Purification of R-12 for refrigerant reclamation using existing industrial-scale batch distillation: design, optimizatio
- PDF / 334,786 Bytes
- 6 Pages / 595 x 842 pts (A4) Page_size
- 1 Downloads / 149 Views
pISSN: 0256-1115 eISSN: 1975-7220
RAPID COMMUNICATION
INVITED REVIEW PAPER
Purification of R-12 for refrigerant reclamation using existing industrial-scale batch distillation: design, optimization, simulation, and experimental studies Nguyen Van Duc Long*,‡, Dong Young Lee*,‡, Thi Hiep Han*,‡, Park Sunyong**, Hwang Byeng Bong**, and Moonyong Lee*,† *School of Chemical Engineering, Yeungnam University, Gyeongsan 38541, Korea **OunR2tech Co. Ltd, Pohang 37553, Korea (Received 12 May 2020 • Revised 18 June 2020 • Accepted 7 July 2020) AbstractMany design variables and constraints, such as operating temperature and pressure of existing batch distillation or operating temperature of existing cooling and heating media, must be verified and satisfied during design and optimization when an existing batch distillation column is utilized for new mixture. The convergence of batch distillation simulation is sensitive with the initial values of these variables. Thus, a new systematic methodology was proposed to design and optimize separation of a new mixture using an existing batch column. The systematic methodology was based on an industrial case study of dichlorodifluoromethane (R-12) reclamation from a waste refrigerant mixture. Based on a comparison of the Pxy diagram with experimental data, “REFerence fluid PROPerties” was selected as the thermodynamic model. After design and optimization using shortcut and rigorous methodologies, the existing batch distillation unit was operated to validate the proposed methodology. The experimented performance match well with the simulated results. Under the optimized operating condition, complete purification of R-12 (purity=99.5%) was achieved experimentally after 28.3 h. The advantages and disadvantages of the proposed methodology were then discussed. Keywords: Batch Distillation, Design, Experiment, Refrigerant Reclamation, R-12, Separation
often form azeotropic mixtures with fluorocarbons [5,7]. Various techniques have been developed to facilitate the separation of azeotropic mixtures, including the use of various zeolites and molecular sieves [7-11]. However, these techniques have not been entirely satisfactory because the components of these azeotropic mixtures often have similar boiling points, thereby making it difficult to separate highly pure components. In addition, prior art zeolite/molecular sieve processes need frequent changing and/ or regeneration of the zeolite material or molecular sieves, thus requiring that the separation process be stopped for a period of time. Batch distillation, which is preferable to continuous distillation when small quantities need to be separated, can be considered [12-15]. The most outstanding feature of batch distillation is its flexibility, which allows overcoming the uncertainties of feedstock or product specification [16]. The design and optimization of batch distillation columns have received significant research attention [12,13,17-19].
INTRODUCTION Hydrochlorofluorocarbons (HCFCs) are chemicals that are mainly used as refrigerant
Data Loading...
