Promotion of Cleaner Technology in China's Chemical Industry (II)    

(Continued page 13, issue 10)

Dyestuff sector

By 2012, the dyestuff sector should apply the hydrogenation reduction cleaner production technology of dyestuff and pigment intermediates into 60% of its capacity, complete the technological renovation of 250 000 t/a dyestuff and pigment intermediate capacity with cleaner production technologies like the hydrogenation reduction technology and the sulfur trioxide sulfonation technology to reduce waste emissions by 1.8 million tons, COD emissions by 60 000 tons (the wastewater mainly contains nitrobenzene, aromatic amines like aniline, sulfuric acid, and acetic acid) and aromatic amine-containing harmful residue discharge by 90 000 tons; use cleaner production technologies like the membrane filtration technology and the puree drying technology into 80% of its capacity, complete the technological renovation of 300 000 t/a water-soluble dyes capacity with the membrane filtration technology and the puree drying technology, reducing wastewater discharge by 10 million tons and COD emissions by 170 000 tons; use organic solvents to replace water media in 60% of its capacity, complete the technological renovation of 50 000 t/a dyestuffs and pigments intermediates capacity with this cleaner production technology to reduce waste discharge by 360 000 tons and COD emissions by 900 tons; and use the acid-containing and salt-containing wastewater recycling technology into 50% of its capacity, complete the comprehensive utilization of salt-containing waste acids released from 200 000 t/a synthetic dyes plants, reducing waste residue discharge by 900 000 tons and salt-containing dilute acid discharge by 1.5 million tons.

Caustic soda sector
By 2012, the caustic soda sector should reduce the average comprehensive energy consumption to about 700.5 kilogram standard of coal per tons of caustic soda and reduce the total energy consumption by 2.155 million tons of standard coal a year; reduce salt slurry by 9.1 kilogram per ton of caustic soda and the total salt slurry discharge to 900 000 tons a year, down by 200 000 tons per year; and reduce the total waste asbestos fiber discharge to 460 tons a year, down by 620 tons a year.
   China will strengthen the research of the oxygen cathode and try to build a 100 000 t/a demonstration production project before 2012.
   China will promote the demonstrative project using domestically developed ion-exchange membrane technology, diaphragm caustic soda three-phase flow evaporation technology and ultrasonic anti-scale technology.
   By 2012, ion membrane caustic soda capacity should take 85% of the total capacity; and all common diaphragm caustic soda units should complete the expanded anode and modified diaphragm renovation.
   The caustic soda sector should complete the application of zero-pole electrolyzers into 3 million t/a caustic soda capacity and the application of membrane denitrification technology into about 10 million t/a caustic soda capacity, which accounts for about 40% of China's total caustic soda capacity; and apply the three-way counter-current membrane evaporation technology into 2 million t/a caustic soda capacity and the hydrogen-chloride-synthesis heat recovery technology into 300 million t/a caustic soda capacity.   (end)