35
30
29
25
20
18
Bio f ilm detection & control program me
17
15
15
15
11
10
10
9
9
5
5
3
3
3
3 3
2
2
2 2
2
1
0
0 0
0
0
0 0 0 0
0
-5
Figure 6 Heat exchanger cleanings before and after implementation of the biofilm detection and control programme
presented in Figure 7 shows fewer heat exchanger failures with the implementation of the biofilm detection and con - trol programme. The number of heat exchanger failures decreased by 85%, and no new failures have been recorded since February of 2016. Implementation of the performance monitoring and bio- film detection and control programmes provided a docu - mented annual net return on investment (ROI) of seven figures. This ROI was based on increased crude charges, increased production through the FCC, overall increased production, reduced propane in the fuel gas, reduced fre- quency of exchanger cleanings, reduced frequency of cool- ing tower deck cleanings, and increased heat exchanger life. Overall, the programmes significantly improved the refinery’s profitability. Continued success A sister refinery experienced issues with biofilm and
MIC on a large cooling water system, so much so that the expense for sodium hypochlorite and non-oxidising biocide had soared to almost $85,000 per month with its existing treatment programme. The refinery leadership implemented the heat exchanger performance monitoring programme and new biofilm detection and control pro - gramme. After the implementation of the programmes, the monthly chemical expenditure decreased to roughly $10,000 per month. The system that once had experienced leaks at least annually, now saw only one leak in the three years after the implementation of the new programmes. Shortly after implementation, that ‘annual’ leak, unrelated to water chemistry, occurred again. Under normal circumstances, that amine-related leak would have resulted in an immedi- ate need to shut down to repair the heat exchanger. Instead, the biofilm detection and control programme maintained microbiological control and corrosion rates in the system for
12
11
11
10
9
9
8
Bio f ilm detection & control program me
7
6
6
6
5
5 5 5
5
5
5
4
4
3
3
3
3
2
2
2
2
2
1
1
0
0
0 0
0 0 0 0 0 0 0
0
-1
Figure 7 Heat exchanger failures before and after implementation of the biofilm detection and control programme
36
PTQ Q1 2024
www.digitalrefining.com
Powered by FlippingBook