Energy center enhancements deliver more steam

Six approaches provide range of solutions to squeeze out more power for production. This contribution appears in the March issue of EPM.
By Darrell Pedersen | February 09, 2016

Many ethanol producers are facing considerably complex decisions regarding the age-old quandary—how to increase production. The need to increase production universally affects each and every plant, be it new, large, small and particularly those that are aging and find themselves in a competitive battle.  

The challenges are as diverse as the ethanol industry itself. Large plants want to seize on expanding markets. Smaller plants need to enhance their production efficiencies to compete against the larger competitors that have economies of scale. Aging plants find themselves struggling with major potential capital expenditure decisions to remain competitive. All want to be sure that they’re in position to withstand the inevitable down times and low-profit margin periods that the ethanol industry faces by having an efficient and optimized plant that’s running at peak.   

The common link is production efficiency. It is critically important for plant operators to stay current on all maintenance requirements, while at the same time removing the bottleneck and modernizing to allow plants to remain competitive in periods where margins are diminished. 

The dilemma of how to squeeze more production has been faced at every ethanol plant from the day they were built. There are a multitude of product solutions that have been implemented to help address the fundamental issue of increased production. With the majority of ethanol plants running well-above their original nameplate design, there is one consistent element that they’re running short of—steam. The ability to generate more steam is an integral component in the long term strategy to increase production.

There are several tangible and proven approaches to achieving more steam from the boilers in a plant’s operation. Implemented either separately or in tandem, they are sure to have a significant impact on production. Each comes with capital investment, both large and small, and with short- and long-term implications from a budgeting standpoint.  What may be right for one plant may not be the answer for another. It depends upon the number of years the plant has been in operation, the production metrics requirement and the available budget dollars.

There are six approaches to delivering on the requirement to realize more steam:

1. Add boiler capacity: The most rapid way to gain more steam for production is through either replacing existing boilers or adding new ones. This is especially true in aging plants operating original boilers. This involves planning for a capital expenditure and allowing for the potential downtime for installation. With Victory Energy’s boilers serving the majority of the ethanol plants across North
America, this experience and industry understanding minimizes downtime. 

2. Conduct proper maintenance: There is an industry adage that you either “schedule your downtime or it will schedule you.”  It is proven that boilers run far more efficiently when operators follow the recommended annual boiler manufacturer maintenance recommendations, as well as the daily, weekly, monthly and semimonthly routine maintenance. Victory Energy’s end-market team is aligned to help ethanol plants stay ahead of unplanned shutdowns through comprehensive preventative maintenance programs.

3. Maintain proper boiler water chemistries: Overlooking this element in proper boiler maintenance is the largest single direct cause of boiler outages. When boiler feedwater and boiler water fail to receive proper preparation and treatment, the results are scale and sludge deposits that cause corrosion and pitting of boiler surfaces—all of which is preventable. Always seek a quality water treatment company or a qualified boiler feedwater consultant to monitor your boiler’s water chemistries. It is preventative maintenance that pays for itself.

4. Install economizers: Defined as a “device that utilizes the waste heat from a boiler flue to preheat the feedwater,” economizers are not limited to feedwater and can be air-to-air or air-to-liquid. It is generally accepted in industry that boiler efficiency is increased by 1 percent for every 40 degrees Fahrenheit reduction in flue gas temperature. In addition to a faster response to load changes, using economizers greatly reduces the emissions and carbon footprint of a plant, reducing fuel and power costs. The payback is rapidly realized. In the United States, every year, over 5 to 13 quadrillion Btu are lost as waste heat, representing anywhere from 20 to 50 percent of industrial energy.

5. Install baffle assemblies: The installation of baffle assemblies in waste heat boilers down-stream of thermal oxidizers (TO) delivers a multitude of benefits across the plant. The baffle assemblies redirect flue gas into a designated flue gas path. The overriding benefit of baffle assemblies is the ability to increase steam capacity, a critical component for achieving better production metrics. It is a cost-effective retrofit solution with minimal downtime that pays immediate dividends with increases in plant production. 

6. Install steam separators: As an increasing number of ethanol plants are being operated above nameplate, a common issue facing operators is carryover, generally comprised of entrained liquids, though it can include solid or vapor contaminants. This can lead to steam control valves sticking, corrosion and erosion, formation of mineral deposits and contamination of the process steam. Dealing with the effects of carryover is potentially costly in downtime, maintenance and repair man-hours associated with on-the-fly fixes. One proven way to overcome carryover issues is through steam separators that remove liquids and improve steam quality. Many plants that have installed steam separators have virtually eliminated false low water indications and TO trips.  

All of these approaches are time-tested methods to enhance and increase production by adding more steam or assuring the steam being produced is at an optimum state.  They’ve been proven in multiple boiler applications in ethanol plants throughout North America. Victory Energy can assist in helping implement a boiler strategy that is right for what you’re trying to accomplish through productivity increases.

Author: Darrell Pedersen
Regional Account Manager, End-Market Sales, Victory Energy