Dry sorbent injection

DSI is relatively simple and versatile flue gas treatment process. It is based on the dry injection of one or more sorbents into the flue gas before a filtering unit, usually a bag filter, or an electrostatic precipitator. The sorbent reacts with the pollutants in a single pass. DSI allows the simultaneous removal of acidic gas components with calcium hydroxide Ca(OH)₂ for example, and micropollutants.

The reaction between the gas-phase pollutants and the sorbent occurs in the reactor or flue gas duct and continues in the filter, especially with a bag filter. The reaction products and fly ash from the process are captured by downstream filtering equipment

This process is considered to be ideally suited to low-capacity incinerators. It can easily be incorporated into existing installations and offers the following advantages: 

• low investment cost 
• simplicity of design and operation 
• extreme space efficiency 
• easy to automate 
• low consumption of compressed air, electricity and water 
• flexible operation in terms of temperature and capacity. 

In addition, the purification process by-product is a dry powder which is easy to handle. To minimize the quantity of secondary products yielded, Lhoist has developed highly reactive hydrated limes (Sorbacal^® SP, Sorbacal^® SPS, Sorbacal^® H, and so on) that make dry processing a very competitive solution for a growing number of applications. 

DSI with Sorbacal^® products has been demonstrated to be capable of achieving very high removal efficiency (up to >95% for SO₂ and >99% for SO₃, HF and HCI).

• Sorbacal^® SPS
• Sorbacal^® Micro
• Sorbacal^® SP
• Sorbacal^® H