Hydrogen Economy
What is Hydrogen?
Hydrogen is a natural
chemical element. In nature, it exists as a molecule. That means that it is
made up of two hydrogen atoms, which is why its chemical formula is H₂. It is perhaps best known as
one of the elements that makes up water. The other is oxygen. That is why
water’s chemical formula is H2O. In fact, it is
naturally linked to other elements. That is, it does not exist on its own.
Hydrogen is the simplest and
most abundant element on earth—it consists of only one proton and one electron.
Hydrogen can store and deliver usable energy, but it doesn't typically exist by
itself in nature and must be produced from compounds that contain it.
Hydrogen gas has remarkable
characteristics including colourless, tasteless and invisible that make it
hotly pursued. It can also be transformed into a renewable, non-polluting and
zero emission energy resource. It’s considered the cornerstone of the new
energy economy. The pursuit of hydrogen energy began way back in 1776
by the British scientist Henry Cavendish.
He first identified it as a
distinct element after he developed hydrogen gas by subjecting zinc metal to
hydrochloric acid. Henry Cavendish made another remarkable discovery during a
demonstration to the Royal Society of London when he introduced a spark to
hydrogen gas, producing water in the process. This historic development led to
his conclusion that water (H2O) is composed of hydrogen and oxygen. Since then,
hydrogen technology has grown in leaps and bounds, and today, it is used as an
energy source to power cars, electric systems, and production of pure water.
What is Hydrogen energy?
Hydrogen energy involves
the use of hydrogen and/or hydrogen-containing compounds to generate energy to
be supplied to all practical uses needed with high energy efficiency,
overwhelming environmental and social benefits, as well as economic
competitiveness.
Energy efficiency and
sustainability are two important factors driving the transition from the
present fossil fuel–based economy to a circular economy, that is, a renewable
circular sustainable fuel utilization cycle that will characterize the highly
efficient engineering and the energy technological choices of the 21st century.
What is Hydrogen Economy?
The hydrogen economy is an
envisioned future where hydrogen is used as fuel for vehicles, energy storage
and long-distance transport of energy.
Hydrogen is a promising energy
carrier and has the potential to address various energy sector
challenges and technically from the application point of view, substituting
conventional fuels. Its use can reduce CO2 related emissions
significantly and decarbonise the entire value chain, enabling
reduced emissions and climate change threats.
Hydrogen can also bridge
the gap between supply and demand, in both a centralized or decentralized
manner, thereby enhancing the overall energy system flexibility. Hydrogen
can be used to meet both seasonal and daily supply-demand mismatch in the
case of renewables. In rural India, where there is no access to the grid,
the use of hydrogen can provide energy services.
In 1970, the
term 'hydrogen economy' was coined by John Bockris. He mentioned that
a hydrogen economy can replace the current hydrocarbon-based economy,
leading to a cleaner environment.
The hydrogen economy is
an envisioned future where hydrogen is used as fuel for vehicles, energy
storage and long-distance transport of energy. The different pathways
to use hydrogen economy includes hydrogen production, storage, transport and
utilization.
At present, the current
global demand for hydrogen is 70 million metric tons, most of which
is being produced from fossil fuels-- 76% from natural gas and 23% from
coal and remaining from the electrolysis of water-- consumes 6% of the
global natural gas and 2% of the global coal. This results in CO2
emissions of around 830Mt/year out of which only 130Mt/year is being
captured and used in the fertilizer industry.
Much of the hydrogen produced
is used for oil refining (33%), ammonia (27%), methanol production (11%),
steel production via DRI (3%) and others.
Hydrogen production from
natural gas without CCUS is the most economic method at a cost of
USD1/kgH2 in the Middle East, while the electrolysis of water is the most
expensive one. However, if the renewables meet the heat/ electricity
requirements, hydrogen is produced using electrolysis or
thermochemical method.
In India, hydrogen is
being commercially produced in the fertilizer industry, petroleum refining
and chemical industries and also as a by-product in chlorine alkali
industries. A limited amount of hydrogen is also produced by electrolysis.
Hydrogen as an alternative to
fuel
Hydrogen is a zero-carbon
fuel and is considered an alternative to fuel and a key source of
clean energy. It can be produced from renewable sources of
energy such as solar and wind. At present, there are a number of ways
to produce hydrogen, but the most common method is natural gas reforming and
electrolysis.
Production
Pathways
Today, hydrogen fuel can be produced
through several methods. The most common methods today are natural gas
reforming (a thermal process), and electrolysis. Other methods include
solar-driven and biological processes.
1.
THERMAL PROCESSES
Thermal
processes for hydrogen production typically involve steam reforming, a
high-temperature process in which steam reacts with a hydrocarbon fuel to
produce hydrogen. Many hydrocarbon fuels can be reformed to produce hydrogen,
including natural gas, diesel, renewable liquid fuels, gasified coal, or
gasified biomass. Today, about 95% of all hydrogen is produced from steam
reforming of natural gas.
2.
ELECTROLYTIC PROCESSES
Water
can be separated into oxygen and hydrogen through a process called
electrolysis. Electrolytic processes take place in an electrolyzer, which
functions much like a fuel cell in reverse—instead of using the
energy of a hydrogen molecule, like a fuel cell does, an electrolyzer creates
hydrogen from water molecules.
3.
SOLAR-DRIVEN PROCESSES
Solar-driven
processes use light as the agent for hydrogen production. There are a few
solar-driven processes, including photobiological, Photoelectrochemical, and
solar thermochemical. Photobiological processes use the natural photosynthetic
activity of bacteria and green algae to produce hydrogen. Photoelectrochemical
processes use specialized semiconductors to separate water into hydrogen and
oxygen. Solar thermochemical hydrogen production uses concentrated solar power
to drive water splitting reactions often along with other species such as metal
oxides.
4.
BIOLOGICAL PROCESSES
Biological
processes use microbes such as bacteria and microalgae and can produce hydrogen
through biological reactions. In microbial biomass conversion, the microbes
break down organic matter like biomass or wastewater to produce hydrogen, while
in photobiological processes the microbes use sunlight as the energy source.
Energy Carrier
Hydrogen is an energy carrier,
not an energy source and can deliver or store a tremendous amount of energy.
Hydrogen can be used in fuel cells to generate electricity, or power and heat.
Today, hydrogen is most commonly used in petroleum refining and fertilizer
production, while transportation and utilities are emerging markets.
Three main types of Hydrogen
·
Grey Hydrogen
o
The most common form of hydrogen, it's created
from fossil fuels and the process releases carbon dioxide which is not
captured.
o
The process used to create hydrogen from
natural gas is called steam methane reforming (SMR), where
high-temperature steam (700°C–1,000°C) is used to produce hydrogen from a
methane source, such as natural gas. In steam methane reforming, methane reacts
with steam under 3–25 bar pressure (1 bar = 14.5 pounds per square inch) in the
presence of a catalyst to produce hydrogen, carbon monoxide, and a relatively
small amount of carbon dioxide. Steam reforming is endothermic — that is, heat
must be supplied to the process for the reaction to proceed.
o
There is also a gasification process which uses
coal as a feedstock, creating brown hydrogen, which also releases carbon
dioxide and can be put in the same category as grey.
·
Blue Hydrogen
o
Blue hydrogen uses the same process as grey,
except this time the carbon is captured and stored. This makes it much more
environmentally friendly, but comes with added technical challenges and a big
increase in cost.
o
Carbon capture and storage (CCS) has
been around a while, with the technology being used by heavy industry and power
generation companies burning fossil fuels. The technology can capture up to 90%
of the CO2 produced, so it isn't perfect but clearly a massive
improvement. Most of the time, this CO2 is then transported by a pipeline
and stored deep underground, often in salt caverns or depleted oil and gas
reservoirs.
o
Countries which do not have access to such
underground options will find it very challenging to establish a blue hydrogen
industry, and it may be more cost-effective to develop green hydrogen as their
primary solution.
·
Green Hydrogen
o
The utopian vision of the future is a net-zero
world where all our electricity and fuel is produced by emission-free sources.
In the context of this piece, that means a fully-scaled green hydrogen industry
on a global scale.
o
Green hydrogen is made by using a process
called electrolysis to split water into hydrogen and oxygen. If that process is
powered by a renewable energy source, such as wind or solar power, then the
hydrogen is referred to as being green.
o
It has the potential to be a major part in
solving the intermittent generating capacity of most renewable energy sources.
Excess electricity can be used to create hydrogen, which is then stored as a
gas or liquid until needed.
Hydrogen Economy in India
India's goal of attaining
175 GW of renewable energy capacity by 2022 and to decarbonise by
2050 got an impetus in the Union Budget 2021-22. The Budget allocated
Rs. 1,500 crores for renewable-energy development and Hydrogen Energy
Mission.
In October 2020, Delhi
became the first Indian city to operate Hydrogen-enriched CNG (H-CNG)
buses in a six-month pilot project.
Companies such as Indian
Oil Corporation and NTPC Ltd are working towards this technology. IOC
has patented the technology for producing H-CNG-- 18% hydrogen in
CNG, directly from natural gas without restoring to conventional blending. It
is also planning to set up a dedicated unit to produce hydrogen to run
buses at its Research and Development Centre in Faridabad.
On the other
hand, state-run NTPC Ltd is planning to start a premium hydrogen fuel bus
service on the Delhi-Jaipur route (the first intercity service on the
aforementioned technology). It is also considering to set up a green
hydrogen production facility in Andhra Pradesh.
The Government of India
is planning to focus on five key areas: (a) Research and
Development (b) Demand creation (c) how to use it in the
industry (d) how to create an eco-system (e) how to bring
it on board along with international partnerships.
Need for Hydrogen
1. It is well-known that India's electricity is heavily coal-dependent. Thus, the introduction of Hydrogen will replace fossil fuels and will address pollution levels and oil-price hike.
2. Hydrogen is the most abundant element in the Universe. It is lighter, energy-dense and is two to three times more efficient than petrol.
3. Hydrogen will benefit transportation which
contributes 1/3 of India's greenhouse-gas emissions, iron and steel and
chemical sectors.
Scaling up around the world
In February, the Hydrogen
Council released a report which outlines the scale of growth. Over
200 projects have been announced by over 30 countries, with investment
totaling over $300 billion.
The main players at the moment
are Australia and Europe, with each adopting a slightly different approach.
Australia has firmly
identified hydrogen as a priority, with the goal of producing
clean/green hydrogen for under $2 per kilogram.
The European Union has a clear
strategy, has formed a clean hydrogen alliance and is developing
"hydrogen valleys" which use the offshore wind capacity of the North
Sea to power electrolysers. The longer-term plan is to use the existing natural
gas pipeline network to enable the transportation of hydrogen across the
continent.
Saudi Arabia recently announced its
intention to enter the market, bringing to bear their enormous solar power
potential and expertise in the development of major energy projects.
Japan have developed a
project which could have wide-ranging potential: turning sewage into
hydrogen via a carbon-neutral process. This could be adopted in every country
with sewage treatment facilities, opening up the possibility of producing
hydrogen locally and reducing the need to transport it.
Sources:
· What Is Hydrogen (H₂)? - Green Economy Journal
· Hydrogen: A Clean, Flexible Energy Carrier | Department of Energy
· Hydrogen Energy: Sustainable and Perennial - ScienceDirect
· Hydrogen Fuel Basics | Department of Energy
· 3 Main Types of Hydrogen - Blue, Grey and Green - Brunel
·
What
is Hydrogen Economy?| Hydrogen Economy in India (jagranjosh.com)
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