A device that converts gas molecules dissolved in a liquid into gas bubbles 

It works particularly well for converting dissolved hydrogen into hydrogen gas 

It goes into the rumen (largest stomach) of a ruminant animal (e.g. cattle, sheep, goat).  

A gas is made of light molecules that zip around like a very tiny very fast ping pong balls.   

They don’t stick to each other. 

Examples of gas molecules found in the rumen include hydrogen, carbon dioxide, nitrogen, oxygen, methane, and the very smelly hydrogen sulfide. 

A liquid is made of molecules that move around and stick to each other in a very flimsy way. 

Examples of liquid molecules are water molecules—They’re everywhere including the rumen. 

A solid is made of molecules of all sizes that stick to each other in a firm way. 

Examples of solids in the rumen include feed particles and plant fibres. 

It’s when each molecule of gas is surrounded by liquid (water) molecules. 

Way 1.  They are made in the liquid by chemical or biochemical processes. 

Way 2.  They collide with the liquid with enough energy and get buried by the liquid molecules. 

The shuttle helps remove dissolved gases, especially dissolved hydrogen, from the rumen of an animal. 

The animal is already trying to do it.  Too much dissolved hydrogen is bad. It inhibits the rumen process. 

By allowing archaea (an ancient type of single-celled microorganism) to make methane in the rumen. 

They get converted into undissolved gases and then the animal belches them out.  That’s called eructation.  

Yes.  The archaea don’t have the extra hydrogen they need to make methane. 

No.  The gas molecules inside a bubble are not surrounded by water molecules even though the bubble is. 

No.  They can only use dissolved hydrogen. 

It floats to the top of the rumen and pops.  The contents of the bubble get belched out. 

Gas molecules stick to the shuttle surface and form bubbles. 

Reason 1.  The shuttle surface is particularly sticky for gas molecules—aerophilic. 

Reason 2. The gas molecules, especially hydrogen, are sticky for the shuttle surface.  

Reason 3. The gas molecules, especially hydrogen are particularly sticky for new gas bubbles. 

Reason 4. The gas molecules, especially hydrogen, are very fast moving in a liquid. 

There is no chemistry! It’s a physical process.  

The dissolved gases are already trying to escape the liquid—in science that’s thermodynamics.  

The shuttle opens the door…lots of doors—in science that’s kinetics. 

The shuttle surface really repels water—hydrophobic. 

That’s a secret! But rest assured, it’s totally safe for the animal and the food chain. 

Like a big pill, it is gently administered through the mouth and down the oesophagus and into the rumen. 

Like other bolus devices, they are recovered from the animal remains. 

We expect that hydrogen degassing is proportional to the liquid accessible surface area of the shuttle.  This gives us plenty of scope to tune the amount of degassing we need. 

The more surface area, the more degassing. 

We don’t know the limits of hydrogen degassing. 

There are lots of careful experiments and trials to do and many ways we can tune the shuttle.

Animals tend to go off their feed if the dissolved hydrogen gets too high, not by making hydrogen low. 

Its early days yet, but we have already seen in pilot studies a 20% reduction in methane. 

Yes, because some other interventions cause dissolved hydrogen to increase. 

The shuttle should complement these by lowering dissolved hydrogen.