Bechtel International Corporation

Bechtel Group, Inc.

Empire State Electric Energy Research Corp. (eseerco)

Jack Z Abrams

Robert M Sherwin

Leon Awerbuch

Alfred N Rogers

August D Benz

Stanley J Zaczek

John Haidinger

Efficient removal of sulfur dioxide from a flue gas stream is achieved in a scrubber using a recirculating aqueous stream containing magnesium hydroxide and magnesium sulfite which together act as SO.sub.2 absorbents. Magnesium sulfite is derived from magnesium hydroxide, which is the product of a reaction between soluble magnesium from the seawater and calcium hydroxide added to the scrubbing system. Magnesium sulfite and bisulfite are oxidized to magnesium sulfate by the introduction of air. Magnesium sulfate is converted back to magnesium hydroxide by reaction with additional calcium hydroxide, with gypsum as a by-product. Gypsum is soluble in large amounts of seawater and may be returned to the ocean without adverse environmental impact.

Use of seawater in flue gas desulfurization

Apparatus and method for the efficient and economic removal of sulfur dioxide from gases, in which the gas is contacted with neutralizing values obtained from presure hydrated lime or pressure hydrated dolomitic lime, i.e. calcined limestone or dolomite and slaked with water under elevated temperature and pressure. The pressure hydrated lime or dolomitic lime may be used in conjunction with a wet scrubber, in a spray dryer or dry scrubber, or directly introduced into the gas passages of a boiler, upstream or downstream of the air preheater, or in the boiler output ducting or the inlet of an electrostatic precipitator. The use of pressure hydrated lime or pressure hydrated dolomitic lime greatly enhances the efficiency of sulfur dioxide removal, thereby providing for enhanced use of base values and a more rapid rate of reaction. The confined zone dispersion scheme permits a partial SO.sub.2 removal (10%-50%) without a scrubber, only by atomizing a slurry of pressure hydrated lime or pressure hydrated dolomitic lime into the flue gas duct of the boiler.

Method for reduction of SO.sub.2 emission for fossil fired boiler

A process for eliminating, reducing or modifying slagging, convective tube fouling, corrosion, sulfur trioxide formation, acid smut and plume visibility by intermittently injecting pressure-hydrated dolomitic lime consisting of porous, particles having a high specific surface and a low settling rate in water into the interior of a combustion system.

Process for treating combustion systems with pressure-hydrated dolomitic

Improved methods are provided for the efficient and economic removal of sulfur dioxide from gases, which comprise contacting the gas with neutralizing values obtained from Type S hydrated lime, i.e. calcined dolomite, slaked with water under elevated temperature and pressure. The Type S hydrated dolomitic lime may be used in conjunction with a wet scrubber to provide base and neutralizing magnesium values, in a spray dryer or dry scrubber, or directly introduced into the boiler. The use of Type S hydrated dolomitic lime greatly enhances the efficiency of sulfur dioxide removal, providing for enhanced utilization of base values and more rapid rate of reaction.

SO.sub.2 removal

Improved methods are provided for the efficient and economic removal of sulfur dioxide from gases which comprise contacting the gas with neutralizing values obtained from Type S hydrated lime, i.e. calcined dolomite slaked with water under elevated temperature and pressure. The Type S hydrated dolomitic lime may be used in conjunction with a wet scrubber to provide base and neutralizing magnesium values, in a spray dryer or dry scrubber, or directly introduced into the boiler. The use of Type S hydrated dolomitic lime greatly enhances the efficiency of sulfur dioxide removal, providing for enhanced utilization of base values and more rapid rate of reaction.

SO.sub.2 Removal

A system for softening of water in a manner to minimize heat requirements in the water softener unit of the system. Flashed water vapor from a flash box coupled to the downstream end of the softener unit is used to preheat incoming hard feed water by directly contacting the feed water in respective preheating chambers upstream of the softener unit. The system is suitable for use in a distillation plant to produce potable water.

Growing community of inventors

San Rafael, CA, United States of America

Jack Z Abrams