Executive Summary
The purpose of this report is to show the cost of compressed air within the Trico production facility in
Matamoros, Tamaulipas Mexico. There is a large potential for energy savings within the compressed
air supply system. This report will show how the following cost savings were discovered.
Existing System
Proposed System
Perfect System
Annual KWh
1,775,164
1,573,931
1,304,446
Annual Cost @$0.08/KWh
$
142,013.12
$
125,914.47
$ 104,355.65
System Efficiency (CFM/KW)
4.1
5.6
Average Flow (CFM)
828.6
828.6
828.6
Average Power (KW)
202.6
179.7
148.9
Equipment
No Loss Drains Qty
$
5,600.00
1500 CFM High Efficiency Filter (for Kaeser compressor)
$
5,760.00
3000 CFM High Efficiency Filter (for discharge of tank)
$
9,120.00
4" flow control valve
$
10,519.20
Total Equipment Cost
$
30,999.20
Annual Savings
$
16,098.65
Return on investment (years)
1.9
Dew Point (F)
Kaeser Discharge Pressure (PSI)
Tank Pressure (PSI)
Flow (SCFM)
Atlas Copco Power (KW)
Kaeser Power (KW)
Min
Avg
Max
Min
Avg
Max
Min
Avg
Max
Min
Avg
Max
Min
Avg
Max
Min
Avg
Max
12-16
32
33
38
106
117
123
100
109
112
0
753
2072
0
6
210
130
182
201
12-17
32
33
55
61
118
123
97
109
111
0
787
1485
0
1
261
0
184
201
12-18
30
38
44
16
48
121
97
104
111
0
655
1212
0
146
272
0
53
203
12-19
29
35
41
15
63
122
97
105
110
0
812
1302
0
119
269
0
84
216
12-20
30
38
47
14
59
122
97
104
111
0
948
2476
13
138
267
0
83
207
12-21
30
37
47
15
87
123
97
106
112
0
926
2200
0
84
262
0
133
205
12-22
30
32
35
106
119
123
99
109
112
0
874
1795
0
8
262
130
188
201
12-23
31
39
59
13
89
123
98
106
111
0
803
2278
0
71
262
0
134
201
12-24
50
54
57
14
15
15
97
102
107
0
473
1114
13
176
258
0
0
0
12-25
50
54
57
13
15
15
0
103
107
0
270
1131
13
136
258
0
2
78
12-26
33
43
63
14
75
123
98
107
112
0
629
1275
13
73
261
0
106
204
Trico Matamoros Compressed Air Study
1: Introduction
Cost reduction is an essential part of a manufacturing facilities sustainability and continued success. This
report shows in detail how the data collection was performed.
**Power cost calculations are based on an electrical cost of $0.08/KWhr**
2: Methodology
Compressed air flow, dew point, and pressure:
The compressed air flow in SCFM (Standard Cubic Feet Per Minute) was measured using
a VP Instruments thermal mass flow meter with integral pressure transducer. The flow
meter was installed in the pipe between the dryers and production. This meter measures
flow and transmits this data to the logging unit via Modbus. The dew point was measured
using a Michell instruments EasyDew dew point sensor and transmitted to the data logger
via a 0 - 10 VDC signal.
Compressor Power:
Compressor power was measured using Veris Industries power meters. The power
transducer monitors the incoming power of the compressor in KW. The power
transducer measures voltage and current and calculates power to be output to the
data logger via a modbus signal.
Data Logger:
The measurements for flow, pressure, and compressor power were recorded one time per
10 seconds using one EZEio data logger/controller. The data is graphed and analyzed
through a powerful graphing software called DPlot.
Trico Matamoros Compressed Air Study
3: Results
Compressed air consumption:
The Trico facility uses an average of 829 CFM to support the daily needs of production. The average power
necessary to generate this amount of flow is 203 KW. The system uses one air compressor to generate the
compressed air necessary and another starts occasionally when pressure falls to the minimum pressure set point.
The graph below shows all data collected during the one week study.
Trico Matamoros Compressed Air Study
Actual flow vs. rated flow
The Atlas Copco GA250-FF air compressor is rated for a flow of 1469 CFM and the Kaeser ESD300 air
compressor is rated for a flow of 1271 CFM. Both compressors use 300 HP motors but the Kaeser is rated for 175
PSI and the Atlas Copco is rated for 125 PSI. The graph below shows that the Kaeser almost reaches its rated
flow, but the Atlas Copco falls around 300 CFM short of its rated flow while consuming more power. The cause of
the Atlas Copco’s reduced flow should be found and corrected.
• Kaeser ESD300 uses 202 KW to generate 1203 CFM
• Atlas Copco GA250-FF uses 268 KW to generate 1177 CFM
Trico Matamoros Compressed Air Study
Pressure:
The two compressors installed in Trico’s compressed air system are rated for different maximum
pressures. The Kaeser is rated for 175 PSI and the Atlas Copco is rated for 125 PSI. The Kaeser normally
operates in a load/unload configuration between 108 PSI and 122 PSI and the Atlas Copco operates between 97
PSI and 105 PSI.
Differential Pressure Across Clean Up Equipment:
The graph below shows the pressure at the discharge of each compressor with the pressure at the
production cell that manufacturers wiper motors. The data shows that the cell operated with a minimum pressure
of 87 PSI. The pressure in the tank was 101 PSI when the pressure at the cell was at the minimum of 87 PSI.
The rule of thumb accepted across the compressed air industry is: 2 PSI increase in discharge pressure is
approximately 1% compressor power. The Kaeser compressor operates at an average pressure of 117 PSI and
the Atlas Copco operates at an average pressure of 102 PSI. If both compressors could operate at a constant
pressure matching the minimum pressure of the production cell it would result in an annual energy savings of at
least $17,000. This report uses a minimum pressure of 90 PSI for savings calculations vs. the 87 PSI minimum
pressure. The reason for this pressure differential is the pressure loss across the filters, dryers, and distribution
piping due to friction. This pressure loss can be minimized by installing filters with a lower pressure differential.
Trico Matamoros Compressed Air Study
Equipment running while not in use:
The graph below shows the amount of power used by the internal dryer on the Atlas Copco air compressor. The
dryer runs constantly if the compressor is stopped or running. The recorded data shows the dryer uses around 15 KW and
has an annual potential savings of around $2,500. Another potential for energy savings is a fan that is running in the
GA180VSD while the power is disconnected from the compressor.
Check Valves:
The photo below shows there is a check valve installed between the Kaeser compressor and the Kaeser
compressed air dryer. This check valve should be removed for a few reasons. The first reason is that the compressor has a
check valve installed internally that prevents system pressure from coming back through the inlet. The second reason is
that the check valve prevents the compressor from sensing system pressure. This means that if the Atlas Copco is running
and has a fault or is unable to keep up with production the Kaeser is unable to start automatically to prevent an interruption
to production due to low pressure. The third reason is that the Kaeser is waiting for the pressure to drop in the small section
of piping between the compressor and the check valve vs. utilizing the entire system including the 3750 Gallon tank as
storage. Removing the check valve will improve the performance of the Kaeser compressor and the compressed air system.
Trico Matamoros Compressed Air Study
The graph below shows the discharge pressure of the Kaeser compressor falling below the pressure in the tank when the
Kaeser is shut down.
Trico Matamoros Compressed Air Study
Condensate drain valves
The compressors, tank and clean up equipment all utilize some form of electric drain valve. The timer operated
drain valves will discharge some amount of compressed air every time they open to ensure all water is removed from that
piece of equipment. This air is wasted every time the valves opens. There are also float operated electric drains. These
drains discharge only water, but it is difficult to determine if the valve is functioning properly. An alternative to the electric
drain valves is the pneumatically operated no loss drain valve. The valves operating status can be determined by looking at
the drain to see if the condensate level is higher than normal. This valve also prevents the waste of air when the timer drain
opens.
The graph above shows the power from a 100 HP variable speed drive air compressor. The peaks are
due to an electric drain valve opening.
The drain valve uses 3 KW worth of compressed air. If this compressor operates 24/7/365 the electric
drain has uses
$2,400.00 worth of air annually.
Trico Matamoros Compressed Air Study
Compressed air dew point:
The dew point of the compressed air entering the plant was recorded to show the effectiveness of the drying
equipment. The graph below shows dew point, compressor room pressure and flow. The dew point rises when
the Atlas Copco is running through its integrated dryer.
Trico Matamoros Compressed Air Study
System Drawings:
Current System
Proposed System
Trico Matamoros Compressed Air Study
4: Conclusions
The compressed air system at Trico’s Matamoros facility has most of the components necessary to operate
efficiently and with 100% redundancy. Installing energy efficient drain valves, new energy efficient compressed air
filtration and a flow control valve along with removing the check valves in the piping will help to maximize the
energy efficiency of the system. The compressed air system should be able to operate at all times with one air
compressor with the exception that production increases above the level during the recorded data.
5: Recommendations
1. Determine the cause of and repair the reduced flow of the Atlas Copco air compressor. This
could be due to a faulty inlet valve, minimum pressure check valve, or deterioration in the
rotors of the compressor.
2. Install a 4” flow control valve to allow the plant pressure to remain constant at its
lowest possible pressure while the compressors can cycle between a larger range of
load and unload pressures
3. REMOVE ALL CHECK VALVES INSTALLED IN THE COMPRESSED AIR PIPING
4. Install no loss drain valves on all drain points in the compressed air system.
5. Replace all existing filters with high efficiency compressed air filters.
6. Permanently install power, flow, pressure, and dew point monitoring system to monitor
system performance.
Daily Graphs:
12/17/2016
Trico Matamoros Compressed Air Study
12/18/2016
12/19/2016
Trico Matamoros Compressed Air Study
12/20/2016
12/21/2016
Trico Matamoros Compressed Air Study
12/22/2016
12/23/2016
Trico Matamoros Compressed Air Study
Trico Matamoros Compressed Air Study
