Control of the combustion process and emission formation in marine gas engines

A smooth transition to the use of gas engines instead of conventional engines in marine shipping is a logical pathway for compliance with tightening environmental regulations. Currently, five major gas engine concepts are applied in maritime sector. In this paper, a review of the marine gas engine concepts was performed with a focus on the control of combustion and emission. To assess all the contributors to combustion and the emission formation process, three main factors were outlined: design, operational parameters and fuel. The assessment of gas engines was conducted based on these factors. The present paper helps to provide an understanding of the current progress in the development of marine gas engines towards improving of combustion efficiency and reducing the emissions. Moreover, the knowledge gaps, particularly in four-stroke marine high-pressure gas engines, were identified.acceptedVersio

Avskrivningsrett ved sale and lease back av løsøre : Med utgangspunkt i en leasingavtale med restverdi

Vurdering av de subjektive kravene for avskrivningsrett ved en sale and lease back avtale med restverdi

Methane slip from gas fuelled ships: a comprehensive summary based on measurement data

Strict NO x emission regulations set for marine vessels by Tier III standard make ship owners/operators finding new efficient methods fulfilling these requirements. Utilization of LNG as main fuel at the moment is one of the most promising solutions with lean burn spark ignited (LBSI) engines and low pressure dual fuel (LPDF) ones being of primary choice. Technology provides not only low NO x levels, but also allows to reduce operational costs due to LNG currently being a cheaper fuel. The main drawback of low-pressure gas engines is rather high levels of methane slip, especially at low loads, as a result of poor fuel utilization due to low operational fuel–air ratios. Nevertheless, there are no standards that directly regulate methane slip for marine gas engines, but the topic starts to receive more and more attention due to the concerns associated with environmental effect of methane as well as due to ship operators analyzing ship data more thoroughly revealing substantial increase in gas fuel consumption at low loads. Presented study summarizes all gas engine technologies that are available for the maritime sector considering their current status and maturity and present a comprehensive measurement data summary for the main groups, namely LBSI and LPDF engines. The measurement data pool consists of both on-board and test-bed emission data revealing an interesting moments such as possible “overtuning” of engines for low NO x resulting in excessive levels of methane slip, importance of on-board measurements due to their more realistic nature, utilization of non-perfections, such as fixed emission weight factors for loads, and in Tier III regulations. The article also quantitatively indicates the progress in gas technology development and provides updated specific emission factors for the considered gas engine types

Reduserte klimagassutslipp 2050. Teknologiske kilder. Innspill til Lavutslippsutvalget

publishedVersio

Control of the combustion process and emission formation in marine gas engines

A smooth transition to the use of gas engines instead of conventional engines in marine shipping is a logical pathway for compliance with tightening environmental regulations. Currently, five major gas engine concepts are applied in maritime sector. In this paper, a review of the marine gas engine concepts was performed with a focus on the control of combustion and emission. To assess all the contributors to combustion and the emission formation process, three main factors were outlined: design, operational parameters and fuel. The assessment of gas engines was conducted based on these factors. The present paper helps to provide an understanding of the current progress in the development of marine gas engines towards improving of combustion efficiency and reducing the emissions. Moreover, the knowledge gaps, particularly in four-stroke marine high-pressure gas engines, were identified

Reduserte klimagassutslipp 2050. Teknologiske kilder. Innspill til Lavutslippsutvalget

publishedVersio

Concept design and environmental analysis of a fuel cell RoPax vessel - Report in the HOPE (Hydrogen fuel cells solutions in shipping in relation to other low carbon options) project

This report includes a ship concept design developed for a RoPax ship (a ferry transporting passengers and goods) with hydrogen fuel cell propulsion for intended operations on the route Frederikshavn (Denmark) to Gothenburg (Sweden). The assessments, performed within the HOPE (Hydrogen fuel cells solutions in shipping in relation to other low carbon options – a Nordic perspective) project, shows that it is technically feasible to build and operate such a ship with existing technology for the studied route between these two Nordic countries. Also, the costs of such a concept are assessed and compared to other fuel options including: battery-electric propulsion, electro-ammonia, electro-methanol, biomass-based methane, or fossil liquefied natural gas (LNG), as well as conventional fossil marine gas oil (MGO). The overall result from the comparative analysis of the estimated costs is that the hydrogen fuel cell ship, when assuming current or near future costs for the technology and the hydrogen, is estimated to be some 25 percent more expensive than a conventional fossil fuelled (MGO) RoPax ship (when including costs for emissions in the EU emission trading scheme). However, the cost developments are uncertain. In the case that fuel cell prices, and hydrogen prices, are decreasing, and todays cost levels of emission allowances in the EU emission trading scheme (ETS) increase, the hydrogen fuel cell ship could possibly be operated at lower total costs compared to the MGO fuelled ship. A cost benefit analysis was also performed, comparing costs linked to the technical implementation of hydrogen fuel cell solutions in shipping (with a private and social perspective) to benefits in terms of reduced external costs linked to lower emissions and potential subsides. The cost benefit assessment also confirms that the investment from a private perspective is not cost effective and that additional subsidies may be needed for investments in fuel cell hydrogen technology to take place. The cost effectiveness from a social perspective is strongly dependent on values of highly uncertain parameters. The impacts of emissions of hydrogen as fuel in a Nordic context were assessed for deployment scenarios for hydrogen and fuel cell solutions in Nordic shipping. There is a considerable potential for emission reductions both in terms of CO2, nitrogen oxides (NOX), sulphur dioxide (SO2) and particulate matter (PM) linked to the implementation of hydrogen and fuel cells in Nordic shipping, particularly in the RoPax segment, representing 30% of total CO2 emissions in 2018. Considering the relatively long lifetime of vessels, investments must be made soon to enable a hydrogen powered shipping fleet in the near future. Since it is currently not economically viable with hydrogen and fuel cells vessels there is need for subsidies and investments in pilots to develop solutions and speed up the process.

Concept design and environmental analysis of a fuel cell RoPax vessel - Report in the HOPE (Hydrogen fuel cells solutions in shipping in relation to other low carbon options) project

This report includes a ship concept design developed for a RoPax ship (a ferry transporting passengers and goods) with hydrogen fuel cell propulsion for intended operations on the route Frederikshavn (Denmark) to Gothenburg (Sweden). The assessments, performed within the HOPE (Hydrogen fuel cells solutions in shipping in relation to other low carbon options – a Nordic perspective) project, shows that it is technically feasible to build and operate such a ship with existing technology for the studied route between these two Nordic countries. Also, the costs of such a concept are assessed and compared to other fuel options including: battery-electric propulsion, electro-ammonia, electro-methanol, biomass-based methane, or fossil liquefied natural gas (LNG), as well as conventional fossil marine gas oil (MGO). The overall result from the comparative analysis of the estimated costs is that the hydrogen fuel cell ship, when assuming current or near future costs for the technology and the hydrogen, is estimated to be some 25 percent more expensive than a conventional fossil fuelled (MGO) RoPax ship (when including costs for emissions in the EU emission trading scheme). However, the cost developments are uncertain. In the case that fuel cell prices, and hydrogen prices, are decreasing, and todays cost levels of emission allowances in the EU emission trading scheme (ETS) increase, the hydrogen fuel cell ship could possibly be operated at lower total costs compared to the MGO fuelled ship. A cost benefit analysis was also performed, comparing costs linked to the technical implementation of hydrogen fuel cell solutions in shipping (with a private and social perspective) to benefits in terms of reduced external costs linked to lower emissions and potential subsides. The cost benefit assessment also confirms that the investment from a private perspective is not cost effective and that additional subsidies may be needed for investments in fuel cell hydrogen technology to take place. The cost effectiveness from a social perspective is strongly dependent on values of highly uncertain parameters. The impacts of emissions of hydrogen as fuel in a Nordic context were assessed for deployment scenarios for hydrogen and fuel cell solutions in Nordic shipping. There is a considerable potential for emission reductions both in terms of CO2, nitrogen oxides (NOX), sulphur dioxide (SO2) and particulate matter (PM) linked to the implementation of hydrogen and fuel cells in Nordic shipping, particularly in the RoPax segment, representing 30% of total CO2 emissions in 2018. Considering the relatively long lifetime of vessels, investments must be made soon to enable a hydrogen powered shipping fleet in the near future. Since it is currently not economically viable with hydrogen and fuel cells vessels there is need for subsidies and investments in pilots to develop solutions and speed up the process.