Biogas is a renewable and sustainable energy that can be created from organic waste. It is produced by anaerobic digestion. Getting the best amount of gas from a biodigester is not hard to do. In fact, with a few simple steps at the beginning, you’ll see how easy it is.
Biogas is a source of clean energy with low emission levels, making it very environmentally friendly.
The biodigester is used in biogas production and is made up of different types of bacteria. These bacteria are responsible for the decomposition process.
There are many factors affecting how much gas can be produced by biodigesters. The main aim of this post is to provide information about how much gas biodigesters produce and what affects their efficiency in producing biogas; we will discuss each factor below:
Table of Contents
What is a Biodigester?
A biodigester is a device that converts organic matter into methane gas. It’s a simple, low-cost technology that works by mixing microorganisms with wastewater and other organic materials in an enclosed tank. The microbes break down the materials, producing methane as a byproduct.
You can use the technology to treat water waste, animal waste, or human waste (which requires more specialized systems).
Working Principle of a Biodigester
A biodigester is an aerobic/anaerobic digester that uses organic waste to produce biogas. Methane, carbon dioxide, and other gases are combined to create biogas, i.e., gases created by fermentation of organic matter. Biogas can be used for cooking or as fuel for vehicles like cars and trucks.
Biodigesters are mainly used for treating municipal and animal waste. Still, you can also use them in your garden if you want to turn your food scraps into useful fertilizer instead of throwing them away.
How Much Gas Can a Biodigester Produce?
The basic rule of thumb is that after 24 hours at body temperature, every liter of digester volume yields the same volume of gas.
That’s a goal that’s rarely achieved. The average home digester, which holds 1,000 liters (275 gallons), should theoretically be able to produce one cubic meter (1,000 liters, 275 gallons) of biogas in about a day after being fed.
A bucket’s worth of food typically produces that volume of gas, with a bucket containing between 20 and 25 liters (5 gallons or so).
People utilize buckets because most have them, and math is generally disliked. We have to face that fact. Full buckets are simpler to recall.
As a result, we state that a bucket of ground-up food waste, along with warm water, should be able to produce enough gas to fill another IBC. IBC tanks are shaped like cubes, making it easier to envision this.
Total Amount Of Gas Produced
Temperature is typically the issue. The slurry in most biodigesters appears to normalize at around 20 C. Only 100 to 300 liters of gas are produced daily by these. At 25, you begin to surpass 300.
You might need 500 liters of gas at 30 C. You may be able to see the theoretical 1000 liters that will allow you to cook for around 2 hours on a single burner at 35 to 37 (98.6 Fahrenheit — body temperature).
The microorganisms are tuned for mammalian body temperature because they originate from an animal’s stomach. Making them pleased will encourage them to create. However, the curve is not linear; at 37 C, they produce much more than they do at 30 C.
They become extremely lethargic at 15 C. Warren Weisman reduces production at Hestia Home Biogas to 13 C. However, it is undeniable that the gas releases more quickly the greater the temperature.
Every 100 liters of gas should provide 15 minutes of cooking time on a single burner with a medium flame, the kind of flame most of us use when we cook.
So don’t worry if it’s only 100 liters a day and it’s 20 C outside; you can still make breakfast till you figure out the best way to keep the tank warm.
Point to Note
In the meantime, it’s not difficult to come up with a bucket of leftover food. Avoid overeating. If you do, you will get acid reflux and indigestion.
If necessary, reinoculate it with new bacteria and feed it an antacid (sodium carbonate is preferable to sodium hydroxide). Return to using new manure or try RidX. Then, start to begin feeding them slowly.
The amount of gas produced by a biodigester will vary depending on the quality of your feedstock and how you manage it. The following factors are vital to take into consideration:
The environment’s temperature is important in determining how much gas can be produced by bacteria. In general, the higher the temperature, the higher the rate of microbial activity and, therefore, the more methane that can be produced.
If you’re looking for a high yield from your biodigester (that is, if you want to make as much methane as possible), it makes sense to keep your system at a warm temperature.
The exact temperature that will give you the best result depends on the type of bacteria that are in your system. It’s important to research and find out what works best for your situation.
Hydraulic Retention Time (HRT)
Hydraulic retention time (HRT) is when waste material remains in a biogas digester. The HRT can be thought of as the “digestion period.”
The length of this period determines how much methane gas you’ll end up with after your generator is done processing all the organic materials in your tank.
The size and volume of your biodigester tank will determine its HRT, which means some generators have longer digestion periods than others. In general, larger tanks have longer HRTs because more mass is converted into biogas over time.
The pH of Digester Contents
The pH of the digester contents is important to maintain the activity of microbes. Having a pH that is too low, it will be difficult for microbes to digest the material in the digester.
In this case, you may need to add a buffering agent (such as lime or soda ash) and check your pH again to achieve proper digestion.
However, if your pH level is too high, you may have over-acidified the system. This could have unfavorable impacts like damage to equipment and even death for some organisms living within your biodigester system if left untreated long enough – so keep an eye out for these issues!
The Organic Loading Rate
Another factor to consider is the organic loading rate. This refers to the amount of food or organic material added to the biodigester.
The more food you add, the more gas you can produce. But how much food a person adds depends on their goals and how much gas they want to produce.
The higher the organic loading rate, the more gas can be produced. You will also need to add water and other chemicals like oxygen and enzymes.
Salinity on Biogas Yield
When salinity is too high, the rate at which microbes can break down organic material slows down. This is because water’s salinity level directly affects microbial activity.
The higher the salt content in your digester, the lower its pH will be, and thus the less biogas you will be able to produce.
On the other hand, when salinity levels drop below a certain point (known as an optimum level), microbial activity increases exponentially: it takes less time for microbes to decompose organic matter into methane gas.
It should also be noted that different kinds of microorganisms have different digestion rates at different levels of salinity; some may prefer low-salt environments while others thrive in high-salt ones—it all depends on what kind of environment they’re used to being in.
Read More: Bio-Digester vs Composter
The amount of gas you can produce with the biodigester will depend on what you put in it and how much time you give it to work. The good news is that once a biodigester gets going, it can produce a lot of methane.
Operating conditions matter: low temperatures slow down microbial activity and decrease production, while high temperatures accelerate and increase production.
Waste is an opportunity. A biodigester can help turn waste into something useful like methane gas, which can be used as fuel for other things like cooking or heating water. It’s just another way to be more sustainable!