Papers by Luigi Vecchione
The security of supply and climate change issues and the linked recent growth of the local power ... more The security of supply and climate change issues and the linked recent growth of the local power generation by means of renewable energies technologies are providing real opportunities for the development of small scale biomass gasification systems. The present paper reports the state of art of the small scale gasification power plants. Initial attention has been given to the different biomass feedstock suitable for gasification, focusing on residues with low cost and low environmental impact. Then the two major typologies of gasifiers (fixed and fluidized bed) have been analyzed in terms of raw gas yield, composition and tar and particulate content. The different cold and hot raw gas conditioning systems, highlighting their compatibility with the different gasification system, are described. High efficiency examples of power production by means of internal combustion engine, micro gas turbine, Solid Oxide Fuel Cell or a mix of them, both as realized plants and process simulated ones, have been then reported. The paper provides an overview of the different power plants in terms of efficiency, reliability and cost.
Nowadays, the increasing of the energy consumption is producing serious global warming issues. Ma... more Nowadays, the increasing of the energy consumption is producing serious global warming issues. Mainly most of greenhouse gas emissions in developed countries come from building equipments. In this context, GCHPs (ground coupled heat pumps) are candidate solution as air conditioning systems in buildings due to their higher efficiency compared to conventional devices. Actually, ground coupled heat pump systems are widely, recognized among the most efficient and comfortable used systems. Nevertheless , economic efficiency of the ground coupled heat pumps has to be proved. In this study, DEA (data envelopment analyses) method is applied to a real case in Italy.
One of the most important issues in biomass gasification is the correct prediction of gasificatio... more One of the most important issues in biomass gasification is the correct prediction of gasification products, with particular attention to the Topping Atmosphere Residues (TARs). In this work, performed within the European 7FP UNIfHY project, develops and validates experimentally a model able of predicting the outputs, including TARs, of a steam-fluidized bed biomass gasifier. Pine wood was chosen as biomass feedstock: the products obtained in pyrolysis tests are the relevant model input. Hydrodynamics and chemical properties of the reacting system are considered: the hydrodynamic approach is based on the two phase theory of fluidization, meanwhile the chemical model is based on the kinetic equations for the heterogeneous and homogenous reactions. The derived differentials equations for the gasifier at steady state were implemented and solved via MATLAB. Simulations were carried out varying steam/biomass ratio (0.5-1) and operating temperature (750-850°C).The comparison between model and experimental results showed that the model is able of predicting gas mole fractions and production rate including most of the representative TARs compounds.
Ammonia decomposition over Ni-loaded SiO 2 catalysts (Ni/SiO 2) was observed in a fixed-bed react... more Ammonia decomposition over Ni-loaded SiO 2 catalysts (Ni/SiO 2) was observed in a fixed-bed reactor at different temperatures (ranging from 773 to 973 K) and ammonia feeding rates (ranging from 1200 to 18,000 h À1). As support materials, several porous and inert SiO 2 particles with different mean pore diameters ðdÞ ranging from 7.7 to 34.8 nm were used to clarify the effect of pore diameter on the kinetic parameters for catalytic ammonia decomposition. The Ni/SiO 2 catalyst with the smallest pores, d ¼ 7.7 nm, showed the highest activity at temperatures below 923 K, while the activity of this catalyst at 973 K was lower than that of catalysts with larger pores. Kinetic analysis indicated that the activation energy for d ¼ 7.7 nm was significantly decreased at higher temperatures, suggesting the occurrence of strong diffusion resistance of ammonia molecules in the pores. Our experiments also confirmed that almost complete decomposition of ammonia could be achieved over Ni/SiO 2 with d ¼ 26.7 nm at 973 K and a gas hourly space velocity as high as 42,000 h À1 .
The use of biomass waste in high efficient low pollutants emissions micro-cogeneration plants ove... more The use of biomass waste in high efficient low pollutants emissions micro-cogeneration plants overcomes the main biomass barriers: competition with the food and material uses, dispersion of a low energy density fuel and high emissions. This paper is focused on a small (100 kW th ) steam gasification fluidized bed and hot gas conditioning system. In fact, the gasification without air leads to a high calorific value gas; the hot gas conditioning allows reducing pollutants by converting more gas; the fluidized bed allows a better process and heat transport management.
One of the most important issues in biomass biocatalytic gasification is the with particular atte... more One of the most important issues in biomass biocatalytic gasification is the with particular attention to the Topping Atmosphere Residues (TARs). In this work, performedwithin the European 7FP UNIfHY project, we develops and validate experimentally a model which is able of predicting the bed biomass gasifier. Pine wood was chosen as biomass feedstock: the products obtained in pyrolysis tests are the relevant mo input. Hydrodynamics and chemical properties of the reacting system are considere two phase theory of fluidization, meanwhile the chemical model is based on the kinetic equations for the heterogeneous and homogenous reactions. The derived differentials equations for the gasifier at steady sta consecutively carried out using the Boubaker Polynomials Expansion Scheme by varying steam/biomass ratio (0.5 temperature (750-850°C).The comparison between models and experimental results showed th mole fractions and production rate including most of the representative TARs compounds.
The activities showed here are part of the simulations activities carried out in the European 7FP... more The activities showed here are part of the simulations activities carried out in the European 7FP UNIfHY project. In particular the aim of this work is to develop and validate experimentally a model capable of predicting the performance of a steam blown fluidized bed biomass gasifier during steady state operation. This model will be utilized in future works for the simulations of a pilot scale steam fluidized bed gasifier (100 kWth) fed with different biomass feedstocks. The input variables of the computer program included steam flow rate and biomass to steam ratio. Pine wood was chosen as biomass feedstock in the process. The gasifier model for the simulation receives as input the results of the pyrolysis tests products. Experimental tests on a bench scale fluidized bed reactor were carried out in the temperatures range adopted for the simulation (750-850 °C). The results of the tests include produced gas and tar composition as well gas, tar and char yield. In order to consider tar evolution different representative compounds were chosen: Benzene, Toluene, Phenol, Naphthalene, Anthracene, Pyrene. The comparison between the results of the model and of experiments are showed.
The security of supply and climate change issues and the linked recent growth of the local power ... more The security of supply and climate change issues and the linked recent growth of the local power generation by means of renewable energies technologies are providing real opportunities for the development of small scale biomass gasification systems. The present paper reports the state of art of the small scale gasification power plants. Initial attention has been given to the different biomass feedstock suitable for gasification, focusing on residues with low cost and low environmental impact. Then the two major typologies of gasifiers (fixed and fluidized bed) have been analyzed in terms of raw gas yield, composition and tar and particulate content. The different cold and hot raw gas conditioning systems, highlighting their compatibility with the different gasification system, are described. High efficiency examples of power production by means of internal combustion engine, micro gas turbine, Solid Oxide Fuel Cell or a mix of them, both as realized plants and process simulated ones, have been then reported. The paper provides an overview of the different power plants in terms of efficiency, reliability and cost.
Among Renewable Energy Sources (RES), biomass represent one of the most common and suitable solut... more Among Renewable Energy Sources (RES), biomass represent one of the most common and suitable solution in order to contribute to the global energy supply and to reduce greenhouse gases (GHG) emissions. The disposal of some residual biomass, as pruning from pine trees, represent a problem for agricultural and agro-industrial sectors. But if the residual biomass are used for energy production can become a resource. The most suitable energy conversion technology for the above-mentioned biomass is gasification process because the high C/N ratio and the low moisture content, obtained from the analysis. In this work a small-pilot bubbling-bed gasification plant has been designed, constructed and used in order to obtain, from the pine trees pruning, a syngas with low tar and char contents and high hydrogen content. The activities showed here are part of the activities carried out in the European 7FP UNIfHY project. In particular the aim of this work is to develop experimental test on a bench scale steam blown fluidized bed biomass gasifier. These tests will be utilized in future works for the simulations of a pilot scale steam fluidized bed gasifier (100 kWth) fed with different biomass feedstock. The results of the tests include produced gas and tar composition as well gas, tar and char yield. Tests on a bench scale reactor (8 cm I.D.) were carried out varying steam to biomass ratio from 0.5, 0.7 and 1 to 830°C.
To answer the actual energy, water, economic, social and environmental challenges, renewable, dis... more To answer the actual energy, water, economic, social and environmental challenges, renewable, distributed power plants need to be developed. Among renewables, solar tri-generative power plants can be a solution where there is big low temperature heating/cooling demand and small electricity demand, like many residential and industrial utilities. In this case, solar thermal plants can produce thermal energy with low cost and high efficiency. The higher temperature heat not needed by the user can be exploited via Organic Rankine Cycle to produce electrical energy and desalinized water via reverse osmosis. The present paper analyses, via TRNSYS simulation, a system composed of 50 m 2 of CPC solar thermal collectors, 3 m 3 of thermal storage, a synthetic heat transfer fluid, 3 kW e ORC, 8 kW th absorber, 200 l/h direct reverse osmosis desalination device. The system is able to produce power, heating/cooling and fresh water needs for a residential house. Although system's components are well known technologies, the integration to a efficient and economic working system is still a challenge. Global energy and economic analyses have been performed. Low temperature heating/cooling terminals allow to increase not only the use of thermal energy but also the ORCand absorber efficiency. ORC-Absorber configuration and relative fluids and temperatures are central. Government support and/or cost reduction of 30% are necessary to have positive NPV and acceptable PBT and IRR.
Modern agriculture is an extremely energy intensive process. However, high agricultural productiv... more Modern agriculture is an extremely energy intensive process. However, high agricultural productivities and the growth of green revolution has been possible only by large amount of energy inputs, especially those coming from fossil fuels. These energy resources have not been able to provide an economically viable solution for agricultural applications. Biomass energy-based systems had been extensively used for transportation and on farm systems during World War II: the most common and reliable solution was wood or biomass gasification. The latter means incomplete combustion of biomass resulting in production of combustible gases which mostly consist of carbon monoxide CO, hydrogen H 2 and traces of methane CH 4. This mixture is called syngas, which can be successfully used to run internal combustion engines both compression and spark ignition or as substitute for furnace oil in direct heat applications. The aim of the present paper is to help the experimentation of innovative plants for electric power production using agro-forest biomass derived by hazelnut cultivations. An additional purpose is to point out a connection among the chemical and physical properties of the outgoing syngas by biomass characterization and gas-chromatography analysis.
Decomposition of gaseous NH 3 from ammonia (NH 3 )-containing wastewater was explored using Ni-lo... more Decomposition of gaseous NH 3 from ammonia (NH 3 )-containing wastewater was explored using Ni-loading Al 2 O 3 catalysts. The thermochemical decomposition of an NH 3 /steam mixture (wet-NH 3 ) with different steam contents at 873, 923, and 973 K using a fixed-bed reactor under ambient pressure. The present results indicated that the catalysts can be deactivated by the formation of NiAl 2 O 4 , which can be thermodynamically generated, and confirmed that the extent of deactivation was greatly affected by the partial pressure of the steam (P H 2 O ). The catalytic activities at 873 K decreased with increasing P H 2 O , whereas the activity was constant above P H 2 O of 25 kPa. However, the NH 3 conversion was almost independent of the NH 3 flow rate and temperature, and ∼30% of the NH 3 was decomposed at each temperature. This study indicated that, even in the presence of steam, this catalyst could decompose NH 3 from NH 4 + -containing water.
Nowadays, the increasing of the energy consumption is producing serious global warming issues. Ma... more Nowadays, the increasing of the energy consumption is producing serious global warming issues. Mainly most of greenhouse gas emissions in developed countries come from building equipments. In this context, GCHPs (ground coupled heat pumps) are candidate solution as air conditioning systems in buildings due to their higher efficiency compared to conventional devices. Actually, ground coupled heat pump systems are widely, recognized among the most efficient and comfortable used systems. Nevertheless , economic efficiency of the ground coupled heat pumps has to be proved. In this study, DEA (data envelopment analyses) method is applied to a real case in Italy.
Cultivation of the hazel and almond is widespread in Italy, especially in those small and medium ... more Cultivation of the hazel and almond is widespread in Italy, especially in those small and medium enterprises that work in the confectionery industry. The residual wastes of these productions are mostly shells, of ligno-cellulosic material, very suitable for combustion. The first aim of this work was to carry out the chemical characterization of such wastes (LHV, C, H, N, O, etc) for their energy exploitation. These analyses were performed in the laboratory CIRDER of Viterbo, in accordance with UNI standards. These wastes were then used in a fluidized bed bench scale gasifier to evaluate the composition of the raw gas (H 2 , CO, CO 2 , CH 4 , TAR) obtained during steam gasification tests. The TAR removal efficiencies of two different methods were finally investigated experimentally: catalytic cracking in a secondary reactor with Ni/Al 2 O 3 and scrubbing with vegetable sunflower oil.
The use of renewable energy is becoming increasingly necessary in order to address the global war... more The use of renewable energy is becoming increasingly necessary in order to address the global warming problem and, as a consequence, has become an high priority for many countries. Biomass is a clean and renewable energy source with growing potential to replace conventional fossil fuels. Among biomass, residual and waste ones represent a great resource for energy generation since they permit both to eliminate a possible waste and to produce energy. In the present work, the case of slaughterhouse wastes (SHWs) has been investigated. Anaerobic digestion is nowadays considered as one of the most important and sustainable conversion technology exploiting organic matter and biodegradable wastes. Biogas results from this bio-chemical process and mainly consists of methane and carbon dioxide, leading to produce thermal energy and/or electricity. In this paper, the European Regulations on animal by-products (ABPs) are described, and some previous study on anaerobic digestion and co-digestion of ABPs -more precisely SHWs -are considered and compared in order to fix a starting point for future tests on their co-digestion in a micro-scale pilot digester. This is to define optimal feed ratio values which ensure an increasing content of methane in the outgoing biogas.
The ammonia decomposition process for hydrogen production was studied experimentally in a fixed b... more The ammonia decomposition process for hydrogen production was studied experimentally in a fixed bed tubular micro-reactor (I.D. ¼ 1 cm and h ¼ 20 cm) filled with 15 ml of ACTA Hypermec 10010 Ru catalyst. With the aim of pointing out the best process conditions, experiments were carried out varying the reaction temperature between 400 and 500 C, the feeding gas pressure between 1 and 10 bar and the GHSV (Gas Hourly Space Velocity) between 300 and 2400 h À1 . To maintain the temperature as uniform as possible along the reactor axis, a 3 zone heater was used and each zone was controlled independently. An acid H 2 SO 4 trap was used downstream the reactor to remove by neutralization the residual ammonia from the product gas. Moreover, the residual ammonia amount in the gas and thus the NH 3 dissociation were evaluated for the catalyst in different operative conditions by measuring the PH of the trap and its changing rate over time. Dissociations close to the chemical equilibrium were obtained for every GHSV and temperature we tested with a pressures of 1 and 5 bar in the reactor. In particular, the dissociation was always higher than 99% at 1 bar, while at 5 bar it varied from 96% at 400 C to 99% at 500 C. At 10 bar the chemical equilibrium was reached for all GHSVs only at 450 C and 500 C with dissociations equal to 95.5% and 97.2%. At 400 C a dissociation close to the chemical equilibrium (92%) was reached only for a GHSV of 300 h À1 while for the remaining GHSVs the dissociation was always lower, down to 80.8% for a GHSV equal to 2400 h À1 .
Green Building, Materials and Civil Engineering, 2014
ABSTRACT Cultivation of the hazel and almond is widespread in Italy, especially in those small an... more ABSTRACT Cultivation of the hazel and almond is widespread in Italy, especially in those small and medium enterprises that work in the confectionery industry. The residual wastes of these productions are mostly shells, of ligno-cellulosic material, very suitable for combustion. The first aim of this work was to carry out the chemical characterization of such wastes (LHV, C, H, N, O, etc) for their energy exploitation. These analyses were performed in the laboratory CIRDER of Viterbo, in accordance with UNI standards. These wastes were then used in a fluidized bed bench scale gasifier to evaluate the composition of the raw gas (H2, CO, CO2, CH4, TAR) obtained during steam gasification tests. The TAR removal efficiencies of two different methods were finally investigated experimentally: catalytic cracking in a secondary reactor with Ni/Al2O3 and scrubbing with vegetable sunflower oil.
International Journal of Renewable Energy Development (IJRED), 2015
One of the most important issues in biomass biocatalytic gasification is the with particular atte... more One of the most important issues in biomass biocatalytic gasification is the with particular attention to the Topping Atmosphere Residues (TARs). In this work, performedwithin the European 7FP UNIfHY project, we develops and validate experimentally a model which is able of predicting the bed biomass gasifier. Pine wood was chosen as biomass feedstock: the products obtained in pyrolysis tests are the relevant mo input. Hydrodynamics and chemical properties of the reacting system are considere two phase theory of fluidization, meanwhile the chemical model is based on the kinetic equations for the heterogeneous and homogenous reactions. The derived differentials equations for the gasifier at steady sta consecutively carried out using the Boubaker Polynomials Expansion Scheme by varying steam/biomass ratio (0.5 temperature (750-850°C).The comparison between models and experimental results showed th mole fractions and production rate including most of the representative TARs compounds.
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Papers by Luigi Vecchione