• Energy Research

This paper combines an existing projection of the development of electricity production with a technology-specific environmental assessment. The combination of these two approaches, which so far have only been performed separately, allows a discussion about environmental effects of carbon capture and storage (CCS) implementation strategies on a national level. The results identify the future role of lignite and hard coal in German power production. The implementation of CCS technology leads to a considerable loss of efficiency. Due to CCS, about 50 million t of lignite will be additionally required in 2030 in comparison to the reference case without CCS in 2010. Increasing demand, the replacement of old plants and the compensation of efficiency losses lead to highly ambitious expansion rates. In the case of CCS implementation, the global warming potential (GWP) can be reduced by up to 70%. However, other environmental impacts increase in part considerably. Compliance with national ceilings for NOx emissions can only be reached by compensation measures in other sectors. The results of the environmental assessment demonstrate the significant role of the coal composition, coal origin and the required transport. CO2 pipeline transport and CO2 storage make a fairly minor contribution to the overall environmental impact.

Abstract 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.

Abstract CO 2 reduction from fossil-fired power plants can be achieved by carbon dioxide capture and storage (CCS). Among different CO 2 capture technologies for power plants the oxyfuel power plant concept is a promising option. High temperature ceramic membranes for oxygen production have the potential to reduce the associated efficiency losses significantly compared to conventional air separation using cryogenic techniques. Focus of this paper is the environmental performance of membrane-based oxygen production for oxyfuel power plant technology. Included into the analysis are the production of the perovskite membrane (BSCF=Ba 0.5 Sr 0.5 Co 0.8 Fe 0.2 O 3− δ ), the incorporation into a steel module, and the integration of several modules into an oxyfuel power plant. The membrane-based oxygen production is compared to the conventional cryogenic air separation in oxyfuel power plants in an ecological way. The evaluation is performed using life cycle assessment (LCA) methodology from “cradle to grave”. The share in the overall environmental impacts of respective life cycle elements like membrane and module production but also coal supply processes as well as the operation of the oxyfuel power plant are identified. Sensitivity analyses referring to life-time, permeability and housing conditions of the membranes set benchmarks for further membrane development.

Copper is, due to its divergent properties, a popular metal. Nevertheless, from the ecological point of view, processing of copper has some drawbacks. For example, copper ores contain elements, like sulphur, which could be damaging. Recently, global copper-demand increased, mainly due to rising Chinese imports. In the longer-term, the environmental impacts could intensify as an increase in demand for copper products is expected, so enforcing growing mining and processing activities. However, at least two trends can counteract these developments: technical progress and increased use of recycled metal. The objective of this study is to discuss whether the trends will enforce a sustainable development of the copper material flow, focusing on carbon-dioxide emissions and sulphur. The study is made by using a process-based partial equilibrium model, modelling the global copper material flow, considering recycling of copper as well as by-products. The allocation of output and technology to regions is based on economic decisions subject to the constraints set by existing techniques. By discussing the longer-run development of the global copper material flow, one scenario will be computed.

AbstractThe Rio +20 conference in 2012 confirmed not only the sustainability concept as the new development goal but also introduced the green economy as its implementation strategy and the life cycle assessment (LCA) as one of its analysis tools to reveal the current production and consumption patterns which affect human well-being.Human well-being therefore has to be defined. We describe human well-being using the capability approach of Amartya Sen. Current production and consumption patterns have an influence on human well-being, on people's functioning and capabilities. Consumption patterns alter and the energy sector is in Germany at the centre of that process. Renewable energy technologies are seen as instruments for a transformation of the energy system, causing non-renewable (mineral) resources such as the rare earth elements to be of high significance for the transformation. To analyse social conditions (human well-being) throughout the life cycle of the product we focused on five major functionings (welfare basis, health & safety, social participation, democracy & freedom, decent life) and assigned 24 impact issues to them to enable an assessment of the social effects of the rare earth production along the whole process chain.The analysis of social impacts of the production of the rare earth elements using S-LCA is developed to illustrate the connection between the S-LCA and the capability approach – Amartya Sen's concept of human well-being.

AbstractDue to an increased awareness of climate change and limited fossil resources, the demand for alternative energy carriers such as biomass has risen significantly during the past years. This development is supported by the idea of a transition to a bio‐based economy reducing fossil‐based carbon dioxide emissions. Based on this trend, biomass for energy is expected to be used in the EU mainly for heating until the end of the decade. The perennial herbaceous mallow plant Sida hermaphrodita (L.) Rusby (‘Sida’) has high potential as an alternative biomass plant for energy purposes. Different density cultivation scenarios of Sida accounting for 1, 2, or 4 plants per m2 resulted in a total biomass yield of 21, 28, and 34 tons dry matter/ha, respectively, over a 3‐year period under agricultural conditions while the overall investment costs almost doubled from 2 to 4 plants per m2. Subsequently, Sida biomass was used as SI) chips, SII) pellets, and SIII) briquettes for combustion studies at pilot plant scale. Pellets outcompeted chips and briquettes by showing low CO emission of 40 mg/Nm3, good burnout, and low slagging behavior, however, with elevated NOx and SO2 levels. In contrast, combustion of chips and briquettes displayed high CO emissions of >1,300 mg/Nm3, while SO2 values were below 100 mg/Nm3. Contents of HCl in the flue gas ranged between 32 and 52 mg/Nm3 for all Sida fuels tested. High contents of alkaline earth metals such as CaO resulted in high ash melting points of up to 1,450°C. Life cycle assessment results showed the lowest ecological impact for Sida pellets taking all production parameters and environmental categories into consideration, showing further advantages of Sida over other alternative biomasses. Overall, the results indicate the improved applicability of pelletized Sida biomass as a renewable biogenic energy carrier for combustion.

Abstract As part of a comprehensive evaluation of the use of Sida hermaphrodita (hereafter referred to as Sida) biomass as a solid biofuel, a life cycle assessment (LCA) according to ISO 14040/14044 was carried out by means of a suitable cradle-to-gate system design. The supply and use of chips, pellets and briquettes was studied by internal and external comparisons to show competitiveness and improvement options. The results show fewer differences within the Sida process chain designs but larger distinctions to compared alternative biofuels such as wood or Miscanthus pellets. A major finding is that Sida process chains cause lower environmental impacts in comparison with alternative biofuels. The study identified hot spots within the Sida process chains and starting points for further improvement. A sensitivity analysis of important parameters, such as specific yield or heating values was performed. Because there are no similar investigations on the environmental impact of Sida used as a biogenic solid fuel to date this manuscript presents first results. So far, the results indicate that Sida provides a more sustainable option for the use of biomass in combustion processes in relation to environmental impacts.

AbstractIncreasing renewable energy generation influences the reliability of electric power grids. Thus, there is a demand for new technical units providing ancillary grid services. Intermittent renewable energy sources can be balanced by energy storage devices, especially battery storage systems. By battery systems grid efficiency and reliability as well as power quality can be increased. A further characteristic of battery systems is the ability to respond rapidly and precisely to frequency deviations, making them technical ideal candidates for primary control provision (PCP). PCP by battery systems is applied in form of positive (discharge mode) and negative control (charge mode) and can reduce must-run capacity of fossil power plants.In this study environmental impacts of PCP by novelLi-ion large-scale battery energy storage systems (BESSs) are compared to impacts of PCP by state-of-the-art coal power plants (CPPs) using a Life Cycle Assessment (LCA) approach. An inventory of all relevant inputs (resources, material and energy flows) and outputs (emissions, wastes and waste water) is compiled. Environmental impacts associated with these inputs and outputs are evaluated. Finally, PCP by BESSs and fossil power plants are compared in terms of environmental performance. Different scenarios are analyzed by varying sensitive parameters like efficiency loss due to PCP at fossil power plants and required must-run capacity for PCP.