Green Hydrogen

Action on “Green Hydrogen” is heating up following Linde’s announcement of building a 24 MW electrolyser, to start production in second half of 2022. To be located in Germany, this will be the largest Proton Exchange Membrane (PEM) electrolyser in the world overtaking the 20 MW electrolyser recently built by Air Liquide in Canada. In contrast, the largest alkaline water electrolyser, the competing technology for Green Hydrogen, is 10 MW at Fukushima, Japan.

Green Hydrogen is the term used to denote Hydrogen produced by water electrolysis exclusively using renewable power. It is interesting to note that the capacities of electrolysers are stated in terms of power consumed and not Hydrogen produced. This is only appropriate because Hydrogen in this case acts essentially acts as a carrier of energy generated from renewable resources like hydro, solar and wind. Bulk of the Green Hydrogen will be used to power fuel cells, the competitor for batteries, to be deployed in EVs.

Linde’s announcement is also a clear indication that PEM technology is pulling away from the older alkaline water electrolysis. One of the important advantages of PEM electrolyser is that it is much more responsive to fluctuations in power, which is a typical characteristic of renewables like solar and wind. But PEM electrolysers are expensive because they require platinum.

A 3^rd technology, Anion Exchange Membrane (AEM), is rapidly emerging from the shadows. A consortium funded generously by EU is developing this technology, which claims to be cheaper because it operates in alkaline conditions and hence does not need the precious metals used by PEM. At the heart of this technology is a breakthrough development in membranes, which are reshaping and redefining many chemical processes. The developers of AEM technology are targeting to halve the cost of PEM electrolysers.

Perovskites

 

There is a new buzzword in the photovoltaic market – Perovskite. It may be the holy grail that the solar power industry has been seeking. 90% of the photovoltaic cells today are Silicon based and they have already reached the theoretical maximum efficiency postulated by the Shockley – Quiesser limit.

Recently, Oxford PV, a start-up spawned by Oxford University, announced a record efficiency of 29.5% for a solar cell, compared to 15-25% for today’s commercial solar cells. The researchers achieved this incredible success by coating Silicon cells with a thin film of Perovskite.

Perovskite was originally a mineral discovered in the Ural Mountains of Russia in 1839 and named after the Russian mineralogist, Lev Perovski. Today it is synthesised in the laboratories and refers to a class of materials that have the same crystal structure as Calcium Titanate, the original mineral. A typical Perovskite structure is ABX₃, where A is an organic cation, B is a metal (usually lead) and X is a halide anion.

Oxford PV is boosting the cell efficiency by capturing more of the energy available in solar radiation. The thin Perovskite layer absorbs shorter wavelengths and Silicon absorbs the longer ones.

Perovskite has many other advantages. It is more tolerant of defects unlike silicon which is required in very high purity. Also it is needed in much smaller quantities. The Perovskite solar cell is thus likely to be much cheaper.

There are question marks on the stability of Perovskites in hot and saline environments and also their environmental compatibility. Besides Oxford PV, at least a dozen other start-ups are working on the Perovskite technology. Commercial rollout is likely in 2022.

Lightweighting

 

Tesla Model S weighs 2250 kg, of which the battery contributes 540 kg, a whopping 24%. A vehicle that weighs more will proportionately consume more energy. Thus a quarter of Tesla’s battery charge is expended on its own transportation. Auto makers are seized of this weight problem and are looking to offset the increased weight due to battery by reductions elsewhere. This is where new age materials – plastics and composites – are likely to play a huge role.

Volkswagen is in the process of developing high performance materials at its polymers laboratory attached to its Chattanooga plant in USA. One of the innovative solutions to come out of this lab is a lightweight polypropylene door frame. Other auto makers are pursuing similar objectives. The main challenge before the auto makers is in substituting sheet metal. How much metal can they take out and replace with plastics and composites.

Car designers are adopting lightweight materials for building chassis, interiors, powertrains and under the hood applications. Among the materials being tried out are aluminium, carbon-fibre composites, high-strength steel, and a host of polymers and rubbers, including natural fibres such as bamboo and jute. A report by McKinsey suggests that carbon-fibre composites could become the spine for the auto industry’s lightweighting strategy in this decade.  

Lightweighting is a concept followed by many industries, wherein they seek to reduce the weight of components with a view to improve performance while simultaneously reducing the environmental footprint The auto industry has already adopted lightweighting as its key strategy to increase fuel efficiency and reduce emissions. The EV revolution is further expected to catalyse lightweighting. The global market for vehicle lightweighting technologies was $130 billion in 2019 and is expected to grow at a CAGR of about 13% to reach $250 billion by 2024.

As lightweighting gathers momentum, the chemical industry will play a key role in the development and manufacture of new age polymers and composites.

The EV Revolution

The EV Revolution

It is a near certainty that this decade will witness an exponential growth of EVs. Historically, the automobile industry has had a deep connect with the chemical industry over last several decades. The EVs will be no different. It will profoundly reshape the chemical industry in the next decade and the decades to come. The impact will be driven by two factors:

1)    How will the EVs be powered?

2)    How will the weight of EVs be reduced?

There are 2 ways to power the EVs – Batteries and Fuel Cells.

The battery vs fuel cell debate has been raging for many years now. The automakers have been split between the 2 camps. Both camps have passionate proponents. The main advantage of fuel cells over batteries was their higher energy to weight ratio. Also batteries typically need several hours for charging. But fuel cells are expensive, and a fuel cell powered car has to carry compressed hydrogen, a potentially unsafe proposition.

But this argument appears to have been turned on its head, by Toyota’s dramatic announcement of a solid-state Lithium battery that can be charged fully in 10 minutes and deliver a trip of 500 kms. Also very significantly, the solid-state battery eliminates the use of flammable liquid electrolytes. Solid-state battery would be a game-changer in the growth of EVs. Other automakers, notably Nissan and Volkswagen are also believed to be actively pursuing this route.

As the name suggests, solid-state batteries use solid electrolytes. Three types of solid electrolytes have been recognised:

1)    Inorganic solid electrolytes

2)    Polymer electrolytes

3)    Composite electrolytes

Lot of action is expected in the next 2 years in the development of robust solid electrolytes. The first solid-state battery powered vehicle is expected to be rolled out in 2023-24.