Gasification applications

The heatpipe reformer process concept for hydrogen-rich syngas production. (Reproduced from Karellas, S., Metz, T., Kuhn, S., and Karl, J., Online analysis of the tar content of the product gas from biomass gasification. Application on the BIOHPR. 14th European Biomass Conference Exhibition, Biomass for Energy, Industry and Climate Protection, ETA-Renewable Energies, Paris, 2005. With permission.)... 

FI CU RE 4.29 A schematic illustration of the ion transport membrane (ITM) device developed and patented by Air Products and Chemicals, Inc. The supported membrane wafers are separated by spacer rings and attached to a common product withdrawal tube. (From Armstrong P. A., Stein V.E.E., Bennet D.I., Foster E.P., Ceramic Membrane Development for Oxygen Sypply to Gasification Applications, Air Products and Chemicals, Inc., Allentown, PA, 2002. With permission.)... 

Armstrong PA, Stein VEE, Bennet DI, and Foster EP. Ceramic Membrane Development for Oxygen Sypply to Gasification Applications. Allentown, PA, Air products and Chemicals, Inc., 2002. 

One of the most irrportant barriers to an accelerated penetration of all biomass conversion technologies is that of adequate resource supply. Figure 2 depicts the technology reliability of using the most important feedstocks in gasification applications. 

Refuse Derived Fuel has significant potential for gasification applications since gasification docs not have such a negative public image as incineration and there is sufficient experience by TPS (26) and FOSTER WHEELER (12). However, the feeding systems for fluff RDF need to be developed further to ensure reliable operation and more experimental results at large scale applications are needed to prove efficient operation. 

Finally sludge can also be utilised in gasification applications and although there exists little experience, it is expected that the application with sludge may increase in the future. Technical reliability still has to be demonstrated. 

The efficient removal of tar still remains the main technical barrier for the successful commercialisation of biomass gasification technologies and unless this barrier will be properly addressed biomass gasification applications for power, with the exception of pressurised IGCC, will never materialise. There arc several groups which have been working extensively on tar, however the most prominent teams arc those (in alphabetical order) of the University of Madrid (30, 31), The Royal Institute of Technology in Stockholm (32, 33) and VTT (34, 35). 

The various gasification applications for power and or heat are shown in Fig. 6 in terms of their market potential and overall technology reliability. Each of these applications will be discussed in the subsequent sections and the most advanced plants in each application will be presented in terms of their status and future prospects. It is of course beyond the scope of this overview to present all known activities, however, the most significant of these will be discussed as a means of presenting their achievements for the benefit of the other projects, which are still in the development stage. All demonstration projects had to overcome numerous teclinical and non-technical barriers as this is an emerging technology, however, many of these problems are common to all projects in the same application field and thus the projects still in the development face could learn from the experiences of the others. 

Since the heterogeneity of gasification feedstocks results in a formation of a wide variety of products of different chemical nature it is envisaged that the sampling system will have to be enhanced and up-dated on a short term basis. Therefore, there is room for improvement in sampling methods in order to meet all the requirements of the different gasification applications. 

L Foscolo P. U. (1998) Production of Hydrogen-Rich Gas by Biomass Gasification Application to Small-Scale Fuel Cell Electricity Generation in Rural Areas, EU Final Report, Contract JOR3-CT95-0037... 

Coconut shell, groundnut shell, wood, coconut coir and rice husk are better suited candidates compared to the other biomass studied for pyrolytic gasification applications. 

Armstrong PA, Bennett DL, Foster EPT, van Stein EE. Ceramic membrane development for oxygen supply to gasification applications. Gasification Technol. 2002. 

Natesan, K., "Corrosion and Mechanical Behavior of Materials for Coal Gasification Applications, Argonne National Laboratory, Report ANL-80-5, May 1980. 

Acid gas removal extracts most of the H2S and COS in coal gasification processes (see the more detailed discussion later in this section). The COj may be removed along with the H2S and COS, depending on the acid gas removal process and the coal gasification application. The acid gas removed from the coal gas is converted into elemental sulfur. 

Alternatives. Conventional acid gas removal is quite inexpensive yet very efficient. The challenge is to choose the correct process for each application. Well over 30 acid gas removal processes are in common commercial use throughout the oil, chemical, and natural gas industries. Table 2-3 lists the prominent acid gas removal processes and licensors of systems considered for coal gasification applications. 

Acid Gas Removal Processes Considered for Coal Gasification Application... 

As already shown in Figure 2.1, coal is the main feedstock in current gasification applications and the highest growth is expected for it. Hence, the following discussion will focus solely on coal. When selecting the appropriate coal for gasification, there are technical and economic aspects to be considered. 

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