February 4, 2000
Esprit First Ozone-Bleached Pulp Manufacturing in Japan
Nippon Paper Industries Co., Ltd.
Nippon Paper Industries will manufacturing ECF pulp by ozone bleaching (does not use chlorine for bleaching). This use of ozone in the pulp-manufacturing process is a first in Japan.
Kraft pulp (KP) is produced by cooking wood chips (raw material) in caustic soda, extracting the fibers from the wood, and then bleaching them with chemicals. The bleaching chemicals used include chlorine, chlorine dioxide, hypochlorite soda, and oxygen, but recently, ECF (Elementary Chlorine Free) methods that do not use chlorine (Cl2) have started gaining popularity, mainly in the U.S. and Europe. Our project has the following objectives:
1) Fully replace the chlorine used in the first stage of the traditional bleaching process with ozone in the KP system (daily production average: 520-t) at our Yufutsu Mill.
2) Build a new plant to manufacture the ozone we will use. One unit will be able to produce 120 kg/hour, the highest production capacity in Japan.
As a result, AOX, the measure for dioxin release, will approach zero. This will further decrease environmental load, even more so than the ECF method (currently used in Japan) that employs chlorine dioxide instead of chlorine. (Note)
Our company group already operates a 363 t/day conifer pulp ECF system at our Kushiro Mill and a 100 t/day conifer pulp ECF system at our Asahikawa Mill. In May this year, we plan to complete the ECF conversion of Tohoku Paper's (a group company) Akita Mill. (All of these ECF systems use chlorine dioxide.) Our latest project will be our fourth new system, and it will enable us to study the feasibility of incorporating ozone bleaching into KP systems at our other company mills.
|Plant Overview||1)||New ozone plant (120 kg/hour)|
|2)||New oxygen plant (20 t/day)|
|3)||Enhancement of ozone bleaching process (added to the first stage of the bleaching process|
|Construction||To commence in Feb. 2000|
|Completion scheduled for Dec. 2000|
Note: Chlorine and Dioxin
Since using large quantities of chlorine for bleaching may produce dioxin, the Japan Paper Association has established an independent standard for controlling AOX (measure of dioxin release) to within 1.5 kg/ton of pulp. Dioxin is no longer being released at previous levels, and all of our company's conventional systems are satisfying that standard, but by converting to ECF, which includes the introduction of ozone bleaching, we aim to further reduce AOX.