Comparison of Single-Tower and Two-Tower Processes for Absorption of Carbon Dioxide From Marine Engine Exhaust

An overview of the deactivation mechanism and modification methods of the SCR catalysts for denitration from marine engine exhaust

Considerations in analysing elemental carbon from marine engine exhaust using residual, distillate and biofuels

The considerable energy waste in maritime transport and the need to obtain alternatives to reduce emissions of polluting gases are factors that have motivated the study of waste heat recovery systems for marine engines. The system studied herein relies on a binary vapor cycle that uses water for the topping cycle while three organic fluids were investigated for the bottoming cycle: R601a, R134a, and R22. Each of these belongs to a different category of fluid, namely, dry fluid, isentropic fluid, and wet fluid, respectively. Two engines of different ratings and two different pressures of the heat recovery steam generator have been considered for each engine. Various outlet pressures for the topping turbine, which is the most liable to erosion and corrosion due to wet steam, have been investigated. The maximum efficiency achieved for the waste heat recovery system peaked at 21% while the maximum electric power accounted for 4.2% of engine brake power. Therefore, the employment of a waste heat recovery system based on a binary cycle seems a promising alternative to harnessing heat from the exhaust gases of marine engines.

A brand new two-phase wet oxidation absorption system for the simultaneous removal of SO2 and NOX from simulated marine exhaust gas

Thermo-economic analysis based on objective functions of an organic Rankine cycle for waste heat recovery from marine diesel engine

When a certain ship was sailing in the ocean, the top extension guide pin of the diesel engine power exhaust valve of the main engine broke, which triggered profound thinking on the ship's power system. Taking this as an opportunity, we conducted research and designed an intelligent alarm system. The intelligent alarm system consists of PLC and touch screen as the core components. The PLC serves as the “brain” of the system, responsible for receiving and processing various data from the ship's power system. As the “eyes“ of the system, the touch screen provides operators with an intuitive and convenient interactive interface. The two jointly build an intelligent alarm system for real-time monitoring, which can achieve comprehensive monitoring of the ship's power systeml'l, This intelligent monitoring system not only effectively monitors the working status of the exhaust valve of the diesel engine host, but also demonstrates strong versatility in later applications. With slight improvements, the system can be well applied to other devices, providing reference for the safe operation of systems such as ship power and intelligent power grids.

In this paper, in terms of diagnostic tests, functional systems composed of a technical object that is marine diesel engine piston were presented. This decomposition enables the identification of diagnostic systems, where failures occur most frequently and those whose failure may cause serious This decomposition enables the identification of diagnostic systems, where failures occur most frequently and those whose failure may cause serious consequences further consequences. Marine diesel engine was divided into the following functional systems: piston-crank exchange of the working medium, fuel supply, lubrication, cooling, starting, starting and reversing. Operating practice shows that the most common marine engine failure include damage to the injection system, the injectors, injection pumps, fuel system, speed controllers, lubrication system, timing mechanism, as well as the cooling system malfunctions. In this paper, examples of currently used diagnostic systems were described. In addition, the unconventional methods of diagnosing piston engines were presented. These are new, increasingly completely without disassembly and without any interference in the process of the internal combustion engine technical condition testing methods. Measurement systems computerization causes they are used with the simultaneous use of artificial intelligence and especially expert systems. These include, inter alia, vibration analysis, marine engine exhaust gas analysis, acoustic emission, endoscopy and quick photography in research diagnostics. Then infirmities cooling system were presented. The problem of development of methods of diagnosis and diagnostic system for marine diesel engine cooling system was formulated. It has been found that the developed diagnostic system would be a good complement to the existing electronic surveillance systems of the marine engine technical state.

Methods for infra-red analysis of rocket flames in situ

Chemical absorption into concentrated slurry: Absorptions of carbon dioxide and sulfur dioxide into aqueous concentrated slurries of calcium hydroxide

The rates of absorption of pure carbon dioxide into aqueous monoethanolamine solutions with a surface active agent were measured at 15°, 25°, 35°, and 45°C in a liquid jet column and a wetted wall column. Experimental results were analyzed with the chemical absorption theory based on the penetration model. Physical solubility of carbon dioxide in aqueous monoethanolamine solutions was determined from the absorption rates measured in a near pseudo first‐order reaction regime and was shown to be considerably larger than the physical solubility in water. The measured absorption rates were in good agreement with the theoretical predictions for gas absorption with an irreversible second‐order reaction, when the variation of the physical solubility of carbon dioxide due to the change in the composition of the solution during the absorption process was taken into account.

Solvents with better properties than the ones presently in use for carbon dioxide (CO2) absorption processes would make absorption technology more attractive for large scale reduction of CO2 emissions. In this work, more than 2000 solvents comprising of four groups were considered for screening. The groups are: amine solvents (primary, secondary, tertiary, sterically hindered, multiple amines and physical solvents), neutral solvents, mixed solvents and ionic liquids (ILs). Conductor-like screening model for real solvents (COSMO-RS) model was used in predicting thermodynamic properties, such as Henry’s constant, octanol-water partition coefficient, solubility in water and vapour pressure of all the solvents. The best two solvents from each of the four groups were selected based on the criteria of high capacity and high selectivity of the solvent in comparison to a benchmark solvent (BS), that is, [methyl-diethanolamine (MDEA) + Piperazine]. All the eight selected solvents were found to be environmental friendly having very low octanol-water partition coefficient KOW, which is far less than the hazard limit of 10,000. Out of the eight selected solvents, sulfolane (S), (NMP + S), and ([N,N,N,N,N-Pentamethyl-N-IsopropylGuanidinium][Br]) were recommended for having better properties than the BS. Key words: Henry’s constant, conductor-like screening model for real solvents (COSMO-RS), carbon dioxide absorption, capacity, selectivity.

Carbon dioxide absorption with aqueous amine solutions promoted by piperazine and 1-methylpiperazine in a rotating zigzag bed

To the Editor: Three cases of carbon dioxide rebreathing without a significant color change in the appearance of the canisters were experienced during general anesthesia with the same model anesthesia machines; Aestiva/5 (Datex Ohmeda, Wisconsin, USA) with a fresh gas flow of 1–2 l/min. Carbon dioxide rebreathing was recognized because the inspiratory carbon dioxide baseline of the capnogram trace gradually rose. The inhalational carbon dioxide concentration decreased immediately after increasing the fresh gas flow, and rose again with decreasing the fresh gas flow. This indicates that carbon dioxide rebreathing was due to carbon dioxide accumulation in the semi-closed circuit system of the anesthesia machines. A color change in the appearance of the carbon dioxide absorbent was recognized only in the upper part of the canister (Fig. 1a). The top surface of the canister showed a significant color change limited to the middle part of it (Fig. 1b). The section image of the canister showed a significant columnar color change of the carbon dioxide absorbent along the full length of the center part of it (Fig. 1c). The observation of the canister bottom of Aestiva/5 revealed that only the center part of it had the mesh part for the exhaled gas, and the color change of the carbon dioxide absorbent seemed to accord with the mesh part of the bottom (Fig. 1d). As an experiment, when a transparent plastic partition wall was settled in the canister before filling with carbon dioxide absorbent, the columnar color change was no longer visible. This indicated that the flow of the exhaled gas was influenced by the wall in the canister. Considering these results, it is supposed that the structural characteristic of the canister bottom of the anesthesia machine; Aestiva/5, caused channeling and the inhomogeneity of the current of inhaled gas in the canister led to the columnar color change of the carbon dioxide absorbent. The role of the carbon dioxide absorbent canister becomes more important as the fresh gas flow quantity decreases. A technique of using a fresh gas flow of 1 l/min was reported first in 1952 [1]. The technique with the fresh gas flow less than 1 l/min subsequently became known as ‘‘low-flow anesthesia’’. Afterwards, a technique using a fresh gas flow of 500 ml/min was reported as ‘‘minimal flow anesthesia’’ [2]. These cases of carbon dioxide rebreathing without significant color change in the appearance of the canisters provide very important information not only for anesthesiologists, but also for all persons using anesthesia machines. When carbon dioxide rebreathing is recognized, carbon dioxide accumulation in the circuit system of the anesthesia machines should be suspected and exhaustion of the carbon dioxide absorbent should be immediately T. Yamamoto (&) Department of Pediatric Anesthesiology and Critical Care Medicine, Children’s Hospital Asklepios Klinik Sankt Augustin, Arnold-Janssen-Str. 29, 53757 Sankt Augustin, Germany e-mail: yamatomo270@hotmail.com; t.yamamoto@asklepios.com

Mass transfer performance of rotating packed beds with blade packings in carbon dioxide absorption into sodium hydroxide solution

Abstract. Ruziman HH, Mohti A, Yo NESC, Pardi F. 2024. Comparative assessment of carbon dioxide (CO2) absorption capacities in Koompassia malaccensis and Hopea nervosa in Tekam Forest Reserve, Pahang, Malaysia. Nusantara Bioscience 16: 185-191. Trees, the dominant life form in forests, are essential in the functioning of the terrestrial biosphere, especially for the carbon cycle of the ecosystem. This study aims to assess CO2 absorption by two forest production species: Koompassia malaccensis Maingay and Hopea nervosa King. The experiment was carried out in an acrylic box, and the variation of carbon dioxide concentration, humidity, light, and temperature was measured using a Carbon Dioxide, Light, Temperature, and Humidity (CLTM) sensor. The experiment was conducted in an open area from 7:30 am to 6:30 am the next day (23 hours). The results showed that H. nervosa absorbed more CO2 (71.13 ppm/hour) than K. malaccensis (51.54 ppm/hour), thus promoting its ability to address climate change in the microenvironment. As for the relationship between carbon dioxide absorption and photosynthesis variables, both species show a positive correlation between CO2 absorption and humidity. In contrast, light and temperature were very weakly correlated to CO2. Therefore, it was identified that H. nervosa (Dipterocarpaceae) and K. malaccensis (Fabaceae) are tree species with high CO2 absorption capacity and thus can be considered suitable trees for replanting, especially in light of carbon mitigation initiatives.