Lotte Engineering and Construction (Lotte E&C) announced on Jan. 19 that the company patented a sludge treatment technology and received its green technology certificate from the Ministry of Environment on Jan. 7.
Sludge is waste from a process to treat sewage and wastewater. “The sludge drying technology which uses high-pressure dehydrators and paddle driers” of Lotte’s own development first removes about 30 percent of water in sludge with high-pressure press dehydrators. The next steam-based drying process proceeds and finally gives rise to a 30 percent reduction of fossil fuel use for drying sludge.
Accordingly, this can slash operational costs by over ten percent. In addition, dried sludge can be used as alternative fuel which has about 70 percent of coal’s calorific value. A recent ban on dumping sludge is driving the development of technologies to reclaim sludge after drying it on land or making use of it as a fuel. The 2013 sewage statistics in Korea said that Korea produced about 10,000 tons of sludge a day.
In the event that Lotte’s new technology is applied to sludge drying facilities with a daily capacity of sludge, it will be able to cut down on the use of light oil by about 30,000 tons a year.