Global Nest Journal最新文献

{"title":"International overview on waste to biofuel options with a focus on waste potentials in Germany and funding incentives in the EC.","authors":"J. Kretzschmar, S. Majer, M. Kroeger, G. S. Miguel, S. Rincón, D. Vagiona","doi":"10.30955/gnj.000850","DOIUrl":"https://doi.org/10.30955/gnj.000850","url":null,"abstract":"Biofuels represent a possibility to reduce greenhouse gas (GHG) emissions within the transport sector. In this context the sustainability of biofuels, especially so called 1 generation biofuels led to controversial discussions in the past. Biofuels from waste and residues represent a well suited but quantitative limited alternative due to their sustainability. At an international level, different approaches for converting waste and residues into biofuels can be found. Developing countries in general use classic transesterification of waste fats to produce biodiesel. Technically advanced options such as pyrolysis, gasification, Fischer-Tropsch-Diesel, anaerobic fermentation and distillation, as well as biogas production coupled with biomethane upgrading, are mostly found in industrialized countries. Within this study, different waste to biofuel options are reviewed ranging from small scale to industrial scale and take into account used raw materials, technological application and (potential) GHG-reduction. Further the potential of several wastes and residues for gasification processes and synthesis of biofuels in Germany is described. Biofuel from waste offers promising funding incentives because of the “double counting” according to 2009/28/EC and the switch in mandatory blending from an amount based quota to a GHG-based blending quota in 2015.","PeriodicalId":55087,"journal":{"name":"Global Nest Journal","volume":"14 1","pages":"183-191"},"PeriodicalIF":1.1,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69259068","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Anaerobic treatment of sewage sludge and grease trap sludge in continuous co-digestion.","authors":"E. Neczaj, J. Bien, A. Grosser, G. Worwag, M. Kacprzak, G. S. Miguel, S. Rincón, D. Vagiona","doi":"10.30955/gnj.000851","DOIUrl":"https://doi.org/10.30955/gnj.000851","url":null,"abstract":"In recent years many researchers show a high interest in co-digestion, simultaneous anaerobic decomposition of a homogenous mixture of at least two biodegradable waste. Anaerobic codigestion is reported to offer several benefits over digestion of separate materials, such as increased cost-efficiency, increased biodegradation of the treated materials, as well as increased biogas production. Most often sewage sludge is digested alone while co-digestion with other substrates could be beneficial. In this study, the feasibility of co-digestion sewage sludge and grease trap waste (GTW) from meatprocessing plant was investigated in lab-scale reactor experiment. The research was made on the sewage sludge coming from municipal wastewater treatment plant and grease trap waste coming from meat industry company. Anaerobic co-digestion was studied in semi-continuous experiment at 37 o C. Feeding of reactors was performed once a day with hydraulic retention time (HRT) of 10 days. The grease trap waste accounted for 2, 4, 6, 8 and 10 % of the mixture on the volatile solids basis. The mixtures were analyzed for the following parameters: total solids, volatile solids, pH, volatile fatty acids and long chain fatty acids (LCFAs). The control of digestion process was made every day on the basis of the measurement of the biogas production. What is more, there was determined the volatile solid removal as well the biogas yield in order to assess the efficiency of co-digestion process. It was found that co-digestion of sewage sludge and grease trap waste improved both biogas production and methane content. Grease trap waste addition of 10% of feed VS increased the biogas production by 16 % as well as methane concentration (72 % of biogas) compared to the period when reactor was feed only with sewage sludge. Moreover, the addition of GTW to the anaerobic digestion of sewage sludge increased organic matter removal. Although, the significant variations in LCFAs reduction, the biogas production and methane yield increased with higher addition of GTW. The results of the present laboratory study revealed that the use of GTW as a co-substrate is considered to be interesting option for sewage sludge digestion due to increased methane production. However, the feed should be planned carefully with stepwise increase to the desired feed ratio in order to acclimatize the bacteria and to prevent reactor overloading.","PeriodicalId":55087,"journal":{"name":"Global Nest Journal","volume":"36 1","pages":"141-148"},"PeriodicalIF":1.1,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69259079","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of microbiological contamination in the quality of biodiesel fuels.","authors":"G. S. Dodos, T. Konstantakos, S. Loginos, F. Zannikos, G. S. Miguel, S. Rincón, D. Vagiona","doi":"10.30955/gnj.000856","DOIUrl":"https://doi.org/10.30955/gnj.000856","url":null,"abstract":"The introduction to the European Market of biodiesel blends along with the minimization of the sulphur content in automotive diesel has rejuvenated the research interest on the microbial stability of diesel fuel. Several microorganisms are able to metabolize hydrocarbons contained in conventional fuels and particularly in diesel and jet stocks. With the advent of FAME (Fatty Acid Methyl Esters) as a diesel fuel substitute there has been an increase in the number of samples suspect of microbial contamination with confirmative results. The aim of this study was to investigate the microbiological stability of FAME/diesel blends and consequently the impact of microbial proliferation on their quality. A commercially available FAME was blended with Ultra-Low Sulphur (ULSD) and Low Sulphur (LSD) conventional automotive diesel fuels in mixing ratios of 5, 10 and 20 % v/v. The resulting blends were contaminated with bottom-water of known viable microbial colonies and were stored for a period of 16 weeks. During storage the microbiological growth was evaluated by employing both semi-quantitative and quantitative methodologies. At the same time the devolution of certain quality parameters, namely oxidation stability and acid number, which could be influenced by microbial growth was examined. The overall results reveal the need to establish a scheduled inspection plan adapted to the diesel fuel supply chain infrastructure aiming to control and remedy efficiently the microbiological growth issues.","PeriodicalId":55087,"journal":{"name":"Global Nest Journal","volume":"14 1","pages":"175-182"},"PeriodicalIF":1.1,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69259098","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Use of alternative fuels obtained from renewable sources in brayton cycles.","authors":"Marcos Escudero, Á. Jiménez, Ignacio López, J. Rodriguez, G. S. Miguel, S. Rincón, D. Vagiona","doi":"10.30955/gnj.000857","DOIUrl":"https://doi.org/10.30955/gnj.000857","url":null,"abstract":"Analysis and simulation of the behaviour of gas turbines for power generation using different nonconventional fuels obtained from different renewable sources are presented. Three biomass-tobiofuel processes are considered: anaerobic digestion of biomass (biogas), biomass gasification (synthesis gas) and alcoholic fermentation of biomass and dehydration (bioethanol), each of them with two different biomass substrates (energy crops and municipal solid waste) as input. The gas turbine behaviour in a Brayton cycle is simulated both in an isolated operation and in combined cycle. The differences in gas turbine performance when fired with the considered biofuels compared to natural gas are studied from different points of view related with the current complex energetic context: energetic and exergetic efficiency of the simple/combined cycle and CO2 emissions. Two different tools have been used for the simulations, each one with a different approach: while PATITUG (own software) analyses the behaviour of a generic gas turbine allowing a total variability of parameters, GT-PRO (commercial software) is more rigid, albeit more precise in the prediction of real gas turbine behaviour. Different potentially interesting configurations and its thermodynamic parameters have been simulated in order to obtain the optimal range for all of them and its variation for each fuel.","PeriodicalId":55087,"journal":{"name":"Global Nest Journal","volume":"14 1","pages":"157-165"},"PeriodicalIF":1.1,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69259111","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Environmental and energy assessment of new vehicle technologies in the greater Athens area","authors":"Christos Xiouras, A. Angelis-Dimakis, G. Arampatzis, D. Assimacopoulos","doi":"10.30955/gnj.000865","DOIUrl":"https://doi.org/10.30955/gnj.000865","url":null,"abstract":"The transport sector in Greece has the largest share in the final energy consumption and thus a great potential for energy savings. The resulting emissions are also one of the main sources of atmospheric pollution. This situation is worse in the prefecture of Attica, where almost half of the country’s private cars circulate in an area equal to the 3% of the total country area. Gasoline and diesel fuels are used almost exclusively in present internal combustion engines. The low efficiency of these engines, the environmental problem caused by cars and the limitation of fossil fuels are demanding new engine technologies and new fuels. This paper examines energy saving and environmental impacts reduction from the penetration of eco-friendly technology passenger cars in the Greater Athens Area. Three vehicle technologies are considered: (i) conventional hybrid electric vehicles, (ii) battery electric vehicles and (iii) fuel cell electric vehicles. The displacement of gasoline consumption largely depends on the level of penetration of new technologies in the vehicle fleet. The hybrid and battery electric vehicles have already been introduced in the market but their share is still low. On the other hand, fuel cell vehicles still need more improvement before their commercialization. For these reasons, two alternative scenarios are formulated. The first one involves the substitution of all the passenger cars that were registered during the last year (2010) with hybrid and battery electric vehicles that already exist in the Greek market. The second scenario examines the penetration of fuel cell electric vehicles. For the purpose of this analysis, a number of fuel cell vehicles are designed that satisfy common performance requirements, similar to the existing cars. A parametric vehicle energy consumption model has been adapted for the analysis. The share of registered passenger car technologies and the annual vehicle kilometres for the study area are taken from literature data sources. Two different driving cycles, the New European Driving Cycle and the Athens Driving Cycle are used and the results are compared. The sizing of fuel cell vehicle components is achieved using a vehicle design model, on the basis of input performance constraints. Both scenarios are evaluated on the basis of their expected energy savings and greenhouse gas emissions reduction. A 5% to 7% reduction of the CO2 emissions is expected if these measures are applied in a five year period.","PeriodicalId":55087,"journal":{"name":"Global Nest Journal","volume":"14 1","pages":"210-217"},"PeriodicalIF":1.1,"publicationDate":"2011-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69258677","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Catchment scale hydrological modelling: a review of model types, calibration approaches and uncertainty analysis methods in the context of recent developments in technology and applications","authors":"I. Pechlivanidis, B. Jackson, N. McIntyre, H. Wheater","doi":"10.30955/gnj.000778","DOIUrl":"https://doi.org/10.30955/gnj.000778","url":null,"abstract":"In catchment hydrology, it is in practice impossible to measure everything we would like to know about the hydrological system, mainly due to high catchment heterogeneity and the limitations of measurement techniques. These limitations and the need to extrapolate information from the available measurements in both space and time initiated the application of hydrological models. However, hydrological models suffer from uncertainty in their predictions, which reduces applicability of and confidence in such models. In this review, we summarise the different classifications of hydrological model types, and discuss relative advantages and disadvantages of each type of model. In addition, we summarise established model calibration processes and discuss the sources of uncertainty that affect model predictions. We summarise different methods to quantify uncertainty in the model predictions that could sit well within a model evaluation framework. And, finally, some recent developments in hydrological modelling are reviewed.","PeriodicalId":55087,"journal":{"name":"Global Nest Journal","volume":"13 1","pages":"193-214"},"PeriodicalIF":1.1,"publicationDate":"2011-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69258861","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"REMOVAL OF A BASIC DYE FROM AQUEOUS SOLUTION BY ADSORPTION USING RICE HULLS","authors":"A. El-Maghraby, H. A. E. Deeb","doi":"10.30955/gnj.000560","DOIUrl":"https://doi.org/10.30955/gnj.000560","url":null,"abstract":"The removal of dyes from colored effluents, particularly from textile industries, is one of the major environmental concerns these days. Current methods for removing dyes from wastewaters are costly and cannot effectively be used to treat wide range of such wastewaters. This work describes the use of grounded rice hull as adsorbent material. Aqueous solutions of various methylene blue dye concentrations (5-25 mg l -1 ) were shaken with certain amount of adsorbents to determine the adsorption capacity. Both treated and untreated rice hulls were used for methylene blue adsorption. The effects of adsorbents dose, initial pH, initial dye concentration and contact time on dye removal have been studied. Maximum dye was sequestered from the solution within 60-90 min after the beginning of every experiment. The adsorption capacity increased from 72 to 94 % with increasing the pH from 3 to 10. Pretreatment of rice hulls with citric acid did not reveal any beneficial effect. Rice hulls were more effective compared to commercial used adsorbents used. The results showed that ground rice hulls can be considered as potential adsorbents for methylene blue removal from dilute aqueous solutions.","PeriodicalId":55087,"journal":{"name":"Global Nest Journal","volume":"13 1","pages":"90-98"},"PeriodicalIF":1.1,"publicationDate":"2011-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69257368","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hybrid solar - biomass plants for power generation; technical and economic assessment.","authors":"J. Servert, G. S. Miguel, Diego López","doi":"10.30955/GNJ.000696","DOIUrl":"https://doi.org/10.30955/GNJ.000696","url":null,"abstract":"Environmental, economic and strategic reasons are behind the rapid impulse in the deployment of renewable energy sources that is taking place around the world. In addition to overcoming economic and commercial barriers, meeting the ambitious objectives set by most countries in this field will require the development of novel technologies capable of maximising the energy potential of different renewable sources at an acceptable cost. The use of solar radiation and biomass for power generation is growing rapidly, particularly in areas of the globe where these resources are plentiful, like Mediterranean countries. However, solar energy plants necessarily suffer from the intermittency of day/night cycles and also from reduced irradiation periods (winter, cloudy days, short transients). Biomass power plants have to confront the logistic problems associated with the continuous supply of very large amounts of a relatively scarce and seasonal fuel. Hybrid systems may provide the solution to these limitations, maximising the energy potential of these resources, increasing process efficiency, providing greater security of supply and reducing overall costs. This work provides a practical introduction to the production of electricity from conventional Concentrating Solar Power (CSP) and biomass power plants, which is used as the basis to evaluate the technical and economic benefits associated with hybrid CSP-biomass energy systems. The paper initially analyses alternative configurations for a 10 MWe hybrid CSPbiomass combustion power plant. The Solar Advisor Model (SAM) was used to determine the contribution of the solar field using quasi-steady generation conditions. The contribution of the biomass and gas boiler to the power plant was estimated considering the available radiation throughout the year. An economic assessment of a 10 MWe power plant based on conventional CSP, biomass combustion and hybrid technology is calculated. The results show that investment costs for hybrid CSPbiomass power plants are higher than for conventional CSP and biomass combustion plants alone. However, owing to the shared use of some of the equipment, this value is significantly lower (24% saving) than a simple addition of the investment costs associated with the two standard technologies. In contrast, effective operating hours and, therefore, overall energy generation, are significantly higher than in conventional CSP (2.77 times higher) and avoids the need for highly expensive heat storage system. Owing to the lower biomass requirements, hybrid plants may have larger capacities than standard biomass combustion plants, which implies higher energy efficiencies and a reduced risk associated with biomass supply. Universidad Politecnica de Madrid (UPM) is currently collaborating with a consortium of private companies in the development of a first commercial hybrid CSP-biomass combustion power plant that is expected to start operating in 2012.","PeriodicalId":55087,"journal":{"name":"Global Nest Journal","volume":"13 1","pages":"266-276"},"PeriodicalIF":1.1,"publicationDate":"2011-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69258378","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modelling the dispersion of harmful algal bloom (HAB) in the Thermaikos Gulf (NW Aegean Sea)","authors":"Y. Savvidis, C. Koutitas, D. P. Patoucheas, G. Nikolaidis","doi":"10.30955/gnj.000670","DOIUrl":"https://doi.org/10.30955/gnj.000670","url":null,"abstract":"Coastal hydrodynamics are directly related to important environmental and ecological issues. This paper focuses on the study of harmful phytoplankton cells’ dispersion, after an episode of an algal bloom, based on mathematical modeling. The case of Thermaikos Gulf was used for the simulation. The necessary hydrodynamic information was obtained by the application of a 2D hydrodynamic model directly coupled with a transport model for the simulation of the harmful cells’ dispersion. The model describes hydrodynamic and biological processes such as advection, dispersion and cell growth and losses. The mechanical processes are described with the mass and momentum conservation equations while the movement of the particles is described with the Random Walk simulation. The biological processes of cell growth rate were described as a function of temperature light and nutrients, and embodied to the simulation as input data for the model runs while the biological losses are simulated by the removal of particles randomly selected from the field. The reliability of the model was tested using data of a real algal bloom episode. Finally the study is completed with the detection of the distribution of the harmful phytoplankton cells in Thermaikos for different wind conditions and different sources of algal bloom.","PeriodicalId":55087,"journal":{"name":"Global Nest Journal","volume":"56 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2011-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69258569","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"ANALYSIS OF TOURISM POTENTIAL FOR CRETE ISLAND, GREECE","authors":"A. Matzarakis, P. Nastos","doi":"10.30955/gnj.000774","DOIUrl":"https://doi.org/10.30955/gnj.000774","url":null,"abstract":"To describe the tourism potential of an area, not only single meteorological parameters have to be taken into account, but also thermal sensation and people’s thermal comfort. The latter can be estimated by the use of human energy balance models and the derived thermal indices, which comprise all relevant meteorological parameters like air temperature, air humidity, wind speed, and short and long wave radiation fluxes. This paper makes an attempt to assess and analyze climatological parameters and the thermal comfort of Crete, its variations and trends for the period of time 1955-2001. In addition, a definition and quantification of the island’s tourism potential is carried out. Long term data from several stations are used from the existing climatic and synoptic network of Crete, including daily mean, maximum and minimum temperature, relative humidity, wind speed, and cloud cover over the whole island, in order to derive the daily Physiologically Equivalent Temperature (PET) and precipitation. In addition, possible trends of thermal comfort and precipitation on an annual and seasonal basis are analyzed. Additionally, data of the 10-minutes climatology of the Climate Research Unit of the University of Norwich have been processed in order to create high resolution (1 km) mean monthly maps for climatological parameters such as air temperature, precipitation and Physiologically Equivalent Temperature.","PeriodicalId":55087,"journal":{"name":"Global Nest Journal","volume":"13 1","pages":"141-149"},"PeriodicalIF":1.1,"publicationDate":"2011-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69258840","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}