Tag Archives: NH3 combustion

Exploring ammonia’s potential as a marine fuel

Niels de Vries, C-Job Naval Architects, Netherlands

15th Annual NH3 Fuel Conference, Pittsburgh, PA, October 31, 2018
NH3 Energy+ Topical Conference at the AIChE Annual Meeting

ABSTRACT

International shipping is responsible for approximately 90% of the world trade. Looking to the relative emissions, in gram CO2 per ton km, maritime transport score significantly better compared to others like rail, road and airfreight. However, since most of the transport is done by ships the absolute contribution of greenhouse gases (GHG) by the maritime industry is clearly visible. Of all the global emissions the maritime industry is responsible for 3% CO2, 13% SOx, and 15% NOx.

To reduce SOx and NOx several regulations are either upcoming or already in play. Current regulations require the sulphur emissions to be less than 0.1% in all Environmental Control Areas (ECA). A global sulphur cap is upcoming in 2020 limiting the sulphur emissions to 0.5%. NOx emissions are currently regulated by IMO Tier II where IMO Tier III is already in affect in the ECAs yet IMO Tier III is still pending for global enforcement. Basic regulations have also been arranged to reduce CO2 emissions by means of an Energy Efficiency Design Index (EEDI). However, the EEDI requirements are not very strict yet.

To comply with these new and upcoming regulations the marine industry is moving towards the application of natural gas as a fuel, exhaust gas treatment and usage of cleaner marine diesel fuels. With the goals of IMO to reduce the total GHG by at least 50% by 2050 (compared to 2008) this shift alone will not be enough to meet up with these ambitions. Since shipping (and aviation) were not covered by the Paris agreement these IMO goals are an important push towards renewable fuels. The challenges for implementation of renewable fuels in the maritime industry regard both a significant expansion of renewable energy production and viable business cases for ship owners. For the ship owner this can come for either a cargo owner willing to pay more for clean transport or taxations on harmful emissions.

Applying renewable fuels for the maritime industry one can think of several options like: liquid methane, ethanol, methanol, liquid ammonia, liquid hydrogen and compressed hydrogen. Considering the importance of volumetric energy density [GJ/m3] and also renewable synthetic production cost [MJ/MJ] ammonia turns out to be a very balanced solution. Ammonia has a significant higher volumetric energy than liquid hydrogen yet requiring clearly less energy for renewable synthetic production than the carbon carriers. These are the main reasons to further investigate the potential of ammonia as a fuel.

Suitable types of marine power generation need to be able to cope with the marine environment. Dynamic behaviour and load response are crucial aspects for configurations which have the engine directly connected to the propeller. Furthermore, part load conditions are also important aspects since most operational profiles cover several modes.

To realise ammonia as marine fuel the internal combustion engine seems to be a good solution for now. Ammonia + hydrogen (obtained from ammonia cracking) mixtures are capable to approach similar characteristics as fossil fuels like methane. Therefore, scaling up the ammonia combustion engine should not be a problem. In the future fuel cells could be replacing the combustion engine as they are capable delivering higher efficiencies and do not emit NOx. Yet nowadays fuel cells capable using ammonia directly lack power density and cost effectiveness.

Read the abstract at the AIChE website.

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Experimental and Computational Study for Reduction of NOx Emissions in the Ammonia / Methane Co-Combustion in a 10 KW Furnace

Ryuichi Murai*, Ryohei Omori, Takahiro Kitano, Hidetaka Higashino, Noriaki Nakatsuka, Fumiteru Akamatsu, Osaka University, Japan; Yuya Yoshizuru, UBE Industries, Japan; Jun Hayashi, Kyoto University, Japan

15th Annual NH3 Fuel Conference, Pittsburgh, PA, October 31, 2018
NH3 Energy+ Topical Conference at the AIChE Annual Meeting

ABSTRACT

There are severe issues on increasing amount of carbon dioxide (CO2) emission in the world. Many studies are devoted to alternative fuels. One of promising candidates is the utilization of ammonia which is zero emission of CO2, a hydrogen energy carrier, and also can be burned directly as a fuel.

For direct combustion of ammonia in industrial furnaces, there were two issues which were weaker radiative heat flux and a huge amount of NOx emission compared with the combustion of methane. We already have reported [1] the solution of the former issue by using the oxygen enriched combustion.

The objective of this research is to study the reduction mechanism of NOx emissions in the ammonia / methane co-combustion in an industrial furnace both experimentally and numerically. Experimentally we measured the radiation spectra and the total radiative thermal flux under the condition of the ammonia fuel burned in a 10 kW furnace with a coaxial jet flame and additional two oxidizer inlets for the staging combustion. The spectrum measurement results show that the amount of NOx emission was in reverse proportion with the intensity of N2O spectrum in the downstream of the reaction zone in the furnace. This indicates that N2O, which is one of main intermediate species of NH3, reacts with NOx as a reduction reactant to nitrogen molecule. Continue reading

Auto-Ignition Kinetics of Ammonia at Intermediate Temperatures and High Pressures

Xiaoyu He, Bo Shu, Kai Moshammer, Ravi Fernandes*, Physikalisch-Technische Bundesanstalt, Germany; David Nascimento, Mario Costa, Instituto Superior T├ęcnico – Universidade de Lisboa, Portugal

15th Annual NH3 Fuel Conference, Pittsburgh, PA, October 31, 2018
NH3 Energy+ Topical Conference at the AIChE Annual Meeting

ABSTRACT

The anxiety over global greenhouse gas emissions has intensified the demand for the development and use of CO2-neutral energy technologies. Ammonia is now attracting attention as a carbon-free energy carrier, because it has good energy density (22.5 MJ/kg) and can be easily liquefied (about 10 bar at 298 K). In addition, ammonia is produced according to the Haber-Bosch process, which makes it one of the most widely-produced inorganic chemical in the world. It could also be produced with renewable energy sources such as wind and solar energy using P2X technology.

As a potential fuel for applications in gas turbines and gas engines, ammonia is less reactive than most hydrocarbons and its ignition and combustion characteristics are not yet well understood. A major part of the previous research has focused on the ammonia oxidation at high temperatures or low pressures [1-3], while ignition measurements for pure ammonia or ammonia mixed with other gaseous fuels (such as hydrogen or methane) at high pressures and low-to-intermediate temperature is rare.

Rapid compression machines (RCMs) are regarded as an important experimental apparatus for investigating auto-ignition behavior at low-to-intermediate temperature conditions, which are quite relevant to the application in internal combustion engines and gas turbines [4,5].

In this study, autoignition properties of NH3/O2 and NH3/H2/O2 mixtures have been studied in a RCM at pressures from 20 to 60 bar, temperatures from 950 to 1150 K, and at equivalence ratios from 0.5 to 2. The effect of hydrogen-ammonia ratio in fuel has been also investigated. Continue reading

Improved Method of Using Hydrogen and Ammonia Fuels for an Internal Combustion Engine

David Toyne*, Solutions for Automation, USA; Jay Schmuecker, Pinehurst Farm, USA

15th Annual NH3 Fuel Conference, Pittsburgh, PA, October 31, 2018
NH3 Energy+ Topical Conference at the AIChE Annual Meeting

ABSTRACT

A tractor mounted internal combustion engine is fueled by Hydrogen or a combination of Hydrogen and Ammonia.

Developments of an improved method of fuel injection and ignition control. Hydrogen is port injected in the intake manifold, and liquid ammonia is injected in the throttle body. A dual fuel ECU, Engine Control Unit, controls the fuel mixtures and the firing of multiple coils for ignition.
The paper will address significant engine performance improvements and the resulting fuel consumption and engine emissions levels. Continue reading

Ignition of an Aqueous Ammonia/Ammonium Nitrate Fuel

Bar Mosevitzky*, Gennady E. Shter, Gideon S. Grader, Technion – Israel Institute of Technology, Israel

15th Annual NH3 Fuel Conference, Pittsburgh, PA, October 31, 2018
NH3 Energy+ Topical Conference at the AIChE Annual Meeting

ABSTRACT

To achieve a truly renewable energy market, the intermittent power generation of sources such as solar and wind must be overcome. Renewable ammonia can be synthesized using these sources to be used as a long-term energy storage medium. For this reason, the use of ammonia as a synthetic fuel has garnered significant attention in recent years. Aqueous AAN (ammonia/ammonium nitrate) is a carbon-free ammonia based monofuel suitable for energy storage applications. This fuel is safe to store and transport, and its combustion products consist mainly of water and nitrogen. Effective use of this fuel requires an in-depth understanding of the reaction pathways dominating its ignition.

In this work, the accumulated results from experiments conducted to test the effects of water content, equivalence ratio, and diluent pressure on AAN ignition will be reviewed. The use of simulations to reproduce these results will be evaluated, and the data generated by rate-of-production and sensitivity analyses will be reviewed. Finally, the reaction pathways involved in AAN ignition and their relation to its water content, equivalence ratio and diluent pressure will be presented, and the implications of the rate-determining steps for AAN ignition will be discussed. Continue reading

Optimization of the NOx Reduction Condition in the Combustion Furnace for the Combustion of “Heavy-Oil – NH3 System” Using CFD

Yuya Yoshizuru*, Takeshi Suemasu, Masayuki Nishio, UBE Industries, Japan; Ryuichi Murai, Fumiteru Akamatsu, Osaka University, Japan

15th Annual NH3 Fuel Conference, Pittsburgh, PA, October 31, 2018
NH3 Energy+ Topical Conference at the AIChE Annual Meeting

ABSTRACT

In late years the discharge of the CO2 became the very big problem. The combustion of the fossil fuel in particular exhausts much CO2. Our project team (SIP) is intended to reduce CO2 by using NH3 (10%~30%) in substitution for heavy oil. The ‘SIP energy carriers’ was launched in 2014 (SIP: Strategic Innovation Promotion Program). Ammonia direct combustion team was formed. We conducted a co-research program with Osaka University in this project. We performed experiment of heavy oil – NH3 mixed combustion in the 10kW furnace. As the results, we obtained much experimental data. When we were combusted NH3 and heavy-oil, a large quantity of NOx is exhausted. We need to conduct that out under many different conditions for NOx reduction (for example, temperature, flow rate and so on.). However, it is impossible to perform it in limited time. Therefore I found some conditions to reduce NOx using CFD. Furthermore, we introduce some conditions to optimize NOx reduction. The combustion mechanism compared the model using the detailed chemical reaction and the simplification reaction mechanism with the experiment. As a result, we became able to be combusted NH3 (30%) under a NOx condition same as heavy-oil (100%). Continue reading

Simulation Analysis of NH3 Mixed Combustion in Clinker Manufacturing Process

Tatsurou Izumi*, Hiroki Kujiraoka, Yuya Yoshizuru, Takeshi Suemasu, Makoto Ueda, Toyoaki Niki, Takayasu Itou, Masayuki Nishio, UBE Industries, Japan; Ryuichi Murai, Fumiteru Akamatsu, Osaka University, Japan

15th Annual NH3 Fuel Conference, Pittsburgh, PA, October 31, 2018
NH3 Energy+ Topical Conference at the AIChE Annual Meeting

ABSTRACT

Recent years, the action for the low-carbon society becomes active all over the world. NH3 has potential to become the free-carbon energy source. In SIP project, that Cabinet Office started, we work on the technology development applying NH3 to the field of industrial furnace (SIP: Strategic Innovation Promotion Program).

In this study, we evaluated the effect of NH3 use in the cement clinker manufacturing process. Cement manufacturing is one of the fields of industry to exhaust large amounts of CO2. As past works, we studied for the reduction of heat consumption rate, troubleshooting and so on by using kiln operation analysis tool, KilnSimu. This time, we applied the KilnSimu analysis technology to this work. Continue reading

Two Stage Ammonia Combustion in a Gas Turbine like Combustor for Simultaneous NO and Unburnt Ammonia Reductions

Akihiro Hayakawa*, K.D. Kunkuma A. Somarathne, Masaaki Tsukamoto, Taku Kudo, Hideaki Kobayashi, Tohoku University, Japan

15th Annual NH3 Fuel Conference, Pittsburgh, PA, October 31, 2018
NH3 Energy+ Topical Conference at the AIChE Annual Meeting

ABSTRACT

Ammonia is expected not only as a hydrogen energy carrier but also as a carbon free fuel. Recently, ammonia fueled gas turbine combustor was successfully demonstrated. However, large amount of NOx was produced when ammonia burns because ammonia includes nitrogen atom in the ammonia molecule. In addition, unburnt ammonia concentration in exhaust gas also needs to be reduced. In this study, we proposed a combustion concept in order to reduce NO and unburnt ammonia concentrations in the exhaust gas simultaneously in a gas turbine like model swirl combustor. In this concept, two stage (rich – lean) combustion was employed. Two stage (rich – lean) combustion has been already employed in hydrocarbon fueled gas turbine combustors in order to reduce thermal NOx. However, the two stage combustion for ammonia fuel is different from that of hydrocarbon because production path of NO is different each other, i.e., NOx is generated via fuel NOx path in the ammonia flame. Continue reading

Development of Low-NOx Combustor of Micro Gas Turbine Firing Ammonia Gas

Osamu Kurata*, Norihiko Iki, Takahiro Inoue, Takayuki Matsunuma, National Institute of Advanced Industrial Science and Technology (AIST), Japan; Taku Tsujimura, Hirohide Furutani, Fukushima Renewable Energy Institute, AIST (FREA), Japan; Masato Kawano, Keisuke Arai, Toyota Energy Solutions, Japan; Ekenechukwu C. Okafor, Akihiro Hayakawa, Hideaki Kobayashi, Tohoku University, Japan

15th Annual NH3 Fuel Conference, Pittsburgh, PA, October 31, 2018
NH3 Energy+ Topical Conference at the AIChE Annual Meeting

ABSTRACT

A massive influx of renewable energy is required in order to mitigate global warming. Although hydrogen is a renewable media, its storage and transportation in large quantity is difficult. Ammonia, however, is a hydrogen energy carrier, and its storage and transportation technology is already established. Although ammonia fuel combustion was studied in the 1960s in the USA, the development of an ammonia fuel gas turbine had been abandoned because combustion efficiency was unacceptably low [1]. Recent demand for hydrogen energy carrier revives the usage of ammonia fuel. The National Institute of Advanced Industrial Science and Technology (AIST) in Japan, in collaboration with Tohoku University successfully realized ammonia-kerosene gas turbine power generation in 2014, and ammonia fuel gas turbine power generation in 2015 by using 50-kWe class gas turbine [2, 3].

The drawback of the facility is that it requires a large-size selective catalytic reduction (SCR) to decrease the high concentrations of NOx. In order to promote the widespread of ammonia combustion gas turbine system, it is necessary to downsize SCR NOx reduction. In other words, it is important to reduce NOx emission from ammonia gas turbine combustor. AIST has begun developing low-NOx combustors by using a combustor test rig. Simultaneously, fundamental research was carried out at Tohoku Univ. It was found at Tohoku Univ. that rich-lean two-stage combustion method and a control of equivalence ratio of the primary combustion zone to around the value of 1.1 to 1.2 significantly decreases NO emissions in gas-turbine swirl combustor [4, 5]. Continue reading

Basic Co-Firing Characteristics of Ammonia with Pulverized Coal in a Single Burner Test Furnace

Akira Yamamoto*, Masayoshi Kimoto, Yasushi Ozawa, Saburo Hara, Central Research Institute of Electric Power Industry (CRIEPI), Japan

15th Annual NH3 Fuel Conference, Pittsburgh, PA, October 31, 2018
NH3 Energy+ Topical Conference at the AIChE Annual Meeting

ABSTRACT

Ammonia is expected as a potential fuel to substitute fossil fuels, because it does not discharge carbon dioxide and is easily handled by liquefaction. There are several ways for the direct use of ammonia as a fuel; for example, use in fuel cells and combustion devices. One of the possible application is the combustion use in thermal power plants. In particular, co-firing of ammonia in coal-fired power plants seems to have a relatively great advantage on the suppression of greenhouse gases, because coal is one of the main emission source of carbon dioxide. On the other hand, it is concerned that concentration of nitrogen oxides (NOx), which is one of the typical atmospheric pollutant, in the flue gas would considerably increase due to the oxidation of ammonia. To utilize ammonia as a co-firing fuel in existing pulverized coal-fired power plant, without causing additional costs for the modification of the denitration equipment, it is important to develop a combustion technology that can suppress the NOx concentration in the flue gas. Co-firing characteristics of pulverized coal and ammonia, however, had not been evaluated except in the case of very low co-firing rate for the purpose of denitration in the pulverized coal flame. In this study, basic co-firing characteristics of pulverized coal and ammonia were investigated using a bench-scale single burner test furnace. Continue reading