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This paper aims to briefly overview gasification technologies of biomass and heterogeneous wastes as a means for syngas production. For this purpose, an overview of the existing technologies, their main advantages, limitations, and costs, as well as commercial plants and projects (lower TRL) operating with these technologies and syngas applications is presented. The type of technology and operating parameters should be selected considering the quality of the syngas as it will dictate its end use. Syngas quality is determined by the combination of feedstock properties, type of technology and process operating conditions, and the scale of operation. For smaller projects with a capacity of up to 10 MWth, fixed-bed technologies have been a recurring choice, while fluidized bed reactors can have an installed capacity above 100 MWth and are, therefore, more suitable for medium- and large-scale projects. Fluidized bed gasification technology supports feedstock flexibility, has scale-up potential, and presents relatively low cost, making it a suitable solution and a frequent choice for heterogeneous waste gasification in medium- or large-scale projects. Commercializing waste gasification technology is already a reality. However, more efforts need to be made so that pilot and demonstration projects can overcome the technological and economic problems and move towards commercialization.

This paper aims to briefly overview gasification technologies of biomass and heterogeneous wastes as a means for syngas production. For this purpose, an overview of the existing technologies, their main advantages, limitations, and costs, as well as commercial plants and projects (lower TRL) operating with these technologies and syngas applications is presented. The type of technology and operating parameters should be selected considering the quality of the syngas as it will dictate its end use. Syngas quality is determined by the combination of feedstock properties, type of technology and process operating conditions, and the scale of operation. For smaller projects with a capacity of up to 10 MWth, fixed-bed technologies have been a recurring choice, while fluidized bed reactors can have an installed capacity above 100 MWth and are, therefore, more suitable for medium- and large-scale projects. Fluidized bed gasification technology supports feedstock flexibility, has scale-up potential, and presents relatively low cost, making it a suitable solution and a frequent choice for heterogeneous waste gasification in medium- or large-scale projects. Commercializing waste gasification technology is already a reality. However, more efforts need to be made so that pilot and demonstration projects can overcome the technological and economic problems and move towards commercialization. [ABSTRACT FROM AUTHOR]

This review paper aims to explore the research progress in the formation of hydrogen rich gas from different innovative coal gasification parameters. Promotion effects of parameters such as pressure, temperature, catalyst, coal type, reactor setup, and gasification agents (H 2 O, O 2 , supercritical water) were extensively analysed. The formation of hydrogen gas through coal gasification was sub-divided into H 2 production from fixed bed gasification system, fluidized bed system, and entrained flow system. The advantages of coal and biomass co-gasification towards clean energy formation was also reviewed. Co-gasification and elevated temperatures, pressures, and steam-carbon ratios were reported to positively influence the yields of H 2 gas by facilitating steam reforming and water gas shift reactions. The presence of different catalyst and sorbents in the gasification reaction systems was also noticed to enhance the concentration of hydrogen in the gaseous products. Production of hydrogen rich syngas from fixed bed and fluidized bed gasifiers was assessed, and both methods were found to favour the formation of hydrogen gas. The polygeneration of hydrogen gas, electricity and carbon dioxide capture was discovered to be feasible via coal gasification techniques. • Higher temperatures, pressures, and steam-carbon ratio were reported to enhance the yields of H 2 gas. • Presence of Na, K, Ca, and Fe derived catalysts favoured H 2 gas production reactions. • The use of sorbents like CaO have facilitated the yields of hydrogen gas. • Co-gasification of coal with biomass has a positive influence on hydrogen gas formation. • Both fluidized bed and fixed bed reactors were efficient in producing hydrogen gas. [ABSTRACT FROM AUTHOR]

This article is about the rapid transition to gasifiers in Sweden during World War Two, which made it possible to fuel cars with domestic wood instead of petrol, the imports of which seized during the war. The transition had been prepared in the interwar period and was executed very effectively in the beginning of the war. However, when the war was over and petrol became available again most gasifiers were quickly dismantled. In the concluding discussion, the concepts of head wind and tail wind transitions are introduced to analyze why gasifiers were introduced so rapidly in the beginning of the war, and why they were dismantled just as quickly after the war. It is argued, that the gasifiers were a clear example of a head wind transition, and the gasifier transition is briefly contrasted with two other energy transitions in Sweden that were tail wind transitions: the development of hydropower and of nuclear power. [ABSTRACT FROM AUTHOR]

Traditional coal-processing technology is compared with Fast Engineering® technology developed on the basis of catalytic reactors, heat exchangers, mass-transfer systems, and other innovative equipment. Operational experience is described. The economic, operational, and environmental benefits of the new technology are noted, and means of using the products in gasification are described. [ABSTRACT FROM AUTHOR]

Biomass is a renewable energy source, its use has received great attention due to environmental considerations and the increased need for energy worldwide, is clean and emit low greenhouse gas emissions compared with fossil fuels. The bark of cashew nuts (CCC), waste from the processing of almonds, which is excessively generated in our state and has not been administered correctly, so it is wasting its full potential, i.e., the main source for generating energy from biomass is in the waste. However, the use of agro industrial wastes energy is obtained by performing the archaic form of direct burning in ovens and chairs. Through the biomass gasification, process which converts the waste gas with an energy properties. We studied the conditions for utilization of biomass in order to obtain the best thermochemical conversion of biomass (direct combustion, pyrolysis and gasification). Had the opportunity to know the full operation of the gasifier, the phases of operation (heating, drying, pyrolysis and gasification) and to influence and select the ideal operating conditions. Applying methods of thermodynamic analysis and energy found in the literature and using data collected from tests performed in the fluidized bed gasifier installed was possible to determine the efficiency and potential (energy available and dissipated) of the gasifier. [ABSTRACT FROM PUBLISHER]

The utilisation of energy in waste, Waste to Energy (WtE), has become increasingly important. Waste is a wide concept, and to focus, the feedstock dealt with here is mostly municipal solid waste. It is found that combustion in grate-fired furnaces is by far the most common mode of fuel conversion compared to fluidized beds and rotary furnaces. Combinations of pyrolysis in rotary furnace or gasification in fluidized or fixed bed with high-temperature combustion are applied particularly in Japan in systems whose purpose is to melt ashes and destroy dioxins. Recently, also in Japan more emphasis is put on WtE. In countries with high heat demand, WtE in the form of heat and power can be quite efficient even in simple grate-fired systems, whereas in warm regions only electricity is generated, and for this product the efficiency of boilers (the steam data) is limited by corrosion from the flue gas. However, combination of cleaned gas from gasification with combustion provides a means to enhance the efficiency of electricity production considerably. Finally, the impact of sorting on the properties of the waste to be fed to boilers or gasifiers is discussed. The description intends to be general, but examples are mostly taken from Europe. [ABSTRACT FROM AUTHOR]

Abstract: Gasification of fuel cane bagasse, the waste residue from fuel cane, a hybrid of wild and commercial clones of sugar cane, was carried out in a novel 50kWe air-blown autothermal downdraft gasifier. The speciation and distribution of alkali, alkali earth metals and major ash forming elements during gasification were investigated to evaluate the extent of volatilisation of these elements into the syngas and to determine the likely impact on syngas fuelled solid oxide fuel cell systems. Also assessed was the potential for defluidisation of the fuel bed due to agglomerate and deposit formation. Chemical fractionation studies showed that 30% of the potassium was captured by aluminosilicates and was retained in the ash, thereby reducing the alkali loading in the syngas and that more than 50% of the alkali earth metals were released to the syngas. In contrast, although the major ash forming elements were transformed from acid insoluble to acid soluble forms during gasification they remained hard bound in the ash and less than 30% of each one was released into the gas phase. The composition of clinkers and agglomerates produced during gasification was investigated by SEM-EDX and XRD which confirmed the presence of the eutectic systems KAlSi2O6–SiO2, KAlSi2O6–CaMgSi2O6–SiO2 and CaMgSi2O6–NaAlSi3O8. A preliminary model of the distribution behaviour during gasification of the ash forming elements has been developed. [Copyright &y& Elsevier]

Abstract: A comprehensive simulation program for fluidised bed equipment (CSFB) has been improved and is now able to predict operational conditions of bubbling and circulating fluidised bed equipment such as boilers, gasifiers, dryers, shale-retorting reactors, and pyrolysers with various designs and consuming a wide range of feedstock. This paper concentrates on the improvements on the original bubbling model. Comparisons between simulation results and real equipment operational conditions under bubbling fluidised bed techniques are presented. Since those comparisons showed relatively low deviations, it is believed that CSFB is useful for improving operational conditions of existing industrial units and as auxiliary tool for designing of new equipment. [Copyright &y& Elsevier]

The blast furnace process is still the predominant method for primary iron production. However, the disadvantages inherent to the process led to the development of alternative processes such as the mini blast furnace process, smelting reduction process, and direct reduction process. Many of these alternative processes are still under development. However, direct reduction processes have reached some level of commercial applicability and are considered to be the most developed alternative ironmaking route. It is coke-less and environmentally friendlier when compared to the blast furnace process. In addition, direct reduced iron has a well-defined chemical composition when compared with steel scrap and has efficient melting properties in the electric arc furnace. Consequently, there is a great increase in the demand for direct reduced iron in electric arc steel making. These attractive features have led to an increase in worldwide production of direct reduced iron, which is currently approaching 50 million tons. Thus, direct reduced iron is gaining more importance. Hence, this article summarizes the basic properties and features of direct reduced iron. [ABSTRACT FROM AUTHOR]

There has been much debate in recent years as to the effectiveness of enhancing heat and mass transfer rates with resonant acoustic oscillations in industrial equipment such as boilers, dryers, calciners, gasifiers, and others. This article will briefly discuss the theoretical background of acoustic drying, the setup of the experimental apparatus used to investigate the feasibility of acoustically enhanced drying, the results of these experiments, and, finally, some conclusions drawn from this work. The theoretical discussion focuses on the use of the quasi-steady assumption to estimate the potential for enhancing the heat and mass transfer rate to and from the material using acoustic oscillations. The experimental work reported focuses on the successful application of acoustical oscillations to drying a cellulose sponge, which is a material that readily transports moisture to its surface where it can be effectively dried. Also reported is the unsuccessful application of acoustic oscillations to the drying of polyethylene terephthalate, which is a saturated, thermoplastic, polyester resin made by condensing ethylene glycol and terephthalic acid and is commonly used in the manufacture of plastic food and drink containers. Reasons for success and failure in each case are discussed along with the implications of these to the successful application of acoustic oscillations to future drying applications. [ABSTRACT FROM AUTHOR]

In this study, different biomass gasification applications and strategies that affect the gasifier which makes electricity in Turkey were investigated. Gasification technologies provide the opportunity to convert renewable biomass materials into clean fuel gases or synthesis gases. These gaseous products can be burned to generate heat or electricity, or they can potentially be used in the synthesis of liquid transportation fuels, hydrogen, or chemicals. Gasification offers a combination of flexibility, efficiency, and environmental acceptability that is essential in meeting future energy requirements. The future of biomass electricity generation lies in biomass integrated gasification/gas turbine technology, which offers high-energy conversion efficiencies. [ABSTRACT FROM AUTHOR]

Abstract: The gasification of coal to produce hydrogen for use either in power generation or/and for synthesis applications and transport is attracting considerable interest worldwide. Three types of generic gasifiers (entrained flow, fluidised bed and fixed bed gasifiers) presently in use in commercial gasification plants or under development worldwide are described. Their suitability for processing all types of coals is discussed. This includes an assessment of the impact of some of the major properties of coal on the design, performance and maintenance of gasification processes. [Copyright &y& Elsevier]

Abstract: Although coal may be viewed as a dirty fuel due to its high greenhouse emissions when combusted, a strong case can be made for coal to be a major world source of clean H2 energy. Apart from the fact that resources of coal will outlast oil and natural gas by centuries, there is a shift towards developing environmentally benign coal technologies, which can lead to high energy conversion efficiencies and low air pollution emissions as compared to conventional coal fired power generation plant. There are currently several world research and industrial development projects in the areas of Integrated Gasification Combined Cycles (IGCC) and Integrated Gasification Fuel Cell (IGFC) systems. In such systems, there is a need to integrate complex unit operations including gasifiers, gas separation and cleaning units, water gas shift reactors, turbines, heat exchangers, steam generators and fuel cells. IGFC systems tested in the USA, Europe and Japan employing gasifiers (Texaco, Lurgi and Eagle) and fuel cells have resulted in energy conversions at efficiency of 47.5% (HHV) which is much higher than the 30–35% efficiency of conventional coal fired power generation. Solid oxide fuel cells (SOFC) and molten carbonate fuel cells (MCFC) are the front runners in energy production from coal gases. These fuel cells can operate at high temperatures and are robust to gas poisoning impurities. IGCC and IGFC technologies are expensive and currently economically uncompetitive as compared to established and mature power generation technology. However, further efficiency and technology improvements coupled with world pressures on limitation of greenhouse gases and other gaseous pollutants could make IGCC/IGFC technically and economically viable for hydrogen production and utilisation in clean and environmentally benign energy systems. [Copyright &y& Elsevier]

Abstract: The performances of four IGCC plants employing Shell, Texaco, BGL and KRW gasifiers were simulated using ASPEN Plus software for three different feeds. Performance analyses and comparisons of all four IGCC plants were performed based on the established data bank from the simulation. Discussions were focused on gas compositions, gasifier selection and overall performance. [Copyright &y& Elsevier]

The paper addresses case studies of a low temperature and a high temperature industrial heat requirement being met using biomass gasification. The gasification system for these applications consists of an open top down draft reburn reactor lined with ceramic. Necessary cooling and cleaning systems are incorporated in the package to meet the end use requirements. The other elements included are the fuel conveyor, water treatment plant for recirculating the cooling water and adequate automation to start, shut down and control the operations of the gasifier system. Drying of marigold flower, a low temperature application is considered to replace diesel fuel in the range of 125–150 l h−1. Gas from the 500 kg h−1, gasifier system is piped into the producer gas burners fixed in the combustion chamber with the downstream process similar to the diesel burner. The high temperature application is for a heat treatment furnace in the temperature range of 873–1200 K. A 300 kg h−1 of biomass gasifier replaces 2000 l of diesel or LDO per day completely. The novelty of this package is the use of one gasifier to energize 16 burners in the 8 furnaces with different temperature requirements. The system operates over 140 h per week on a nearly nonstop mode and over 4000 h of operation replacing fossil fuel completely. The advantage of bioenergy package towards the economic and environmental considerations is presented. [Copyright &y& Elsevier]