Chlorine Conditioning for Incinerators
#Reduce Dust Emission and #Improve Gypsum Quality

Flue Gas Conditioning

Simply explained

WELCOME! Let me explain Flue Gas Conditioning.

The best way to reduce fly ash resistivity in electro static precipitators.

SO3 is injected into the flue gas duct

Before the ESP to reduce fly ash resistivity.

The minimized resistivity maximizes the impact of ESP

Back corona is eliminated and the filter can run at full performance.

You don’t need to enlarge the ESP

To increase gypsum quality and reduce solid emission.

PENTOL ASSISTS YOU DURING THE WHOLE PROCESS

  • Supply of turnkey equipment
  • Supply of rental units
  • Supply of test units
  • ESP Assessmentation
Summary

Keeps chlorine in balance with SO3

During combustion of biomass, chlorine is released in different forms and in different quantities, depending on the type of biomass.

In combination with alkali metals contained in the fuel, alkaline chlorides are formed and cause heavy corrosion in the plant.

To avoid damage to the superheaters, the chlorine conditioning process of Pentol uses SO3 gas to establish a sulfur- chlorine equilibrium. By balancing the chlorine with the SO3, high temperature corrosion can be stopped completely and corrosive deposits on the superheaters are removed.

Action principle

Sulfur / chlorine balance

Pentol’s approach to reduce chlorine corrosion is based on the assumption that the corrosion found on the surfaces of the super heaters is based on the mechanism of high temperature chlorine corrosion.

SO3 is injected to sulfatise the chlorides in the flue gas in the 2nd pass of the boiler. The alkali chlorides are transformed to alkali sulfates. With a high or even full sulfatisation of the alkali chlorides in the flue gas, alkali chlorides can no longer condense on the super heater and take part in the corrosion process. Without the base material the corrosion process is slowed down or even stopped completely.

SO3 is chosen over SO2 because of its high reactivity.

The sulfatisation process is described in the following reactions:

2 KCl + SO3 + H2O –> K2SO4 + 2 HCl

2 KCl + SO3 + 1/2 O2 –> K2SO4 + Cl2

Similar reactions take place with sodium or calcium.

Theoretically, it is possible to burn a sulfurous fuel for co-combustion to sulfatise the alkali chlorides. However due to the slow reaction speed of SO2 the sulfatisation process is not sufficient for complete sulfatisation. In tests it has been found that SO3 reacts about 1000 times faster than SO2.

Sulfatisation of NaCl and KCl through SO3 (and SO2) are most efficient if the alkali chlorides are gaseous. The best temperature range for the sulfatisation process starts at 600°C. However the temperature range is limited to 800°C, as the free SO3 above this temperature will be reduced to SO2 for thermodynamic reasons.

For an ideal sulfatisation of the alkali chlorides in the flue gas according to the reactions described, a molar ratio of Cl/S = 2 is sufficient. Because of the non-linearities of the technical process, a higher ratio will be required in real world applications.

Benefits

Dosing point

SO3 is ideally injected directly into the combustion air. As an alternative it can also be injected into the second draft, with the limitation that there will be less reaction time.

 

Fully automatic operation

Low operating cost:

1 kg Sulfur costs approx 0.20 €

Low steam and energy consumption (Exothermal reaction of sulfur combustion is used to heat the system)

Pentol has supplied more than 90 units in Europe.

Satisfied customers can be visited anytime.

Next steps

We need to get in touch personally.

Questions regarding function, support, and sales are answered via online chat support and e-mail to sales@pentol.net, as fast as possible.

Now it´s time for a common test run with a test unit.
Let’s discuss the best individual implementation.
Each power plant is unique

 

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TECHNOLOGY – Chlorine Conditioning (Corrosion Treatment)

 English