Traditionally gasificaton utilizes a Wet Gas Cleaning process to scrub the producer gas of particulates. Wet Gas Cleaning can require a large quantity of water and can contaminate the water due to its direct contact with gas. In addition it can consistently increase the tar particulate concentration levels in the water if a recirculation process is used. The pond or cooling tower can also emit vapors of PAHs (Polycyclic Aromatic Hydrocarbons) and Ammonia. Wet Gas Cleaning systems typically also generate large quantities of water that will need treatment for longer reuse and eliminates the opportunity for heat recovery. Our company found these conditions to be a significant barrier for many installations in various countries so they put their scientists to work and developed this exclusive Dry Gas Cleaning System.
Dry Gas Cleaning Delivers Installation Opportunities
With Dry Gas Cleaning there is no direct contact with the producer gas therefor no process water generation. It eliminates challenges of a foul smell as there is no process water pond and evaporation cooling requirements and offers a substantial savings in water otherwise needed for gas cooling. There is no slug produced with Dry Gas Cleaning, eliminated cumbersome sludge handling requirements. Best of all heat is recovered from hot gas which can be used for drying applications.
Gasifier Schematic with Dry Gas Cleaning System
| 1) | Gasifier | 9) | Mist Eliminator |
| 2) | Screw Conveyor | 10) | Fine Filter |
| 3) | Dry Ash Collection Box | 11) | Pleated Filter |
| 4) | Startup Sub-System | 12) | Dry Blower |
| 5) | Gas Temperature Control Sub-system | 13) | Header Box |
| 6) | Automated Ultra Gas Purification Sub-system | 14) | Flare |
| 7 & 8) | Condenses Removal Sub-sysem | 15) | Engine |
Producer Gas (Syngas) Quality & Dry Gas Cleaning Benefits
The Gas cleaning is consistent which allows for a smooth operation of the gas engine without fluctuations of power.
- Average CV of the Gas is >1152 kcal/Nm3.
- Tar content in gas after cleaning is <5 mg/Nm3.
- Particulates after filtering is <5mg/Nm3.
Both particulates and tar are removed in a dry form which makes handling easier. Ammonia is also removed through dissolution in condensate and only a small quantity (condensate) needs to be treated. There is also a possibility of recovering ammonium salts, which is a useful fertilizer, from condensate. And hot air is generated in the Gas Temperature Control Sub-system during the cooling of the gas which can also be used for drying of the biomass.
Dry Gas Cleaning totally eliminates any adverse environmental impact as no harmful vapours or particulates are released into the environment. The systems are extremely user-friendly and have no adverse health impact of operators or other associated people.
