US EPA

4824535 

Journal Article 

Utilization of Adipic Acid Byproducts for Energy Recovery and Enhancement of Flue Gas Desulfurization 

Lester, JH; Chi, CT 

1989 

Beneficial utilization of two waste streams from adipic acid manufacture has resulted in the creation of product for the enhancement of flue gas desulfurization in coal fired power plants and for energy recovery. The first stream was a waste liquor from the crystallization of adipic acid, containing adipic, glutaric, and succinic acids. This mixture (AGS) was found to be very effective in improving the efficiency of limestone scrubbers for removing SO2 from coal fired power plant gases. Most of this waste liquor is directed to an evaporator and concentrated to 50% organic solids for sales to coal-fired utilities. AGS enhances mass transfer of SO2 in limestone scrubbers by acting as a suitable buffer and increases removal efficiency by 50-90% enabling the user to meet regulatory requirements. The sale of AGS has resulted in a growing multimillion pound per year business. The second waste stream was a residue from cyclohexanol refining. The waste liquor contains 25% dibasic acids, water and sodium and boron contaminants. The inorganics are removed by liquid-liquid extraction in a contact centrifuge, while the oil phase plus excess AGS is incinerated in the plant boiler for fuel value recovery. (Doyle-PTT) 

Chemical wastewater Desulfurization Emissions control Energy; recovery Waste recovery Waste utilization Wastewater treatment; Additives Energy use efficiency Organic acids Separation; techniques Sulfur dioxide