Stationäre Chemische Energieumwandlung als Herausforderungen für den Verfahrensingenieur

Meeting future energy demands with more efficient, lower emission, and safe energy technologies has top priority in the medium term. Consumer-friendly energy concepts, integrated into regional and supraregional energy supply structures, represent further elements. These will make important contributions to resource-conserving and environmentally compatible power supplies utilizing local energy sources including renewable resources. Supplying energy to large areas involves additional tasks, from compensation of large amounts of fluctuating energy to the transport of fluctuating energy to the transport of renewable energy over long distances. Solar dish, parabolic section, and tower power generating plant have considerable economic and CO₂-reduction potential in sunny countries, such as in the Mediterranean region, However, the costs of solar-thermal electricity generation have to be reduced by a factor of 1.5 to 2. Fuel cell systems can attain particular significance as efficient low-emission energy conversion systems in power plant and automative engineering once their technical and economic potential can be realized.     

Modelling the energy balance of an anaerobic digester fed with cattle manure and renewable energy crops

Knowledge of the net energy production of anaerobic fermenters is important for reliable modelling of the efficiency of anaerobic digestion processes. By using the Anaerobic Digestion Model No. 1 (ADM1) the simulation of biogas production and composition is possible. This paper shows the application and modification of ADM1 to simulate energy production of the digestion of cattle manure and renewable energy crops. The paper additionally presents an energy balance model, which enables the dynamic calculation of the net energy production. The model was applied to a pilot-scale biogas reactor. It was found in a simulation study that a continuous feeding and splitting of the reactor feed into smaller heaps do not generally have a positive effect on the net energy yield. The simulation study showed that the ratio of co-substrate to liquid manure in the inflow determines the net energy production when the inflow load is split into smaller heaps. Mathematical equations are presented to calculate the increase of biogas and methane yield for the digestion of liquid manure and lipids for different feeding intervals. Calculations of different kinds of energy losses for the pilot-scale digester showed high dynamic variations, demonstrating the significance of using a dynamic energy balance model.     

Pan-European regional income growth and club-convergence

Club-convergence analysis provides a more realistic and detailed picture about regional income growth than traditional convergence analysis. This paper presents a spatial econometric framework for club-convergence testing that relates the concept of club-convergence to the notion of spatial heterogeneity. The study provides evidence for the club-convergence hypothesis in cross-regional growth dynamics from a pan-European perspective. The conclusions are threefold. First, we reject the standard Barro-style regression model which underlies most empirical work on regional income convergence in favour of a two regime [club] alternative in which different regional economies obey different linear regressions when grouped by means of Getis and Ord’s local clustering technique. Second, the results point to a heterogeneous pattern in the pan-European convergence process. Heterogeneity appears in both the convergence rate and the steady-state level. But, third, the study also reveals that spatial error dependence introduces an important bias in our perception of the club-convergence and shows that neglect of this bias would give rise to misleading conclusions.     

Empirische nichtlineare Berechnung von Kombinierten Pfahl‐Plattengründungen (KPP)

Empirical nonlinear analysis of combined piled‐raft foundation (CPRF). Depending on load‐settlement curve obtained from field measurements or empirical relations, a nonlinear analysis of combined piled‐raft is presented to take into account the actual response of subsoil behavior. In the analysis, each pile is treated as two units, shaft and base, having a uniform settlement along the pile shaft and in the pile base. This assumption enables modeling the nonlinear behavior of combined piled‐raft. The nonlinear response of the pile is based on the DIN 4014 empirical relation of load‐settlement curve. Connecting between empirical and theoretical procedures, a method termed NPRD for nonlinear analysis of combined piled‐raft using DIN 4014 is developed. The procedure meets the requrements of the KPP‐guideline, section 6, to a computation model. The efficiency of NPRD is demonstrated in a comparison computation of Frankfurt Messeturm with the results of different authors. The proposed method was implemented in the program ELPLA. The special cases “single pile/pile group” and “raft” are contained in.