Economic and Environmental Assessment of Biomass Power Plants in Southern Italy

In 2019, Europe adopted the New Green Deal as a strategic plan to become a competitive, resource-efficient, and driven economy by reducing its gas emissions and carbon footprint. Due the COVID-19 pandemic, this strategic plan was recently updated to expedite the green transition of European industries. Therefore, the present paper deals with the problem of deciding an appropriate size for a biomass plant that directly produces electric energy by means of two different conversion processes: combustion and gasification. After an initial estimation of the energy potential in western Sicily, GIS data of biomass growth were used to identify the appropriate size for the power plants under investigation. The economic feasibility of biomass utilization was evaluated over a capacity range of 10 to 30 MW, considering total capital investments, revenues from energy sales, and total operating costs. Moreover, the effect of variations on incentive prices was analyzed by means of a sensitivity analysis. Comparing the different plant solutions considered, the environmental sustainability was also analyzed using the life cycle assessment (LCA) approach. The results showed that the combustion solution had a higher profitability and a lower environmental impact for each plant size. The obtained results also demonstrated that providing power from residual biomass in small agricultural communities would significantly reduce their environmental impacts while improving the economic feasibility of their waste management practices

Syngas Use in Internal Combustion Engines - A Review

Syngas is a comparatively low energy fuel gas that can be utilized in spark ignition and compression ignition (diesel) internal combustion engines manufactured to run on gasoline or diesel fuels to reduce or eliminate the petroleum fuel requirement for the engine. Syngas can be produced from any carbonaceous material including many forms of biomass. Engine power derating when operating with syngas is typically 15% - 40%, less than the difference in energy content between producer gas and petroleum fuel would indicate largely because of the disparity of stoichiometric air-fuel requirements of producer gas and gasoline or diesel fuel

Simulation and life cycle assessment of algae gasification process in dual fluidized bed gasifiers

We present simulation results for the production of algae-derived syngas using dual fluidized bed (DFB) gasifiers.Part of this work was funded by the Technology Strategy Board (TSB) grant programme, “Carbon Abatement Technologies, Phase 2 competition for collaborative R&D and feasibility”, Grant No. TS/J004553. MK acknowledges support by the Singapore National Research Foundation under its Campus for Research Excellence And Technological Enterprise (CREATE) program.This is the accepted manuscript. The final version is available at http://pubs.rsc.org/en/Content/ArticleLanding/2015/GC/c4gc01698j#!divAbstract

Thermodynamic Analysis For Improving Understanding And Performance Of Hybrid Power Cycles Using Multiple Heat Sources Of Different Temperatures

Past studies on hybrid power cycles using multiple heat sources of different temperatures focused mainly on case studies and almost no general theory about this type of systems has been developed. This dissertation is a study of their general thermodynamic performance, with comparisons to their corresponding single heat source reference systems. The method used in the dissertation was step-wise: to first analyze the major hybrid power cycles (e.g. Rankine, Brayton, Combined Cycles, and their main variants) thermodynamically, without involving specific operation parameter values, and develop some generalized theory that is at least applicable to each type of system. The second step was to look for commonalities among these theories and develop the sought generalized theory based on these commonalities. A number of simulation case studies were performed to help the understanding and confirm the thermodynamic results. Exergo-economic analysis was also performed to complement the thermodynamic analysis with consideration of externalities, and was compared to the conventional economic analysis method. The generalized expressions for the energy/exergy efficiency differences between the hybrid and the corresponding single heat source systems were developed. The results showed that the energy and exergy efficiencies of the hybrid systems are higher than those of their corresponding single heat source reference systems if and only if the energy/exergy conversion efficiency (defined in the dissertation) of the additional heat source (AHS, can be any heat source that has lower temperature) is larger than that of the original heat source. Sensitivity analysis results showed the relations between the temperature and heat addition rate of the AHS and the energy/exergy efficiency of the hybrid systems. Other big advantages of hybrid systems, i.e. the effects on replacement of fossil fuel by renewable, nuclear and waste energy, lower emissions and depletion of fossil fuel, were revealed in the economic analysis, by considering the cost reduction from fuel saving and carbon tax. Simple criteria were developed to help compare the hybrid and reference systems and determine under which conditions the hybrid systems will have better thermodynamic or economic performance than the reference ones. The results and criteria can be used to help design the hybrid systems to achieve higher energy and/or exergy efficiencies and/or lower levelized electricity cost (LEC) before detailed design or simulation or experiment. So far, 3 archival journal papers and 3 conference papers were published from this dissertation work

Emission and energy analysis of self-sufficient biomass power plant to achieve near net zero CO₂ emission

The use of biomass to fuel power plants is considered by many to be a carbon neutral solution to carbon dioxide emissions. One objection to this method of power generation is the gasoline or diesel spent in the transportation and feedstock production, which is a major contributor to carbon emission. In addition, costs associated with the transportation of the biomass fuels are also a major limiting. This work investigates the use of a hybrid farming facility as a means of distributed generation combined. A model that incorporates a small scale biomass power facility located within a farming facility is examined. By locating the power facility at the center of the facility and having the biomass crop fields surrounding the power plant, transportation costs for power generation are greatly reduced. In addition, the use of electric powered farm equipment for sowing seeds, harvesting, and fertilizer application reduces fossil fuel consumption to near zero. Powering these vehicles with the electrical energy from the power plant on site allows for a self-sufficient agricultural facility with near zero emissions. --Abstract, page iii

CFD model for tubular SOFC stack fed directly by biomass

The energy transition can also be promoted by the sustainable use of biomass. Residual biomass in the Mediterranean areas can be exploited to a greater extent through highly efficient fuel cell systems. The Direct Biomass-SOFC project is based on a direct coupling between biomass power supply and SOFC tubular cells. This research project stems from the need to cover the electricity demand, avoiding the use of non-renewable sources. It will be investigated the unused or little-used biomass sources that can be exploited from the Mediterranean area. To this purpose, analyses were conducted to model a SOFC tubular cell stack by investigating the optimal configuration. The basic objective is to design a SOFC tubular cell stack, fed by syngas to produce at least 200 W. Two configurations were chosen: a square and a circular arrangement. Another objective of the study is to choose the best temperature control system. It have been selected a pressurised water system and an air system. The results show that the best performance is guaranteed by a square arrangement with an air temperature control system. The circular configuration provides less power than the square configuration, being limited by the multiple series connection to the lowest current value. The maximum electrical power produced with the square configuration is 225 W

USING BIOMASS TO DUAL FUEL A 4.5 KW DIESEL GENSET TO INVESTIGATE REDUCING WASTE DISPOSAL COSTS FOR A SMALL U.S. MUNICIPALITY

This study explores dual fueling a diesel genset with producer gas made from biosolids , wastepaper and woodchips generated at or brought into the Minoa (a village in New York) Wastewater Treatment Plant (MWTP) and the possibility of a dual fueled genset and gasifier reducing the MWTP operating costs. The producer gas resulted from gasifying the biomass in a downdraft Imbert style gasifier. Gasification of woodchips was first studied in the gasifier using two different sizes and types of woodchips. It was found that the denser hardwood chips 2 cm x 2 cm x 0.6 cm gave better performance than less dense willow chips 1 cm x 1 cm x 0.15 cm. The smaller, less dense chips restricted air flow and reduced temperatures in the gasifier oxidation and reduction zones. Particle size distribution from samples taken vertically through the gasifier also indicated restriction of air and fuel flow through these zones with the smaller, lighter chips. Dual fueling of the genset with the larger, denser woodchips reduced diesel consumption by approximately 75%. Wastepaper, primarily newspaper, was then studied as gasifier fuel. It was first pulped, then the wet pulp was formed into 60 cm3 chunks, then dried and gasified. The wastepaper fuel was generally difficult to gasify because of its low density and tendency to hang up in the gasifier. Dual fueling the genset with producer gas from wastepaper only reduced diesel consumption by approximately 30%. Since wastepaper can be recycled by Minoa at no cost, gasifying its wastepaper was not recommended. Biosolids were then studied as gasifier fuel. Copious ashes were removed from the gasifier oxidation and reduction zones. Dual fueling the gasifier with producer gas from biosolids reduced diesel consumption by 70% - 90%. Biosolids first processed through a filter press then pressed into roughly 15 cm3 chunks and dried gasified easily as long as the grate was continuously agitated. By generating electricity and the potentially valuable soil amendment biochar dual fueling a diesel powered genset with producer gas generated from biomass could save Minoa more than $14580 annually