Thermo-economic evaluation of coal power plants with CO2 capture

Actually the world is facing the dual challenge of energy supply security and mitigating climate change due to greenhouse gas emissions. In this context different alternatives to reduce the atmospheric CO2 emissions are increasing the efficiency, switching to renewable resource and reduce emissions from fossil resources by CO2 capture and storage (CCS) . In power plants three different CCS concepts have emerged: post-combustion applying an end of pipe technology to remove CO2, oxy-fuel combustion (i.e. pure O2 oxidation) and pre-combustion (i.e. H2 routes). Coal power plants are supplying a large amount of the world's electricity and contributing to the CO2 emissions increase. The goal of the project is to study the performance of coal power with CO2 capture and to assess the energy penalty and cost of capturing CO2.

Performance evolution and modeling of PEM fuel cell systems

Nicolas Roggo

In the context of climate change mitigation, different alternatives to reduce the atmospheric CO2 emissions are; increasing the efficiency, switching to renewable resource and reduce emissions from fossil resources by CO2 capture and storage (CCS) . Hydrogen is considered as potential alternative to cover the energy needs by using it as a fuel in internal combustion engines or fuel cells, or as chemical source. In proton exchange membrane (PEM) fuel cells, also known as polymer exchange membrane fuel cells, pure hydrogen fuelis combined with the oxygen from the atmosphere to produce water, heat and electricity. Many research has been done in recent years on fuel cell systems leading to higher efficiencies. The performance is influenced by the membrane properties, the catalysts, the number of cells and the operating conditions. For studying the performance of fuel cell systems process modeling is a well-known approach. Here the evolution of fuel cell efficiency, especially of PEMFC is studied within the aim of updating previously developed PEMFC process models to integrate them with different hydrogen production processes using fossil and renewable resources in order to assess the competitiveness on the energy market.

2012

Thermo-environomic evaluation of the ammonia production

François Maréchal, Matthieu Perrenoud, Laurence Tock

Within the global challenge of sustainable energy supply and greenhouse gas emissions mitigation, carbon capture and storage (CCS) and the deployment of renewable resources are considered as promising solutions. In this context, the production of ammonia mainly used in the fertilizer industry that is responsible for a large part of the global CO2 emissions is analyzed in detail in this study. Considering natural gas and biomass as a resource and the option for CO2 capture and storage, different process configurations are systematically compared with regard to energetic, economic and environmental considerations. A consistent thermo-environonomic optimization approach combining flowsheeting, process integration techniques, economic performance evaluation, life cycle assessment and multi-objective optimization is applied for the conceptual process design and the assessment of the competitiveness and the trade-offs. It is highlighted that the quality of the process integration is a key factor for improving the process performance by valorizing the heat excess through electricity cogeneration. Including CO2 mitigation in the ammonia production allows to reduce the emissions, but leads to a slight efficiency decrease due to the additional energy consumption for the compression. For the natural gas fed process yielding an energy efficiency around 65%, the overall life cycle emissions can however be reduced to 0.79kgCO2/kgNH3 with CO2 capture compared to 1.6kgCO2/kgNH3 without capture and to -1.79kgCO2/kgNH3 for the biomass process having an energy efficiency of 50%. The economic competitiveness highly depends on the resource price and the introduction of a carbon tax. This study reveals the potential of the decarbonization of the fertilizer industry.

SFGP2013

Thermo-environomic evaluation of the ammonia production

François Maréchal, Matthieu Perrenoud, Laurence Tock

Within the global challenge of sustainable energy supply and greenhouse gas emissions mitigation, carbon capture and storage and the deployment of renewable resources are considered as promising solutions. In this study the production of ammonia mainly used in the fertilizer industry and responsible for around 2-3% of the world greenhouse gas emissions is analyzed. Considering natural gas and biomass as a resource and the option of CO2 capture and storage, different process configurations are systematically compared with regard to energy, economic and environmental considerations. A consistent thermo-environonomic optimisation approach combining flowsheeting, process integration techniques, economic performance evaluation, life cycle assessment and multi-objective optimisation is applied for the conceptual process design and competitiveness evaluation. It is highlighted that the quality of the process integration is a key factor for improving the performance by valorizing the heat excess through electricity cogeneration. Including CO2 mitigation in the ammonia production allows to reduce the emissions, but leads to a slight efficiency decrease due to the energy consumption for the CO2 compression. For the natural gas fed process yielding an energy efficiency around 65%, the overall life cycle emissions can be reduced to 0.79kgCO2/kgNH3 with CO2 capture compared to 1.6kgCO2/kgNH3 without capture. Considering the biogenic nature of the carbon in the biomass, the emissions drop to -1.79kgCO2/kgNH3 for the biomass process having an energy efficiency of 50%. The economic competitiveness highly depends on the resource price and the introduction of a carbon tax. This study reveals the potential of the decarbonisation of the fertilizer industry. This article is protected by copyright. All rights reserved

Wiley-Blackwell2015