In this article, we will explore the future role that clean Pyrolysis can play in energy production.
Generally speaking, Pyrolysis is a process by which a solid (or a liquid) undergoes thermal degradation. It is converted into smaller molecules. In other words, an original source changes its properties under increased temperature, usually without oxygen. Either to create energy or because the changed source is valuable.
The creation of energy is specifically crucial to us in this article.
Pyrolysis is a blanket term used for this process. However, it can vary significantly depending on several factors. These include:
- the original source
- whether oxygen is present
- chemicals used
- rate of temperature rise
- and the temperature at which it is burned.
The concept of Pyrolysis is not new. Thomas Edison used the Pyrolysis of the carbon filament of bamboo splinters to make the bulb. It has been used in everything from creating energy to cleaning ovens.
However, it is the technological advances in producing clean Pyrolysis that interests us. In other words, looking at how we can use Pyrolysis to generate clean, sustainable energy. In this article, we’re going to focus on Pyrolysis for biomass and the Pyrolysis of methane.
Using Pyrolysis of biomass under the right conditions allows a high energy yield to be produced sustainably. This is exciting, as methane pyrolysis for hydrogen is a non-polluting industrial process.
We can extract carbon from natural gas, which significantly impacts our ability to create cleaner energy at scale.
Biomass as clean Pyrolysis
Biomass is one of the most sustainable and eco-friendly renewable energy sources experts are exploring right now.
By the utilization of thermochemical processes, biomass can be converted into energy-yielding end products.
Lignocellulosic biomass is the most available renewable carbon source on the planet.
Available biomass sources include:
- forest residues
- crop residues
- purpose-grown energy crops
- animal wastes
- food wastes
Plant fibrous structural parts are composed mainly of cellulose, hemicellulose, and lignin. They are actually pretty challenging to deconstruct to create chemical building blocks. This means utilizing this carbon source has been challenging.
The objective has always been to convert biomass into energy products such as hydrocarbon biofuels. But in a way that is so advanced, they become indistinguishable from fossil-based gasoline, diesel, or jet fuels.
Pyrolysis is one such process. It can convert biomass to an intermediate liquid product. This liquid can then be refined to drop-in hydrocarbon biofuels, oxygenated fuel additives, and petrochemical replacements.
Pyrolysis is the heating of organic material, commonly known as biomass, usually with no oxygen present. Biomass pyrolysis is typically conducted at or above 500 °C.
This provides enough heat to deconstruct the strong bio-polymers that make it challenging to deconstruct biomass.
Because no oxygen is present, combustion can not occur. Alternatively, the biomass thermally decomposes into combustible gasses and biochar.
Most of these combustible gasses can be condensed into a combustible liquid called pyrolysis oil (bio-oil).
Some permanent gasses can be combusted to provide the heat for the process. In other words, the Pyrolysis of biomass produces three products:
- one liquid, bio-oil
- one solid, bio-char
- one gaseous, syngas
The proportion of these products will depend on a variety of factors. Primarily the composition of the particular source of biomass, the heat and speed of heating, and whether any other chemicals are used.
As a general rule of thumb, bio-oil is most effective when the temperature is up around 500 °C, with a high heating rate (1000 °C/s). We expect bio-oil yields of 60-70 wt% will be achieved from a typical biomass feedstock, with 15-25 wt% yields of biochar. The remaining 10-15 wt% is syngas.
This is what we classify as fast Pyrolysis.
Slow Pyrolysis is burning biomass at a significantly slower heating rate and lower temperatures, producing far more biochar. This is the process that has been used for centuries to make charcoal.
The discovery of fast Pyrolysis has been exciting thanks to the higher yields of bio-oil whilst producing significantly higher energy density than the original biomass.
Methane pyrolysis – the future of clean energy?
Methane Pyrolysis is a more recent process technology that has the capacity to change the energy industry. Generally speaking, methane pyrolysis splits natural gas or biomethane directly into the components of hydrogen and solid carbon.
What makes this process exciting is that it requires relatively little energy. In fact, electricity generated from renewable resources can be used and so can hydrogen originating from methane, making the process both effective and clean.
Access to hydrogen is essential. Hydrogen is a critical component for future energy systems because its energetic use does not lead to direct CO2 emissions.
Therefore, both methane pyrolysis and the use of hydrogen need to be clean processes.
The carbon is not combusted within this process; instead, the solid carbon is disposed of naturally, having no negative impact on atmospheric CO2.
Alternatively, carbon can be used as a raw material in other processes. Including electronics, medical devices, aerospace composite materials, and building systems
With the right processes and infrastructure in place, the sale of carbon for carbon products offsets the cost of hydrogen production, making it both a clean energy source and a cost-effective solution.
This idea has existed for decades but has consistently failed due to technical implementation. However, thanks to cutting-edge technology from companies such as Modern Electron, methane pyrolysis will play an essential role in the future of clean energy.