Techno-economic and Environmental Comparison of Internal Combustion Engines and Solid Oxide Fuel Cells for Ship Applications

Solid oxide fuel cells (SOFCs) have the attractive feature to be able to make use of hydrocarbon fuels in their operation by reforming the fuel into pure hydrogen, either internally or externally. This can open up for a smoother transition from the existing hydro-carbon economy toward a more renewable hydrogen economy. Since both SOFCs and internal combustion (IC) engines can make use of hydrocarbon fuels, it is of interest to examine the major differences in their utilization of the hydrocarbons and investigate how this type of fuel contributes to the power output of the respective systems. Thereby, various advantages and disadvantages of their reactions are raised. It was shown that even though there are fundamental differences between SOFCs and IC engines, both types face similar problems in their designs. These problems mostly include material design and operation management, but even problems related to the chemical reactions, e.g., carbon deposition for SOFCs and pollutant formation for IC engines.

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Cost Requirements for a Small-Scale SOFC Fed From Agricultural-Derived Biogas

Journal of Electrochemical Energy Conversion and Storage ◽

10.1115/1.4035891 ◽

2017 ◽

Vol 14 (1) ◽

Cited By ~ 4

Author(s):

Samuel Majerus ◽

Dirk Lauinger ◽

Jan Van herle

Keyword(s):

Fuel Cells ◽

Solid Oxide Fuel Cells ◽

Internal Combustion Engines ◽

Lifetime Cost ◽

Solid Oxide ◽

Small Scale ◽

Combustion Engines ◽

Oxide Fuel ◽

Main Challenge ◽

Investment Cost

In this work, the use of fuel cells for valorizing agricultural-derived biogas in Switzerland is studied. The Swiss agricultural case is characterized by farms with small numbers of animals (20 cows) and high feed-in tariffs (FIT) for biogas-derived electricity (0.49 CHF/kWhel). Thus, small-scale biogas installations are reviewed and the possibility to couple them with solid oxide fuel cells (SOFCs) and photovoltaic (PV) panels is analyzed. To date, less than 5% of the Swiss agricultural biogas potential is used. It is possible to increase this value significantly up to 86% through the deployment of 2 kWel engines. The small size of the Swiss farm requires biogas installations in the kW-range. Small-scale biogas facilities are not profitable yet: the main challenge is to bring down the lifetime cost of the fuel cells to 11,000 CHF/kWel (considering a lifetime of ten years) and to reduce the investment cost (IC) of small-scale biogas facilities to around 9500 CHF/kWch. In the kW-range, solid oxide fuel cells (SOFCs) have higher electrical conversion efficiencies than internal combustion engines (ICEs). It is shown that SOFCs become competitive over combustion engines if the investment cost of the former decreases below 13,000 CHF/kWel for a lifetime of 11 years. Combining the biogas facility with a PV-battery system, which covers the digester's electricity needs, is found to be beneficial. A considerable reduction in the feed-in tariffs would make small- to medium-scale biogas installations unprofitable, at current cost. In order to reach a break-even under these conditions, the investment cost of the biogas plant needs to drop below 4000 CHF/kWch, whereas the investment cost of the SOFC needs to drop below 3400 CHF/kWel.

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Energetic and Exergetic Analysis of Building Cogeneration Systems

ASME 2008 2nd International Conference on Energy Sustainability, Volume 1 ◽

10.1115/es2008-54033 ◽

2008 ◽

Author(s):

Yilmaz Yoru ◽

T. Hikmet Karakoc ◽

Arif Hepbasli ◽

Enis T. Turgut

Keyword(s):

Fuel Cells ◽

Solid Oxide Fuel Cells ◽

Gas Turbines ◽

Internal Combustion Engines ◽

Internal Combustion ◽

System Capacity ◽

Combustion Engines ◽

Exergetic Analysis ◽

External Combustion ◽

Thermophotovoltaic Systems

This study deals with types of micro cogeneration (or micro combined heat and power, MCHP) systems and reviews energetic and exergetic analysis of MCHP systems, which are also called building cogeneration systems. These are classified as micro and macro cogeneration systems and figured within subgroups. Previously conducted studies on exergy and energy analyses of internal combustion engines (micro turbines), external combustion engines (Ericsson engines), fuel cells (solid oxide fuel cells) and thermophotovoltaic systems are treated in this paper. The main objectives of this study are to classify MCHP systems used in building cogeneration systems, to introduce types of MCHP systems and to better define micro cogeneration systems in the light of previously conducted studies. In this regard, energetic and exergetic efficiencies of various MCHP systems are graphically obtained. Under grouping presented MCHP systems, internal combustion engines based MCHP systems are defined to be the best choice with energetic and exergetic efficiency values of 86.0% and 40.31%, respectively. Micro gas turbines and Ericson engine based micro cogeneration systems are also obtained as valuable systems with the energetic values of 75.99% and 65.97% and exergetic values of 35.8% and 38.5%, respectively. However, in this building cogeneration group, energetic and exergetic efficiencies of the thermophotovoltaic systems have 65.0% and 15.0%, respectively. It may be concluded that system choice depends on the type of the system, energy flow of the system, system parts and developments, while building, system capacity, comfort and maintenance are the other factors to be considered.

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