Carbon plants

Fig. 5. Diagram of large Lurgi Spblgas carbonization plant A, coal conveyor B, movable distributor C, coal bunker D, drying zone E, connecting shafts ...

Production of one metric ton of molten aluminum requites about 500 kg of anode carbon and 7.5—10 kg of cathode blocks which is the largest industry usage of carbon materials. Aluminum smelters generally have an on-site carbon plant for anode production. Anode technology is focused on taw materials (petroleum coke and coal-tar pitch), processing techniques, and todding practices (74). 

Partly because of their low cost, aqueous solutions of sodium or potassium carbonate also are used for CO9 and H9S. Potassium bicarbonate has the higher solubility so the potassium salt is preferred. In view of the many competitive amine and carbonate plants that are in operation, fairly close figuring apparently is required to find an economic superiority, but other intangibles may be involved. 

Many operating data for carbonate plants are cited by Kohl and Riesenfeld (Gn.s Purification, Gulf, 1985) but not including tower heights. Pilot plant tests, however, are reported on 0.10- and 0.15-m (4- and 6-in) columns packed to depths of 9.14 m (30 ft) of Raschig rings hy Benson et al. (Chem. Eng. Prog., 50, 356 [1954]). 

Carbonisier-anlage, -anstalt, /. carbonizing plant. bad, n. carbonizing bath, carbonlsierecht, a. fast to carbonizing, carbonisieren, v.t. carbonize carburize carbonate. 

Schwel-. relating to low-temperature carbonization smoldering, -anlage,/. low-temperature carbonizing plant. 

P. R. Darrah, Models of the rhizosphere. I. Microbial population dynamics around the root releasing. soluble and in.soluble carbon. Plant Soil 733 187 (1991). 

G. Johansson, Carbon distribution in grass (Festuca pratensis L.) during regrowth after cutting-utilization of. stored and newly a.ssimilated carbon. Plant Soil I5I I (1993). 

Guy RD, Fogel ML, Berry JA (1993) Photo synthetic fractionation of the stable isotopes of oxygen and carbon. Plant Phys 101 37 7... 

Crude Tar and Tar Products. Where the tar distillery is sited close to the carbonizing plant, the crude tar is transferred directly from the tar—liquor separating vessels on the by-product recovery unit to the storage tanks. Otherwise, it is shipped in rail or road tankers or by barge. Crude tar is stored in mild-steel tanks maintained at 40—50°C by steam coils. 

Peat partially carbonized plant matter, formed by slow decay in water. 

Darrah,P. R. (1991). Models of the rhizosphere. 1. Microbial dynamics around a root releasing soluble and insoluble carbon. Plant Soil 133,187-199. 

Guy, R. D., M.L. Fogel and J.A. Berry (1993) Photos5nithetic fractionation of stable isotopes of oxygen and carbon. Plant Physiol. 101, 37-47. 

The ammonia recovery system of modern configurations of Solvay plants is quite efficient. Only about 3 kg of ammonia make-up is required to maintain the 300 kg or so of absorbed ammonia, which is needed for each tonne of sodium carbonate produced [17]. This high ammonia-recovery efficiency was the feature that gradually spelled the end of the commercial Le Blanc sodium carbonate plants, the last of which closed down in the period 1920-1930 [15]. 

A shift to the processing of substantial alternate natural mineral sources of sodium carbonate in the U.S. has eliminated the calcium chloride disposal problems of the Solvay process for sodium carbonate production. Coupling this advantage to the much lower capital cost of a natural sodium carbonate plant has contributed to the shift away from synthetic sodium carbonate in the U.S. [13] (Table 7.3). Kenya is the only other country reported to be recovering natural sodium carbonate and was operating at 260,000 metric toimes in 2001 [19]. China, the second largest producer, and all other world producers still rely heavily on the ammonia-soda process [17, 24] (Table 7.4). 

Mixed cresols are available in India both from coal and lignite carbonization plants and are also produced synthetically, particularly p-cresol, using toluene as the critical feedstock. 

While phenol downstream chemistry has been well known and gradually developed during the last hundred years, cresols have been relatively unknown even some 50 years ago. Mixed cresols, also known popularly as cresylic acids, derived from coal carbonization plants and also from the spent washes... 

Mixed cresols, also known as cresylic acids, the lowest among the alkyl phenols, were primarily produced as by-products from coal carbonization plants or recovered from the petroleum refinery caustic washes. These cresols obtained from natural sources were known to the chemical industry for the last 75 years and had limited uses. Production of synthetic cresols from toluene opened up new avenues for these products... 

The availability of organic carbon is a second variable that affects rates of Fe(III) reduction in wetland and aquatic sediments (Thamdrup, 2000 Roden and Wetzel, 2002 Megonigal et al., 2004). For example, Roden and Wetzel (2002) demonstrated that although Fe(III) reduction kinetics were affected primarily by Fe(III) availability, Fe(III) reduction rates also correlated directly with tlie availability of organic carbon. Plant roots can serve as sources of labile organic... 

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