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Biomass gasification is a promising technology to produce secondary fuels or heat and power, offering considerable advantages over fossil fuels. An important aspect in the usage of producer gas is the removal of harmful contaminants from the raw syngas. Thus, the object of this study is the development of a simulation model for a gasifier including gas clean-up, for which a fluidized-bed gasifier for biomass-derived syngas production was considered, based on a quasi-equilibrium approach through Gibbs free energy minimisation, and including an innovative hot gas cleaning, constituted by a combination of catalyst sorbents inside the gasification reactor, catalysts in the freeboard and subsequent sorbent reactors, by using Aspen Plus software. The gas cleaning chain simulates the raw syngas clean-up for several organic and inorganic contaminants, i.e. toluene, benzene, naphthalene, hydrogen sulphide, hydrogen chloride and ammonia. The tar and inorganic contaminants final values achieved are under 1 g/Nm3 and 1 ppm respectively. • A simulation model for a biomass fluidized-bed gasifier was developed by Aspen Plus. • The gasification model is the quasi-equilibrium approach based on Gibbs free energy minimisation. • The simulation includes a gas cleaning chain simulates for several contaminants. • The contaminants considered are toluene, benzene, naphthalene, H 2 S, HCl and NH 3. • Tars drops at 3 g/Nm3; H 2 S, HCl and NH 3 drops at 3.7, 0.5 and 0.6 ppm respectively. [ABSTRACT FROM AUTHOR]

Abstract The development of small-scale efficient and low-cost Organic Rankine Cycle (ORC) units using low temperature waste heat for electricity production is attracting a lot of interest nowadays. This paper presents the thermodynamic simulation of a small scale regenerative ORC testing facility. The facility mainly consists of an electric steam generator to produce steam at 170oC and 7.5 bar as hot source, water at 20oC as cold sink and a scroll compressor converted to be used as expander. Simulation was performed by means of MATLAB, and CoolProp external library was used for the thermo-physical properties of the R245fa, the organic working fluid. The performance of the system in a certain range of working conditions has been calculated, obtaining maximum efficiency of 9.6% and net power of 17 kW. Simulations are used to understand the effect of different characteristics of main components on the performance of the system before running the test bench. Thus, allowing the future experimental campaign that will verify the validity of the model. [ABSTRACT FROM AUTHOR]

The development of low cost small scale Organic Rankine Cycle (ORC) has a very interesting potential in generating electricity using low temperature waste heat sources. Moreover, HVAC companies could significantly extend their market if a commercial scroll compressor can be converted into an expander using similar units. Therefore, this work reports experimental test funded by an Italian HVAC company on a scroll compressor modified to work as scroll expander in a non-regenerative cycle and a subcritical fluid regime, aimed at reducing system cost and complexity. The scroll expander has been tested with its fluid R410A in a ORC cycle in order to obtain the isentropic efficiency of the scroll expander (0.5) and the pump (0.4). On the basis of the experimental tests, a model accomplished by means of MATLAB/CoolProp has been set up to evaluate the performance of the ORC group to achieve 10 kWe as target power output. Four operative fluids have been simulated, i.e. R245fa, R134a, R1234yf, R1234ze, fixing 100°C as evaporating temperature and considering the condenser temperature in the range 20-50°C. The results have showed that R245fa is the most promising working fluid since there is a higher expansion ratio within lower pressure values. As a consequence, not only a lower mass flow rate is necessary, but overall a lower pump consumption is needed, reaching greater overall conversion efficiency (about 6.5% with condensing temperature of 20°C) and power. Thus, a commercial heat pump scroll compressor can be effectively converted into an expander. The fluid selection shows that the most common ORC fluid can be used with relative low performance but at low cost and easy management. [ABSTRACT FROM AUTHOR]

Concentrated solar technologies coupled with ORC system is a well-known topic in temperature ranges lower than 200°C. However, the integration to an efficient and economic working system is still a challenge especially at small scale. Efforts exist to achieve higher overall efficiencies but they are solely focused on thermal and electrical production while few of these is encompassing small-scale solar trigeneration systems. In the present article, the potential of a small scale concentrated solar Organic Rankine Cycle plant coupled with an absorber is investigated using a simulation analysis of a small scale 50 m2 CPC solar field, a 3.5 kWe ORC and a 17.6 kWc absorption chiller to satisfy respectively heating, electricity and cooling needs of a residential user. The simulation analysis of the overall system has been carried out in TRNSYS and an own model of the ORC system has been developed by the authors in Matlab thus improving the previous general model. The final aim of the proposed work is indeed the performance assessment of the small scale integrated system in order to evaluate the potential feasibility of such a system for residential applications. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The use of biomass waste in high efficient low pollutants emissions micro-cogeneration plants overpasses the main biomass barriers: competition with the food and material uses, dispersion of a low energy density fuel and high emissions. Evaluations of present technical aspects, economic benefits and their future projections are very important to bring into focus the needs of the technological development of this energy application. This paper is focused on a small (250 kWth) steam gasification fluidized bed and hot gas conditioning system, contextualized in the case study of a farm situated near Rome. Since most of usable biomass waste comes from agriculture, appraisal of applicability to real rural contexts deserves closer examination, considering the necessity of a small size solution as well. A feasibility study of an actual employment of this energy system has included: biomass availability and energy consumption analysis, biomass and gasification tests, power plant sizing, using experimental data and chemicad simulation. Finally an economic analysis has been carried out by varying the main economic parameters. Olive pruning are confirmed as very suitable, and in this case, able to satisfy the farm energy consumption. Global electrical efficiency of 25% can be achieved without any auxiliary fuel consumption. Consumption of 60% of the heat generated are required, meanwhile investment and biomass costs up to 8000 €/kW and 100 €/t can be sustained, especially if the farm electricity cost are higher than 0.15 €/kWh. [ABSTRACT FROM AUTHOR]

Today, in the grid there are more and more installation of renewable energy plants. The renewable sources are so discontinues and they may affect the stability and efficiency of the grid. Many distribution service operators are experimenting the battery energy storage systems (BESSs) to integrate them on the grid and resolve these problems. This paper analyses the energy performance under real conditions of a BESS prototype. The real BESS under focus has made by a lithium battery pack of 16 kWh, a DC/DC converter of 20 kW and an IGBT inverter of 30 kVA with a direct voltage bus of 600 V. The energy analysis has been performed through an integrated data acquisition system that take data from on-board electronic diagnostic measurements and from smart metering data. This latter using remote devices. The tests have been carried out on the system to monitor the following characteristic parameters: current and voltage of the batteries, current and voltage of the grid and current and voltage of the auxiliaries. The system energy performances have been analyzed in dynamic and real conditions with particular reference to the following quantities: energy consumption for the auxiliary system and overall efficiency of the system in a distributed energy resources microgrid. The entire system has been analyzed until twenty-four hours. [ABSTRACT FROM AUTHOR]

Abstract: The development of reliable fuel cells power plant based on renewable fuels stands out as one of the promising energy systems solutions for the future. Indeed fuel cells can increase the efficiency and the cleaning of the electrical energy production from renewable fuels. Process simulations of advanced power plants fed by low cost renewable fuels like biomass waste are a key step to develop renewable resources based on high temperature fuel cells applications. The aim of this work is to predict the component behaviour of a specific power plant mainly composed of a small indirectly heated gasifier and a Solid Oxide Fuel Cell (SOFC) and fed by chestnut coppice, waste available in great quantity in Central Italy, as well as in several other European regions. The plant''s thermodynamic behaviour is analysed by means of the process simulator CHEMCAD© in which particular models for the SOFC and the gasifier have been developed in FORTRAN by the authors and then interfaced to commercial software. The results of the predictive model are presented and discussed, showing the possibility of an extremely interesting “carbon neutral” small plant configuration with high electrical and global efficiency exclusively based on the use of low cost renewable resources. [Copyright &y& Elsevier]

Abstract: This paper reports the preliminary experimental evaluation of a four wheel motors series hybrid prototype equipped with an internal combustion engine coupled to a generator and an energy recovery system (batteries plus ultracapacitors). The paper analyses global efficiency (energy dissipated to overcome the dissipative forces on energy dissipated in fuel), autonomy in electric configuration, and the efficiency of the regenerative braking system. The tests were carried out in a test cell equipped with a chassis dynamometer. The tests were performed according to the current regulated procedures. A constant speed test was performed in order to evaluate the autonomy of the vehicle in the electric configuration. The results show that the real tank to wheels efficiency is about 30% for HOST as a series hybrid and 79% for HOST as an electric vehicle. [ABSTRACT FROM AUTHOR]

Abstract: The crucial mission of energy research is the promotion and implementation of methods, technologies and processes for a sustainable economic and social development. Within this framework the key progress energy systems is the realization of Closed Cycles of Energy Resources—CCER, whose goal is to achieve zero consumption in terms of non-renewable resources and no impact on the environment. A CCER can be realised with biomass, a renewable energy resource, and hydrogen, the “cleanest” fuel. This solution can supply secure and environmental friendly energy for medium electric and heating power demand. This context meets the actual trend towards cleaner, greener, smaller and more decentralized energy production facilities. The paper, after a brief description of closed hydrogen cycle and biomass resources, presents a comprehensive overview of the topic. The review of sustainability of biomass hydrogen systems shows how these systems, even if they require further research and demonstration activity, can obtain a remarkable electricity and heat production with near “zero” pollution. Furthermore, using refusals or “trash” materials and “standard” technologies, the biomass to hydrogen systems can provide in many case economic and social advantages. [Copyright &y& Elsevier]

Many countries in Europe are investing in fuel cell bus technology with the expected mobilization of more than 1200 buses across Europe in the following years. The scaling-up will make indispensable a more effective design and management of hydrogen refueling stations to improve the refueling phase in terms of refueling time and dispensed quantity while containing the investment and operation costs. In the present study, a previously developed dynamic lumped model of a hydrogen refueling process, developed in MATLAB, is used to analyze tank-to-tank fuel cell buses (30–40 kg H2 at 350 bar) refueling operations comparing a single-tank storage with a multi-tank cascade system. The new-built Aalborg (DK) hydrogen refueling station serves as a case study for the cascade design. In general, a cascading refueling approach from multiple storage tanks at different pressure levels provides the opportunity for a more optimized management of the station storage, reducing the pressure differential between the refueling and refueled tanks throughout the whole refueling process, thus reducing compression energy. This study demonstrates the validity of these aspects for heavy-duty applications through the technical evaluation of the refueling time, gas heating, compression energy consumption and hydrogen utilization, filling the literature gap on cascade versus single tank refueling comparison. Furthermore, a simplified calculation of the capital and operating expenditures is conducted, denoting the cost-effectiveness of the cascade configuration under study. Finally, the effect of different pressure switching points between the storage tanks is investigated, showing that a lower medium pressure usage reduces the compression energy consumption and increases the station flexibility. • Single-tank versus multi-tank hydrogen storage system techno-economic analysis for heavy-duty application. • Investigation of the lowest compressor energy consumption for different storage switching points. • The storage system design does not affect the vehicle refueling time and hydrogen dispensed. • The cascade system reduces compressor energy demand and gas heating increases station flexibility and is more economic. [ABSTRACT FROM AUTHOR]

The foreseen uptake of hydrogen mobility is a fundamental step towards the decarbonization of the transport sector. Under such premises, both refueling infrastructure and vehicles should be deployed together with improved refueling protocols. Several studies focus on refueling the light-duty vehicles with 10 kg H2 up to 700 bar, however less known effort is reported for refueling heavy-duty vehicles with 30–40 kg H2 at 350 bar. The present study illustrates the application of a lumped model to a fuel cell bus tank-to-tank refueling event, tailored upon the real data acquired in the 3Emotion Project. The evolution of the main refueling quantities, such as pressure, temperature, and mass flow, are predicted dynamically throughout the refueling process, as a function of the operating parameters, within the safety limits imposed by SAE J2601/2 technical standard. The results show to refuel the vehicle tank from half to full capacity with an Average Pressure Ramp Rate (APRR) equal to 0.03 MPa/s are needed about 10 min. Furthermore, it is found that the effect of varying the initial vehicle tank pressure is more significant than changing the ambient temperature on the refueling performances. In conclusion, the analysis of the effect of different APRR, from 0.03 to 0.1 MPa/s, indicate that is possible to safely reduce the duration of half-to-full refueling by 62% increasing the APRR value from 0.03 to 0.08 MPa/s. [Display omitted] • A hydrogen refueling 0-D model is developed and applied to heavy-duty vehicles. • Real case refueling (10 min;half tank) results are within the safety limits. • Refueling is analyzed for different ambient temperature and vehicle tank pressure. • The correlation between the refueling time and the refueling speedis non-linear. • The maximum allowable mass flow rate limits the maximum APRR to 0.08 MPa/s. [ABSTRACT FROM AUTHOR]

In this paper, the potential of a small scale concentrated solar Organic Rankine Cycle unit coupled with an absorption chiller for trigeneration purposes is investigated using a simulation analysis. At the moment, only few research works encompass small-scale solar trigeneration systems and most of them do not refer to real plant. On the contrary, in this work electric, heating and cooling maximum generation of a real and experimental small scale prototype system composed of a 50 m 2 CPC solar field, a 3.5 kWe ORC plant and a 17 kWc absorption chiller is investigated by means of TRNSYS. In particular, this work relies on the evaluation of the dynamic performance of the mentioned plant varying some selected system parameters to provide proper modifications of its design configuration and operation. More precisely, working temperature ranges, heating and intermediate fluid flow rates as well as volume of the storage tanks and size of the solar field have been varied within the simulation model. Results have shown that operating temperature ranges of the storage tanks considerably affect the overall performance of the system; by appropriately choosing these ranges the primary energy production can be increased by 6.5% compared to the baseline configuration without any additional investment costs. Moreover, setting suitably some design parameters can significantly contribute to extend the operating hours and the feasibility of a such small scale integrated system for residential applications. [ABSTRACT FROM AUTHOR]

Concerns about energy security, energy prices and climate change led scientific research towards sustainable solutions to fossil fuel as renewable energy sources coupled to hydrogen as energy vector and carbon capture and conversion technologies. Among the technologies investigated in the last decades, biomass gasification acquired great interest owing to the possibility to obtain low cost and CO 2 negative emission hydrogen production from a large variety of everywhere available organic wastes. Upstream and downstream treatment were then studied in order to maximize hydrogen yield, reduce the content of organic and inorganic contaminants under the admissible levels for the technologies which are coupled with, capture, and convert carbon dioxide. However, studies which analyse a whole process made of all those technologies is still missing. In order to fill this lack, the present paper investigated the coexistence of Hydrothermal Carbonization (HTC), Sorption Enhance Gasification (SEG), Hot Gas Cleaning (HGC), and CO 2 conversion by Dielectric Barrier Discharge (DBD) plasma reactor for H 2 production from biomass waste by means of Aspen Plus software. The proposed model aimed to identify and optimise the performance of the plant by varying operating parameters (such as temperature, CaO/biomass ratio, separation efficiency, etc.). The carbon footprint of the global plant is 2.3 kg CO 2 /kg H 2 , lower than the latest limit value imposed by the European Commission to consider hydrogen as "clean", that was set to 3 kg CO 2 /kg H 2. The hydrogen yield referred to the whole plant is 250 g H2 /kg BIOMASS. • A global simulation model for SEG, HTC, HGC and plasma for H 2 production was developed. • The carbon footprint of the global plant is 2.3 kg CO 2 /kg H 2. • The hydrogen yield referred to the whole plant is 250 g H2 /kg BIOMASS. [ABSTRACT FROM AUTHOR]

In this work, the results of two years of experimental tests on an innovative dual bubbling fluidized bed gasifier are reported. These are related to the activities of the BLAZE project (Horizon 2020) for the integration of steam biomass gasification and solid oxide fuel cell. Several tests were carried out on the pilot-scale reactor at various operating conditions, and in this work the results are reported in terms of dry gas composition and yield, organic and inorganic contaminants (tar, particulate matter, H 2 S). The compact design of the gasifier (a single reactor with two concentric chambers and in-situ hot gas cleaning and conditioning) reduces the heat losses and produces close to nitrogen-free syngas. Preliminary tests using a filter candle filled with conventional catalyst, installed in the freeboard of the gasifier, show that the tar content dropped to about 2 g/Nm3, and the H 2 concentration increased up to 41% vol,dry. • Experimental study on an innovative pilot scale dual bubbling fluidized bed gasifier. • The results obtained demonstrate the reliability of the innovative gasifier. • Highest operating temperature with LPG/Biomass ratio of 20% as energy input. • Preliminary test with ceramic filter candle filled with catalyst in the freeboard. • Tar of 2 g/Nm3 and H 2 concentration of 40 % vol,dry obtained in test long run. [ABSTRACT FROM AUTHOR]

Worldwide about 550 hydrogen refueling stations (HRS) were in operation in 2021, of which 38% were in Europe. With their number expected to grow even further, the collection and investigation of real-world station operative data are fundamental to tracking their activity in terms of safety issues, performances, maintenance, reliability, and energy use. This paper analyses the parameters that characterize the refueling of 350 bar fuel cell buses (FCB) in five HRS within the 3Emotion project. The HRS are characterized by different refueling capacities, hydrogen supply schemes, storage volumes and pressures, and operational strategies. The FCB operate over various duty cycles circulating on urban and extra-urban routes. From data logs provided by the operators, a dataset of four years of operation has been created. The results show a similar hydrogen amount per fill distribution but quite different refueling times among the stations. The average daily mass per bus and refueling time are around 14.62 kg and 10.28 min. About 50% of the total amount of hydrogen is dispensed overnight, and the refueling events per bus are typically every 24 h. On average, the buses' time spent in service is 10 h per day. The hydrogen consumption is approximately 7 kg/100 km, a rather effective result reached by the technology. The station utilization is below 30% for all sites, the buses availability hardly exceeds 80%. • Small/medium-sized hydrogen refueling stations performance analysis. • Investigation of fuel cell buses operation under real-world conditions. • Actual demand is lower than the planned maximum capacity suggesting future bus fleets ramp up potentiality. • On average, the fuel cell buses consume 7 kg H2 /100 km, meeting the EU targets. • The majority of the refuelings are performed overnight from 8 p.m. to 3 a.m. to secure capacity and availability. [ABSTRACT FROM AUTHOR]

Abstract: The aim of this work is to experimentally and numerically analyze the performance of a integrated power plant composed by a steam oxygen fluidized bed biomass gasifier fed by woods, a Solid Oxide Fuel Cell (SOFC) and a micro Gas Turbine (mGT). The numerical analysis is carried out by using ChemCAD software. In particular, SOFC and gasifier were modeled using proper developed Fortran subroutines interfaced to the basic software. The adopted SOFC model was already validated by the authors in previous works, while the gasifier model was here developed and validated by means of experimental activities carried out by using a bench scale gasifier. Different compounds (Benzene, Toluene, Naphthalene, Phenols) were chosen to analyze the tar evolution in the gaseous stream during the gasification process. Hot gas cleaning (based on catalytic ceramic filter candles inserted in the freeboard of the gasifier – UNIQUE concept) was adopted to remove tar and particulates from the fuel hot gas stream. Different moisture contents in the range between 10 and 30% (i.e. in a deviation of 10% around the usual wood moisture content of 20%) were numerically simulated as well as the degree of purity of the oxygen utilized in the power plant (between 25% and 95%, the rest being N2). The power requirement for pure oxygen production leads to a reduction of the electrical efficiency of the whole power plant. For this reason, a sensitivity analysis was conducted to find the optimal operation conditions in order to maximise the syngas (H2, CO) content in the produced gas, while maintaining a high overall electrical efficiency. [Copyright &y& Elsevier]

Biomass gasification has acquired considerable interest as a sustainable and environmentally friendly way to produce heat, hydrogen or electricity from agro-industrial wastes or other kinds of biomass. A very effective solution for the achievement of high electrical efficiency (up to 55%) is the integration of biomass gasification with solid oxide fuel cell (SOFC) technology, including the necessary gas cleanup to avoid degradation of the SOFC. For this reason, this paper first shows in detail the risk and the impact of carbon deposition, exposure to tar, hydrogen sulphide, hydrogen chloride and alkali metals on SOFC anode and then, considering the tolerance limit for inorganic and organic contaminants (<1 ppmv for H 2 S, HCl and alkali and <10 ppmv for tar), offers an overview of the most relevant and effective technologies to remove these contaminants and to feed safely a SOFC system. • Effect of exposure to tar on SOFC anode has been studied. • Effect of exposure to H 2 S, HCl and alkali metals on SOFC anode has been studied. • Overview on the technologies to remove contaminants and feed safely a SOFC system. [ABSTRACT FROM AUTHOR]

H 2 production from solar electricity in the region of the Atacama Desert – Chile – has been identified as strategical for global hydrogen exportation. In this study the full supply chain of solar hydrogen has been investigated for 2018 and projected to scenarios for 2025-2030. Multi-year hourly electrical profiles data have been used from real operating PV plants and simulated Concentrated Solar Power "CSP" plants with Thermal Energy Storage "TES" as well as commercial electricity Power Purchase Agreement "PPA" prices reported in the Chilean electricity market were considered. The Levelized Cost of Hydrogen "LCOH" of each production pathway is calculated by a case-sensitive techno-economic MATLAB/Simulink model for utility scale (multi-MW) alkaline and PEM electrolyser technologies. Successively, different distribution, storage and transportation configurations are evaluated based on the 2025 Japanese case study according to the declared H 2 demand. Transport in the form of liquefied hydrogen (LH 2) and via ammonia (NH 3) carrier is compared from the port of Antofagasta, CL to the port of Osaka, JP. • Cost-competitive solar hydrogen can be produced in Chile. • Oversized PV-supplied systems lead to lower LCOH than smaller CSP-supplied systems. • The LCOH of PV-PPA+ALK can reach 2.20 US$/kg in 2018 and 1.67 US$/kg in 2025. • Storage and transport phases are CAPEX intensive, favoured by flat supply schemes. • Competitive H 2 can be delivered in Japan in 2018 and 2025 respect to target prices. [ABSTRACT FROM AUTHOR]

Reliable and low-cost expanders are fundamental for the competitiveness of small-scale Organic Rankine Cycle (ORC) plants using low-temperature heat sources. Regenerative flow turbines (RFTs) can be considered a low-cost and viable alternative expander, yet their performance needs to be fully investigated. Therefore, the use of an RFT in a micro-scale ORC test bench is investigated in this work through a modelling study. Specifically, three-dimensional CFD simulations are carried out to assess the performance of the considered expander with varying operating conditions and a numerical model of a non-regenerative, small-scale ORC system is developed to investigate its potential in waste heat recovery (WHR) applications. Using R245fa as the working fluid, the CFD analysis shows that the expander achieves a maximum total-to-static isentropic efficiency of about 44% in the investigated operating range. The small-scale ORC system has a net output power in the range 100–600 W and a net cycle efficiency of 1–2.3%. Moreover, a comparison with two scroll expanders having different built-in volume ratios shows that the RFT operates with higher isentropic efficiencies in low mass flow rates and pressure ratios thus highlighting its suitability for low-temperature WHR applications, especially when considerable fluctuations of the heat source are expected. • Characteristics of an RFT working with R245fa is presented using CFD simulation. • A micro-scale ORC unit with RFT is simulated in low pressure ratios. • Performance of the RFT is compared with those of two scroll expanders with different BVRs. • RTF shows higher performance in low pressure ratios compared to scroll expanders. • RFTs can be introduced as alternative technology for low-temperature WHR applications. [ABSTRACT FROM AUTHOR]

Life-cycle assessment (LCA) and data envelopment analysis (DEA) were combined in the environmental sustainability assessment of bioelectricity production by means of vineyard waste biomass gasification. Fifty vineyards were assessed following LCA and DEA methodologies to estimate their technical efficiency. Moreover, target performance values benchmarked for inefficient vineyards, and the potential reductions in their environmental impact linked to the improvement in technical efficiency, were evaluated with the aim of verifying eco-efficiency criteria. The DEA results showed an average reduction of up to 30% per input of material for the vineyards, leading to impact reductions that ranged from 29% to 60% depending on the chosen impact category. Photochemical oxidation and terrestrial ecotoxicity had the highest environmental inefficiencies. Electricity generated from vineyard pruning residue gasification—as an alternative to conventional electricity and in comparison to electricity generation via combustion—was a suitable solution for reducing environmental impact under the studied categories. The innovative value of the present work is further based in the integrated application of LCA and DEA methodologies for the previously unexplored Iranian context. The results show that operational efficiency within vineyards is required to ensure that bioelectricity is significantly advantageous with regards to environmental performance in comparison to national grid electricity. The analysis further emphasises that increasing the operational efficiency of biomass production is a feasible way to achieve significant and wide-ranging environmental sustainability benefits. • Combined LCA, DEA and process simulation of Iranian vineyards crops for bioelectricity. • Pruning waste aimed to bioelectricity valued in proportion to economic allocation. • Use of fertiliser and pesticides is the chief cause of environmental impact. • LCA and DEA show a 20–52% achievable reduction on operational inputs. [ABSTRACT FROM AUTHOR]

Gasification is one of the most effective and studied methods for producing energy and fuels from biomass as different biomass feedstock can be handled, with the generation of syngas consisting of H 2 , CO, and CH 4 , which can be used for several applications. In this study, the gasification of hazelnut shells (biomass) within a circulating bubbling fluidized bed gasifier was analyzed for the first time through a quasi-equilibrium approach developed in the Aspen Plus environment and used to validate and improve an existing bubbling fluidized bed gasifier model. The gasification unit was integrated with a water-gas shift (WGS) reactor to increase the hydrogen content in the outlet stream and with a pressure swing adsorption (PSA) unit for hydrogen separation. The amount of dry H 2 obtained out of the gasifier was 31.3 mol%, and this value increased to 47.5 mol% after the WGS reaction. The simulation results were compared and validated against experimental data reported in the literature. The process model was then modified by replacing the PSA unit with a palladium membrane separation module. The final results of the present work allowed comparison of the effects of the two conditioning systems, PSA and palladium membrane, indicating a comparative increase in the hydrogen recovery ratio of 28.9% with the palladium membrane relative to the PSA configuration. • Gasification of hazelnut shells process modelled by Aspen Plus. • Gibbs reactor with a quasi-equilibrium approach used to achieve a major exactness. • Data fit of experimental data executed. • Effects on gas composition of temperature and steam variation determined. • Hydrogen recovery ratio with Pd membrane is 28.9 % more favorable respect to PSA. [ABSTRACT FROM AUTHOR]

Catalytic steam reforming of tar is a very efficient process to clean the gas produced by biomass gasification. Ni catalysts remain an affordable solution for this problem, even if this catalytic material suffers degradation due to carbon deposition and sulphur poisoning. In this study, the properties of a new catalyst Ni/Mayenite (Mayenite as binder), prepared by impregnation method and tested with a real gas obtained from a bench scale fluidized bed steam gasification of biomass, were investigated. Experiments were carried out in a microreactor fed by a slipstream coming from the bench scale gasifier to evaluate gas cleaning and upgrading options. Preliminary tests were carried out at three different temperatures, 700, 750 and 800 °C. In all the tests, the catalysts showed high activities reaching to a conversion rate of 90% in the case at highest temperature (800 °C). The conversion efficiency remained stable around this value during a 3 h test. A decrease in the performance was observed at 700 and 750 °C, even if the conversion remained stable around a lower value. An increase of H 2 (>50%) and a decrease of CH 4 were observed at all the temperatures, due to the occurrence of steam reforming reaction. A long duration test (12 h) was carried out at 800 °C and demonstrated that, at this temperature, the conversion was stable for a longer period. [ABSTRACT FROM AUTHOR]

• A sustainable scheme of biomass-fuelled micro-CHP system is proposed. • Steam injection increases the net power of the mGT and of the integrated system. • Adoption of the wet cycle penalizes the net electrical efficiency of the system. • Using syngas instead of NG reduces the net electrical efficiency noticeably while increasing the thermal power output. • Net electrical efficiency improves slightly using a bottom ORC system. Proper integration of different energy systems is one of the most effective strategies to achieve higher conversion efficiencies and to reduce emissions in power systems. Hence, in this study a biomass-fuelled Steam Injected micro Gas Turbine (SImGT) coupled to a bottom Organic Rankine Cycle (ORC) unit is investigated to better exploit the primary energy use while lowering the environmental impact. In the proposed integrated system configuration, a Heat Recovery Steam Generator (HRSG) produces steam for both the gasification process and the SImGT. To conduct a realistic simulation, several gas conditioning units are included in the configuration of the integrated system to purify the produced syngas to the allowable limit of mGTs. The impacts of both the mass flow rate of the injected steam and the S/B ratio on the performance of the integrated system have been assessed. Results of the analysis have shown that the produced electrical power increases as the mass flow rate of the injected steam increases, while the net electrical efficiency of the integrated system is penalized marginally. At its maximum net electricity production, the integrated system has an output of 127.6 kW el and 78.7 kW th with 23.6% electrical efficiency when the mass flow rate of the injected steam to the combustion chamber is 25 g/s, which corresponds to the maximum of the investigated range in this study. [ABSTRACT FROM AUTHOR]