Experimental study on performance of compact three-chamber RTO system for treating waste gas containing ethyl acetate

doi:10.11949/0438-1157.20241224

Abstract

Abstract:

The emission of volatile organic compounds (VOCs) has emerged as an increasingly prominent environmental concern, posing significant threats to both ecological systems and public health. Aiming at the problem of VOCs emission, this study designed and built a compact three-chamber RTO device with an air intake volume of 200 m³/h and a size of 2915 mm×1150 mm×2200 mm. The experimental investigation focused on ethyl acetate, a predominant VOC emission in the pharmaceutical industry, as the target compound. The study examined the removal efficiency, thermal efficiency, and temperature characteristics of the heat storage chamber, oxidation chamber, and outlet under various operating conditions. Experimental results demonstrated that the RTO system achieved VOCs removal efficiencies exceeding 97% when the oxidation chamber temperature ranged from 750℃ to 850℃. Furthermore, reducing the intake airflow enhanced the oxidation and decomposition efficiency of ethyl acetate, while increasing the reverse purge airflow improved its removal effectiveness. The valve switching time was found to influence both the temperature of the heat storage chamber and the pressure within the oxidation chamber, consequently affecting system stability and thermal efficiency. The compact three-chamber RTO device developed in this study demonstrated highly efficient treatment of ethyl acetate waste gas, achieving removal rates between 97% and 99%, with thermal efficiency exceeding 96%.

Key words: volatile organic compounds, three-chamber RTO, reactors, oxidation, pollution, waste treatment, environment

摘要：

挥发性有机化合物（VOCs）的排放问题日益凸显，对生态环境及公众健康构成了严重威胁。针对治理VOCs排放问题自行设计并搭建了进气风量为200 m³/h、尺寸为2915 mm×1150 mm×2200 mm的紧凑式三室RTO实验装置，以制药行业中排放量占比较大的乙酸乙酯作为研究对象，探究在不同工况条件下紧凑式RTO装置处理乙酸乙酯废气的去除效率，热效率以及蓄热室、氧化室和出口的温度特性。实验结果表明，氧化室温度在750~850℃范围内，RTO系统对VOCs的去除效率大于97%。此外，进气风量降低可以提高乙酸乙酯的氧化分解效率，吹扫风量增加亦能提升乙酸乙酯的去除效果，阀门换向时间会影响蓄热室温度和氧化室内压力，进而影响系统的稳定性和热效率。本设计开发的紧凑式三室RTO装置在处理乙酸乙酯废气方面表现出高效性能，去除率在97%~99%之间，热效率超过96%。

关键词: 挥发性有机化合物, 三室RTO, 反应器, 氧化, 污染, 废物处理, 环境

CLC Number:

O 643.2⁺1

Peng YANG, Wanli YOU, Zhongqian LING, Xianyang ZENG, Yunchao LI, Jiayi LIN, Lijian WANG, Dingkun YUAN. Experimental study on performance of compact three-chamber RTO system for treating waste gas containing ethyl acetate[J]. CIESC Journal, 2025, 76(7): 3585-3595.

杨鹏, 尤万里, 凌忠钱, 曾宪阳, 李允超, 林佳一, 王丽建, 袁定琨. 紧凑式三室RTO系统处理乙酸乙酯废气性能的实验研究[J]. 化工学报, 2025, 76(7): 3585-3595.

Figures/Tables 21

Fig.1 Principle diagram of RTO system

Fig.2 Physical diagram of RTO system

Table 1 Oxidation chamber temperature test operating conditions

氧化室温度/℃	乙酸乙酯浓度/（mg/m³）	进气风量/（m³/h）	阀门切换时间/s
600	1000	200	120
650	1000	200	120
700	1000	200	120
750	1000	200	120
800	1000	200	120
850	1000	200	120

Table 2 Inlet air flow test operating conditions

进气风量/（m³/h）	乙酸乙酯浓度/（mg/m³）	氧化室温度/℃	阀门切换时间/s
100	1000	800	120
120	1000	800	120
140	1000	800	120
160	1000	800	120
180	1000	800	120
200	1000	800	120

Table 3 Purge flow rate test operating conditions

吹扫风量/（m³/h）	乙酸乙酯浓度/（mg/m³）	氧化室温度/℃	进气风量/（m³/h）	阀门切换时间/s
0	1000	800	200	120
16.2	1000	800	200	120
32.4	1000	800	200	120
48.6	1000	800	200	120
64.8	1000	800	200	120
81.0	1000	800	200	120

Table 4 Valve switching time test operating conditions

阀门切换时间/s	乙酸乙酯浓度/（mg/m³）	氧化室温度/℃	进气风量/（m³/h）
60	500，1000，1500，2000，2500	850	200
120	500，1000，1500，2000，2500	850	200
180	500，1000，1500，2000，2500	850	200
240	500，1000，1500，2000，2500	850	200

Fig.3 Effect of oxidation chamber temperature on inlet and outlet gas temperatures

Fig.4 Effect of oxidation chamber temperature on removal efficiency and thermal efficiency

Fig.5 Internal flame combustion of RTO at different oxidation chamber temperatures

Fig.6 Relationship between inlet air flow rate and average temperature of heat storage chamber

Fig.7 Relationship between inlet air flow and inlet/outlet gas temperatures

Fig.8 Effects of inlet air flow rate changes on thermal efficiency and removal efficiency

Fig.9 Relationship between average temperature of regenerator and purge air flow rate

Fig.10 Relationship between purge air flow rate and inlet/outlet gas temperature

Fig.11 Effect of purge flow rate on removal efficiency and thermal efficiency of regenerative chambers

Fig.12 Relationship between regenerator temperature, inlet/outlet gas temperature and valve switching time

Fig.13 Relationship between temperature wave height, monitoring point temperature and valve switching time

Fig.14 Relationship between valve switching time and oxidation chamber temperature fluctuation

Fig.15 Pressure fluctuation and average temperature in oxidation chamber under 180 s valve switching time condition

Fig.16 Effect of valve switching time and waste gas concentration on removal efficiency

Fig.17 Relationship between valve switching time and thermal efficiency

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