Harvey S. Rosenberg

Nitrogen oxides (NOx) influence on sulfite oxidation and scaling in lime/limestone flue gas desulfurization (FGD) systems

Experiments were conducted to determine the influence of nitrogen oxides on the solid phase oxidation of sulfite to sulfate in slaked lime slurries from lime/limestone scrubbing systems. Nitric oxide is observed to act as an inhibitor and nitrogen dioxide as a promoter of the oxidation of sulfite. Nitric oxide present at the same concentration as nitrogen dioxide is unable to inhibit the oxidative influence of the latter. At a mole ratio of 12:1, the promotive action of nitrogen dioxide is offset, and the total oxidation is no greater than it would be without the presence of nitric oxide. Oxidation inhibition merits consideration as a way to avoid sulfate scaling in such scrubbing systems. (1 diagram, 1 graph, 6 references, 1 tables)

Status and Problems of Regenerable Flue Gas Desulfurization Processes

Fourteen sulfur and/or sulfuric acid producing regenerate FGD processes were discussed at the 1974 FGD Symposium in Atlanta. During the period elapsed since then, considerable status change has occurred on many of these regenerable processes. Other regenerable processes which were not as well known during 1974 have surfaced in 1975. The problems of obtaining reducing gases (hydrogen sulfide, carbon monoxide, and hydrogen) for the reduction of sulfur dioxide product streams to elemental sulfur have become severe due to shortages of natural gas or other petroleum based feedstock. A new sulfur producing process which employs CO and H2 directly (rather than the H2S required for liquid and vapor base Claus reactions) is gaining attention. This paper discusses briefly: (1) the announced status of the many regenerable FGD processes, (2) the problem of reductant gas supply, and (3) the effect on FGD processes of using coal based reducing gas instead of reformed natural gas.

Technical Aspects of Lime/Limestone Scrubbers for Coal-Fired Power Plants Part II: Instrumentation and Technology

This is the conclusion of a 2-part article dealing with the technical aspects of lime/limestone scrubbers for coal-fired power plants, it covers instrumentation, participate removal and sludge disposal. Part I (June JAPCA) covered process chemistry and scrubber systems

Sorption of SO2 on Ground Nahcolite Ore

Large quantities of nahcolite ore, a naturally occurring mineral containing between 70 and 90% sodium bicarbonate are known to occur in the Green River Formation of the Piceance Creek Basin of northwestern Colorado.1 Deposits occur in two major forms, as either bedded or disseminated ore. In the latter case, the host rock is oil shale, a dolomitic marlstone containing kerogen material. Bench and pilot scale studies have shown finely divided nahcolite ore to be an effective SO2 sorbent in baghouse filters.2 These studies form the basis of the nahcolite ore injection process as a means for controlling SO2 emissions to the environment.3 Although there have been published investigations of reactions of SO2 with Na2CO3and NaHCO3, 4 no reference could be found to a systematic study of nahcolite ore reacting with SO2.

The Use of Nahcolite Ore and Bag Filters For Sulfur Dioxide Emission Control

This paper describes some technical and economic aspects of the nahcolite ore injection process for the simultaneous removal of fly ash and sulfur oxides from stack gases. The process is capable of removing greater than 99% of the particulate matter and greater than 70% of the sulfur oxides present in such gases. In the process, nahcolite ore, a naturally occurring material containing 70 to 90% sodium bicarbonate, is ground to 90% passing through —200 mesh screens. Approximately 20% of the ground ore is used to precoat the filter bags in a baghouse filter while the remainder of the material is fed into the flue gas Just ahead of the baghouse. The flue gas is drawn through the baghouse by induced draft fans and sent up the stack. Most of the SO2 and practically all of the fly ash in the flue gas can be removed as the gas passes through the filter bags. The spent nahcolite ore and fly ash are collected and conveyed to waste disposal as landfill, or alternatively processed for insolubilization by coprecipita...