Techno-economic analysis of hydrogen production using biomass gasification. A small scale power plant study

Hydrogen has the potential to be a clean alternative to the fossil fuels currently used. This is especially true if hydrogen is manufactured from renewable resources such as biomass. However, hydrogen from biomass faces techno and economic challenges especially in the small size required for the decentralized hydrogen production. In this purpose, a techno economic analysis was carried out on small scale (100kWth) system. The plant is mainly composed of gasifier (double bubbling fluidized bed reactor) coupled with a Portable Purification Unit (PPS: catalytic filter candles, Water Gas Shift and Pressure Swing Absorption). This work focuses on system costs to identify barriers to the development of this technology. A sensitivity analysis was conducted to study hydrogen production cost as a function of capital cost, operating cost and hydrogen production efficiency. The results showed that although efficiency of the production system is the main factor to fall production cost, it cannot be able to reduce costs to favorable level alone. In other words, PPS cost recognized as the major cost is requisite to go down. Therefore, the 50% reduction of PPS cost and the variation of steam to biomass from 1 to 1.5 allow the special cost to fluctuate between 12.75-9.5 €/kg

parametric performance analysis of renewable energy sources hvac systems for buildings

Abstract The indoor climate control of buildings represents today the highest percentage of energy consumption in European Union. Hence the evaluation of the best performing HVAC system is a strategic target for both energy consumption and greenhouse gas emissions reduction. This paper presents a deep analysis of the performance of Renewable Energy Sources HVAC systems for buildings. The technologies considered are biomass boiler, aerothermal, geothermal and absorption heat pumps. The proposed method estimates all the parameters according to the theory of the "big is better". For each parameter a function has been defined to evaluate how much the performance of each technology depends from it. The analysis take in account also the environment in which each technology operates. The result is a set of dimensionless parameters, through which it is possible to extrapolate the assessments of performance. It can include both cost-effectiveness and feasibility of a given technology and the contribution to the achievement of European objectives to 2020

Experimental tests of solar collectors prototypes systems

Solar thermal collectors represent one of the most widely used technologies for heat production from renewable energy sources. To increase efficiency and to not increase too much cost different type of solar collectors, and in particular of evacuated tube collectors have been realized. In order to compare performance, tests at different conditions and in different configurations have to be performed. The aim of this paper is to establish the performance of a new prototype via an experimental evaluation of the performance in different conditions and configurations of three collectors. The prototype is particular owing to his new head configuration that permits an innovative parallel configuration way. Therefore, parallel and series configurations have been analyzed applying the UNI-EN 12975, in a steady-state regime. The efficiencies of the two configurations have been tested for different flow rates and different inflow water temperatures. The experimental results show that, with the same input flow rate to the single collector, the parallel configuration has higher performance than the series one, reaching 15% higher level of efficiency. Thus, it seems that these prototypes in optimized configuration can lead to a systems improvement, thereby increasing the overall energy production or giving the same energy production with smaller collector area. © 2015 Published by Elsevier Ltd

Biomechanics parameters in teenage cyclist – SUV accident and comparison with the pedestrian

The study of the injury caused by the vehicle-teenage cyclist crash is presented in this paper. The vehicle is a SUV, with high frontal part, in order to compare the results with those obtained previously in the sedan- teenage cyclist crash and begin a study of the influence of the frontal shape of the vehicle. No variation is executed on the model of the teenage cyclist and the bike. Three different positions are analyzed: front, rear and lateral position. The injury on the cyclist head is examined by HIC criterion, in the way indicated in the rules. Correlation HIC – AIS is used to calculate the lethality of the injuries. The principal conclusion is done that the injury of the head is more dangerous for the SUV impact than the sedan, but only at the maximum speed (50 km/h). The injury to the chest is analyzed by 3 ms criterion; the injury is greater for the SUV impact than the sedan, but the entity is strongly dependent on the cyclist position. A comparison is executed with both the teenage and adult pedestrian concluding that the pedestrian is subjected to greater injury, because the bike absorbs a part of the energy in the front and side crash. The more dangerous injury is the telescoping. A further comparison show that the shape of the bonnet and the height of the frontal part have to be studied in an accurate way to reduce the injury to pedestrians and cyclists

Evaluation of Environmental and Economic Sustainability for the Building Envelope of Low-Carbon Schools

To achieve a carbon-free economy by 2050, the construction of low-carbon schools in Italy must select the proper structural and technological solutions for the building envelope while ensuring a low economic cost. The aim of this study was to analyze and compare several technological solutions for the building envelope and the related structural solutions in terms of thermo-dynamic properties, energy performance, environmental sustainability parameters, and economic evaluations, to obtain one or more alternatives. After a general study, the binomial load-bearing structure–external wall was investigated given its strong influence on both the environment and the total cost. The solutions were used in a new typological model for the kindergarten. All the solutions are comparable from an energy and environmental point of view, obtaining a primary energy demand of <25 kWh/(m2year) and an environmental impact of <20 kWh/(m2year). However, considering the economic factor and analyzing the binomial load-bearing structure–external wall, the advisable solutions are those that use wooden structures with insulation layer in wood fiber as they have a significantly lower environmental impact, along with the same good energy performance and have an acceptable cost compared to other analyzed solutions

Hydrogen-rich gas production by sorption enhanced steam reforming of woodgas containing TAR over a commercial Ni catalyst and calcined dolomite as CO2 sorbent.

The aim of this work was the evaluation of the catalytic steam reforming of a gaseous fuel obtained by steam biomass gasification to convert topping atmosphere residue (TAR) and CH 4 and to produce pure H 2 by means of a CO 2 sorbent. This experimental work deals with the demonstration of the practical feasibility of such concepts, using a real woodgas obtained from fluidized bed steam gasification of hazelnut shells. This study evaluates the use of a commercial Ni catalyst and calcined dolomite (CaO/MgO). The bed material simultaneously acts as reforming catalyst and CO 2 sorbent. The experimental investigations have been carried out in a fixed bed micro-reactor rig using a slipstream from the gasifier to evaluate gas cleaning and upgrading options. The reforming/sorption tests were carried out at 650 °C while regeneration of the sorbent was carried out at 850 °C in a nitrogen environment. Both combinations of catalyst and sorbent are very effective in TAR and CH 4 removal, with conversions near 100%, while the simultaneous CO 2 sorption effectively enhances the water gas shift reaction producing a gas with a hydrogen volume fraction of over 90%. Multicycle tests of reforming/CO 2 capture and regeneration were performed to verify the stability of the catalysts and sorbents to remove TAR and capture CO 2 during the duty cycle