Design guidelines for urea hydrolysers for ammonia demand of the SCR DENOX project in coal-fired power plants

doi:10.1007/s11708-012-0225-7

Front Energ

0, Vol.

Issue () : 127-132 https://doi.org/10.1007/s11708-012-0225-7

RESEARCH ARTICLE

Design guidelines for urea hydrolysers for ammonia demand of the SCR DENOX project in coal-fired power plants

Peng ZHENG, Xuan YAO(

), Wei ZHENG

Beijing GUODIAN Longyuan Environmental Engineering Company Limited, Beijing 100039, China

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Abstract

Ammonia is highly volatile and will present substantial environmental and operation hazards when leaking into the air. However, ammonia is the most common reactant in the DENOX project to eliminate NO_x in the flue gas. The storage and transportation of liquid ammonia has always been a dilemma of the power plant. Urea is a perfect substitute source for ammonia in the plant. Urea hydrolysis technology can easily convert urea into ammonia with low expense. Presently, there is still no self-depended mature urea hydrolysis technology for the DENOX project in China; therefore, this paper proposes several guidelines to design the urea hydrolyser by theoretical analysis. Based on theoretical analysis, a simulation model is built to simulate the chemical reaction in the urea hydrolyser and is validated by the operational data of the commercial hydrolyser revealed in the literature. This paper endeavors to propose suggestions and guidelines to develop domestically urea hydrolysers in China.

Keywords urea hydrolyser ammonia selective catalytic reduction (SCR)

Corresponding Author(s): YAO Xuan,Email:yaox08@mails.tsinghua.edu.cn

Issue Date: 05 March 2013

Cite this article:

Peng ZHENG,Xuan YAO,Wei ZHENG. Design guidelines for urea hydrolysers for ammonia demand of the SCR DENOX project in coal-fired power plants[J]. Front Energ, 0, (): 127-132.

URL:

https://academic.hep.com.cn/fie/EN/10.1007/s11708-012-0225-7
https://academic.hep.com.cn/fie/EN/Y0/V/I/127

Fig.1 Process and pathway of a urea hydrolyser

Fig.2 NHCOONH decomposition condition and recommend process window

Fig.3 Corrosion rate of 316 L stainless steel with temperature variation

Fig.4 Composition of product vapor and consuming heat

Fig.5 Liquid composition in the hydrolyser with 40% urea feed stock under 6.0 bar

Fig.6 Dew point of the product vapor under different operation conditions

Tab.1 Kinetic date for urea hydrolysis in a batch reactor[14]

Fig.7 The kinetic character of urea hydrolysis reaction

Fig.8 Comparison of the simulation and industry result of the hydrolyser (The hydrolyser operating at 6.0 barg with 50 wt% urea feed)

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