Issues Related to Carbon Deposition

However, there are two major issues related to the application of metal-based catalysts (1) catalyst deactivation and (2) separation of carbon products from catalysts. Carbon-based catalysts offer certain advantages over metal catalysts because of their availability, durability, and low cost [13]. The other important features of carbon-based catalysts are that they are sulfur tolerant and can withstand higher temperatures. The benefit of using catalytically active carbon particles for methane decomposition is that carbon formed from the reaction can deposit on the surface of the original carbon catalysts. These carbon particles serve as a new carbon catalyst to conhnue the decomposition reaction. No new external catalysts are needed. Additionally, no separation of carbon products from catalysts is needed because the catalysts and products are the same types of carbon. Many types of carbon-based catalysts have been used in hydrogen production via methane decomposition. 

The second way to enhance the usability of ICPs is to apply coatings thereof on textile materials. A very thin layer of conductive polymers can be applied on the surface of textile substrates by solution casting, inkjet printing, in situ polymerization, vapor phase polymerization, and chemical vapor deposition techniques [26—29]. The nano-microscale conductive coatings not only provide high level of conductivity but also preserve the flexibility and elasticity of substrate fibers. However, due to the health-related issues of some carbon-based materials one has to be observant about what is possible and what is not in apparel applications. 

Direct oxidation (or direct utilization) The fuel is oxidized directly in the SOFC without external reformation. The SOFC has been shown to have the capabihty for direct oxidation of different types of fuels [4, 36-38]. To address the carbon deposition issue associated with nickel commonly used in the anode composition, other metals such as copper have been tested. The abihty of copper to resist carbon formation leads to the development of a composite anode composed of a ceria support and a copper phase [38]. The key technical challenges in the development of direct-oxidation SOFCs relate to the anode, especially the electrode s performance, stability, and direct-oxidation capabihty. 

Section Durability/ReliabUity of SOFC Systems describes durability/reliability of SOFC systems. Failures of system operation are first described. Then, failures of stacks and degradation of cell performances are described in detail with focuses on chromium poisoning, nickel sintering, carbon deposition, sulfur poisoning, etc. Results of field tests are also described in relation to reliability. Section Cost Issues describes the cost issue and Future Directions of SOFC development are given finally in section Future Directions. ... 

The nature of the SEI, which is dependent upon the nature of the electrolyte and the nature and composition of the solvent components is a crucial issue governing the performance of both hard and soft carbon anode materials as discussed above. The determination of individual processes which limit the low temperature curabilities of carbon-based anodes is complex, but experiments have been designed to identify, at least qualitatively, individual mechanisms relating to dissolution or growth of the SEI, Li(m) deposition, or to slow electrode kinetics and/or slow solid-state diffusion. In "half-cells" of the type... 

Petropolitics is concerned with the interplay between politics and oil/petroleum. It is thus an aspect of politics concerned almost entirely with carbon. The term was coined in the early 1970s when a major international oil crisis occurred and which highlighted the close, almost perilous, relationship between oil availability and international politics. The ownership of oil deposits confers power and advantage in an oil-fuelled world lack of it confers disadvantage. Since oil is necessary for industrial/economic development it becomes a direct political instrument. The other factors to which oil is related, such as war, climate and poverty, also contribute to petropolitics. Indeed, the issue of global climatic change has rapidly developed a focus in international politics, as discussed in Section 7.6 below. According to Wikipedia (2004), four distinct oil crises can be identified as discussed below. 

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