DE based economic control chart design and application for a typical petrochemical process

Abstract

Petrochemical industry plays an important role in the development of the national economy. Purified terephthalic acid (PTA) is one of the most important intermediate raw materials in the petrochemical and chemical fiber industries. PTA production has two parts: p-xylene (PX) oxidation process and crude terephthalic acid (CTA) hydropurification process. The CTA hydropurification process is used to reduce impurities, such as 4-carboxybenzaldehyde, which is produced by a side reaction in the PX oxidation process and is harmful to the polyester industry. From the safety and economic viewpoints, monitoring this process is necessary. Four main faults of this process are analyzed in this study. The common process monitoring methods always use T ² and SPE statistic as control limits. However, the traditional methods do not fully consider the economic viewpoint. In this study, a new economic control chart design method based on the differential evolution (DE) algorithm is developed. The DE algorithm transforms the economic control chart design problem to an optimization problem and is an excellent solution to such problem. Case studies of the main faults of the hydropurification process indicate that the proposed method can achieve minimum profit loss. This method is useful in economic control chart design and can provide guidance for the petrochemical industry.

Keywords

petrochemical / PTA / economic control chart design / process monitoring / DE algorithm

References

[1] Azarpour A, Zahedi G (2012). Performance analysis of crude terephthalic acid hydropurification in an industrial trickle-bed reactor experiencing catalyst deactivation. Chemical Engineering Journal, 209: 180–193

[2] Chen Y K, Hsieh K L, Chang C C (2007). Economic design of the VSSI control charts for correlated data. International Journal of Production Economics, 107(2): 528–539

[3] Chih M, Yeh L L, Li F C (2011). Particle swarm optimization for the economic and economic statistical designs of the control chart. Applied Soft Computing, 11(8): 5053–5067

[4] Costa A F B (1993). Joint economic design of X¯ and R control charts for processes subject to two independent assignable causes. IIE Transactions, 25(6): 27–33

[5] Costa A F B (1997). Chart with variable sample size and sampling interval. Journal of Quality Technology, 29(2): 197–204

[6] Das S, Suganthan P N (2011). Differential evolution: a survey of the state-of-the-art. IEEE Transactions on Evolutionary Computation, 15(1): 4–31

[7] Hu Y, Ma H, Shi H (2013). Enhanced batch process monitoring using just-in-time-learning based kernel partial least squares. Chemometrics and Intelligent Laboratory Systems, 123: 15–27

[8] Lee J M, Yoo C, Lee I B (2004). Statistical process monitoring with independent component analysis. Journal of Process Control, 14(5): 467–485

[9] Li Z, Zhong W, Liu Y, Luo N, Qian F (2015). Dynamic modeling and control of industrial crude terephthalic acid hydropurification process. Korean Journal of Chemical Engineering, 32(4): 597–608

[10] Li Z, Zhong W, Wang X, Luo N, Qian F (2016). Control structure design of an industrial crude terephthalic acid hydropurification process with catalyst deactivation. Computers & Chemical Engineering, 88: 1–12

[11] Lu N, Gao F, Yang Y, Wang F (2004). PCA-based modeling and on-line monitoring strategy for uneven-length batch processes. Industrial & Engineering Chemistry Research, 43(13): 3343–3352

[12] Montgomery D C (1980). The economic design of control charts: a review and literature survey. Journal of Quality Technology, 12(2): 75–87

[13] Rahim M A, Banerjee P K (1993). A generalized model for the economic design of x̄control charts for production systems with increasing failure rate and early replacement. Naval Research Logistics, 40(6): 787–809 

[14] Wang L, Shi H (2014). Improved kernel PLS-based fault detection approach for nonlinear chemical processes. Chinese Journal of Chemical Engineering, 22(6): 657–663

[15] Zhou J, Zhang T, Sui Z (2006 a). Hydropurification of terephthalic acid over Pd/C I. thermodynamcis and feature analysis. Journal of East China University of Science and Technology, 32(5): 374–380

[16] Zhou J, Zhang T, Sui Z (2006 b). Hydropurification of terephthalic acid over Pd/C II. apparent kinetics of 4-CBA hydrogenation on catalysts of different sizes. Journal of East China University of Science and Technology, 32(5): 503–507

RIGHTS & PERMISSIONS

The Author(s) 2017. Published by Higher Education Press. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0)