Synthetic carbon and graphite

Asbestos fibers are found worldwide in many products as reinforcement in cement water pipes and the inert and durable mesh material used in filtration processes of chemicals and petroleum, for example. However, asbestos is not the only inorganic fiber in use today. Synthetic inorganic fibers abound. Glass fibers have replaced copper wire in some intercontinental telephone cables. Fiberglas (a trade name) has become the insulation material of choice in construction. Carbon and graphite fiber composites are favored materials for tennis racket frames and golf clubs. Fibrous inorganic materials have become commonplace in our everyday lives. 

This brief summary of the composition and structural characteristics of glass fibers, whiskers, and carbon and graphite fibers illustrates the ranges of synthetic inorganic fibrous materials. The purposes of the construction of these materials is to capitalize on the physical and chemical advantages of the fibrous morphology, size, and state. 

The concept of this process is shown in Figure 6. The carbon in biomass which is fixed by photosynthesis from atmospheric C02 is converted into i) solid carbon (various kinds of charcoal, carbon and graphite) for use as materials or for storage, which is a stable state of carbon element ii) synthetic fuels such as FT diesel oil, DME or hydrogen, which can replace fossil fuels as carbon neutral alternate fuels (Hori, 2007, 2007a, 2007b). 

Large Scale Production of Synthetic Carbon and Synthetic Graphite... 

Carbon and graphite can be manufactured by many processes. The industrially operated processes are generally purely thermal and utilize solid, liquid or gaseous carbonizable or graphitizable materials. Synthetic carbon is produced in the first process step and is converted into graphite in a second step. 

Smaller utensils can easily be prepared in the laboratory from pieces of pure synthetic carbon or graphite. Tubes, plates, valves and other shapes made of pure graphite, as well as of graphite reinforced with synthetics, are commercially available. 

Two forms of carbon materials are used as additives in the battery industry carbons and graphites. Carbons, in turn, are carbon blacks, activated carbon, etc. Graphites are also available in several forms purified natural flake graphites, expanded graphites, synthetic spherical graphites, etc. Table 7.1 summarises the basic characteristics (particle size, specific BET surface area, trade name) of some of the commercially available carbon and graphite materials. 

The manufacture of synthetic graphite basically involves the transition of an organic precursor through a carbonization and graphitization process to yield a char, which may be graphitized with difficulty, or a coke that is a graphitizable carbon (Table 2.3). 

Chapters 2 and 3 were a review of the carbon atom and its bonding mechanisms and howthese atoms combine tofonn graphite crystals. Inthis and the next six chapters, the focus wiil be on how iarge numbers of these crystallites are combined to form synthetic (and naturai) carbon and graphite products. The various types of synthetic materials will be reviewed including their production processes, their properties and characteristics, and their present and potential applications. 

Graphites (natural or synthetic) are black semireinforcing fillers used almost exclusively in rotary shaft seal applications where surface lubricity and abrasion resistance must be enhanced (see Carbon, natural graphite). 

---