Many chemical plants are “major sources” for existing steam generation equipment (boilers) and process heating equipment, and must comply with boiler maximum-achievable-control-technology (MACT) regulations by Jan. 31, 2016. For major sources, all units that use 10 MMBtu/h of fuel must undergo a one-time energy assessment.
The law also requires investigation of a certain percentage of end-use systems for energy-savings opportunities. This is akin to a systems approach and promises significantly larger potential benefits. Boiler MACT defines the minimum extent of the end-use system energy assessment based on the amount of total energy input to the unit. This can be confusing and lead to very varied definitions and scopes for the energy assessment. Hence, take care identifying the end-use areas that must be covered as a minimum in the energy assessment. The boiler MACT guideline specifies assessment of a minimum of 50% of the end-use system energy for energy usage less than 0.3 Trillion Btu/yr (TBtu/yr) and a minimum of 33% for energy usage between 0.3 and 1 TBtu/yr. Energy usage greater than 1 TBtu/yr requires a minimum assessment of 20% of the end-use system energy.
For an energy assessment to be effective and lead to successful energy-saving project implementations, a Qualified Energy Assessor (QEA) must conduct it. The Federal Register defines the QEA as, “someone who has demonstrated capabilities to evaluate energy savings opportunities for steam generation and major energy using systems.” The Federal Register also provides guidance on certain areas of expertise that a QEA should have — such as boiler combustion, boiler thermal energy recovery, cogeneration, condensate recovery and process heating. In addition, it recommends experience with operating and maintenance practices with steam and process heating, as well as assessment activities and report writing.
The QEA can be an external consultant or an in-plant “energy champion.” The U.S. Department of Energy’s roster of Qualified Steam and Process Heating Specialists is another source of reliable energy assessors. Boiler MACT also provides a guideline for the level of effort for the one-time energy assessment based on the energy usage of the units. Energy usage less than 0.3 TBtu/yr should call for a maximum of up to 8 hours of effort. Energy usage between 0.3 and 1 TBtu/yr should take a maximum of up to 24 hours. Energy usage greater than 1 TBtu/yr should involve a maximum of 24 hours plus 8 hours per additional TBtu/yr with a cap at 160 hours..
As mentioned earlier, the one-time energy assessment requirements in the boiler MACT are self-explanatory; the main items are listed below:
1. A visual inspection of the units (e.g., cracks, corrosion, leaks);
2. An evaluation of operating characteristics of the units, specifications of energy-using systems, operating and maintenance procedures, and unusual operating constraints;
3. Inventory of major systems consuming energy from affected unit(s);
4. A review of available architectural and engineering plans, facility operation and maintenance procedures and logs, and fuel usage;
5. An appraisal of the facility’s energy management practices with recommendations for improvements;
6. A list of cost-effective energy conservation measures;
7. A run down of the energy-savings potential of the energy conservation measures identified; and
8. A comprehensive report detailing ways to improve efficiency, the cost of specific improvements, benefits, and the time frame for recouping those investments.
These requirements ensure that energy assessments conform to a minimum standard to deliver quality results that can then be successfully implemented as energy-saving projects. Assessments that surpass these requirements will, of course, provide better quality results but may cost more. I recommend plants undertake energy assessments that also align with existing Energy Assessment Standards — ASME EA-1-2009 and ASME EA-3-2009 for process heating and steam systems, respectively.
About Our New Energy Columnist
Riyaz Papar, PE, CEM, is director, Global Energy Services, at Hudson Technologies Company, Pearl River, N.Y. He has more than 20 years of experience in industrial energy systems and with best practices. He also is a U.S. Department of Energy (DOE) Steam Best Practices senior instructor and a DOE steam energy expert. He has provided energy consulting services in 100+ industrial plants in the U.S. and internationally. You can email him at firstname.lastname@example.org.