Reduction of Particulates in Gas Streams

A method for reducing a spark rate and/or increasing the voltage in a cold-side electrostatic precipitator through which a particulate-containing gas stream is directed, wherein said electrostatic precipitator has a spark rate and a voltage, which method comprises injecting an amount of a halogenated carbonaceous substrate formed from a carbonaceous substrate and an elemental halogen and/or a hydrohalic acid into the particulate-containing gas stream upstream of the electrostatic precipitator, such that the spark rate decreases by about 40% or more and/or such that the voltage can be increased by about 20% or more than when said halogenated carbonaceous substrate is not injected, as compared to said cold-side electrostatic precipitator when halogenated carbonaceous substrate is not injected into the particulate-containing gas stream.