The low-grade heat recovery system consists of high temperature absorber,high temperature circulating pump,steam generator, and feed water heater.
Primary converted gas from the conversion section enters the bottom of the high temperature absorber,where high-temperature concentrated sulphuric acid (99%) is sprayed from the top, in order to absorb SO3, after which the circulating acid pump into t he steam generator to heat up the feed water in the boiler to generate low pressure steam. Cooled acid will be mixed with water to get circulation. Excess high temperature concentrated sulphuric acid will be extracted from the outlet of the steam generator and go to the feed water heater that to be cooled before going to the acid circulating vessel in the drying and absorption section. After absorption, the gas will go to the conversion section waiting for secondary conversion.
1: Heater for boiler
2:Seam generator
3: Circulating acid pump
4:Circulating acid tank
5: Absorbing tower
The main advantage is that can increase steam generation by 0.4-0.5t/ton sulphuric acid
This technology has been adopted by more than 50 sulphuric acid plants with production capacities ranging from 100kt/a to 800kt/a.
Post time: Dec-08-2023