Yang Guihua

Cold alkali pre-impregnated poplar Alkaline Peroxide Mechanical Pulping

Energy-saving and emission-reduction is the only way for “cyclic economy” and “low-carbon economy” of pulping and papermaking industry. Using cold alkali pre-impregnation method to produce poplar Alkaline Peroxide Mechanical Pulping. Key factors on properties of pulp were statistical analyzed by response surface analysis software. The optimal ratio of NaOH to H<inf>2</inf>O<inf>2</inf> is 1∶1. The best temperature is 75 °C. The results showed that H<inf>2</inf>O<inf>2</inf> had a beneficial effect on brightness. In a low alkali level, H<inf>2</inf>O<inf>2</inf> had a rarely effect on breaking length. However, breaking length increased sharply with H<inf>2</inf>O<inf>2</inf> dosage from 10% to 18%, when the dosage of NaOH was 18%. This indicated that the amount of NaOH and H<inf>2</inf>O<inf>2</inf> were 18% had a positive synergy effect on physical properties of paper. On the other, using high dosage cold alkali pre-impregnation method shortened the holding time, saving energy consumption significantly. Bleaching composition are H<inf>2</inf>O<inf>2</inf> and NaOH, waste liquor does not contain toxic substances. Under the conditions were NaOH: 16%, H<inf>2</inf>O<inf>2</inf>: 16%, time 20 min, temperature 75°C. The brightness of paper was 77 %ISO, breaking length 3.6 km, yield 79%.