Truck & Off-Highway Engineering - April 2023 - 40

SAE/RYAN GEHM
Q&
A
Kubota Engine high on HVO, H2
As part of its path to carbon neutrality, Kubota Engine engineers
have developed a new 3.8-liter hydrogen engine that
was introduced at CONEXPO 2023 in Las Vegas. The 4-cylinder
spark-ignited engine employs port fuel-injection and provides
85 kW (114 hp), which is the output required for a 45kVA
generator, the company notes.
Kotaro Shiozaki, PR manager, Industrial Engine at Kubota
Corp., said that hybrid powertrains also are an effective solution
for reducing CO2
from industrial engines, and he's confident
they will be more than just an interim solution. Kubota
displayed three hybrid solutions: a P0 micro-hybrid that will be
available later this year, a P1 hybrid that
provides brief periods of motor assist
when high output is required and a P2
hybrid engine scheduled for production in
2025 that offers electric-motor drive.
All Kubota diesel engines in Europe
are approved to use paraffin-based fuels
- gas to liquid (GTL) and hydrotreated
vegetable oil (HVO) fuels - that comply
with European standard EN15940. The
company announced that HVO now is
approved for use in its diesel engines in
the U.S., enabling a CO2
and hybrids
allowed then we can fit whatever we have today. I believe aftertreatment
systems will be involved, but maybe less than with
diesel because it doesn't emit CO2
and almost no particles (PM).
Are you testing your hydrogen engine in the real world?
Most of the development is happening within Kubota in Japan.
Another part of the development needs to be coworking with
the machine manufacturers. When it comes to matching between
the applications, it's local. So, if the customer is located
in the U.S., we have a U.S. resource to help the customer to
match up the engine to the application.
What applications are you targeting?
This past September we made an announcement
with Denyo, a leading genset
company in Japan. We believe the genset
[an engine-generator combination] can
be a good application to start with hydrogen
engines. The genset does not move
around; it could sit on-site so we can have
a big fuel tank nearby. And then maybe
next is tractors or excavators.
emissions reduction
of up to 90% with no engine modifications,
Shiozaki said. He spoke with
TOHE in Las Vegas about these technologies
and discussed Kubota's plans to
bring them to market.
What is your outlook for H2
engines?
Kotaro Shiozaki, PR manager,
Industrial Engine at Kubota Corp.
Tell me about Kubota's hydrogen engine.
This is really based on what we have today
from the spark-ignited engines.
Achievability of the [hydrogen] engine is
not so difficult, I would say. The most concern
is twofold: one is the procurement of
a hydrogen infrastructure and the second
is emissions regulations. The regulation is
based on the type of fuel - today we
don't have regulations for the hydrogen,
that's why we cannot sell this product in
the market yet. So once those two aspects
are solved, then we believe we'll be ready.
[While TOHE was talking with Shiozaki, California Air
Resources Board (CARB) reps came to check out the H2
" Whatever we are
improving with the
diesel engines can
be transferred to
the hybrid or the
hydrogen engines. "
engine.]
You can actually witness that they are trying to understand
what we can do. And then we are [encouraging] them
to set up the regulations. We need to have the regulations.
Though H2
is cleaner, there still are emissions.
NOx. NOx can be handled with the SCR [selective catalytic reduction],
which is already available. We have a variety of options.
Again, back to the applications, if you have X amount of NOx
40 April 2023
What are Kubota's plans for future diesel development?
We are still working on it - on new combustion and injection
technologies. As you see, the base technology of hybrid or
hydrogen is based on diesel [and SI] technologies. Whatever
we are improving with the diesel engines can be transferred
to the hybrid or the hydrogen engines, so there's no reason
for us to stop doing the research on diesel.
Ryan Gehm
TRUCK & OFF-HIGHWAY ENGINEERING
It's up to the applications, but we believe
this will be a good alternative solution to
replace diesels. It will probably take five to
eight or maybe 10 years. Again, back to
how soon the infrastructure will be ready.
Are hybrids a good interim solution?
Yes, interim and also permanent. These
engines are covering the use of HVO,
which is already carbon-neutral. So, if customers
or the owner of the machine are
able to procure HVOs, then they are done
with carbon-neutral. In that case, I'd say
it's a permanent solution. In some countries
like Scandinavian, HVO is already
popular. For commercial use, they can
procure it. In the U.S., I think it's starting
up. You can't buy it at a gas station around
the corner, but if you're in the commercial
business, then you can have [an avenue] to procure it.
Truck & Off-Highway Engineering - April 2023

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