Piperazine (PZ) based amine blends are promising solvents for post-combustion CO₂ capture, but PZ can form potential carcinogenic nitrosamines from nitrite. In this work, the kinetics of the reaction between nitrite and PZ to form N-nitrosopiperazine (MNPZ) was determined in 0.1–0.5 mol L⁻¹ PZ in the presence of 17–170 mmol L⁻¹ formaldehyde at 60–135 °C. The nitrosation of PZ can be catalyzed by formaldehyde, a primary degradation product of PZ. And the reaction involving nitrite and PZ is first order in nitrite, formaldehyde, and hydronium ion. A kinetic model was established, and the activation energy is 33.6 ± 1.8 kJ mol⁻¹ with a rate constant of 2.3 × 10³ ± 0.4 × 10³ L² mol⁻² s⁻¹ at 100 °C. The kinetics will be helpful to develop strategies to reduce nitrosamine formation and accumulation in PZ based CO₂ capture systems.

基于哌嗪（PZ）的胺混合物是燃烧后捕获CO _2的有前途的溶剂，但PZ可以从亚硝酸盐形成潜在的致癌亚硝胺。在这项工作中，在60–135°C下存在17–170 mmol L ^-1甲醛的条件下，在0.1–0.5 mol L ^-1 PZ中测定亚硝酸盐与PZ之间形成N-亚硝基哌嗪（MNPZ）的反应动力学。。PZ的亚硝基化可以通过甲醛（PZ的主要降解产物）进行催化。涉及亚硝酸盐和PZ的反应是亚硝酸盐，甲醛和水合氢离子的一级反应。建立了动力学模型，活化能为33.6±1.8 kJ mol ^-1，速率常数为2.3×10 ³  ±0.4×10 ³ L在100°C下为²  mol ^-2  s ^-1。动力学将有助于开发策略，以减少基于PZ的CO ₂捕集系统中亚硝胺的形成和积累。