METHOD FOR REDUCING SULFUR-OXIDE EMISSIONS FROM AN ASPHALT AIR-BLOWING PROCESS

摘要

A method for substantially reducing sulfur-oxide emissions from an asphalt air-blowing process (51) involves adding an emission reducing additive (53) to the asphalt prior to air blowing, or early in the air-blowing process. The emission-reducing additive includes at least one of metal hydroxide, metal oxide, metal carbonate, or metal bicarbonate, where the metal is sodium, potassium, calcium, magnesium, zinc, copper, or aluminum. The asphalt is subjected to an air-blowing process that produces flue gases, including sulfur containing compounds. The flue gases are passed through a filter (50), preferably of the fiber-bed type, to remove at least a portion of the sulfur-containing compounds via condensation. After passing through the filter, the gases are subjected to an incineration process (55) before being passed to the atmosphere. The combination of filter and emission-reducing additive can advantageously reduce sulfur-oxide emissions from the asphalt air-blowing process by at least 50 % over the same process without the filter and additive.