Select the Right NOx Control Technology

Most major industrialized urban areas in the U.S. are unable to meet the National Ambient Air Quality Standards (NAAQS) for ozone. Atmospheric studies have shown that ozone formation is the result of a complex set of chemical reactions involving volatile organic compounds (VOCs) and nitrogen oxides (NOx). Those studies indicate that many urban areas with VOC/NOx ratios greater tan 15:1 can reduce ambient ozone levels only by reducing NOx emissions. Many states, therefore, are implementing NOx control regulations for combustion devices in order to achieve compliance with the NAAQS ozone standard.

This article discusses the characterization of NOx emissions from industrial combustion devices. It then provides guidance on how to evaluate the applicable NOx control technologies and select an appropriate control method.

Characterizing Emissions

Most industrial combustion devices have not been tested to establish their baseline NOx emission levels. Rather, the NOx emissions from these units have been simply estimated using various factors. In light of recent regulations, however, it is mandatory that the NOx emissions from affected units now be known with certainty. This will establish each unit’s present compliance status and allow definition of fee applicable control technologies for those units that will require modification to achieve compliance.

It is, therefore, important to test each combustion device to Advancedmd verify its NOx emissions characteristics. The testing process should be streamlined to provide timely and necessary information for making decisions regarding the applicability of NOx control technologies.

The basic approach is to select one device from a class of units (that is, of same design and size) for characterization testing (NOx, CO2, and 02). Testing is conducted at three load points that represent the normal operating range of the unit, with excess oxygen variation testing conducted at each load point. Figure 1 illustrates the typical characterization test results. The remaining units in the class are tested at only one load point, at or near full load.

The operational data obtained during testing, in conjunction with the NOx and CO data, are used to define the compliance status of each unit, as well as the applicable NOx control technologies for those devices that must be modified. In most instances, this approach will allow multiple units to be tested in one day and provide the necessary operational data the engineer needs to properly evaluate the potential NOx control technologies.

Fundamental Concepts

Reasonably available control technology (RACT) standards for NOx emissions are defined in terms of an emission limit, such as 0.2 lb NOx/MMBtu, rather than mandating Specific NOx control technologies. Depending on the fuel fired and the design of the combustion device, a myriad of control technologies may be viable options. Before selecting RACT for a particular combustion device, it is necessary to understand how NOx emissions are formed so that the appropriate control strategy may be formulated.

Technology is advancing at lightning speed. Faster all the time, it is spreading into all areas of our lives. Equipment that once was obsolete two years ago is now obsolete within 6 months. Technological tools are getting smaller and more affordable to the entire world. Businesses and governments are trying to find their economic equilibrium as consumers purchase goods laterally, from one another through the Internet, often avoiding traditional consumer shopping or payment of sales tax.

Humanity is reeling from the physical effects of technology as well. Normal human development does not happen at lightning speed; it is a timed and sequenced process that requires human interaction, behavioral learning, and real experiences, if we are to learn the full spectrum of emotion and mature into healthy and happy adults. In times past, the way we lived our lives incorporated human interaction. Technology has now changed the way we live. Pushed too rapidly, human development becomes distorted or retarded, and emotional maturity goes awry.

While we continue to crave new and faster technology, as physical beings, we also feel the physical effects of getting what we want. We are becoming isolated and narrow in focus, perpetuating a narrow, superficial, and isolated existence. Human beings were not meant to live in this way. The human spirit needs to be nourished and replenished with work, play, friendship and love. At the core of us, we are emotionally and physically interactive beings. When we lose our ability and the opportunity for emotional connectedness, we are in danger of becoming as inanimate as the technology we so greatly desire.

Our electronic media culture bombards the current world with mass reproduction and reproducibility that can fool the human eye. Reality can become distorted; what’s real and what’s not real? The word, simulacrum means an unreal or superficial likeness, a copy without the original. Photographs, TV, video games, advertising, special effects, and computers are part of our electronic media, offering images so realistically created or altered, they can appear real, even when they are not. This inability to differentiate the real from the not real causes us to question our reality and we begin to mistrust our own perceptions. We begin to believe that nothing is real. This leads to feelings of apathy, hopelessness, and, ultimately, anarchy. If nothing is real, then nothing really matters. We become as robotic as our technological inventions, and just as cold and unfeeling. This is death to a human spirit that requires the warmth of human connection, touch and trust as its foundation. And, the human spirit will not go quietly into the night; it will not vanish without a fight. It will find some other way to express itself, too often in the sensual world of substance abuse and addiction.

A basic knowledge of human development is needed to understand the fundamental nature of the gap that has been created by our technological advancements. Our experiences from birth to age five set in place the neurological foundations upon which future learning depends: self-awareness, self-regulation, communication skills, personal relationships and the ability to learn from cause and effect. When one of these core developmental processes is not successfully navigated, it alters the ability to learn, evolve and mature. As human beings, we respond to and grow from being held, talked to, read to, listening to music, and played with, and pleasurable physical experiences with others. Without these foundations we regress, into human beings with no self-awareness, no self-control, unable to communicate our ideas, needs or desires to others, difficulty making or keeping relationships. And, not aware of what is wrong, we are unable to learn from our mistakes.