Section 1670. Definitions

A. For the purpose of these regulations and subsequent amendments or any orders issued by the board, the words or terms shall have the meanings given them in subsection C of this section.

B. As used in this article, all terms not defined here shall have the meanings given them in 9VAC5 Chapter 10 (9VAC5-10-10 et seq.), unless otherwise required by context.

C. Terms defined.

"Black liquor solids" means the dry weight of the solids which enter the recovery furnace in the black liquor.

"Condensate stripper system" means a column, and associated condensers, used to strip, with air or steam, total reduced sulfur compounds from condensate streams from various processes within a kraft pulp mill.

"Cross recovery furnace" means a furnace used to recover chemicals consisting primarily of sodium and sulfur compounds by burning black liquor which on a quarterly basis contains more than 7.0% by weight of the total pulp solids from the neutral sulfite or other semichemical process and has a green liquor sulfidity of more than 28%.

"Digester system" means each continuous digester or each batch digester used for the cooking of wood in white liquor, and associated flash tanks, below tanks, chip steamers, and condensers.

"Green liquor sulfidity" means the sulfidity of the liquor which leaves the smelt dissolving tank.

"Kraft pulp mill" means any facility which produces pulp from wood by cooking (digesting) wood chips in a water solution of sodium hydroxide and sodium sulfide (white liquor) at high temperature and pressure. Regeneration of the cooking chemicals through a recovery process is also considered part of the kraft pulp mill.

"Lime kiln" means a unit used to calcine lime mud, which consists primarily of calcium carbonate, into quicklime, which is calcium oxide.

"Multiple-effect evaporator system" means the multiple-effect evaporators and associated condensers and hotwells used to concentrate the spent cooking liquid that is separated from the pulp (black liquor).

"Neutral sulfite semichemical pulping operation" means any operation in which pulp is produced from wood by cooking (digesting) wood chips in a solution of sodium sulfite and sodium bicarbonate, followed by mechanical defibrating (grinding).

"New design recovery furnace" means a straight kraft recovery furnace that has both membrane wall or welded wall construction and emission control designed air systems. A new design furnace shall have stated in its contract a TRS performance guarantee or that it was designed with air pollution control as an objective.

"Old design recovery furnace" means a straight kraft recovery furnace that does not have membrane wall or welded wall construction or emission control designed air systems.

"Pulp and paper mill" means any kraft pulp mill or any paper mill using a semichemical pulping process.

"Recovery furnace" means either a straight kraft recovery furnace or a cross recovery furnace, and includes the direct-contact evaporator for a direct-contact furnace.

"Semichemical pulping process" means any pulp manufacturing process in which the active chemicals of the liquor used in cooking (digesting) wood chips to their component parts in a pressurized vessel (digester) are primarily a liquor of sodium hydroxide and sodium carbonate. The major difference between all semichemical techniques and those of kraft and acid sulfite processes is that only a portion of the lignin is removed during the cooking (digesting), after which the pulp is further reduced by mechanical disintegration.

"Smelt dissolving tank" means a vessel used for dissolving the smelt collected from the recovery furnace.

"Straight kraft recovery furnace" means a furnace used to recover chemicals consisting primarily of sodium and sulfur compounds by burning black liquor which on a quarterly basis contains 7.0% by weight or less of the total pulp solids from the neutral sulfite or other semichemical process or has green liquor sulfidity of 28% or less.

"Total reduced sulfur" or "TRS" means the sum of the following sulfur compounds (hydrogen sulfide, methyl mercaptan, dimethyl sulfide and dimethyl disulfide, reported as hydrogen sulfide) that are released during any kraft wood pulping operation.

"Twenty-four hour average" means the average of data over a 24-hour period beginning at midnight.

Historical Notes

Derived from VR120-04-1302, eff. October 1, 1989; amended, Volume 15, Issue 12, eff. April 1, 1999.

Statutory Authority

§ 10.1-1308 of the Code of Virginia.