The 2nd Symposium on Nitrogen Circulation
UTokyo,November 21, 2022

deNOxからreNOxへ

燃焼排ガス中のNOxを利用した
アンモニア生成触媒プロセス開拓

from deNOx to reNOx

NH3 generation by use of NO incombustion exhaust
小倉 賢/MASARU OGURA
生産技術研究所/INSTITUTE OF INDUSTRIAL SCIENCE
東 京 大 学 / T H E U N I V E R S I T Y O F TO K Y Ocontent
I. from deNOx to reNOx
II. take-home message
consumption-oriented to recycling-orientedsociety

outline~What is reNOx?
deNOx: the catalytic processes for the removal of nitrogen oxides, have beenstudied, typically emitted from automobiles.
As a “reactive nitrogen compound（反応性窒素化合物）”, NOx, ammonia,
and urea are involved in the deNOx catalytic system.

This approach to environmental issues has led us to turn in the direction ofsynthesizing ammonia from NOx in an energy-saving manner. ..reNOx
Catalytic and scientific approaches to the recycling-oriented society in thefuture, is introduced, including our preliminary, latest results as well as ourmotivation.

When you google “Reactive Nitrogen”・・・

Source: Toru Sano(佐野 亨), 「反応性窒素の無害化から資源化へゲームチェンジを目指す」
NEDO Web Magazine, Focus NEDO，Vol. 84
4our energy enjoyment society
based on oxidizing/consuming reactions
酸化・消費型社会である現代X + O2 → XO2 ΔrH < 0CO2NOx＝> Energy＝> Environmental issues
CO2 and environmental problems are produced simultaneously with energy.
=Ex5

shift to a society
based on reducing/producing reactions
還元・生産型社会へ

XO2 + R → X(or X’) + RO2＝ Energy
H2ΔrH < 0C ＝ Reductant
NH3

CO2 and NOx are used to regenerate energy (re)sources.
=>reNOx

6

from deNOx
to reNOx
production of valuable N compounds
by energy-less catalytic processrepresentative “catalysis” so far
deNOx for environmental issue
direct decomposition→N2 + O2

the most ideal and difficult

reduction＋HC→N2 + CO2 + H2O＋CO→N2 + CO2

the current technology ingasoline-engine deNOx
less selective in O2＋NH3→N2 + H2O

the current technology instationary and heavy duty deNOxurea needed from external

production of NH3 for food problem
N2 + H2 → NH3

the Haber-Bosch process
under high T and P conditions
8NOx as the source of NH3
LNG
thermal powergamechanger※reNOx＜NOx reformer＞

Reductant (H source)※deNOx（CH4, H2…）＜deNOx plant＞（”Reactant”）

NH3（combustion exhaust）

NONO

N2

Merit 1
Reducing agent, NH3, by itself
Locally-produced, locally-consumed

NO＋NH3→N2

Merit 2
No huge energy totransformation

NH3
Merit 3Elimination of thedependence on
import of NH3NO＋(H source)→NH39

our target of NTA (NOx-to-Ammonia) reNOx
combustion
exhaust

Ox
NOx

NOx
1st goal:
NTA 50% in the exhaustis achieved.
Then, deNOx is attained.
NOx= NOx =NH3SCR

NOx

NTA

Reductant(HC, CO+H2O, H2)

N2

NH3
2nd goal:
NTA more than 50% in the exhaustis achieved.
Then, residual NH3 is recovered andrecycled as the chemical source.
NOx=NH3> NOx
10

MS NTA teamDirect NTA (1 step NTA)
Storage NTA
2 step NTA

materials
investigators

theoreticalevaluators

2 step NTA

NOxNOx ad &conc.

Oxygen-rich【Gas Turbin】
Large mass

Oxygen-free

Conversion
to NH3@high T

【Dust comb】
Small and low
Flow rate

Conversion
to NH3NH3(re)use

NH3 ad &conc.

1 step NTA

112 step NTA team
2 step NTA

NOx【gas turbin】
large mass
【dust comb】
small and low
flow rate

NOx ad &conversion
conc.
to NH3oxygen @low T oxygen @mid T-rich-poor

NH3変換

NH3分離

触媒変換

高純度化

NH3資源（ガス状NH3等）

Our strategy: Placing an adsorbent capable of separating and recovering NO even under oxygen-rich conditions to recover only NO.
The concentrated NO is fed to the NTA catalyst in the subsequent step, where it reacts with a reductant to produce NH3.

12

summary of the result by the 2 step NTA

NO adsorbent

NTA catalyst
Gas flow

19take-home messagefrom the society dependent on internal combustion:oxidizing and consuming
to a society with recycling-oriented
materials/resource: reducing and producing
酸化消費型の社会から，還元生産型の社会へ
our approach ”reNOx”, producing NH3 not from N2 but
NOx, resulting in a deNOx method in a style of“local production for local consumption”
N2から生産しているNH3をNOxから生産するreNOxに挑戦=“地産地消型”のdeNOx