Interpretation

Graph 1 shows the amount of gas produced per week. The time of these weeks were from August 13th to September 9th (4 weeks). In the graph you can see the first week shows carbon dioxide. The reason for this is because when I attempted to light the gas in the first week of production I noticed that it wasn't lighting. Knowing that the methane does not produce until all the oxygen inside of the container has been used and it becomes a true anaerobic environment the gas produced at the start is mainly carbon dioxide just to make sure i also tested it. I decided to do a limewater test, I passed the gas that was produced through limewater. After doing this the limewater turned milky which meant that the gas was carbon dioxide. In the graph you can see that the digester produced the most gas in the third week, though the average temperature was not the highest this could mean that at the beginning the digester takes time to start up than produces greater amounts later and in week four it shows it slowing down. There could be several reasons for this; one could be that since it was the end of August the temperatures were colder than before and a second reason could be that the digester was beginning to slow down production because it was running out of material (manure does not actually disappear but the ability of it to produce more methane does stop at a point).

Graph 2 shows how much gas would be produced from certain amounts of manure. This was just determined by increasing the scale of the amount of manure in the digester and gas produced so it would show the amount of gas more manure would make.

Analysis

After the production did begin the amount of gas produced was approximately 4 full balloons. Since each balloon contained 12320 ml of gas this means it produced 12320 ml x 4 which is 49280 ml of gas or 49.28 liters of gas. Therefore since we know the amount of manure was 8kg we can say for every 8kg of manure 49 liters of gas is produced or for every 1kg of manure 6.74L of gas is produced.

(fig 9-1) This image shows the size of one full balloon. Each balloon produced contained approximately 12.32 L of gas.

With knowing this we can further calculate to find out how much manure is required to generate enough gas for the summer months (June, July, August). By looking at an average house bill I found the amount of gas used through the months of June, July and August are 9.4 m3 of natural gas, this means it is 9400L of gas. To produce 9400L of gas 2744.56 kg of manure is required. Also if you built this container you can put more than just manure to generate the gas. You can put in any organic waste/garbage you have such as leftovers. If we were to build a digester at our house, in order for us to be able to produce 9400L of gas, the dimensions (of a rectangular shaped container) including the room left for the expanding would have to be 1.38m * 1.38m * 2m = 3.812m3. The shape of the container is irrelevant other than the fact that a wider and more flat, instead of tall container would have more surface area therefore being able to have more sunlight on it (to heat it) but the disadvantage would be that it would take more room and would be disliked for that fact.

The amount for how much gas Canada can produce was also calculated. This was done by finding the number of cows in Canada than multiplying it by how much waste they produce in one day, which than was multiplied by 365 days in a year. Doing that showed how much manure in 1 year all the cows in Canada could produce. Than this was multiplied by the amount of gas each liter of cow manure could produce. This showed how much gas Canada could make in a year using all the manure. The amount of gas was 70,767,376,030 L or 707,673,760.03 m3. After that I subtracted that amount from how much Canada uses for residential. 169,534,963,700m3 - 707,673,760.03 m3 = 16,827,289,939.97 m3. This means with all the manure you would be able to supply about .42%. This seems like a tiny amount of gas produced but it is impossible to replace all the gas with a single energy source. Also, this is excluding other sources for bio-gas mentioned earlier such as landfill, swamp and bog gas. Other reasons for this would also be that the generator wasn't kept in idle conditions for the generation of biogas. To optimize the conditions the idle temperature, pH and water to manure content would be need to be discovered.