| 摘要 |
Lignin and other organic substances are precipitated in a carbonising tower. Black lye enters the tower at the top and passes downwards. Carbon dioxide from flue gases (e.g. from the lime sludge furnace) enters the tower further down and flows upwards to meet the black lye. Both the tower and flue gas are at 65-80 deg. C. The pH of the liquid having the tower is measured and adjusted to be 8.7-9.6 by controlling the supply of lye and carbon dioxide to the tower. |
