A review of metallic tanks for H2 storage with a view to application in future green shipping

This paper attempts to review the implications of the sulphur oxides (SOx), nitrogen oxides (NOx) and nitrous oxide (N2O) emissions to the design of fluidised bed combustion (FBC) operations. The review focuses on how the knowledge of SOx and NOx emissions trends can be applied to influence the design of FBC operations. The effects of the emission trends of these noxious gases on the design operations for FBC such as temperature control, nozzle designs, sorbent selection design, air supply and control designs were reviewed. The implications of SOx, N2O and NOx emissions on the design of FBC systems rest primarily on the need to design the operational conditions of the system. The design for the precise location of the fuel feeding ports, secondary air feeding ports, limestone feeding ports and a prescribed size and quantity of sorbents to feed into the system was found to be crucial for reduction of these emissions. The emissions also have an impact on the design of the distributor plate of the system; reduction of the emissions necessitates good fluidisation and well-regulated temperature within the system. The review therefore concludes that there is a close nexus between the design and operation of FBC systems with NOx, N2O and SOx emissions.

Spatiotemporal Autoregressive Models of Country-Level Emission of Transboundary Pollutants

In many parts of the world, shipping-related emissions have already exceeded or are expected to soon exceed those from land-based sources. Shipping emissions can be reduced substantially by using some of the same technologies being applied to land-based sources, including cleaner engines and fuels, exhaust control methods, and operational modifications. Various ports are testing the feasibility of these mechanisms with varying degrees of success. What is perhaps most greatly needed is expedited creation of better regulations at all levels, from the International Maritime Organization to port city authorities.

Effect of hydrogen sulfide content on the combustion characteristics of biogas fuel in homogenous charge compression ignition engines

In recent years, regulations of environmental pollution have gradually been strengthened worldwide. The International Maritime Organization (IMO) has adopted the “agreement of air pollution prevention of ships” which regulates the emission of air pollutants from ships. Regulation of nitrogen oxide (NOx) emissions of large marine diesel engines below 130 rpm have been strengthened. In the case of large marine diesel engines, the regulations for Tier-III, which took effect in January 2016. It has been reinforced to less than 14.4 g/Kwh, which is a regulation that must reduce nitrogen oxides by more than 80% compared to Tier-II. In addition, since 2020, the emission of sulfur oxides (SOx) has been regulated to less than 0.5% and the ships sailing in coastal and exclusive economic zones are regulated to be limited to 0.05%. In order to reduce the emission of nitrogen oxides (NOx) and sulfur oxides (SOx) generated from ships, it is essential to install post-treatment devices such as SCR and scrubber. The annual average amount of particulate matter (PM) in Korea is 24.8 ㎍/㎥, which is said to be the worst among the OECD countries and the 26th most serious in the world. The government aims to reduce domestic particulate matter (PM) emissions by 30% until 2022. Currently, the port cities of Busan, Incheon, and Ulsan have poor air quality, and air pollutants generated from ships are introduced and are affected by serious environmental pollution. In the future, regulations on particulate matter (PM) are expected as environmental regulations are strengthened in the International Maritime Organization as well. Currently, most studies on post-treatment devices to reduce nitrogen oxides (NOx) and sulfur oxides (SOx) generated from ships are conducted; however, there is almost no research on the reduction of particulate matter (PM) for ships. Therefore, in this study, it was conducted on an electric precipitator for reducing particulate matter (PM) in a 300 kW class of marine diesel engine. The electrostatic precipitator is a device that collects particulate matter (PM) from a collecting plate by causing a corona discharge phenomenon. In this study, three types of dust collector plates and electrode plates, which are components of the electrostatic precipitator, were designed and structural stability was derived through numerical analysis.

Advanced Techniques in Automation of Fluidized Bed Boilers

Problem. Automobile transport has a huge negative influence on the environment, not only during using, but also during its service. Goal: to analyze the influence on the atmosphere of the work of car service stations. Methodology: The calculation of atmospheric emissions during the operation of the main production units was carried out according to the standard method. Gas analysis was carried out using an OKCI-5M-5H gas analyzer. Originality: Calculated amounts of emissions of major pollutants, which are formed during the operation of internal combustion engines and during the operation of the main units of the station, determined the amount of pollution from decentralized space heating. Recommendations for reducing the amount of pollutants and the negative influence of stations on the environment within the city are proposed. Practical value. When liquefied gas is used as a combustible gas, emissions of pollutants into the atmosphere are noticeably reduced both in quantitative terms and in qualitative composition. At the same time, the emissions of methane and sulfur oxides decrease by half. There is a significant decrease in carbon monoxide and nitrogen oxide (II) emissions. Analysis of the data obtained shows that when wood is used as a fuel, there are no emissions of sulfur oxides, but the amount of nitrogen and carbon oxides is higher. Particulate matter emissions are not significantly dependent on the type of fuel. During the operation of the service station, the largest amount of gaseous emissions into the atmosphere occurs in the service box of the internal combustion engine. In general, during the operation of a car service station, a significant amount of harmful substances is not added to the atmosphere.

Dynamic modeling and offset-free predictive control of LNG tank

_ The present paper proposes using methanol fuel in ships to meet emissions regulations established by the International Maritime Organization. An analysis of the use of twin fuel engines operated by diesel and methanol has been conducted from environmental and cost-effective viewpoints. As a case study, a tanker vessel operated by two fuels was investigated. The environmental results showed decreases in SOx, NOx, PM, CO2, and CO pollutant emissions by 90%, 76.80%, 83.49%, 6.43%, and 55.63%, respectively. A selective catalytic reduction (SCR) measure is installed onboard the vessel to decrease NOx emissions in case diesel fuel is used. Economically, the dual-fuel engine will save on SCR costs. The cost-effectiveness values for using a methanol engine will be $242.3/ton and $764.7/ton for reducing CO2 and NOx emissions, respectively. Finally, the cost-effectiveness for reducing NOx emissions using SCR system is $536.6/ton for the conventional diesel engine. Introduction The majority of all cargo delivered worldwide is transported by sea (Zhou et al. 2020; Aarflot et al. 2022). Petroleum and other liquid fuels are the dominant sources for transporting this cargo. According to the International Maritime Organization (IMO), worldwide ships consume 309 million tons of fuel annually. These fuel consumptions result in yearly emissions of 11 million tons of sulfur oxides (SOx), 22 million tons of nitrogen oxides (NOx), 1.71 million tons of particulate matter (PM), 1056 million tons of carbon dioxide (CO2), and 844 million tons of carbon monoxide (CO) (IMO 2020). These emissions contribute to air pollution and climate change, highlighting the need for more sustainable shipping practices.

Lowering the use of fossil fuels not only mitigates climate effects by decreasing the emission of greenhouse gases, but also reduces the release of harmful air pollutants into the atmosphere. Thus, the transition to a carbon-free energy system in the upcoming years could potentially have a major impact on lower air pollutant emissions, leading to better air quality and less harmful impacts on human health and ecosystems.Currently, emissions from power plants in the energy supply sector (e.g. coal or oil) contribute strongly to total air pollutant emissions in Europe. Among others, especially emissions of sulphur oxides (SOx), nitrogen oxides (NOx) and particulate matter (PM) are highly relevant regarding air quality issues. In order to be able to make informed statements about the impact of the European energy transition and the phase-out of fossil fuels on air quality, providing detailed information on the temporal and spatial character of air pollutant emissions in the future are required. However, the future projection of air pollutant emissions from power plants poses a major challenge because it is influenced by various factors like the pace of renewable energy rollout, power line capacities and the phase-out of fossil power plants.This work aims to provide estimates of NOx, SOx and PM emissions from power plants in Europe for the year 2030 and to analyse the temporal and spatial dynamics of these emissions in differing energy transition scenarios compared to current emission characteristics.The energy system model framework REMix is used to model activities of power plants in 2030. It considers the effects of power line capacities, renewable energy capacity increase, consumption patterns and the future power plant fleet of European countries in order to simulate power plant activities in high spatial and temporal resolution. The corresponding emission projections are based on current emission factors of power plants, e.g. from emission reports and information on installed flue gas cleaning systems, and are modelled considering the implementation of European emission standards for power plants in 2030.The results show that ambitious scenarios for the energy transition cause significant changes in the spatial and temporal occurrence of the considered air pollutant emissions compared to the current emission characteristics of power plants in Europe.

Major gas emissions from combustion of slurry fuels based on coal, coal waste, and coal derivatives

Historically, cargo ships have been powered by low-grade fossil fuels, which emit particles and particle-precursor vapors that impact human health and climate. We used a global chemical-transport model with online aerosol microphysics (GEOS-Chem-TOMAS) to estimate the aerosol health and climate impacts of four emission-control policies: (1) 85% reduction in sulfur oxide (SOx) emissions (Sulf); (2) 85% reduction in SOx and black carbon (BC) emissions (Sulf-BC); (3) 85% reduction in SOx, BC, and organic aerosol (OA) emissions (Sulf-BC-OA); and (4) 85% reduction in SOx, BC, OA, and nitrogen oxide (NOx) emissions (Sulf-BC-OA-NOx). The SOx reductions reflect the 0.5% fuel-sulfur cap implemented by the International Maritime Organization (IMO) on 1 January 2020. The other reductions represent realistic estimates of future emission-control policies. We estimate that these policies could reduce fine particulate matter (PM2.5)-attributable mortalities by 13 300 (Sulf) to 38 600 (Sulf-BC-OA-NOx) mortalities per year. These changes represent 0.3% and 0.8%, respectively, of annual PM2.5-attributable mortalities from anthropogenic sources. Comparing simulations, we estimate that adding the NOx cap has the greatest health benefit. In contrast to the health benefits, all scenarios lead to a simulated climate warming tendency. The combined aerosol direct radiative effect and cloud-albedo indirect effects (AIE) are between 27 mW m−2 (Sulf) and 41 mW m−2 (Sulf-BC-OA-NOx). These changes are about 2.1% (Sulf) to 3.2% (Sulf-BC-OA-NOx) of the total anthropogenic aerosol radiative forcing. The emission control policies examined here yield larger relative changes in the aerosol radiative forcing (2.1%–3.2%) than in health effects (0.3%–0.8%), because most shipping emissions are distant from populated regions. Valuation of the impacts suggests that these emissions reductions could produce much larger marginal health benefits ($129–$374 billion annually) than the marginal climate costs ($12–$17 billion annually).

Natural gas furnaces are the most common space heating equipment in the U.S. residential and commercial building markets. However, current residential natural gas condensing furnaces generate substantial acidic condensate as well as significant emissions of sulfur oxides (SOx), nitrogen oxides (NOx), carbon monoxide (CO), hydrocarbons (HC), and methane (CH4) contributing to environmental degradation of air, water, and soil. This report describes a novel solution to reduce the environmental impact of natural gas condensing furnaces based on the technology of a monolithic acidic gas reduction (AGR) catalyst for SOx trapping, NOx redox to nitrogen, and oxidation of formic acid, CO, HC, and CH4. The AGR technology offers the following benefits: (1) a neutral furnace condensate with a pH of ~7, allowing its safe release into the sewer system thus eliminating a second drainage system; (2) trapping and removing nearly all SOx emissions; (3) NOx emissions nearly at nearly 1-2 ng/J, more than 95% lower than new emissions standards in California; (4) the use of a low-cost heat exchanger as a condensing heat exchanger (HX) since the condensate is not acidic, avoiding the need for expensive stainless steel alloys; and (5) unburnt fuel energy recovery to boost efficiency.The AGR component and AGR-enabled furnace performance were broadly tested to determine their effects on long-term reliability and durability, as well as SOx storage and regeneration activity. The AGR regeneration does not impair the performance in achieving neutral condensate and ultra-low NOx emissions, and the AGR catalyst subjected to regeneration activities continued to function well and achieved slightly better annual fuel utilization efficiency (AFUE). The 400-hour reliability and durability test of the retrofitted condensing furnace with the AGR component shows that the furnace unit still achieves a neutral furnace condensate with a pH of ~7 and enables 0~3 ng/J of NOx emissions. However, the 400-hour operation slightly degraded the AFUE because of soot particle accumulation caused by frequent incomplete combustion owing to inappropriate condensate drainage during testing. Thus, proper condensate drainage is critical for AGR-enabled furnaces. Furthermore, neutron computed tomography was employed to survey the aged AGR component and demonstrate high-resolution 2D and 3D representations for the nondestructive diagnosis of the AGR component. The tomography showed that the AGR component did not deform or suffer broken AGR channels. A new AGR catalyst with low precious metal loading was preliminarily explored to identify a pathway of optimizing AGR material loading and maximizing acidic gas reduction at low cost. The new AGR component can reduce precious metal loading by 38% and still achieve neutral condensate and ultralow NOx emissions. The furnace with the AGR component of low Pt/Rh loading enables a maximum AFUE of 97%, which is meaningfully higher than the original furnace. Long-duration testing for the furnace enabled with the low precious metal loading AGR component will be vital in future research. Although the current work demonstrates a proof of concept for the AGR-enabled furnace, the AGR assembly needs to be optimized and integrated into the design of new OEM furnace products. Furthermore, the AGR technology can be applied not only for residential gas furnaces, but also for commercial rooftop units, gas heat pumps, gas-fired water heaters, combustion boilers, and other systems.

Coal has been used as the most commonly energy source for power plants since it is relatively cheap and readily available. Thanks to these benefits, many countries operate coal-fired power plants. However, the combustion of coal in the coal-fired power plant emits pollutants such as sulfur oxides (SOx) and nitrogen oxides (NOx) which are suspected to cause damage to the environment and also be harmful to humans. For this reason, most countries have been strengthening regulations on coal-consuming industries. Therefore, the coal-fired power plant should also follow these regulations. This study focuses on the prediction of harmful emissions when the coal is mixed with high-quality and low-quality coals during combustion in the coal-fired power plant. The emission of SOx and NOx is affected by the mixture ratio between high-quality and low-quality coals so it is very important to decide on the mixture ratio of coals. To decide the coal mixture, it is a prerequisite to predict the amount of SOx and NOx emission during combustion. To do this, this paper develops a deep neural network (DNN) model which can predict SOx and NOx emissions associated with coal properties when coals are mixed. The field data from a coal-fired power plant is used to train the model and it gives mean absolute percentage error (MAPE) of 7.1% and 5.68% for SOx and NOx prediction, respectively.

The purpose of the article is to examine whether environmental taxes affect the level of nitrogen oxides (NOx) and sulfur oxides (SOX) emissions based on the data for 33 countries in the years 1996-2021. The research method used is the analysis of panel regression with fixed effects. For both pollutants, a model without lags and models with one-year and two-year lags were estimated. The results show that environmental tax revenues have a negative and statistically significant but rather symbolic impact on SOx emissions, while these revenues do not affect NOx emissions. In addition, the gross domestic product (GDP) per capita and the share of the urban population in the total population are found to be significant determinants of NOx emissions. The higher the GDP per capita and the share of the urban population, the lower the NOx emissions per capita. The results can be useful for policymakers in assessing the effectiveness of environmental taxes.