Sulfuric Acid Concentration
In the early 1970s, our engineers set out to improve the sulfuric acid concentration process building upon their knowledge and experience with nitric acid concentration.
Using reliable materials like glass lined steel, PTFE, tantalum and zirconium the engineers at Chemetics developed the vacuum evaporation process that still forms the heart of our technology today. This process is characterized by the extensive use of gravity flow to transfer hot acid between the various process steps and by the use of natural circulation thermosyphon loops for the acid evaporators. These natural circulation evaporators allow high heat transfer rates, large turndown, minimize fouling and avoid the use of pumps in hot acid service which increases both safety and reliability. Multiple stages are used for large capacities or for large increases in concentration.
In 1975, after extensive pilot plant work, the first Chemetics Sulfuric Acid Concentration plant was designed and built for the Air Products DNT facility in Texas, USA where it continues to operate today. Since that time, our design and technology have continued to improve and more than 40 spent acid plants have been delivered to satisfied clients around the globe. Our completed plants range in capacity from 30 to 2200 tons per day and concentrate acid from as low as 7wt% to over 96wt% sulfuric acid concentration.
Although the Chemetics Evaporator System forms the heart of every process, it is very important to incorporate into each plant the appropriate pretreatment of the spent acid to remove (and recover) impurities and to minimize effluent. Chemetics has developed several additional process options that can be used to provide a tailor made process for each spent acid. Examples are: hydrolysis or striping processes to remove organics; fractionation towers to recover valuable byproducts; and NOx absorption systems to clean vent gases prior to discharge.
We also perform extensive safety reviews and operate a testing facility to ensure that optimum conditions are selected for each spent acid. This approach has resulted in safe and reliable plants with availabilities above 95%.
For more information please click the links or Contact Us to discuss your spent acid recovery requirements. We will be happy to assist.