(Go's with This Instructable of a small bio gas generator) https://www.instructables.com/id/Bio-Gas-Generator-Small/
Step 1: Parts Needed.
2: A section of PVC Pipe,about 5inchs.
3: x1 old bike inner tube. (for the rubber)
4: x1 Hotglue & Gun.
5: Aquarium/surgical/Hydroponic Tubing. ( about x3 .3ft pieces)
6: Plastic Tube connector/s (can use super glue and melted plastics to seal tubing)
7: x1 Aluminium Can (Optional)
8: x1 Boxcutter & x1 scissors.
9: x2 Clothes pegs/or clamp devices.
10: x2 Cable ties (small)
11: x1 Heavy Weight (for holding glued parts in place solidly)
(X1 Bio Gas Generator)
Step 2: Construction.
This will be simple to make take the small section of Bike inner tube the length of your PVC pipe piece and cut it the inner tube around half the size of the PVC pipe itself,use rubber or super glue to seal both ends of the inner tube..now cut small holes one in the middle and one on each Side,see pictures.
Once done grab your Plastic Tubing of whichever kind it may be,aquarium,surgical,garden,and cut 3 sections and securely glue them in place in the holes you cut into the Inner tube and let dry,then test blow air into one of the tubes and put your hand over the others,do this partially underwater to be extra sure the seal on each tube is leak free,you don't want to lose all your gas to the atmosphere,once done take your PVC pipe section and cut a hole in the middle now carefully wobble push and twist the inner tube inside of the pipe section see picture and carefully pull the innertubes upper tube section through the hole in the PVC pipe you cut,see picture,now you have the basic mechanism,check both ends and the crimp the tubing on each end using Clothing pegs,or clamps to shut them off.
Now attach a partially air filled balloon to the top part of the gas container and seal it in place using whatever means you can,cable tie and glue,rubber band,few binds of string,and create a seal on the balloon,and your done with the gas collection and release device,if you do not have a balloon use trash/rubbish bags plastic only,and cut off the handles and glue to a narrow point with a hole as long as it can hold air without loosing it through holes etc it can be used.
Attach one end of the collector/container to the bio gas generator and take off the peg/clamp on the tube you connected to the generator to let the gases flow freely into the the Inner tube section and then into the balloon,now all you have to do it connect the remaining pipe section to a small stove etc,and lightly squeeze the balloon to release some gasses light them up with a source of flame and continue to squeeze on the balloon for more gas until it is all run out,or fill up other balloons to store more gas to run apparatus for a longer time,once empty just leave it to recharge and gases to form and collect inside the balloon...
For information on how long bio gas generators take to create bio gas,and how long it will run for..you will have to do some research as time varies in colder climates and bio gas reactions start quicker in hot climates naturally,as such gas creation times can be various.
Step 3: Uses and Testing.
(The final product turned out as more of a Rubber Gas Bladder! created from the inner tube,imagine it can handle some pressure sealed into the section of inner tube,the test video Clearly shows No leaks,and both ends let gases escape at both ends,tested the same way as a punctured bike inner tube underwater,also added a T section pipe fitting at the top in place of a singular piece,as to attach duel balloons to each gas output enabling more gas to be trapped,Functional field testing will take place after i aquire a few thick layered balloons.)