Syngas cleaning systems

Syngas cleaning systems

A cleaning plant / purification of Syngas consists in the removal of dust, tar (TAR) and condensable oily fractions.
An example of application is the cleaning pilot plant Syngas from the gasifier down draft reported below:

Design parameters
The composition of a pyrolysis Syngas dowdraft on which our scrubberaggio system is up and running is as follows:
Flow rate: 105 kg / h
Temperature: ≈ 750 ° C
Pressure: 1,15 bar
Components: H2O 10kg / h
CO 56kg / h
CO2 33 kg / h
H2 4.5 kg / h
CH4 0.44 kg / h
N2 0.76 kg / h

Description of the installation
The powders and volatile organic compounds present in the fumes are removed through a purification system consists of three successive stages:
Stage I: high-energy venturi scrubber by washing;
Stage II: washing using spray tower;
Stage III: in washing tower;
On the basis of the design data it has a capacity of about 400 m3 / h to 750 ° C, which is reduced to ≈ 125 m3 / h at 50 ° C.
The yield of abatement of any wastewater treatment system is a function of the amount of incoming pollutant.
In the specific case we are able to ensure the removal of particles with a diameter of ≥ 1 micron.
The removal of dusty fraction is effected by washing the syngas with water in three different stages characterized by a different level and type of air-water exchange.
The thermal abatement from 750 ° C to 50 ° C takes place by means of heat exchange between the syngas and the washing water. The evaporated fraction will be reinstated in an automatic way by means of level controls in the two places recirculation tanks.

The Stadium: Venturi
The pollutant molecules present in the air flow are of a nature insoluble and have a rather fine granulometry.
The efficiency of the wet treatment system is strictly dependent on the quality of water used in washing; it is inversely proportional to the concentration of pollutants in the water.
The way forward is therefore to maintain as clean as possible the washing liquid of the venturi stage, by a suitable purge of a flow of water; the magnitude of this scope will be defined during the stable operation and is closely related to the duration of the tests.
The abatement of pollutants take place through the exchange of kinetic energy between the water particles injected by the nozzles and those of water-borne dust from the suction flow, suitably accelerated in a venturi throat.
The system is particularly easy to conduct because there are no service parts that can clog.
The flow rate of water fed into the venturi will be displayed with a flowmeter placed on the discharge line of the pump; It will be regulated by the diaphragm valve.
The flow of fumes from the manufacturing facility and the water are intimately mixed by passing through a venturi throat in which there is the dissipation of kinetic energy of the fumes. The atomized water particles are able to intercept the pollutants present in the fumes and transfer them as well in the aqueous phase.
On the line of water supply and air will be present detectors and pressure indicators and temperature.

Stage II: spray tower
At the exit of the venturi scrubber mixed flow of air, water and pollutant enters tangentially in a tower, which will lead to its internal ranks of superimposed nozzles fed by a dedicated pump.
On top of the tower you will have a demister for the removal of still conveyed aqueous particles.
The water containing pollutants will be collected in a tank in AISI 304 at the base of the tower.
On the line of water supply will be present detectors and pressure indicators and temperature.

Stage III: scrubbing tower
The air flow exiting from the spray tower enters into the wash tower in which there is the exchange of matter between liquid and air flow.
A centrifugal pump dedicated fetch water from the tub under the tower and send it to the exchange bed consisting of rashing type rings.
On the line of water supply will be present detectors and pressure indicators and temperature.

Technical features
Theoretical max suction capacity: 400 m3 / h
Theoretical temperature inlet: 750 ° C
Theoretical temperature output: 50 ° C
Head max: 1.15 mbar ca – 11.5 mm ca

Would you like more information or a tailored quotation?