HANGZHOU KUAIKAI HI-TECH CO.,LTD

CN

Number：

+86-571-87177512

Core Technology

Process Characteristics of the Recovery of High-Purity Food-Grade CO₂ from EO/EG Unit Vent Gas

Release Date：2023-10-08

Currently, the CO₂ vent gas generated by EO/EG units both domestically and internationally has a high carbon dioxide concentration, typically around 98% (dry basis). The gas contains no sulfur, but other impurities primarily consist of ethylene, ethylene oxide, and other hydrocarbons with carbon numbers greater than C₂. Since the boiling points of these impurities are similar to that of carbon dioxide and their molecular sizes are also comparable to CO₂, these hydrocarbons cannot be effectively removed through distillation, multi-stage distillation, or adsorption methods.


For CO₂ vent gas from EO/EG plants containing hydrocarbons of C₂ or higher (including oxygenated organic compounds), the most effective method currently available both domestically and internationally for producing food-grade CO₂ or high-purity CO₂ that meets national food safety standards is catalytic oxidation (commonly referred to as hydrocarbon removal) . Currently, many domestic facilities for recovering food-grade CO₂ from EO/EG plant vent gas all employ the catalytic oxidation (dehydrocarbonization) process. To date, our company has designed and constructed numerous similar facilities utilizing this process, including those at Maoming Huayue, Tianjin Lianbo, Taixing Jinyan, Wuhan Hongtai, Zhejiang Petrochemical, Shenghong Petrochemical, and Luoyang Petrochemical.

For CO₂ vent gas generated by EO/EG plants, the catalytic oxidation (dehydrocarbonization) purification method can effectively remove impurities such as ethylene and ethylene oxide. Combined with a liquefaction and distillation system, the resulting liquid carbon dioxide product has a high concentration (up to 99.995% or higher) and is stable, with all performance indicators exceeding the requirements of the high-purity carbon dioxide standard, the “GB 1886.228-2016 National Food Safety Standard for Food Additive Carbon Dioxide,” ISBT standards, as well as the standards set by Coca-Cola, PepsiCo, and others.