Hydrogen is often in the news when it comes to sustainability and energy transition. In our roadmap to climate-neutral production, hydrogen plays a key role. Below, we take a closer look at what exactly hydrogen is and our colleague Jeroen Tap explains why using hydrogen is so important in the transition.
What is hydrogen?
To understand why hydrogen plays such an important role in our transition to carbon-neutral production, Jeroen explains what it is. "Hydrogen, is a colourless, odourless and tasteless gas. A hydrogen atom consists of a nucleus of 1 proton around which 1 electron rotates. Two hydrogen atoms together form the hydrogen molecule. It is the smallest molecule in existence, but also the most abundant element in the entire universe.
Hydrogen has been a common term in recent years, but its use is certainly nothing new. More than a century ago, for example, it was already used to run streetlights. It can also be used as a fuel for cars and trucks, for example, or as a fuel in a chemical process.
Hydrogen does not occur in nature like natural gas or petroleum, for example; it has to be produced. Making hydrogen can be done in different ways and is often referred to as grey, blue, green and purple or pink hydrogen.
Almost all hydrogen made in the Netherlands is grey hydrogen. The colour grey refers to the fossil fuel used to produce hydrogen, which is mainly natural gas. This does result in CO2 emissions.
When producing blue hydrogen, the process is almost the same as grey hydrogen. The difference lies in the fact that the CO2 is captured and it is then stored, reducing CO2 emissions. This method of producing hydrogen is not (yet) used in the Netherlands.
The process to produce green hydrogen is done with water electrolysis. You conduct a 'stream' through water and then the molecules split into hydrogen and oxygen. The electricity to make green hydrogen must be sustainable, green electricity, e.g. from wind or sun.
Purple or pink hydrogen
Purple, or also pink, hydrogen is a variant of green hydrogen, but instead of electricity from wind or sun, it uses nuclear power, e.g. from Borssele. If you produce hydrogen via nuclear electricity, this can be done without CO2 emissions. However, it creates nuclear waste, which has to be stored safely.
The deployment of hydrogen at Dow Terneuzen
To understand how we will deploy hydrogen in the sustainability and energy transition of the site, it is good to know what we do. Our plants produce plastics and chemicals that we use every day. Think of phones or mattresses. The building blocks for these plastics and chemicals are made in our crackers. To produce these building blocks, naphtha and LPG are converted in the crackers under high temperature into smaller building blocks; ethylene and propylene. This production also releases by-products, which we call off-gas consisting of methane and hydrogen. This off-gas then goes back into the production process, it is used as fuel to reach the high temperatures in our cracking process. Burning off-gas does have a drawback, as it releases CO2. Of course, we want to get rid of that and we are doing that with sustainability projects.
As explained, there are different types (colours) of hydrogen. At Dow, we are going to deploy a slightly different variant, namely Circular Hydrogen. To accelerate sustainability at our crackers, we are going to use hydrogen as fuel for our crackers. You then also get the building blocks ethylene, propylene and the by-product off-gas again. The latter, off-gas, we can convert in an ATR reactor, a new plant to be built. This stands for Auto-Thermal Reforming. This is a reactor in which you convert the off-gas to hydrogen and CO2. You then use the hydrogen as fuel for the crackers to achieve the high temperature to optimise the cracking process. The big advantage here is that when you burn hydrogen, only water vapour is released. CO2 is still released, but because this comes out of the ATR reactor under high pressure and high concentration, it is much easier to capture and eventually store. We call this Circular Hydrogen. In short, it comes down to the following: we produce plastics and chemicals via a cracking process, which produces a by-product, namely off-gas. This off-gas is then converted into hydrogen and CO2 via an ATR reactor. We capture and store the CO2 and the hydrogen is then used again as fuel in the cracking process. This is how we complete the circle.
So in our first step towards climate-neutral production, or generation 1 (see above), applied technology with circular hydrogen plays an important role. Jeroen explains why this can be deployed and how it works. "The ATR technology for producing hydrogen has been around for decades. It has just not yet been deployed on such a large scale. It is the cleanest technology that is currently the easiest to realise in a relatively short time. The crackers' furnaces remain the same, only the burners need to be modified and we are investigating whether the piping is suitable for hydrogen. The process computers also need to be modified with the necessary software."
Our roadmap to climate-neutral production
We are working hard to meet our 2050 target of climate-neutral production. For this, we have the Multi Generation Plan. In three generations, we are working towards this. Jeroen Tap explains: "If we take measures now, we can make a turnaround. We investigated various possibilities. One of the possibilities, for instance, was to capture CO2 emissions in the squatters' chimneys. However, the concentration of the CO2 effluent is so small that it requires a very large capture installation and that makes this technique not feasible."
"We are also working on another technique, namely electric cracking, which will allow us to completely reduce our CO2 emissions to 0. We are currently researching this together with Shell, and nice milestones have already been reached in this regard. We cannot deploy this technology at the moment. Of course, we cannot sit still in the meantime, otherwise we will be decades down the road and CO2 emissions will remain as they are now. To reach our target, we have to start now. The first step in that is hydrogen. It is the cleanest method to apply in this first phase of our roadmap to 0. In this way, we remain committed to a sustainable future.