Electrolysis, as an alternative way for hydrogen production using flow meters
In this blog I will highlight an application using both a thermal- and Coriolis mass flow controller. An application for a customer in the field of Renewables & Environment showing us an alternative way to split water for hydrogen production.
Hydrogen production is a multi billion dollar industry worldwide of which the major part is consumed on-site in oil refining and in the production of ammonia and to convert heavy petroleum sources into lighter fraction suitable for use as fuels. The most known technogies used here are steam reforming, electrolysis and thermolysis. About 95% of the hydrogen produced is from using fossil fuels.
Steam reforming technology
The overwhelming majority of hydrogen is generated in a chemical way, through the reaction of hydrocarbons such as natural gas with steam at high temperatures, the so-called steam reforming technology. In this process, hydrogen is released from the natural gas with the greenhouse gas carbon dioxide as a by-product
Solar thermal energy and electricity is the most common way to produce renewable clean hydrogen.
Another, novel way to generate hydrogen is using water splitting. This is a chemical reaction in which water is separated into oxygen and hydrogen. Various techniques of water splitting can be used and are already patented, such as splitting water electrochemically. A more alternative way to split water into hydrogen and oxygen is using electrolysis and other physical processes. Both gases have to be separated from each other with a membrane, to obtain hydrogen as pure as possible.
Using mass flow controllers for water splitting
To effectuate the electrolysis process properly, mass flow controllers can be used. How does this work?
As part of the process, the performance of the membrane that separates hydrogen from oxygen has to be measured. To that end, both hydrogen and oxygen have to be supplied to the membrane in known amounts in an accurate way, and the flows that leave the membrane also have to be measured accurately.
For a German customer in the field of Renewables & Environment, Bronkhorst provided an experimental setup consisting of a Coriolis mass flow controller to control the oxygen and a thermal mass flow controller for hydrogen. In this way, hydrogen and oxygen are fed to the membrane in a controlled way.
The permeate - that is the part of the feed that passes the membrane - enters a three way valve where a choice can be made to measure the flow rate or the composition of the permeate gas flow. The flow rate is measured using another thermal device, and the gas composition by means of a binary gas sensor. This sensor can only handle a specific mass flow. To measure the mass flow of the retentate – part of the feed that is retained by the membrane - a second Coriolis instrument can be used.
For more information about this application, please download our application note.
Or download our white paper with in-depth information about our thermal mass flow meters/controllers.
Green Team Twente makes a move in the right direction
Everyone knows the battery-electric Tesla’s. In 2012, they introduced their model S which gave the sales of electric vehicles a boost in countries like the US, China, UK, Norway and the Netherlands. During the same year, Green Team Twente was founded at the University of Twente, the Netherlands. They did a great job by building a magnificent hydrogen car, which won the first place at the European Championship for ultra-efficient hydrogen cars.
Since then, the battle of future mobility has begun. Will the battery electric car like the Model S win or will it be a hydrogen electric vehicle? At the moment hydrogen cars are at the beginning of their growth stage, but consumers are not really aware of their existence and car companies are waiting for a proper hydrogen refueling infrastructure. Therefore, the market for hydrogen cars is currently less developed than the battery electric market, but both have the same potential. Hydrogen vehicles are known for their longer range and shorter refueling times compared to battery electric cars. This potential has to be made reality within the upcoming years.
During my studies MSc Industrial Engineering and Management at the University of Twente I wanted to do something which creates an impact. At the Green Team Twente we are working on building the most efficient hydrogen car. The estimations for this year are high, but realistic. With a fuel efficiency of 1L to 1000 km (gasoline equivalent) we belong to one of the top teams in the world.
We will participate in the Urban Concept class at the SEM, the Shell Eco-Marathon. This year it takes place at the Queen Elizabeth Olympic Park in London, UK on May 25-28. There, over 200 different student teams of all around Europe will battle for having the most energy-efficient car. Seen by 30.000 visitors, every team has to succeed 10 laps of 1659 meters within a certain amount of time. The team that uses the least amount of fuel wins.
As mentioned at the beginning, the first year was a great success. With a fuel efficiency of 727 km/l we became the number one of Europe. During the following years, the track became a lot harder and even some hills were added. It is a very realistic simulation of normal day to day driving, but it makes it very tricky to drive as efficient as possible. Last year, June 2016, we were back in business with a third place.
The Green Team-ers
We are working with the most motivated people you will find at the University of Twente. We create impact and are able to push ourselves to the limit. We have a great diversity with 19 students from different studies and different nationalities. They are working on a full-time or part-time base for one year. A very appealing setting for this student team is that team members can integrate parts of their study, so they really can become a specialist in their discipline.
The team consist of car enthusiasts, so a lot of inspiration is fetched through Formula One teams. They know how to build a car and process it in a professional way. For example, we like the way they express their partners on the car or how they handle data acquisition. In the future it would be great to learn more from those teams.
Partners are key
In order to build one of the most fuel efficient cars, we depend on good relations with our partners. Every new team meets existing partners and are looking for new ones to improve our network. Since 2014, Bronkhorst is one of our partners. By supplying us with their flowmeters, we are able know the exact flow of hydrogen and air in our fuel cell. Which is extremely important during the race, in order to optimize our driving strategy.
Our powertrain consists of a PEM fuel cell with super capacitors that work like a buffer. The fuel cell generates a constant amount of power whereby the capacitors are used to release or capture extra energy during acceleration or braking. While driving we can control the amount of energy produced by the fuel cell by adjusting the flow of air. Of course we want to finish with the least amount of hydrogen used, so knowing the exact flow of air will benefit us to make the car as efficient as possible.
It will be exciting to see if we are going to win the European Championship again, follow us from May 25th to May 28th on our social media! For now, we, the Green Team Twente and Bronkhorst, are going to continue to realize more awareness and popularity of hydrogen powered cars by pushing the current technology to the limits of efficiency.