By Bryan Dusza

Reducing particulate matter emissions from standby generators has become an increasingly important goal for mission-critical facilities. The responsibility to
ensure operations do not harm the environment or public health as well as comply with current and emerging environmental regulations and demonstrate a commitment
to sustainable practices is vital. Ultimately, investing in clean energy sources and emission-reducing technologies can benefit both the environment and the long-term
sustainability of mission-critical facilities.

Impacts of Diesel Emissions on Climate Change and Public Health
Diesel particulate matter, or PM, is made up of black carbon, or soot, in addition to many organic compounds. Diesel exhaust also contains gaseous pollutants including volatile organic compounds (VOCs) and nitric oxides(NOx). NOx emissions from diesel engines are important because they can undergo chemical reactions in the atmosphere leading to formation of particulate matter and ozone. Diesel exhaust also contains carbon dioxide (CO2).

Calculating the precise volume of particulate matter generated
by diesel engines annually can be challenging, as it varies depending on engine type, fuel type, and operating circumstances. According to some estimates, diesel engines generate a staggering 1.3 billion tons of particulate matter globally each year.

Black carbon is a known carcinogen and causes strokes, heart attacks and chronic respiratory disease. The California Air Resources Board (CARB) estimates that diesel PM
contributes to approximately 1,400 premature deaths from cardiovascular disease a year in California alone. And a 2022 study even links low-level exposure to particulate matter to behavior issues and lower IQ scores in 2- to 4-year-olds.

Having clean air to breathe is a key social determinate of health and should be treated just as importantly as access to education, healthy foods, employment and
shelter.

Emissions Standards Impacting Mission- Critical Facilities
In recent years, emissions regulations have increased across North America, with California leading the charge. Mission-critical facilities often house a vast number
of generator units in a relatively condensed area.

“When you have facilities with 30 to 50 units, multiplied across several facilities in a geographic area, the concern for regulation ramps up, especially when there are existing nighborhoods or communities in that area,” said Roberto Montero of Rypos, a manufacturer of diesel exhaust aftertreatment filters.

As sustainability measures and ESG goals become increasingly critical, and concern over community health intensifies, reducing diesel engine emissions is a visible and
measurable solution.

Diesel Particulate Filters and Their Role in Mission-Critical Facilities
Diesel Particulate Filters (DPFs) are xhaust after-treatment devices that can be fitted to a wide variety of engines, including the back-up generators essential to powering mission-critical facilities should a power failure occur. DPFs work to reduce exhaust emissions by trapping exhaust particulates in the filter, thus removing many harmful emissions from ever entering the air.

With continued use, DPFs need to be cleaned to remove the buildup of captured particulate matter. This cleaning occurs when the DPF system enters regeneration mode. Regeneration is initiated by the system/operator when the exhaust back pressure reaches an engine limit due to captured particulate matter.

Active vs. Passive Regeneration in DPFs — Understanding the Difference
There are two types of diesel particulate filters on the market today: active and passive. Passive diesel particulate filters trap soot and rely on the heat of combustion to regenerate and burn off soot caught in the filter. In cases of intermittent demand, the most likely scenario being standby generators used in data centers
or mission-critical infrastructure, the exhaust may decrease by the time it gets to the filter, preventing the DPF from performing the job efficiently. The case of poor
performance during a power outage as a result of clogged passive DPFs is a common problem.

Active diesel particulate filters actively regenerate, or “selfclean,” during normal engine operation, which ensures maximum flexibility in how facility operators choose to run their generators. Operating independently of exhaust temperatures means a mission-critical facility does not have to install costly generator load banks or run the generator sets for extended time periods to enable filter cleaning. They also reduce diesel fuel consumption on units where filtration is needed.

Benefits of Utilizing CARB-Verified Active DPFs in Power Generation Standby Systems