Coal continued sulfur content

Atlantic Richfield Company has reported strains of Pseudomonas sp. CB1 (ATCC 39381) [108] and Acinetobacter species CB2 [109] (ATCC 53515) to be effective for the removal of sulfur from organic molecules found in petroleum, coal, etc. In fact, the aerobic and heterotrophic soil microorganisms Pseudomonas CB1 and Acinetobacter CB2 were reported to convert thiophene sulfur into sulfate, using a bench-scale continuous bioreactor. The direct contact with Illinois 6 coal reduced the organic sulfur content in about 40% to 50%. As already mentioned, most of this work was carried out on coal. Further work was not pursued probably due to decrease in coal usage or due to the economics of the processes. 

A neutron sulfur meter was developed for continuous monitoring of the sulfur content of coal from a preparation plant. Neutrons from a radioactive source... 

Another slurry pipeline desulfurization experiment was conducted using Indiana 3 (Ayrshire) coal as a 25 wt% slurry in deionized water. The other process variables were carefully controlled flow rates 6-6.5 ft/sec, temperature 70-90°F, and pH 2.5 -2 8.The experiment was continued for 14 days, and the slurry samples for pyritic sulfur determination were taken daily. The desulfurization rates with Indiana 3 coal in the pipeline experiment are shown in Table 4 and are in good agreement with the laboratory data and the results with Illinois 6 coal. As observed in the laboratory experiments, the rate of desulfurization of bituminous coals is directly proportional to the pyritic sulfur content and inversely to the particle size of the coal sample. 

Other procedures include high-temperature tube furnace combustion methods for rapid determination of sulfur in coal and coke, using automated equipment. The instrumental analysis provides a reliable and rapid method for determining sulfur contents of coal or coke. By this method, total sulfur as sulfur dioxide is determined on a continuous basis. 

Low sulfur fuel oils were prepared from a high volatile bituminous coal by hydrogenation under high temperatures and pressures. At a coal conversion of 80%, the ratio of oiU to-gas yields was about three, and 23% of the coal sulfur was contained in the oil. Sulfur content of the oil, however, remained the same at different coal conversion levels. The data obtained in the semi-continuous, dilute phase hydrogenation system showed that the whole oil can be directly used as a fuel oil where 1% sulfur is tolerated. Fuel oils containing 0,5 and 0,25% sulfur were produced by desulfurization of the whole oil, A preliminary economic evaluation indicated that low sulfur fuel oils can be produced from coal by hydrogenation at a manufacturing cost of about 5-6 per barrel. 

Coal is the most familiar of the fossil fuels not necessarily because of its use throughout the preceding centuries (Galloway, 1882) but more because of its common use during the nineteenth century. Coal was largely responsible not only for the onset but also for the continuation of the industrial revolution. Coal occurs in various forms defined in a variety by rank or type (Chapter 2) and is not only a solid hydrocarbonaceous material with the potential to produce considerable quantities of carbon dioxide as a result of combustion, but many coals also contain considerable quantities of sulfur (Table 22.1). Sulfur content varies (Table 22.2) but, nevertheless, opens up not only the possibility but also the reality of sulfur dioxide production (Manowitz and Lipfert, 1990 Tomas-Alonso, 2005). 

There are three basic uses of waste oil as an opportunity fuel in small space heaters and boilers, in larger boilers, and in cement kilns. Of these, cement kilns are the most prominent due to their continued search for low cost alternatives to coal, oil, and traditional energy sources. In New Zealand, for example, two cement kilns dominate the use of all waste oil in that country. T3rpical emissions from the combustion of waste oil in various applications are shown in Table 7.19. Note that SOj is not shown in Table 7.19, due to its dependency on the sulfur content of the incoming fuel. 

For the first step, 12 g. of ground coal and 120 ml. of alkaline solution were mixed and placed in a 300-ml. stainless steel autoclave equipped with a turbine agitator. The system was flushed with nitrogen and then heated to the desired temperature while the mixture was stirred continuously. After a period of treatment at constant temperature and pressure, the autoclave was cooled quickly, and the contents were filtered to recover the coal. The filter cake was washed with 400 ml. of distilled water, dried at 90 C for 4 hr., weighed, and analyzed for total sulfur and ash. A portion of the alkali-treated coal (usually 2.5-3.0 g) was leached for an additional... 

Attempts to increase pyrite removal by increasing the reaction time met with limited success under our standard conditions because reaction of the ferric ion with the coal matrix depleted the ferric ion that was needed for extraction of the pyrite. Thus, for example, increasing the coal reaction time from 2 to 12 hrs only increased pyritic sulfur removal from 60 to 80% for Pittsburgh coal. Similar results were obtained for the other three coals. The only alternatives were to increase the amount of leach solution or to use a continuous or semi-continuous (multiple-batch) reactor. A multiple-batch mode was chosen because it was a simple laboratory procedure and at the same time it could approximate conditions encountered in a commercial plant. A 1-hr-per-batch leach time was used because our 2 hr results indicated that in the early stages of removal the rate begins to decrease after 1 hr, and six leaches (or batches) per run were used to assure that any pyrite that could be removed in a reasonable amount of time was removed. The progress of removal was monitored by analyzing the sulfate content in each spent leach solution elemental sulfur was not removed until all the leaches were completed. Table VII shows pyrite extraction as a function of successive leaches as followed by sulfate analysis of the leach solution. Note that the major portion of pyritic sulfur is removed in the first two leaches or 2 hrs, followed by lesser amounts in... 

The fuel gas produced has a heat content of ca. 150 Btu/ft and is composed primarily of carbon monoxide, hydrogen, and nitrogen. The melt also contains ash and sulfur residue from the coal and hence part of the melt must be continuously withdrawn from the reactor for purification while additional fresh sodium carbonate is added. 

Applications to neutron activation analysis constitute another important use of Cf neutron sources. Neutron capture in many elements forms radioactive species that then decay with highly characteristic gamma-ray emissions. This analytical procedure is very sensitive and specific, and is widely used for the analysis of trace elements. Neutron activation finds use in uranium borehole logging to make accurate determinations of the uranium concentrations in boreholes as little as 100 parts per million of UaOg can be detected by this procedure. Other industrial uses for Cf sources are in the continuous monitoring of the sulfur and ash content of coal on a moving conveyor belt at the rate of SO tons per hour. Batch analysis of the vanadium content of crude oil is still another application of neutron activation analysis. 

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