Petra Zapp

Worldwide innovations in the development of carbon capture technologies and the utilization of CO2

While Carbon Capture and Storage (CCS) technologies are being developed with the focus of capturing and storing CO2 in huge quantities, new methods for the chemical exploitation of carbon dioxide (CCU) are being developed in parallel. The intensified chemical or physical utilization of CO2 is targeted at generating value from a limited part of the CO2 stream and developing better and more efficient chemical processes with reduced CO2 footprint. Here, we compare the status of the three main lines of CCS technologies with respect to efficiency, energy consumption, and technical feasibility as well as the implications of CCS on the efficiency and structure of the energy supply chain.

Meta-Analysis of Life Cycle Assessment Studies on Electricity Generation with Carbon Capture and Storage

In the last decade, numerous life cycle assessments (LCAs) on environmental impacts of electricity generation with carbon capture and storage (CCS) have been conducted. This meta‐analysis comprises 15 LCAs of the three CCS technologies (postcombustion, oxyfuel, precombustion) with a focus on greenhouse gas reduction for different regions (Europe, United States, Japan, global), different fuels (hard coal, lignite, natural gas), and different time horizons (between the present and 2050). It presents a condensed overview of methodological variations, findings, and conclusions gathered from these LCAs. All LCAs show the expected reduction in global warming potential but an increase in many other impact categories, regardless of capture technology, time horizon, or fuel considered. Three parameter sets have been identified that have a significant impact on the results: (1) power plant efficiency and energy penalty of the capture process, (2) carbon dioxide capture efficiency and purity, and (3) fuel origin and composition. This meta‐analysis proves that LCA is a helpful tool to investigate the variety of environmental consequences associated with CCS. However, there are differences in the underlying assumptions of the LCAs as well as methodological shortcomings that yield heterogeneity of results. Without a better understanding of the technology, it is not possible to give a comprehensive picture. There also remains a wide field of subjects and technologies that have not yet been covered.

Future carbon dioxide emissions in the global material flow of primary aluminium

This study assesses the future carbon dioxide emissions in the global material flow of primary aluminium. The model of the global aluminium industry (GlobAl model) is used for scenario calculations. It simulates a market economy and allows an integrated analysis of the material flow and the corresponding carbon dioxide emissions. 1995 is the base year and the future horizon of the scenario calculations is 2010. The critical parameter ‘global demand for primary aluminium’ is varied. According to the scenario calculations, the absolute carbon dioxide emissions in the global material flow of primary energy will not increase until the growth rate of demand reaches 2% per year. World average specific emissions will decrease remarkably, especially due to the reduced energy-related emissions for smelting. There are three reasons for this. In the first place, the lower CO2-emission factor of electricity generated from fossil fuels leads to reduced emissions. Secondly, modern point-feeder pre-baked plants need less electricity than the Soderberg plants they replace. And, thirdly, the production of primary aluminium is being shifted to regions in which the production of electricity is mainly based on hydropower.

Lessons Learned from a Life Cycle Sustainability Assessment of Rare Earth Permanent Magnets

Summary In order to address methodological challenges during life cycle sustainability assessment (LCSA), this article combines the results of a life cycle assessment (LCA), a life cycle costing, and a social LCA using the example of a complex product: a rare earth permanent magnet for use in wind turbines. The article presents different approaches for combining the results of separate assessments with its attendant methodological challenges. Different normalization, aggregation methods, and weighing factors are applied and their impacts on the results are compared. The underlying case study makes an evaluation of these different methodologies more concrete. Results show that the normalization method applied has a greater influence on the overall results than the aggregation method or weighting factors. Additionally, this study shows that indifference thresholds should be applied to avoid overestimation of small impacts. Indifference thresholds ensure that impact categories with nearly the same results for all analyzed options are treated as identical results. The study also indicates the importance of the question of how much compensation between impacts is desirable. Despite the impact of these factors, the chosen case study of an LCSA for permanent magnets with different supply routes for rare earths shows that the ranking of Chinese production is the most problematic irrespective of the approaches applied.

Environmental Aspects of CCS

The use of CO2 capture technologies causes efficiency losses which leads to an additional demand of fuel and related other emissions. Also necessary operating materials and a change in waste composition are consequences of this utilisation. Life Cycle Assessment (LCA) has proved to be a helpful tool to investigate the different environmental consequences associated with the introduction of CCS. For all capture routes environmental effects of conventional capture technologies are analyzed. Additionally, the impacts of a second generation capture technology, ceramic membranes, are investigated. The share of life cycle segments, such as power plant operation, fuel supply or CO2 transport and sequestration, can be identified for the different impact categories. Generally, the intended decrease of CO2 emissions goes along with an increase in most other impact categories regardless of technology or fuel used.

Power-to-Gas—Concepts, Demonstration, and Prospects

Abstract Power-to-Gas is a concept to store electricity long term in generation systems dominated by renewable electricity sources, to produce fuels for transportation, household, and industry, or to offer flexibility in demand. Most process steps within a Power-to-Gas system are not new and are mostly mature and already part of the conventional energy system, for example, pipeline transportation of gaseous energy carriers. Electrolysis, however, needs to be fit to the requirements of Power-to-Gas because renewable or excess electricity are only temporarily available. The different electrolysis technologies are discussed in this context. Another special process is the methanation. Two different concepts, catalytic and biological methanation, are available. Both technologies are discussed regarding process design and development status. Furthermore, in Europe, 106 Power-to-Gas projects are known. They are analyzed in terms of their concepts, processes used, and other important parameters. Most of the projects are located in Germany. Other countries, however, have shown increasing interest in the last years. Results of an analysis of energy supply scenarios for different countries point out that the Power-to-Gas potential is locally very different and depends highly on the future development of the different national energy systems.

Analyse des Aluminiumstoffstroms — Potenziale zur Reduktion des Ressourcenbedarfs und der Umweltinanspruchnahme

Die Analyse von Metallstoffstromen, insbesondere des Aluminiumstoffstroms, nimmt in der Diskussion zum Stoffstrommanagement breiten Raum ein. Ursache hierfur sind nicht wie bei einigen anderen Metallen durch Aluminium ausgeloste human-und okotoxikologische Effekte, sondern die durch Herstellung und Nutzung des Werkstoffs ausgelosten direkten und induzierten Stoffstrome. Darunter fallen z.B. Bauxit, Energie und Wasser.