×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Alkaline Injection for SO3 Removal

Alkaline Injection for SO3 Removal

Alkaline Injection for SO3 Removal

(OP)
I am looking for information/experience utilizing alkaline injection (MgO, NaHSO3, etc) in an oil-fired utility boiler to reduce SO3 emissions.

Due to stricter emission standards, we are planning to reduce opacity and particulate emissions utilizing dry ESP's in combination with alkaline injection.  Any information (reagent cost, effectiveness, reliability, etc) regarding the use of alkaline injection with dry ESPs would be appreciated.

RE: Alkaline Injection for SO3 Removal

Alkaline injections to reduce SO3 (and SO2) emissions is a common process now. However, according to the chemical compound used (NaOH, MgO, Mg(OH)2, Na2CO3...), results will vary to a large range.
I actually experiment a new range of chemicals which demonstrate the same SOx sorption behaviour and also react on chlorine derivatives and reduce the particulate emissions in one chemical injection. Only electrostatic precipitators or baghouses will be required to recover the salts and large particles.

If you need more information, contact me: cleanfire2000@yahoo.co.uk

RE: Alkaline Injection for SO3 Removal

Mg, Ca will hurt ash resistivity

Na, K will will help

RE: Alkaline Injection for SO3 Removal

Wtflippin:

MgO, mostly as a stabilized oil dispersion, has been very successfully used for at least the past thirty years in oil-fired boilers ranging from small saturated steam units to 850 MW utility units for inhibition of SO3 formation and cold end corrosion protection. Properly applied by proportional injection into the fuel stream just prior to the burners, it is entirely reasonable to expect control of catalytically formed SO3 to not more than 1-3 ppm.

With a MgO dispersion formulation properly structured to incorporate some low micron/submicron particulate MgO material, these fines will transport to the cold end heat recovery zones and lay down as a micro-fine, non-fouling neutralizing protective screen against residual SO3, and therefore H2SO4, deposition and corrosion.

A somewhat more recent development incorporates the application of Mg(OH)2 as a stabilized water dispersion for the same purpose, with about the same results.

Do not go with the use of alkaline sodium compounds, as these will complicate the boiler's hot end slag by complexing with vanadium compounds and forming sulfated materials, both of which a relatively low melting, slag producers and potentially corrosive.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources