Peter Markewitz

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.

Chemical Technologies for Exploiting and Recycling Carbon Dioxide into the Value Chain

While experts in various fields discuss the potential of carbon capture and storage (CCS) technologies, the utilization of carbon dioxide as chemical feedstock is also attracting renewed and rapidly growing interest. These approaches do not compete; rather, they are complementary: CCS aims to capture and store huge quantities of carbon dioxide, while the chemical exploitation of carbon dioxide aims to generate value and develop better and more-efficient processes from a limited part of the waste stream. Provided that the overall carbon footprint for the carbon dioxide-based process chain is competitive with conventional chemical production and that the reaction with the carbon dioxide molecule is enabled by the use of appropriate catalysts, carbon dioxide can be a promising carbon source with practically unlimited availability for a range of industrially relevant products. In addition, it can be used as a versatile processing fluid based on its remarkable physicochemical properties.

How Clean is Clean? Incremental versus Radical Technological Change in Coal-Fired Power Plants

In the discussion on innovations for sustainable development, radical innovations are frequently called for in order that the transformation of society to a system perceived as sustainable can succeed. The reason given for this is the greater environmental efficiency of these innovations. This hypothesis is, however, not supported by empirical evidence. Against the background of a globally increasing use of coal-burning power plants and the environmental impacts to be expected, the hypothesis that radical innovations are superior to incremental innovations is reviewed on the basis of fossil fuel power plants. This paper examines the diffusion of incremental and radical innovations in the field of power plants and the basic obstacles with which these innovations were confronted. To give an example, Pressurised Pulverised Coal Combustion (PPCC) as a radical innovation and supercritical coal-fired power plants as an incremental innovation are compared. An ex-post analysis of the German R&D portfolio in the past three decades in the field of power plants environmentally shows that technologies which were radical innovations had great difficulties in becoming accepted by possible investors. The future potential of radical innovations in the field of power plant technology is to be regarded as relatively low, especially due to comparatively high cost-pressure, the reluctance of utilities to take risks and the temporal dynamics of technological progress facilitating incremental innovations on the basis of conventional reference technology. The conclusion for future R&D work in the sector of large-scale power plants is that an innovation is more likely to succeed the more it follows established technological trajectories. In the context of energy market liberalisation, hardly any radical innovations are expected in this field of technology. The findings of this paper may also be helpful in evaluating risks or probabilities of success of technologies being developed. As an example technological trajectories currently favoured in CO2 capture are discussed.

Opportunities for Utilizing and Recycling CO2

Complementing Carbon Capture and Storage (CCS), the utilization of carbon dioxide (CCU) as chemical feedstock and versatile processing fluid is attracting rapidly growing interest in science and industry. The chemical exploitation of carbon dioxide aims to generate value by producing polymeric and inorganic materials, fine chemicals and other products in which large amounts of carbon are fixated for an extended period of time. Provided that the reaction of the CO2 molecule is enabled by the use of appropriate catalysts and process conditions and that the overall carbon footprint of the CO2-based process chain is competitive with conventional chemical production, carbon dioxide can be a promising carbon source with practically unlimited availability.

Impact of different time series aggregation methods on optimal energy system design

Abstract Modeling renewable energy systems is a computationally-demanding task due to the high fluctuation of supply and demand time series. To reduce the scale of these, this paper discusses different methods for their aggregation into typical periods. Each aggregation method is applied to a different type of energy system model, making the methods fairly incomparable. To overcome this, the different aggregation methods are first extended so that they can be applied to all types of multidimensional time series and then compared by applying them to different energy system configurations and analyzing their impact on the cost optimal design. It was found that regardless of the method, time series aggregation allows for significantly reduced computational resources. Nevertheless, averaged values lead to underestimation of the real system cost in comparison to the use of representative periods from the original time series. The aggregation method itself e.g., k-means clustering plays a minor role. More significant is the system considered: Energy systems utilizing centralized resources require fewer typical periods for a feasible system design in comparison to systems with a higher share of renewable feed-in. Furthermore, for energy systems based on seasonal storage, currently existing models integration of typical periods is not suitable.

The System Value of CCS Technologies in the Context of CO2 Mitigation Scenarios for Germany

This chapter analyses the system value of CCS in Germany within the context of consistent greenhouse gas reduction scenarios with and without the implementation of CCS technologies. The system value of CCS is determined using additional CO2 avoidance costs that would occur if climate change mitigation targets were to be met without using CCS even though CCS technology was available. The development of important parameters, assumptions and energy- and climate-policy targets are represented in scenarios. The methodological basis for the scenario calculations is the bottom-up energy system model IKARUS. The energy economics results comprise energy and CO2 balances, capacity development, and the costs of CO2 reduction strategies. From this, the system value of CCS and the contribution of all sectors to it are derived.

IKARUS - A fundamental concept for national GHG-mitigation strategies

Abstract Within the frame of the German IKARUS project a bottom-up energy optimization model and a macroeconomic simulation model based on the input-output approach have been developed. Under the restriction to reduce energy related CO 2 emissions by 25 % until 2005, first model runs have been done for the German Previous States.

The future role of CO2-capture as part of a german mitigation strategy

Publisher Summary This chapter discusses the role that CO2 capture and sequestration (CCS) technologies could play within the scenarios of Germany as a mitigation strategy. As the presentation shows, the use of CCS can represent an interesting mitigation option in view of stringent CO2 reduction goals. The scenarios, performed with the aid of the IKARUS optimization model, however, show that according to cost-efficiency criteria a large number of measures would have to be taken covering all energy sectors. It may be seen that CCS can compete with other mitigation options and in some cases may be more cost-effective. CCS can at best represent one element in an overall strategy. If the existing total power plant capacity in Germany is extrapolated, a considerable number of outdated power plants will have to be replaced in the next 20 years. To make CO2-free power plants available at that time, there is a need to enhance R&D efforts currently in progress. Furthermore, the application of retrofitting measures should also be considered.

Time series aggregation for energy system design: Modeling seasonal storage

The optimization-based design of renewable energy systems is a computationally demanding task because of the high temporal fluctuation of supply and demand time series. In order to reduce these time series, the aggregation of typical operation periods has become common. The problem with this method is that these aggregated typical periods are modeled independently and cannot exchange energy. Therefore, seasonal storage cannot be adequately taken into account, although this will be necessary for energy systems with a high share of renewable generation.

Carbon Capture Technologies

This chapter focuses on carbon capture technologies that can be used in coal fired power plants and industrial processes. The three technology lines (post combustion, pre-combustion, oxyfuel) will be described in terms of state of the art, efficiency losses and advantages and disadvantages. An outlook will be given of further developments in the long term (second generation). Special attention will be paid to retrofitting options of existing coal fired power plants. An increasing share of highly volatile renewable power generation will change the flexibility requirements of coal fired power plants. Against this background flexibility options will be discussed for power plants with carbon capture technologies.