Compressed Air Energy Savings Project at Archer Daniels Midland BioProducts - Part One
Brent Darnell, John Henry Foster Company
Rodney Dayson, Sustainability & Energy Manager, ADM BioProducts
The Archer Daniels Midland BioProducts plant in Decatur, Ill. (“ADM Bio”) produces products such as lysine and threonine for the feed industry and lactic acid, xanthan gum and crystalline sorbitol for food products including soft drinks, sauces and chewing gum. It has four departments, each of which could be a plant in its own right:
- Fermentation (producing the basis for lysine, threonine, lactic acid, xanthan gum)
- Refinery (processing lysine, threonine, lactic acid from Fermentation)
- BioII ( processing xanthan gum from Fermentation)
- Polyol (processing lactic acid from Refinery and sorbitol from the Corn Plant)
This facility operates one of the largest compressed air installations in industry, with 21 4000 hp process air and five 750 hp instrument air centrifugal compressors to support large-scale aerobic fermentation and related processes that require large volumes of oxygen.
In 2012, in partnership with electric utility Ameren Illinois and Ingersoll-Rand distributor John Henry Foster (JHF), ADM Bio completed a system survey that identified a total savings opportunity of ~6,300 kW and, when Phase I was implemented, yielded verified savings of 670 kW (daily average) and an annualized 5,869,200 kWh. At a U.S Energy Information Administration (USEIA) national average cost of $0.072/kWh for industrial electricity (as of September 2012), that’s $422,582.
Perhaps as important as the achieved energy savings and the identified future savings are the lessons learned about planning, financing, carrying out, and applying the results of a CA system survey. What ADM Bio learned can be applied to any system.
Although he was convinced it was essential, Rodney Dayson, Sustainability & Energy Manager at ADM Bio, faced a number of challenges before this survey could be undertaken:
- The plant’s existing metrics indicated that the CA system was operating efficiently.
- A prior survey had made recommendations that either could not be justified or, when implemented, did not yield the projected savings.
- The potential cost of problems resulting from some of the recommended system changes could be much greater than the projected savings from those changes.
- The cost of another survey could not be justified on the basis of ROI.
- ADM Bio has a long-standing tradition of self-reliance when it comes to operating, maintaining and upgrading its compressed air systems.
“Houston, We Have Ignition”
In July of 2010, a chance meeting at an Ameren symposium between Rodney Dayson and Chad Struckmann, Ingersoll Rand Product Manager, led to further conversation with John Henry Foster.
JHF soon proved themselves to be a key ally in connection with a separate, and much smaller project for ADM Bio’s polyol facility. Dayson called JHF and asked for a quote on a replacement air compressor installation consisting of three new centrifugal compressors. Rather than quote on the request as written, JHF asked the question: Why do you need three compressors? Of course, this was unexpected, coming from an equipment supplier. JHF offered to investigate the opportunity on their dime, and their recommendations saved ADM Bio more than $300,000 in equipment and installation costs.
This experience led to an invitation to JHF to visit the plant. After an intial JHF walk-through of the supply side at ADM Bio, Struckmann issued a formal proposal for a detailed investigation of the entire compressed air system. Recognizing that the plant’s CA technology and controls had last been updated in the early 2000s, JHF offered to provide a free pre-audit.
Dayson then sent compressor data for a low production, average production and high production month to Brent Darnell, JHF General Manager and an experienced system evaluation expert. He evaluated the data and determined that there was an opportunity for energy savings, since the data indicated that two or more compressors were operating more than necessary (Figure 1). The pre-audit proved to be key in obtaining support for the project from Thomas Mort, ADM’s Global Energy Manager.
Selecting an Auditor
Knowing that both future energy savings projects and the credibility of using third-party surveys to identify them were on the line, Dayson established a set of criteria for auditor selection. These criteria can be applied to any system assessment, regardless of the size of the system. According to Dayson:
1. The candidate should provide a sample (sanitized) report. This is important. Any hesitation on the part of the auditor should be a warning.
A review of the report will provide you with a good indication of the depth of the audit that you should expect for your own project, as well as potential findings or solutions. Does it encompass leak assessment only, control valve only solutions, or header additions only? And what of compressor performance? If there is no mention of measuring compressor performance, this should also be a warning.
2. You should ask: What are your deliverables after the audit? Will you provide a detailed report? Do you release the raw data you collect, or is there an additional cost—or no release at all? As with the sample report, any hesitation about data release should be a warning.
3. Ensure that the auditor will agree to survey the entire CA system, not just the compressor room.
4. Determine whether the auditor is interested in creating a change in operational culture at your plant, or will be satisfied with doing one audit and then moving on.
5. Beware of any proposal that is not vendor-neutral.
6. You should ask: What is your usual audit savings ratio (audit savings/audit costs)? A 2 to 3 ratio is a commonly applied standard, with the very minimum being payback in under one year. Keep in mind that most utilities will only provide funds when the savings are identified upfront.
7. Prior to the start of the audit, establish what pre-audit information the auditor will need, as in P&ID drawings and system information such as storage, operations etc. Good auditors want to hit the floor running instead of trying to gather needed information at audit time. Understanding your system also allows the auditor to start the survey with some possible solutions in mind.
8. Be sure that the proposed system optimization includes the following:
- Baseline performance
- Identification of ROI projects
- Gameplan for realizing ROI projects
- Development of agreed-upon performance metrics
- Validation of new baseline
- Game plan for sustaining the gains
Developing the Whiteboard
Drawing on the lessons learned from prior energy audits, in 2010 Dayson developed a preliminary project whiteboard and, after selecting JHF, finalized it with their collaboration in October 2011. Addressing both the efficiency (supply) path and the effectiveness (demand) path, the whiteboard:
- Laid out both JHF (and Ingersoll-Rand) and ADM Bio’s roles and responsibilities.
- Identified deliverables (JHF/IR) and expectations (ADM).
- Projected the costs of each phase.
- Identified some keys to success for the performance testing and scoping audit:
- The core team was assigned to a daily 30 minute meeting.
- The steering team was to participate in the kickoff and outbriefing meetings.
- Acquisition of production load data for the three main process areas
- Scheduling and scope of site pre-work to maximize auditor/technician time on site.
- Listed the key names for both JHF/IR and ADM.
Whiteboard development was often the cause of spirited debate among the team members, with Ernie Pither (IR Director of Engineered Products), Brent Darnell and other JHF/IR participants challenging ADM Bio’s understanding of system operation, and with ADM Bio pressing JHF/IR to substantiate and justify their recommendations for the audit. Nonetheless, it was this close collaboration that Dayson now considers to be a primary contributor to the project’s success.
Utility Financial Incentives
Knowing that this survey would not take place without financial assistance, Dayson approached ADM Bio’s energy utility, Ameren Illinois, about its ActOnEnergy® program (see sidebar). Robert Baumgartner is the Industrial Energy Efficiency Manager at SAIC Energy, Environment & Infrastructure, LLC (an Ameren Illinois ActOnEnergy Partner), and manages the energy incentive dollars for Ameren. He recommended applying for ActOnEnergy’s Compressed Air Retro-Commissioning Program (http://www.actonenergy.com/for-my-business/explore-incentives/retro-commissioning) and then acted as liaison between ADM, JHF and ActOnEnergy. He says, “I advised, consulted, and guided all parties from the incentive application process through project completion. It is important that all parties understand the terms and conditions involved with the energy efficiency incentives.”
Based on ADM Bio’s achieving a minimum of 3,700,000 kWh annual savings, Ameren Illinois quickly approved $53,000, which was 100 percent of the cost of the survey as quoted by JHF. (Upon implementation and verification, an additional $33,722 in implementation incentive was awarded, for a total of $86,722.)
Implementation and Verification
Phase I consisted of three projects that had to meet a one year or less payback:
- Repair of leaks (175 kW)
- Minimization of purposeful drains (371 kW)
- Installation of a software “watchdog” program that provided start-stop signaling for manual compressor control (124 kW)
These projects will be detailed in Part 2 of this article, and consisted of:
- Repair of leaks. This was a straightforward process that is consistently part of energy efficiency efforts in plants. Approximately 375 leaks totaling 1000 scfm were found, using ultrasonic detectors.
- Minimization of 2555 scfm of purposeful drains, such as condensate drains. Some of these were originally designed into the system, and others, such as multiple two-inch lines found to be blowing continuously, were short-term fixes that turned into long-term problems.
- Installation of a “watchdog” control system program that provided start-stop signaling for manual compressor control. After the initial success with leaks and drains, it was determined that adding this feature to the control system could be done at little additional cost. Prior to the program’s installation, the PAC system operated efficiently only 19 percent of the time; when it was properly monitored, the system operated efficiently 38 percent of the time. The results of applying this feature validated the principle of full automatic control.
Keys to Success
Compressed Air Best Practices asked Brent Darnell to identify several key characteristics of a successful compressed air system survey. He said:
- Assess the system, not the individual components.
- Measure improvements not at the demand point of use, but at the compressor room. For example, a new filter reduces the pressure drop at the point of use by 20 psi, but how much effect does that have on the supply side?
- Do not use rules of thumb; measure, measure, measure. Is the DOE’s recommended 20 fps maximum flow velocity valid for this system? Is 0.5 percent per psi the actual reduction in power required when system pressure is reduced?
- Perform a capability test on every compressor, not just one or two—and do not use the OEM factory capability test results.
- Keep Operations and Maintenance involved from the very first pre-planning step, and listen to what employees of those groups have to say.
- Don’t use an auditor who comes in and tells you how he or she is going to perform the survey: use one that asks you for your input from the beginning.
- Validate the audit before you take action on its recommendations.
- Ensure that everyone involved agrees (in writing) how the team will respond to surprises.
- Develop and use a Repeatability, Resilience, and Reliability matrix. (See sidebar.)
But What about Smaller Systems?
Because this was a very large CA system, Compressed Air Best Practices asked Dayson, “What can we say about what you learned from this project that will resonate with owners of smaller systems?” He replied:
“Whether large or small you can get a bad audit, that is, one that includes no actionable capital opportunities and limited or no low cost savings opportunities. My message is: do your homework, demand excellence, and don’t be afraid to say no to the audit. Auditors may want you to part with your money and let them audit your facility. I believe that if you want to audit my plant, you should be able to provide some savings incentive beforehand.”
In spite of the scale of the identified savings opportunities, ADM Bio plans to complete its implementation over the next year. The gains, along with additional Ameren funding, will more than justify the necessary capital investment. Projects include:
- Measurement and validation protocol
- Total control and OEM upgrade of (5) 750 hp IAC compressors at 110 psi
- Total control of (8) 4,000 HP PAC compressors at 50 psi
o Opportunity: 2,238 kW via shutting down one compressor
- Utility Building Temperature Control
o Opportunity: 1,100 kW via moving the PAC inlet filters outdoors
- OEM upgrade of (2) 4,000 HP compressors
- Total control of (11) additional 4,000 HP compressors
o Opportunity: 2,238 kW via shutting down one compressor
(Part 2 of this article will focus on the technical details of ADM Bio’s implementation of the Phase I survey recommendations.)
To read more Energy Manager articles, visit www.airbestpractices.com/energy-manager.