhaust are adaptively extracted by convolution operation. An improved LeNet-5 network model structure is proposed.By changing the activation function and increasing the depth of the model, the batch normalization operation is introduced to improve the accuracy and generalization ability of the model.The experimental results show that the detection accuracy of the model for heavy sulfur black smoke ships can reach 94.52%, which is better than the ordinary CNN network model and the VGG-16 network model.This method can quickly screen suspicious ships with excessive sulfur content, broaden the way for maritime supervision departments to detect ships under the background of “sulfur limit order”, and effectively improve the supervision efficiency of maritime personnel.

Optimization design of marine seawater desulfurization technology

Because ships burn inferior fuel, the emission of ship exhaust gas has a great impact on the environment. In order to effectively deal with the increasingly strict limit of sulfur content and SO2 emission of ship fuel by the International Maritime Organization. On the basis of analyzing the characteristics of SO2 gas soluble in seawater, this paper studies and compares the current industrial seawater desulphurization technology and other flue gas desulfurization technologies, puts forward the feasibility of the application of seawater desulphurization technology in the exhaust gas emission of marine diesel engine, and theoretically designs and calculates seawater desulphurization technology is pointed out.

Study on Efficient Nox Absorption from Simulated Ship Exhaust Gas Using O3/Urea Wet System: Analysis of Removal Efficiency and Ions Concentration

Study on Efficient Nox Absorption from Simulated Ship Exhaust Gas Using O3/Urea Wet System: Analysis of Removal Efficiency and Ions Concentration

PERANCANGAN PEMBERSIH GAS BUANG KAPAL DENGAN KAPASITAS 70.000 KG/JAM

Marine air pollution regulations require the use of low Sulfur fuels to reduce SOx gas. Scrubber offers lower operating costs by allowing the use of high-sulfur fuels that are cheaper for fuel, capital costs and operating costs as an alternative to low-sulfur fuels, such as Liquid Natural Gas (LNG). It is necessary to design a ship exhaust gas cleaner (Scrubber). In the IMO 2020 Rules and Marpol Annex VI there are no Scrubber design standards that regulate calculations, material selection, and others. However, IMO 2020 and Marpol require that the exhaust gas purifier produced by the scrubber released into the air must reach 97.5% ~ 99.5% cleaning and the minimum water pH is 3 which can be determined using the OLIanalyzer Software. The components of the scrubber consist of shell, body flange, scrubber head, nozzle, lug support scrubber, Spray Nozzle, Distributor Pipe, Packing Bed Support, Packing Bed, Venturi Scrubber, Demister. From three times doing scrubber simulation using OLIanalyzer Software on the Delta Pioneer engine, 80% performance was produced and produced gas output of 160 ppm and water pH of 6.6 pH. So that the scrubber design can be applied to the pioneer delta ship engine with a capacity of 70,000 Kg/h.