As energy
consumption increases, air pollution caused by gases emitted during the
combustion of fossil fuels is becoming a serious social issue. Representative
pollutants are nitrogen oxides (NOx), sulfur oxides (SOx), carbon monoxide
(CO), and unburned hydrocarbons (HC). Nitrogen oxides are known to cause damage
to the human body as a cause of photochemical smog, or to cause corrosion of
buildings and acidification of soil and plants as a cause of acid rain.
In this issue, we’d
like to confirm the direction and current position of nitrogen oxide reduction
technology through the overall flow of the technological content and patent
trend of nitrogen oxide pre/post treatment technology, as well as cases and
solutions by source of nitrogen oxide pollution.
1. Nitrogen oxide
and damage
There exist stable N2O,
NO, N2O3, NO2, N2O5 and unstable NO3 in nitrogen oxides, and those that exist
enough to cause problems in the air environment are NO and NO2, and these
substances are usually called nitrogen oxides (NOx) in terms of air pollution.
Representative examples of damage include acidification of soil, plants and
crops caused by acid rain, photochemical smog, and diseases caused by fine dust
inhaled through respiratory tract, and the damage is increasing day by day.
2. Major Nitrogen
Oxide Reduction Pre/Post Treatment Technology
Among the pre- and post-treatment
technologies for reducing nitrogen oxides, two of the most representative
technologies were selected, so we introduce here briefly.
① Low NOx Burner
(LNB)
A method that reduces the combustion
intensity by controlling the mixed characteristics of fuel and air, and controls
the flame temperature and oxygen concentration in the initial combustion region
to suppress the generation of thermal NOx and fuel NOx.
② Exhaust Gas Recirculation
(EGR)
A technology that lowers the combustion chamber
temperature by recirculating a portion of the exhaust gas burned in the engine
back to the engine, thereby suppressing NOx emission.
◎ Post-treatment technology to reduce nitrogen oxides
A. Selective
Catalytic Reduction (SCR)
As a technology for converting harmless N2
and H2O using ammonia as a reducer, is the most representative technology for
reducing NOx among the technologies developed so far because of its high denitrification
efficiency and ease of operation and maintenance.
B. Selective
non-catalytic reduction (SNCR)
It’s a way that a reducer containing nitrogen,
such as ammonia and urea, is sprayed at a temperature of about 870 to 1150°C,
and the sprayed reducer is ionized and reacts with nitrogen oxides in an oxygen
environment to finally decompose into N2, CO2 and H2O.
3. Patent trend of
nitrogen oxide reducing technology
<▼Detailed classification of nitrogen oxide reducing technology>
◎ Application trends by year / country
▲Trends
in the number of applications by year / country
▲Trends in the
number of application counties by year based on main category A tendency to
repeat the trend of increase → decrease → increase is observed, and the results of applications in Korea and China show a continuous upward trend (↗). In
addition, it is observed that post-processing technology is concentrated in an
absolute ratio compared to pre-processing technology, and the market is also
expected to be ubiquitous.
◎ Application Trends by All Applicants
▲ All Top
Applicants
▲Top Applicant's
Nitrogen Oxide Reduction Pre/Post processing Technology Status
The applicant with
the largest number of applications is TOYOTA MOTOR, followed by Hyundai Motor
Co., Ltd., HSD Engine Co., Ltd., and GM GLOBALTECHNOLOGY OPERATIONS in that
order. It tends to focus on post-processing technology.
◎ NOx reduction pre-processing technology application
trend
▲Application Trends
by Nitrogen Oxide Reduction Pre-processing Technology
▲Top
applicant for nitrogen oxide reduction pre-processing technology
Among the nitrogen
oxide reduction technologies, the pre-processing technology is confirmed in the
order of exhaust gas recirculation (A4) > low NOx burner (A6) > water (or
steam) addition (A10), etc.
Top applicants
related to pre-processing technology among nitrogen oxide reduction
technologies were confirmed in the order of UNIV SHANGHAI JIAOTONG (CN), δΈζ΅·εδΉι¦η§ζθ‘δ»½ζιε
¬εΈ (Shanghai Huazhibang
Technology) (CN), Daewoo Shipbuilding & Marine
Engineering (KR), Korea Institute of Industrial Technology (KR).
In addition, out of
a total of 389 nitrogen oxide pre-processing technologies are concentrated in
A4 (about 39%) and A6 (about 38%) subcategories, and it is judged that the
result is due to the reduction efficiency as a characteristic of this technical
field. .
◎ NOx reduction post-processing technology application
trend
▲Application Trends
by Nitrogen Oxide Reduction Post Treatment Technology
▲Top
applicant for nitrogen oxide reduction post-processing technology
Among the nitrogen
oxide reduction technologies, post-processing technologies are confirmed in the
order of selective catalytic reduction (B1) > using other catalysts (B2)
> selective non-catalytic reduction (B3) > wet processing (B4), etc.
Top applicants are
listed in the order of TOYOTA MOTOR, HSD Engine and Hyundai Motor.
Among a total of
2,882 post-processing technologies, patent filing was focused on B1 (about 63%)
sub-class, and it is inferred that demand and applications are active because its
high efficiency is good enough for international environmental regulations.
The nitrogen oxide problem is directly
related to our industrial activities, and it is a pollutant that has a very
high cost in strengthening regulations and applying abatement technology to
prevent it. Therefore, basic data such as recent domestic and overseas
development of NOx reduction technology and cost analysis for each application
are closely required. In addition, policy preparation is also required to be
carried out concurrently through changes in social beliefs and related
legislation.
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※ References
- Automotive fine
dust and nitrogen oxide reduction technology and market trends (2016, KEITI)
- Catalytic
chemistry technology for reducing nitrogen oxides, a mobile pollutant (2020,
New Material Economy)
- Status of
denitrification technology for power generation facilities (2009,
instrumentation technology)
- Trend of nitrogen
oxide reduction technology in cement industry (2020, resource recycling)
- Ultra-low NOx
burner (2016, KISTI Market Report)
- Technology trend
of Hybrid SNCR/SCR (2006, Connectic Report)
- 2020 vision and
strategy for high-performance environmental equipment (2007, KIET)
πReport by JunKyu PARK, powe0519@wips.co.kr
IP Strategy 3 Team l Manager
JunKyu PARK specializes in patent trend analysis and patent big data processing using AI, focusing on major industries such as displays, batteries and polymers.
