Sustainable design of biorefinery processes: existing practices and new methodology

Nowadays, eco-designing products is increasingly practiced. The next challenge for sustain- ability is to optimize production processes. Biorefi neries are particularly concerned with this improve- ment, because they use renewable resources. To identify the contribution of transformation processes to the overall environmental impacts, Life Cycle Assessment (LCA) appears as the adequate method. A literature review highlights that LCA is mainly performed on biorefi neries to compare biomass feed- stocks between them and to a fossil reference. Another part of environmental LCA compares the impacts of different processing routes. Nevertheless, these evaluations concern already designed pro- cesses. Generally, processes are considered as a unique operation in assessments. However, some criteria like operating can notably modify environmental burdens. The eco-design of biorefi nery pro- cesses can be guided by coupling process simulation to LCA. This method has been emerging in the chemical sector in recent years. Consequently, this paper proposes a new methodological approach to assessing the complete sustainability of biorefi nery processes, since its fi rst design stages. In addi- tion to coupling process simulation and environmental LCA, the other pillars of sustainability will be assessed. Indeed, Life Cycle Costing and Social Life Cycle Assessment can be performed to obtain an integrated methodological framework. The simultaneous optimization of the environmental, economic, and social performances of the process can lead to antagonist ways of improving. Consequently, compromises should be realized. Thereby, the multi-objective optimization can be accomplished by a metaheuristic method supported by a decision-making tool. Finally, the main limits of this method and some perspectives and ways for improving are discussed

Geothermal Feasibility Study near Ede (The Netherlands): Application of Seismic/Gravity Interpretation, Log Upgrading and Diffraction Imaging

As part of the application for a geothermal exploration permit in the Ede region (The Netherlands) a geological assessment study was conducted. The geothermal heat shall be used to feed the existing heat network. Major challenges were the interpretation of sparse vintage 2D seismic data in the region and finding a suitable drilling site in an urbanized environment outside the nearby Hoge Veluwe nature reserve. Data used included well data from two wells, gravity and a collection of 2D seismic lines. The workflow involves complete well velocity and density log upgrading, followed by seismic reprocessing, gravity and seismic interpretation and geothermal prospectivity estimation. An attractive reservoir has been found at ~2,5km depth, the Slochteren Sandstone formation, which is a well-known Permian reservoir rock formation. Diffraction imaging on one of the seismic lines demonstrated the presence of fractures that improves the prospectivity of the geothermal reservoir. The permit has been granted and follow-up work is planned

Cardioprotective effect of trimetazidine and nifedipine in guinea-pig hearts subjected to ischaemia

The cardioprotective effects of nifedipine and trimetazidine were evaluated in the Langendorff heart, the working heart and the heart-lung preparation of the guinea-pig. The effects of pretreatment with the drugs on cardiac function and on high energy phosphate content after global ischaemia were determined. Nifedipine was 1000-fold more active than trimetazidine in depressing cardiac functional parameters. In the Langendorff heart, nifedipine, but not trimetazidine, increased the coronary flow. With the exception of trimetazidine (4 x 10-5 mol/l) in the Langendorff heart, nifedipine and trimetazidine markedly improved and in a similar fashion, the recovery of cardiac mechanical parameters in the three models of myocardial ischaemia. Pretreatment with nifedipine, but not with trimetazidine, resulted in slightly but statistically not significant higher ATP-levels after global ischaemia in the working heart and in the heart-lung preparation. After reperfusion, the cardioprotective effect of nifedipine was associated with increased ATP-levels, whereas that of trimetazidine was merely related to increased phosphocreatine (PCr) levels. In the pithed rat, trimetazidine did not influence the vasoconstrictor response to the selective α1-adrenoceptor agonist cirazoline or to the selective α2-adrenoceptor agonist B-HT 920. The latter response is known to be strongly dependent on the influx of extracellular calcium. Nifedipine caused a pronounced inhibition of vasoconstriction evoked by B-HT 920. These results indicate that trimetazidine is devoid of calcium entry blocking activity. The data obtained clearly show that trimetazidine exerts a pronounced beneficial effect on the ischaemic myocardium without influencing hemodynamic parameters. The mechanism of the cardioprotective activity of the drug is not related to calcium entry blockade or α-adrenoceptor antagonism, but rather caused by a mechanism at a cellular level, so far not known in detail