提取木素并结合电解回收碱工艺处理制浆黑液

A Pulping Black Liquor Treatment Method Including Lignin Separating and Alkali Recovering by Electrolysis

关键词:  黑液  木素  UASB  反渗透  电解硫酸钠

Key Words:black liquor  lignin  UASB  reverse osmosis  electrolytic sodium sulfate

摘要:采用传统碱回收方法处理黑液，在回收碱的过程中不仅烧掉了部分木素还会排放大量CO2，造成环境污染。为解决这一问题，介绍一种处理制浆黑液的新方法。该方法工艺流程包括：酸化提木素（A）、冷冻结晶脱盐（D）、上流式活性污泥反应（UASB）、反渗透过滤（RO）和电解硫酸钠（E）5个步骤。结果表明，经该方法处理后的木素得率为28.09%，碱生成速率为2.38 g/（h·L），电解硫酸钠溶液24 h碱回收率为50.64%，再生氢氧化钠的电能消耗为1.598 kWh/kg。

Abstract:Black liquor is always treated by traditional alkali recovery method in which the biomass including lignin is burned to reduce the organic pollutants; and a large amount of CO2 and other harmful gases are generated while generating sodium carbonate. In order to solve this problem， a new method was developed to treat pulping black liquor. The process included five steps: acidified precipitation（A）， desalination by frozen crystallization（D）， upflow activated sludge bed（UASB）， reverse osmosis filtration（RO） and electrolysis（E）. The experimental results ware, the yield of lignin was 28.09% of the mass of the black liquid， the alkali production rate was 2.38 g /（h·L）， when electrolytic for 24 hours， the alkali recovery rate of sodium sulfate was 50.64%，the electric energy consumption was 1.598 kWh per 1 kg of sodium hydroxide.