Inertinite

In fact, inertinite is a misnomer tracing to the teaching that certain constituents remain nonreactive or inert during softening of coking coals. Later, it became clear that inertinite is not inert in the sense described, but it kept the name. However, the alteration during coalification is the least for all maceral groups. Therefore, the term inert may be justified. 

It should be noted that the different thermal conversion properties (e.g., combustion, gasification, coking) between the northern and southern hemisphere coals can be linked to the different maceral group portions for example, high-rank coals from South Africa, India, and Australia are enriched in inertinite [3]. 

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Macerals. Coal parts derived from different plant parts, are referred to as macerals (13). The maceral names end in "-inite" as do the mineral forms of rocks. The most abundant (about 85%) maceral in U.S. coal is vitrinite, derived from the woody tissues of plants. Another maceral, called liptinite, is derived from the waxy parts of spores and poUen, or algal remains. The liptinite macerals fluoresce under blue light permitting a subdivision based on fluorescence. A third maceral, inertinite, is thought to be derived from oxidized material or fossilized charcoal remnants of early forest fires. 

The elemental composition of the three maceral groups varies. The vitrinite, which frequently is about 85% of the sample in the United States, is similar to the patent coal. The liptinites are richer in hydrogen, whereas the inertinites are relatively deficient in hydrogen and richer in carbon. The liptinites also contain more aliphatic materials the inertinites are richer in aromatics. The term inertinite refers to the relative chemical inertness of this material, making it especially undesirable for Hquefaction processes because it tends to accumulate in recycled feedstock streams. 

There are certainly lithotypes that can be handpicked from European and American coals that are relatively rich in fusinite and semifusinite. However, it is perhaps significant that the mean content of total fusinite + semifusinite in 697 coal samples in the Penn State/DOE Data Base is 8.9%. On the other hand, the content of inertinite macerals in the Permian coals of Gondwana-land is notoriously high and much of this inertinite material consists of semifusinite (5,26,33,34), the concentration of which can be as high as 50% in the whole seam. 

Earlier publications have documented the higher reactivities of vitrinite and liptinite group macerals and the lower reactivities of certain inertinite macerals in liquefaction (50,57,68). 

The different slopes for the lines of best fit for total reactives and vitrinite + exinite reflects the special petrology of the majority of South African coals used in this study (see Table III). For these coals the reactives contain a high proportion of semi-fusinite in the inertinite. 

For American and European coking coals the behaviour of semi-fusinite is generally less important since only small quantities of this maceral are usually present. However, South African coal used in coke oven-blends contains as little as 40 per cent vitrinite and as much as 45 per cent reactive semi-fusinite (12). The partial reactivity of the semi-fusinite fraction during liquefaction of Australian coals has been reported by Guyot et al (13). They found that the low reflecting inertinite in two coals up to (a reflectance from 1.40 to 1.49) was reactive. This agrees with the results of Smith and Steyn (12) who consider that the semi-fusinite fraction in South African coals up to V- 5 (1.50 - 1.59) can be reactive to coking. 

In addition, Shibaoka et al (14) during hydrogenation of a New South Wales coal reported that the inertinite with relatively low reflectance became partially liquefied. 

For example, Beynon and Cwm coals when digested in anthracene oil give extraction yields of 68% and 47% respectively. This variation can be explained by reference to the maceral composition of the coals. Beynon coal contains a lower concentration of inertinite than the Cwm coal (Table V). In experiments where relatively pure samples of petrographic species were digested in anthracene oil, exinite and vitrinite were shown to be highly soluble, whilst in comparison the inertinite was almost completely insoluble. Similar variations in reactivity of macerals have been reported from studies of solubility in pure organic solvents (1(3). 

CRC 502) are the most soluble. In comparison, the extraction yields of exinites were independent of coal rank. The subdivision of inertinites into fusinite and micrinite showed that fusinite was completely insoluble in anthracene oil, whilst the micrinite was slightly soluble. 

A system based upon the reactivity of coals during extraction with anthracene oil and phenanthrene has been developed. A convenient graphical method of expressing the data on Seyler s chart has been adopted. This method has limitations when dealing with prime coking coals, which show wide variations in extraction yield. The differences in extraction yield relate to the concentration of inertinite which is virtually insoluble in anthracene oil. 

Australian, Vitrinite 99% concentrate 2 Australian Inertinite 95% concentrate... 

The distribution of products from the hydrogenation of vitrinite and inertinite separated from Australian Bayswater coal is shown in Fig. 3 and Fig. 4 respectively. Fig. 5 shows the distribution of products from the reduction of Soya-Koishi coal by CD + H20. The product distribution shows a similar tendency to that of Yubari coal shown in Fig. 2. Thus, it indicates that the Py-2, Py-1, A, 02 can be considered as intermediate products in a consecutive coal hydrogenation reaction scheme. 

Figure 4. Distribution of products from Bayswater inertinite hydrogenation at...

Liptinites were made up of hydrogen-rich hydrocarbons derived from spores, pollens, cuticles, and resins in the original plant material. Vitrinites were made up of wood, bark, and roots and contained less hydrogen than the liptinites. Inertinites are mainly oxidation products of the other macerals and are consequently richer in carbon. The inertinite group includes fusinite, most of which is fossil charcoal, derived from ancient peat fires. 

Inert ingredients, in pesticides, 18 530 Inertinite, 6 706, 707t, 719 Inert materials, as soap bar additives, 22 745... 

Telnic bronze, 24 426 Telo-inertinite, 6 707t Telomeres, 17 610, 2 814 Telomer formation, 11 865 Telomerization, 2 261 butadiene, 4 374-375 TEMoo mode, 14 683. See also Gaussian mode (TEMoo)... 

The coal studied, 78% C and 15.8% 0 daf, is derived from Carboniferous deposits from the Ziemowit mine in Poland. Its petrographic composition /% vol. dmmf/ is vitrinite, 60 exinite, 12 and inertinite, 28. 

Figure 3. Pyrograms of pure liptinite (o), vitrinite (x) and inertinite (+) for coals with < 75% carbon (daf). The vertical bars denote standard errors.

The correlation of coal characteristics with liquefaction behaviour has received considerable attention (see, for example refs l-7> particularly since the renewed interest during the 1970s in the production of liquid fuels and chemical feedstocks directly from coal. As early as 1940, Storch and coworkers(8,9) demonstrated that coals containing up to 87% dmmf C give high yiel of soluble products (albeit under severe conditions) and materials which today would be classified as vitrinite and inertinite liquefy readily. More recently, the work... 

Note These (maceral) constituents can be identified and quantitatively measured by examining thin sections or polished surfaces under a microscope, and reflect the nature of the primordial source material as well as the conditions under which it was deposited. Vitrinites derive from humic gels, wood, bark and cortical tissues eoi lnites are the remains of fungal spores, leaf cuticles, algae, resins and waxes and inertinites comprise unspecified detrital matter, "carbonized" woody tissues and fungal sclerotia and mycelia. 

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