The correlation between greenhouse gases and global warming was recognised by [Irish physicist] John Tyndall back in 1859. He wrote: “Thus the atmosphere admits of the entrance of the solar heat but checks its exit, and the result is a tendency to accumulate heat at the surface of the planet”.2 Or perhaps it was Eunice Foote who demonstrated the ability of carbon dioxide to absorb heat from the sun in 1856?3 Despite [these warnings], it took humanity a long time to understand that burning fossil fuels and releasing carbon dioxide into the atmosphere would cause humanity major issues.
Focusing on these facts today, there seems to be only one way forward. Move away from fossil fuels and towards green solar and wind energy, fuelled by the only real green source, the sun. You may say, why not use biofuels? Biofuels come from capturing CO2 out of the atmosphere and are converted into biomass, by sunlight. [This is] well known as photosynthesis: 12H2O + 6CO2 → C6H12O6 + 6H2O + 6O2 [the process by which] all kinds of wood and biomass and organic waste can be gasified when bacteria digest the organic matter in the absence of oxygen.
Unfortunately, these process cycles are very slow and leave us with the question of whether it makes sense to grow a tree in 20 years to burn it in a steam boiler in two minutes. Of course, it makes sense to decompose and convert residue coming from cattle and water treatment into biofuels. However, questions remain as to whether there will be sufficient biogas or fuel available for the glass industry, keeping in mind that there is still at least 35% of CO2, H2O, NH3, H2S in biogas that would need to be separated before use. It’s fair to say that there have been successful trials with biofuels but the ones we know all question its future availability and price.
We can of course take natural gas and take out the hydrogen by steam reforming CH4 + H2O → CO + 3H2 → CO + H2O → CO2 + H2. Using the hydrogen and putting the CO2 into where the natural gas came from: the wells. It sounds like a good idea but comes very close to being a landfill. In fact, it comes close to trying to get rid of nuclear waste by putting it underground. Next to that, burning hydrogen is not very energy efficient, that’s why hydrogen cars have fuel cells, so why would the glass industry go down that route if it only needs heat and not specifically hydrogen?
That brings us to another argument against the use of hydrogen in glass manufacturing. Other industries such as aerospace and automotive cannot do without hydrogen gas, and as a result, are willing to pay more for it. Of course, the ability to store hydrogen could become an important argument but compressing it up to 600 bar or cooling it down to -253°C is a challenge and comes with additional energy losses.