Desulfurization Process Introduction - Part II: Double-alkali Desulfurization Principle

The烟气脱硫 technology has become quite mature, with only a dozen or so desulfurization processes being practically valuable among the hundreds available. The dual alkali desulfurization process is widely used in small and medium-sized boilers, primarily developed to overcome the issue of scaling that is common with the limestone-lime method.

Currently, there are many types of dual alkali methods, with the sodium-calcium dual alkali method being commonly used. The sodium-calcium dual alkali method utilizes soda ash to absorb SO2, and limestone to regenerate it. The absorbent is recycled after regeneration, with no wastewater discharge. Designing the process flow under the principles of advanced technology, reliable operation, and economic rationality aims to reduce initial investment, save energy and reduce consumption, and facilitate system maintenance.

The dual alkali desulfurization technology utilizes a solution as the desulfurizing agent, directly injecting the prepared solution into the desulfurization tower to wash and remove SO2 from flue gas. Then, the desulfurization products are regenerated in the desulfurizing agent regeneration pool and recycled back into the desulfurization tower. The desulfurization process mainly includes five parts: (1) absorbent preparation and replenishment; (2) absorbent slurry spray; (3) tower droplets and flue gas contact and mixing; (4) regeneration pool slurry reduction of sodium-based alkali; (5) gypsum dehydration treatment. Key points include:

1. The desulfurization agent utilizes sodium alkali and lime, with the tower's clear liquid absorbing to effectively prevent scaling within the tower.

2. Low liquid-gas ratio; capable of sulfur removal and dust removal in one integrated process.

3. Cost-effective investment, low operation costs, high domestic content

Wide Range of Applications