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The aim of this research is to build a low‐cost gas and temperature profiling system for data acquisition at a biomass gasifier.

A gas and temperature profiling system was developed from NDIR sensors, Pd/Ni sensor, a number of type K thermocouples and a data logger interfaced to a computer.

The results obtained using the system were in agreement with the results obtained using a gas chromatograph for gasses. The temperature recorded during the testing also followed the expected temperature of the gasifier used.

The lifetime of the developed system depends on the lifetime of the sensors used. NDIR sensors have a lifetime of three years working on a continuous basis and the Pd/Ni sensor has a lifetime of ten years. Replacement of the Pd/Ni sensor after ten years is not a problem as the payback period of biomass gasifier systems is around eight to ten years.

The major implication for this research was that low‐cost gas and temperature measuring systems could be developed. These could be useful particularly for PhD students and other researchers who need to get onsite data on gas and temperature profiles at a gasifier system for a period of three years.

Biomass gasifier technologies can be used to provide power in rural areas that are outside the national utility grid but endowed with biomass resources. The provision of electricity to these communities could solve social challenges such as exposure to smoke in open fire normally used by rural women for cooking. The developed data acquisition system is therefore necessary to conduct research on gasification.

The findings of this paper are of importance to researchers who need online data but do not have funding to purchase bulky and expensive equipment's for gas analysis at biomass gasifier systems.

The purpose of this paper is to present a three‐dimensional CFD model that simulates the pyrolysis, combustion and heat transfer phenomena in a refuse‐derived fuel (RDF) gasifier. Correlations between different operation conditions and the waste stack morphology are also investigated. Parametric studies are conducted to optimize operating conditions to achieve an even stack surface minimal the local oxidation in the waste stack.

This paper proposes a Lagrangian pyrolysis submodel which can be applied to determine the local pyrolysis rate and porosity field by introducing the local characteristic diameter of the waste solid sphere. The flow field is described by a single‐phase porous flow model using the SIMPLE algorithm with momentum extrapolation. A one‐step global reaction was adapted for the chemical reactions inside the gasifier.

Computational results produced three‐dimensional distribution of the flow field, temperature, species concentration, porosity and the morphology of the waste stack under different operation conditions. Some parametric studies were conducted to assess the effects of the inlet temperature and the feeding rate on the waste stack shape. The results demonstrated that the model can properly capture the essential physical and chemical processes in the gasifier and thus can be used as a predictive simulation tool.

Due to the lack of accurate reaction rate information, the computational results have not been directly compared against experimental data. Additional refinement and subsequent validation against prototype gasifier experiment will be reported in future work.

A full three‐dimensional computational model is developed for the complex two‐phase flow based on porous medium representation of the solid stack. A Lagrangian pyrolysis model based on the characteristic diameter of the solid waste material was proposed to describe the pyrolysis rate history. The developed model reproduces correct physical and chemical behavior inside gasifier with adequate computational efficiency and accuracy.

The purpose of this paper is to develop a cyclone with an internal electric field to capture dust and fine carbon particles with less than 5 μm diameter.

The cyclone collection efficiency model described by Cooper and Alley was used to design a conventional cyclone, which was later modified by introduction of the solenoid around it to introduce an electric field. The cyclone design performance was later established using ferrosilicon powder with less than 5 μm diameter.

The cyclone was found to have a particle collection efficiency of around 25 per cent for ferrosilicon powder before the introduction of the solenoid; the introduction of the solenoid increased the particle collection efficiency to around 50 per cent and the charging of the solenoid further increased the collection efficiency to 85 per cent at 2 kV DC and 97 per cent at 3 kV DC. When the cyclone was placed back on the gasifier system and supplied with 2 kV DC, it collected up to 270 g of fine carbon particles within 150 min of operation.

The major drawback was that the highest particle collection efficiency for the cyclone could only be achieved at very high voltage (3 kV) but this could not be supplied when the cyclone was back in the gasifier system due to air ionization that results in the corona effect.

The collection of very fine particles (less than 5 μm diameter) in hot gas streams is always a challenge, particularly in biomass gasifier systems. This resulted in a high cost of gas purification or initial investments in downstream processes. The developed cyclone could cut down this expenditure since most of the particles will not go beyond the cyclone.

Electrostatics has been applied in the development of gas cleaning devices, however most of these devices tend to be too cumbersome. The developed cyclone is based on the conventional design, which is less complicated and cheap to manufacture.

The purpose of this paper is to investigate the use of Pinus wood waste in lead adsorption as a remediation technique in aqueous medium and its subsequent use in obtaining synthesis gas.

The capacity of the timber in the lead adsorption was studied in aqueous medium at various pH, determining the amount adsorbed in equilibrium. Then, the same timber was added in a fixed bed, co-current flow of two stage gasifier type, working temperature of 900°C, for obtaining synthesis gas. The synthesis gas composition was evaluated by the spectrophotometry in the infrared region and the gas chromatography and lead content in the ash and gas was determined by the atomic absorption spectrophotometry.

In laboratory tests carried out, the optimal pH for lead removal was pH 4 with 96.15 percent removal rate, reaching equilibrium after 180 min. In pilot scale the lead removal after 72 hours was 96 percent. The average production of syngas was 11.09 m³h⁻¹. For tests with the motor-generator, the best condition occurred with charge of 2.0 kW, wherein gas consumption per kW produced reached 4.86 m³ kW⁻¹, resulting in a 14.81 percent efficiency rate. The gas analysis showed an average concentration of 14.85 percent H₂, 30.1 percent CO₂, and 50.49 percent of atmospheric air. The concentration of lead in the gas was below the limit established by law. Pinus elliottii waste proved to be an excellent adsorbent, with removing more than 96 percent of the Pb ion present in aqueous solution and a starting material in the gasifier to generate synthesis gas.

This paper describes the waste wood application in the treatment of contaminated environments and for obtaining syngas providing a sustainable process.

This paper shows a process that combines the remediation of contaminated environmental with power generation systems, allowing efficient management of contaminated environments.

Renewable energy sources are likely to play a major role in meeting the future energy requirement of a developing country like India. Among the various renewable energy sources, the bio‐energy plays a key role for the power generation. In this paper, an attempt is made to develop a fuzzy based linear programming optimal electricity allocation model (OEAM) that minimizes the cost and determines the optimum allocation of different energy sources for the centralized and decentralized power generation in India with special emphasis to bio‐energy.

The OEAM model optimizes and selects the appropriate energy options for the power generation on the factors such as cost, potential, demand, efficiency, emission and carbon tax. The objective function of the model is minimizing the cost of power generation. The other factors are used as constraints in the model. The fuzzy linear programming optimization approach is used in the model.

The extents of energy sources distribution for the power generation in the year 2020 would be 15,800 GWh (4 per cent) from the coal based plants, 85,400 GWh (20 per cent) from the nuclear plants, 191,100 GWh (44 per cent) from the hydro plants, 22,400 GWh (5 per cent) from the wind mills, 45,520 GWh (11 per cent) from the biomass gasifier plants, 14,112 GWh (3 per cent) from the biogas plants, 8,400 GWh (2 per cent) from the solid waste, 33,600 GWh (8 per cent) from the cogeneration plants and 11,970 GWh (3 per cent) from the mini hydel plants, respectively.

The OEAM has been developed for the electricity demand allocation for the year 2020. An extensive literature survey revealed that carbon tax and emission constraints were never used in the previous models and they are considered in the present model.

H₂O, CO₂ and CO are three main species in combustion systems which have high volume fractions. In addition, soot has strong absorption in the infrared band. Thus, H₂O, CO₂, CO and soot may take important roles in radiative heat transfer. To provide calculations with high accuracy, all of the participating media should be considered non-gray media. Thus, the purpose of this paper is to study the effect of non-gray participating gases and soot on radiative heat transfer in an inhomogeneous and non-isothermal system.

To solve the radiative heat transfer, the fluid flow as well as the pressure, temperature and species distributions were first computed by FLUENT. The radiative properties of the participating media are calculated by the Statistical Narrow Band correlated K-distribution (SNBCK), which is based on the database of EM2C. The calculation of soot properties is based on the Mie scattering theory and Rayleigh theory. The radiative heat transfer is calculated by the discrete ordinate method (DOM).

Using SNBCK to calculate the radiative properties and DOM to calculate the radiative heat transfer, the influence of H₂O, CO₂, CO and soot on radiation heat flux to the wall in combustion system was studied. The results show that the global contribution of CO to the radiation heat flux on the wall in the kerosene furnace was about 2 per cent, but that it can reach up to 15 per cent in a solid fuel gasifier. The global contribution of soot to the radiation heat flux on the wall was 32 per cent. However, the scattering of soot has a tiny influence on radiation heat flux to the wall.

This is the first time H₂O, CO₂, CO and the scattering of soot were all considered simultaneously to study the radiation heat flux in combustion systems.

The purpose of this paper is to assess renewable energy‐based cooling technologies using multi‐criteria methodology.

Analytic hierarchy process (AHP) methodology is applied to obtain the ranking of renewable energy options for cooling technology using five different criteria. In total, seven technologies were analyzed, based on the opinions obtained from experts and the extensive literature survey made and the ranking was obtained using AHP method.

The present findings revealed that the ranking for the renewable energy‐based cooling technologies were in the following order: biomass combustion, biogas, trigeneration, SPV, biomass gasifier, solar thermal storage, and hybrid technology. Only 5 per cent variation in global priority exists among top three options. This variation is considered insignificant due to rapidly varying factors such as technological advancements, government promotional schemes, fuel availability, etc. and hence these three options may be ranked equally.

The research output is helpful in identifying the technology, with promising potential for promoting technology on a wider scale. Additional attributes and sensitivity analysis can be included for further research.

The paper usefully describes the AHP methodology utilized in the present study and the ranking made for the evaluation of renewable energy‐based cooling systems. The outcome of the present study would benefit policymakers, researchers and entrepreneurs when choosing the appropriate cooling technology.

The petroleum shortage of the 1970s (1984 is the tenth anniversary of the OPEC embargo!) motivated tremendous interest in finding alternative raw materials for chemicals. Indeed, in 1975 it was predicted that by 1990, huge and expensive coal gasifiers would be producing CO and hydrogen for synthesis gas, from which the chemical industry would derive many of its raw materials. In 1983 it was apparent that this prediction was far from accurate. To be sure, eventually there will be a shift from petroleum to coal, but it most surely will not be before the end of the century and perhaps not even then. Coal will, however, continue to find increasing use as an energy source. The vast amount of research that has been done on converting synthesis gas to chemicals will continue, although with considerably less intensity. When the time comes, the shift will be made. But that time will be delayed as far as possible because the shift will require tremendous capital investment. Coal gasifiers can cost as much as US$500,000, and the return on such an investment must be assured before it is made. Certainly, coal is a cheap raw material. Thus, its use for chemicals represents a trade‐off between a cheap raw material and a very high capital investment.

The purpose of this study is to investigate the combustion of the n-Heptane droplets in the supersonic combustor with a cavity-based fuel injection configuration. The focus is on the impacts of the droplet size on combustion efficiency.

The finite volume solver is developed to simulate the two-phase reacting turbulent compressible flow using a single step reaction mechanism as finite rate chemistry. Three different fuel injection settings are studied for the considered physical geometry and flow conditions: the gas fuel injection, small droplet liquid fuel injection and big droplet fuel. The fuel is injected as a slot wall jet from the bottom of the cavity.

The results show that using the small droplet size, the complete fuel consumption and combustion efficiency can be achieved but using the big droplet sizes, most fuel exit the combustor in the liquid phase and gasified unburned fuel. It is also demonstrated that the cavity's temperature distribution of the liquid fuel case is different from the gas fuel, and two flame branches are observed there due to the droplet evaporation and combustion in the cavity.

To the best of the authors’ knowledge, this study is performed for the first time on the combustion of the n-Heptane fuel droplets in scramjet configuration, which is promising propulsion system for the future economic flights.

The process of manufacturing an activated carbon nonwoven made by cotton fiber was investigated. The study was focused on cotton nonwoven formation, carbonization, activation, and characterization of the activated carbon nonwoven. Pyrolysis of the cotton carbonization was analyzed using TGA. There was a considerable decrease in weight loss in the region between 250°C to 400°C and the proper carbonized temperature was 400°C. The SEM examination indicated that the surface area of cotton fiber was increased significantly because the inside hollow of cotton fiber was widely opened and some small agglomerated particles were gasified after activation. Absorbability of the activated carbon nonwoven was evaluated using an instrument of inverse gas chromatography. Dispersive surface energy, specific free energy, and total surface energy all indicated this trend: Carbonized Cotton > Activated Cotton > Raw Cotton. The activated carbon nonwoven exhibited the potential for use as high adsorbent and absorbent materials. They are light weight and bulky, advantageous in protective clothing applications and other consumer and industrial applications.