Thermodynamics of the Kraft Causticizing Reaction

硫酸盐苛化反应的热力学

• 批准号: 8610033
• 负责人: Joseph Genco
• 金额: $ 10.02万
• 依托单位: University of Maine
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1986
• 资助国家: 美国
• 起止时间: 1986-11-01 至 1989-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8610033&HistoricalAwards=false
• 关键词: Thermodynamics; Kraft; Causticizing; Reaction

The causticizing reaction plays a crucial role in the chemical recovery cycle of the Kraft pulping process used by most of the paper industry. Kraft recovery operations include concentration of spent pulping liquor, burning to recover energy and chemicals, smelt formation, smelt dissolution, causticizing, white liquor clarification, calcium carbonate thickening, and mud washing. This proposal is part of the PI's work to improve the many aspects of the Kraft process in an attempt to make it more amenable to control. Improved process control should decrease capital and operating cost for the process and increase productivity. Causticizing converts an aqueous solution of sodium carbonate and sodium sulfide (green liquor) into caustic solution (white liquor) and lime mud (CaCO (s)). The product caustic solution is used in the digestion process to delignify wood and other vegetable matter. The objective of the proposed research is to obtain experimental data and estimate parameters required to verify a thermodynamic model of the causticizing reaction. The problem is to determine when equilibrium has been attained and to improve the approach to equilibrium. The causticizing efficiency is a maximum at equilibrium. Increases in productivity and decreased operating and captital costs would result if the causticizing efficiency can be improved. This proposal is aimed at defining an expression for the equilibrium conversion. The data will be directly applicable to processing wood and other vegetable matter into pulp by the Kraft and Soda processes. In addition, the data can be applied to chemical processes wherever causticizing reactions are used; for example, the production of caustic soda.

苛化反应在化学反应中起着至关重要的作用。 大多数国家使用的硫酸盐法制浆工艺的回收周期 造纸工业。 硫酸盐回收作业包括浓缩 制浆废液，燃烧以回收能源和化学品， 熔体形成、熔体溶解、苛化、白色液 澄清、碳酸钙增稠和泥浆洗涤。 这项建议是PI工作的一部分，以改善许多 卡夫工艺的各个方面，试图使其更 服从控制。 改进的过程控制应减少 该过程的资本和运营成本， 生产力 苛化将碳酸钠的水溶液转化为 将硫化钠（绿色液体）转化为苛性碱溶液（白色 液体）和石灰渣（CaCO（s））。 产品苛性碱溶液为 在蒸煮过程中用于木材和其他 植物性物质 拟议研究的目的是 获得实验数据和估计所需的参数， 验证苛化反应的热力学模型。 的 问题是确定何时达到平衡， 改善平衡的方法。 苛化效率 在平衡态下是最大值。 提高生产力和 降低运营和资本成本将导致，如果 可以提高苛化效率。 该提案旨在 来定义平衡转化率的表达式。 的 数据将直接适用于加工木材和其他 用硫酸盐法和苏打法将植物性物质制成纸浆。 在 此外，这些数据还可以应用于任何地方的化学过程， 使用苛化反应;例如， 苛性钠