The Anonymous Widower

The Mathematics Of Blending Twenty Percent Of Hydrogen Into The UK Gas Grid

HyDeploy is a project, that is investigating blending hydrogen into the UK’s natural gas supply to reduce the amount of carbon dioxide produced by the burning of natural gas in power stations, industrial processes and in our homes and other buildings.

To find out more about the project, visit the HyDeploy web site.

This is a paragraph from this page on the HyDeploy web site, which describes the current progress of the project.

HyDeploy is progressing well. The HSE gave the go ahead for a live demonstration, at Keele University, of blended hydrogen and natural gas which began in Autumn 2019 and completed in Spring 2021. The HSE are satisfied that the blend of gas will be as safe as the gas we all currently use. The hydrogen content will be up to 20% and has so far reached 15%.

Note that HSE is the Health and Safety Executive, who are closely involved.

HyDeploy has now moved on to Phase 2 in the North East.

For our North East demonstration, we have contacted everyone who will be involved in that demonstration – more than 650 homes – and arranged for our engineers to carry out Gas Safe checks on their gas appliances and gather information on the range of appliances in the demonstration area. The Gas Safe checks were free of charge. Almost 90% of those homes have engaged with us.

What would be the effects of 20 % of hydrogen blended into natural gas?

Will current boilers, cookers and other gas-powered devices work on a blend of hydrogen and natural gas?

This is one for the scientists and it is one of the objectives of the HyDeploy trial to understand how every use of gas performs if instead of natural gas, the fuel is a mixture of eighty percent natural gas and twenty percent hydrogen.

I will assume that these problems are solvable.

I am not just hoping, but I can remember in the early 1970s, when our elderly gas cooker was successfully converted from town gas, which was typically a mixture of hydrogen (50%), methane (35%),carbon monoxide (10 %) and ethylene (5%), to natural gas, as North Sea gas started to flow.

This document from the UK government is entitled Fuels: Natural Gas, which contains a section entitled Material Properties Relevant To Use, where this is said.

Natural gas is a combustible gas that is a mixture of simple hydrocarbon compounds. It contains primarily methane, along with small amounts of ethane, butane, pentane, and propane. Natural gas does not contain carbon monoxide. The by-products of burning natural gas are primarily carbon dioxide and water vapour. Natural gas is colourless, tasteless and odourless. Because it is odourless, an odorant (80% tertiarybutyl mercaptan, 20% dimethyl sulphide) is added to the gas, to give the gas a distinctive smell. Other beneficial properties of natural gas are a high ignition temperature and a
narrow flammability range, meaning natural gas will ignite at temperatures above 593°degrees and burn at a mix of 4 – 15% volume in air (St. Lawrence Gas, 2015)

As ethane (C2H6), butane (C4H10), pentane (C5H12) and propane (C3H8) are all similar simple hydrocarbons to methane, which burn to produce carbon dioxide and water, I will assume in this analysis, that natural gas is all methane (CH4).

It is reasonable to assume, that currently we use a fuel which is equivalent to 100 % methane and that in the future we could use 80 % methane and 20 % hydrogen. Also in the past, we used to use a fuel, that was 50 % hydrogen and 35 % methane. The carbon monoxide is a poison, so I’ll ignore it, but ethylene (C2H4) is another of those simple hydrocarbons, which burn to release just carbon dioxide and water.

So if we were able to go from town to natural gas fifty years ago, by just adjusting gas equipment, surely we can go partly the other way in the Twenty-First Century.

I can certainly see the UK gas supply containing twenty percent hydrogen, but wouldn’t be surprised to see a higher level of hydrogen in the future.

How Much Hydrogen Needs To Be Added?

This page on worldodometer says this about UK gas consumption.

The United Kingdom consumes 2,795,569 million cubic feet (MMcf) of natural gas per year as of the year 2017.

I will now calculate the weight of hydrogen needed to be added.

• 2,795,569 million cubic feet converts to 79161.69851 million cubic metres.
• I will round that to 79161.7 million cubic metres.
• Twenty percent is 15832.34 million cubic metres.
• A cubic metre of hydrogen weighs 0.082 Kg, which gives that in a year 1,298.25188 million kilograms will need to be added to the UK gas supply.

This is 1,298,251.88 tonnes per year, 3,556.85 tonnes per day or 148.2 tonnes per hour.

How Much Electricity Is Needed To Create This Amount Of Hydrogen?

In Can The UK Have A Capacity To Create Five GW Of Green Hydrogen?, I said the following.

Ryze Hydrogen are building the Herne Bay electrolyser.

• It will consume 23 MW of solar and wind power.
• It will produce ten tonnes of hydrogen per day.

The electrolyser will consume 552 MWh to produce ten tonnes of hydrogen, so creating one tonne of hydrogen needs 55.2 MWh of electricity.

To create 148.2 tonnes per hour of hydrogen would need 8,180.64 MW of electricity or just under 8.2 GW.

How Much Carbon Dioxide Would Be Saved?

This page on the Engineering Toolbox is entitled Combustion Of Fuels – Carbon Dioxide Emission and it gives a list of how much carbon dioxide is emitted, when a fuel is burned.

For each Kg of these fuels, the following Kg of carbon dioxide will be released on combustion.

• Methane – 2.75
• Gasoline – 3.30
• Kerosene – 3.00
• Diesel – 3.15
• Bituminous coal – 2.38
• Lignite 1.10
• Wood – 1.83

Engineering Toolbox seems a very useful web site.

I will now calculate how much carbon dioxide would be saved.

• In 2017, UK methane consumption was 79161.7 million cubic metres.
• One cubic metre of methane weighs 0.554 Kg.
• The total weight of methane used is 43,855,581.8 tonnes.
• Multiplying by 2.75 shows that 120,602,849.95 tonnes of carbon dioxide will be produced.

As twenty percent will be replaced by hydrogen, carbon dioxide emission savings will be 24,120,569.99 tonnes.

That seems a good saving, from a small country like the UK.

The UK would also reduce natural gas consumption by twenty percent or 15832.34 million cubic metres per year.

How many other countries with good renewable and zero-carbon electricity resources like Australia, Chile, Denmark, France, Iceland, Ireland, Jordan, Morocco, Norway, Sweden and the United States will take this route, as it seems a good way to save large amounts of carbon?

There is also the collateral benefit, that countries with a good supply of hydrogen can use hydrogen to decarbonise the heavy transport sectors of rail, road and sea freight transport.

The big winners would appear to be those companies like ITM Power, who manufacture electrolysers and those companies like Fortescue Future Industries, who are prospecting, developing and promoting the hydrogen resources of the planet.

The losers will be countries, who are reliant on importing large amounts of gas and other fossil fuels, who don’t have access to large amounts of renewable energy like geothermal, hydro, nuclear, solar and wind.

Germany’s energy policy of no nuclear, more coal and Russian gas seems to have been a mistake.

But I’m sure, if Olaf Sholz talked nicely to Boris, there is a deal to be made.

• German utilities have already arranged to fund BP’s move into wind farms in Morecambe Bay and the North Sea.
• Norfolk’s gas terminal at Bacton is less than three hundred miles from Germany’s new hydrogen terminal at Wilhelmshaven.

The biggest loser could be Vlad the Poisoner.

February 6, 2022 Posted by AnonW | Energy, Hydrogen | Carbon Dioxide, Fortescue Future Industries, Germany, Health and Safety, HyDeploy, iTM Power, Keele University, Natural Gas | 6 Comments