Agglomerating Burner Process

The oil from the decanter is dehydrated, filtered, and hydrotreated to remove nitrogen, sulfur, and oxygen (forming ammonia, hydrogen sulfide, and water, respectively) to form a heavy synthetic crude oil (ca. 25° API). The char produced by the process is desulfurized in a shift kiln, where hydrogen is treated with the char to produce hydrogen snlfide which is then absorbed by an acceptor, 

The COGAS process involves the gasification of the COED char to produce a synthesis gas composed of carbon monoxide and hydrogen. The heat for the char gasification reaction is provided by the combustion of part of the char. 

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Process parameters of importance for mist and fume control include measures to minimize the moisture content of the combustion air fed to the phosphorus burners. A high moisture content in this gas stream tends to increase mist formation. Solid phosphorus pentoxide has been found to be very difficult to dissolve in either water or phosphoric acid. This prompts temperatures in the hydrator to be maintained high enough so that absorption takes place from the vapor phase. Further studies have shown that uptake of phosphorus pent-oxide vapor in 70% phosphorus acid is only about 60% and climbs with increasing acid concentrations up to about 88% phosphoric acid. Operating with two fiber beds operated in series, the first bed as an agglomerator, and the second as a collector, can also efficiently control mists and fumes from furnace acid plants [30]. Mass containment efficiencies of better than 99.9% were reported for a median aerosol particle diameter of 1.1 to 1.6 fim. 

We have scaled the CVC process to produce test quantities (up to 50 g/hr) of nanophase oxide powders with particles on average less than 20 nm in diameter. This ten-fold increase in production rate was made possible by substituting the hot wall reactor by the flat flame combustor. A short and uniform residence time across the entire surface of the burner at a high temperature, ensures the formation of uniformly sized particles. Since the pyrolysis and subsequent condensation into nanoparticles occurs in a reduced pressure environment, the powder is typically non-agglomerated. 

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