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AbstractWe present a detailed study about the influence of post-deposition temperature treatment on PECVD Al2O3 passivation layers. Fourier transform infrared spectroscopy (FTIR) and quasi-steady-state photoconductance (QSSPC) were applied for characterization. We observed several indications of structural changes of the Al2O3 layer with annealing duration, temperature and layer thickness. A shift and an increase of the Si-O vibrational mode (1100- 980cm-1) in the FTIR measured with changing temperature and layer thickness is presented. Structural changes of the Al2O3 layer with annealing duration, temperature, and layer thickness, caused by changes in the oxygen concentration within the SiOx layer are observed for the different FTIR spectra. We also detected a water band at 1650-1630cm-1 and other OH components around 3200cm-1-400cm-1 depending on annealing temperature and time. For a temperature of 820°C, a dramatic change of the Al2O3 peak (650-700cm-1) is observed. This is probably due to the crystallization of the film.

AbstractGas scrubbing using aqueous amine solutions is the most promising retrofit option for post combustion CO2 capture today. Therefore, new solvents combining favorable characteristics are developed to optimize the overall performance and replace the benchmark process with MEA. This work reports absorption rates and CO2 loadings of fresh and regenerated MEA, EDA, AMP solutions and EDA-AMP blends under different gas compositions. EDA, AMP and their blend show advantageous characteristics during absorption of 100% CO2. However, in presence of SO2 and O2 performance losses occur so that further investigations with degradation inhibitors, varied blend concentrations and blends containing other amines are of interest.

AbstractThe present study deals with the mechanical properties of structured reactors/heat exchangers, for high temperature heat storage via the cobalt oxide cyclic redox scheme. Two different structures (i.e. honeycomb and perforated block) and two different compositions (i.e. 100% cobalt oxide and 90 wt% cobalt oxide – 10 wt% aluminium oxide) were evaluated. During thermal cycling in the range of 800-1000oC, different loads were applied to the sampleswhile monitoring their length variation. The integrity of the samples was assessed after every cycle. It was found that mechanical strength was substantially improvedupon addition of 10 wt% aluminium oxide. The cobalt oxide/alumina composite presented lower maximal expansion during cycling and exhibited higher integrity, already after one thermal cycle.Another important result is that, for both the honeycomb and the perforated block, the load decreases the over-all sample net expansion. Moreover, the perforated block exhibited lower expansion and better mechanical strength as compared to the honeycomb. Due to the better chemical performance expected to be achieved by the honeycomb structure, a compromise between these two structureshas to be chosen (e.g. honeycomb structure with thicker walls). The results are used for building a thermochemical storage system prototype, implemented for the first time in an existing concentrated solar power facility (STJ).

AbstractCCS is discussed in a broad sense throughout Europe. In this paper a cautious, conservative estimate of CO2 storage capacity for Germany and its neighboring countries where CO2 emissions from Germany could possibly be stored (Netherlands, France, Denmark, Norway, UK and Poland) is presented. Such a lower limit calculation is necessary for orientation purposes for potential investors and political decision-makers.Conservative CO2 sequestration capacity in deep saline aquifers for Germany is derived by the volumetric approach where parameters such as efficiency factor, CO2 density, porosity of the geological formation are of interest. It is assumed that every geological system is closed and thus an efficiency factor of 0.1 per cent (based on maximum pressure increase and total compressibility) for saline aquifers is applied. The capacity of German depleted oil and gas fields is based on cumulative recovery data and a sweep efficiency of 75 percent.The storage capacity in the other considered countries, adjacent to Germany, are based on a critical review and adjustment of the results of the European reports JOULE II, GESTCO and GeoCapacity.The conservative capacities for all countries together amount to 49 Gt CO2, from which Norway and the UK provide 36 Gt, all offshore in the North Sea. Compared to the emissions from large point sources in these countries during 40 years (47.6 Gt of CO2), a virtual balance is achieved. This can only be reached, if a large scale CO2 pipeline system is installed to connect these countries, especially Germany, to the large sinks in the North Sea. If additional restrictions like source-sink matching, acceptance issues and injection rates constraints are taken into account, the available storage space gets increasingly scarce.

Abstract A fundamental challenge of the German energy transition is the energy supply of industrial and chemical parks based on renewable energy. Presently, the energy demand of a chemical park with one third electricity and two thirds heat as a rough estimate is commonly supplied by a heat-controlled fossil fired combined heat and power (CHP) plant. If applicable, the surplus electricity generated by such plants is sold and fed into the grid. Since the reliable energy supply of all users and facilities is priority, energy storage can be incorporated, if fluctuating renewable energy sources shall be used. This paper presents energy supply concepts without adjustments to the industrial park infrastructure or the processes themselves and proposes utilization of high temperature thermal energy storage (TES) technologies such as molten-salt, as well as power-to-heat (PtH) technology in the central CHP supply infrastructure. The objective of this study is to identify the major possibilities for integrating TES in a future energy supply system for an industrial park in Germany. It shall be shown how the flexibility of an utility supplier can be increased, so that further revenue can be generated from participating in the energy market. For this task different concepts will be proposed and applicable TES technologies will be identified. The benefits for the utility supplier and how carbon dioxide reduction and integration of renewable energies can be achieved will be highlighted. Finally, an overview of concepts with additional TES and PtH components for the energy supply of industrial or chemical parks in Germany is presented qualitatively. This overview includes the following criteria: flexibility, carbon dioxide reduction and the increased use of CHP. Overall a better understanding of potential flexibility measures for the utility supply infrastructure in the chemical industry is generated.

AbstractThis paper presents two different reactor concepts, an external and integrated reactor, for thermochemical energy stores which are operating in an open process using ambient air for the heat and mass transport. In the external reactor concept the material charging and discharging is performed in a reactor separated from the material store whereas in the integrated reactor concept the charging and discharging take place directly in the material store itself. For both reactor concepts, the heat and mass transfer inside the reactor or the material store respectively, have been analyzed in detail by means of numerical simulations. Based on the theoretical investigations a reactor design and an operation strategy have been developed. At laboratory scale an external test reactor (approx. 20 l of storage volume) has been built and experimentally tested. The experiments have proven the concept of the developed reactor design. A high thermal performance during the charging and discharging process of the thermochemical energy store has been obtained.

AbstractThis study investigates the impact of current steel lintels on the CO2 emissions of a notional building when trying to comply with the new PART L1A 2013 of the Building Regulations of England and Wales. For this purpose different families of lintels were assessed under SAP2009 using 12 different cavity walls with U-value under 0.18W/m2K. Any of the current steel lintels without base plate studied in this research were found to be useable under PART L1A 2013. Their impact, depending also upon the construction detail used, could vary from 3% to 0.7% of the DFEES and from 1.6 to 0.4% of the DER of the notional building here studied.

This research focused on the development of MEPCMs for thermal energy storage in low carbon buildings with poly (methyl methacrylate) (PMMA) shell. The experimental results showed that the best MEPCM sample was prepared with 1 wt% of the thermal initiator and the surfactant of S-1DS. The differential scanning calorimetric (DSC) analysis showed that the best sample has a latent heat of 170 kJ/kg and a melting temperature of 22.68 ℃. Meanwhile, the core material contents and encapsulation efficiencies were calculated according to the measured results of the DSC. Those two values for the sample of PMMA-3 and PMMA-5 were even higher than theoretical values due to the evaporation of shell monomer during encapsulation processes. Finally, the thermogravimetric (TG) analysis of the fabricated MEPCM samples showed good thermal stability behaviors above 161 ℃ and therefore satisfy the environmental requirements for most applications.