Mar 202020
Using Green Power at Home – Is Biogas Really a Dirty Fuel?

First and foremost, thank you for your interest in articles like this. It only shows that you are very invested in taking your step in making this world better.

If you need more, let me offer you a few legitimate tips on how to GO GREEN.

Introduction

Producing biogas mitigates global warming by solving a two-fold problem: (1) lessening the release of methane into the environment and (2) veering away from heavy use of fossil fuels.

Organic matters that are left to rot in landfills produce methane. This is because over time, the landfill is filled and the biodegradable matter on the lower level of the landfill is no longer ventilated, therefore becoming a haven for methanogens (methane-forming microbes).

Composting, however, needs oxygen to hasten the process so it does not produce methane. Remember, methane is only produced when there is no oxygen in the mix. So composting is one way of reducing methane production.

 

What is Biogas?

Biogas is a green energy coming from decomposed organic waste. The more popular choice for green energy nowadays are solar and wind power since they are the easiest to harness.

The other green power alternatives are geothermal and low-impact hydropower. Geothermal energy is harnessed energy from underground heat.

Low-impact hydropower is harnessing river power while considering the water quality and maintaining the life within it, unlike the usual practice in large-scale hydroelectric power plants.

Biogas is harnessing energy from the breakdown of organic matters through anaerobic decomposition. 

Methanogenesis

Anaerobic decomposition is accomplished by storing biodegradable materials into an anaerobic digester where decomposition is done by methane-forming microbes or methanogens.

This process of decomposing materials to produce methane gas is called methanogenesis. Methanogens are members of the Class Methanomicrobia that thrive well in the following conditions: constant temperature, stable pH, zero oxygen and simple organic acids as food.

They can digest a wide variety of organic materials, including sludge, fats, oils and greases that cannot be decomposed immediately in normal conditions. 

While the US calls biogas as a dirty fuel source, it is more helpful to the environment. Methane, a greenhouse gas, when released into the environment causes global warming by trapping in heat.

However, when it is used as a fuel source, the amount of free methane is reduced and carbon dioxide is used in the decomposition process.  

That said, biogas has a two-fold effect on reducing greenhouse gases than otherwise claimed by US authorities. To harvest methane gases, carbon dioxide is pumped into the chamber to flush out the methane.

This results in using excess carbon dioxide while putting methane into good use. Two greenhouse gases that left alone wreak havoc but properly used, they can do wonders.

It has been found out by scientists that methanogenesis is faster when the bond between the carbon and hydrogen isotopes in methane molecules are far apart. However, they are yet to discover the intricacies of this discovery.

Is Methane a Bad Gas?

On its own, methane is a greenhouse gas, second only to carbon dioxide in abundance in the environment. It is produced when organic wastes are digested or decomposed without the aid of oxygen. 

Natural or fossil gas is mainly methane and is a non-renewable energy, that is, it can only do so much. Because it is mainly methane, it is also considered a greenhouse gas but is a lot healthier to use than coal and diesel in producing electricity in power plants. 

However, the burning of methane, whether from the natural gas or biofuels, reduces the release of methane into the environment, thereby mitigating the adverse effects of these greenhouse gases.

The efficiency of methane to trap greenhouse gases is greater than other greenhouse gases so it is best to harness its energy.  

So, yes, methane is a bad gas until we turn it around to do us good. Are you ready to take on this journey with me?

The Pros and Cons of Biogas Production

As in any human endeavor, biogas production has its advantages and disadvantages. The important thing is to weigh each one and then decide if the advantages are worth the risk and hazards the disadvantages may present.

Pros of Biogas Production

It is an eco-friendly source of power

  • Burning methane as a fuel reduces greenhouse gas emissions. Methane traps in 25 times more heat than the same amount of carbon dioxide.
  • Biogas reduces use of fossil fuels, which are non-renewable at the same time releases harmful gases into the environment.
  • It is a good option in carbon sequestration. Carbon sequestration or carbon dioxide removal can be facilitated by growing more trees or through direct capture. This captured carbon dioxide can be used in methane gas harvest.

It reduces soil and water pollution

  • Landfills can be harnessed to harvest methane from it, thereby reducing soil pollution
  • Wastewater can be used to produce biofuel which can help in reducing water pollution
  • Waterways became more navigable. More organic matters in waterways encourages the bloom of water lilies which can affect navigation and productivity of the water body, especially in lakes.
  • Any biomass refuse can be used to feed it – wood chips, biodegradable plastics, grease, fats, animal entrails, etc – reducing chances of dumping it either in the landfill or in waterways

Produces organic fertilizer

  • The “waste” from methane gas had been cleaned up of all kinds of pollutants and other harmful chemicals, making it an ideal organic fertilizer

Low investment, long-term cheap energy

  • Setting up a biodigester at home is simple and dies not need a lot of advanced engineering
  • Livestock farms can greatly benefit from waste-to-energy system, especially for animal dung, uneaten hay and other other organic matters

Can generate green employment

  • A biogas plant cannot operate on its own, it will need manpower to operate and maintain it. Even home systems can impact employment, even indirectly. The materials used for making a DIY biogas system go through the standard fabrication, marketing, delivery, etc.

Green cooking fuel for third world countries

  • Open fire cooking poses more health hazards than smoking and not everyone can afford LPGs and electric stoves.

Cons of Biogas Production

Limited technology innovation

  • Over the years, there is very limited improvement in its technology
  • Some materials used are flimsy and too improvised

Not suitable for all

  • While it good for in cooking and lighting, it contains sediments and other impurities that make it unsuitable for use on engines

Selective site

  • Biogas production is dependent on the ambient temperature. Sudden or climatic changes of temperature affects biogas production. Methanogens are active when temperature inside the digester is between 35-40oC.
  • Biogas plants need a lot of organic matter so it is not effective in highly urbanized areas.

Fires and explosions

  • Fires and explosions can happen, especially when the harvesting tank for the methane is flimsy and easily punctured. Extra care should be taken so no open flames or smoking near the biogas facility

Methane poisoning

  • When working in enclosed spaces where methane is stored, it is best to have a self-contained breathing apparatus on hand in case of emergencies

Spread of diseases

  • Biogas production deals with animal manure as a food source of the methanogens. Handling livestock manure can cause spreading of diseases so it is important to practice caution and strict animal hygiene when handling dung. 
  • This issue can be solved, though, by installing a trough to convey the manure from the farm to the biodigester.

How to Produce Biogas from Home

Producing biogas at home is simpler than you think. However, given the pros and cons listed here, precaution must be taken into intent consideration.

This video is about making a home biodigester with step by step instruction, including actual setting up of the digester and adding organic materials. 

The following should be considered before setting up a small biogas digester at home:

Site

It was mentioned earlier that farms have better access to organic matter that can be used in biogas production.

Livestock plays a major role since the methanogens (methane-producing microbes) dwell in abundance in cow dung. Daily addition of cow dung hastens biogas production but it also needs a periodic addition of other organic matters.

Biogas digesters should be protected from erratic temperature changes since methanogens have a very specific temperature requirement.

It should also be placed at a considerable distance from the house to prevent catching spontaneous fires. 

Level of expertise

Even if there are video tutorials for setting up a biogas digester, this is not enough to equip you with the technical information. There are numerous e-books that you can access to help you set up your biogas system. 

It is also best to consult your local government as to guidelines and technical assistance in setting up your biogas digester.

 

Access to fabrication materials and fabricators

While the materials can be found in most hardwares, the issue may be your access to fabricators unless you are good at doing D-I-Y projects. 

Conclusion

I think I have presented enough arguments to the pros and cons of building a biogas digester at home, it’s your turn to assess if your home is safe enough to set up this system. Just because we want to practice green living and reduce our carbon footprint do we have to put our families in imminent danger.

As a homeowner it is your responsibility to check out with local authorities regarding local ordinances governing green energy. If biogas is not for you, you can always choose to set up a solar or wind power generator for your house.

Producing biogas at home can be messy and it certainly is not for everybody. To help you make your decisions, here are a few videos you can check later. 

So, the question is: is biogas really a dirty energy? It depends on one’s perspective. No one energy source is altogether perfect.

Producing biogas at home has its pros and cons. For sure, not all can use biogas, especially those in the urban areas. But in farms, it is a very viable source of energy. Definitely not dirty.

Word of warning: some of these videos may gross you out so watch at your discretion.

Check out this video for a home experiment on how to do it. This includes adding chopped up food and animal dung into the digester.

How to make biogas from sludge water in 72 hours is another informative video that includes setting up the digester and using it.

 

A Few Final Thoughts

Please feel free to share with us your experience, comments or insights in composting in the city. I will be very happy to answer them according to my knowledge and personal experience.

Join me in my journey of green living by following my social media profile or subscribing to my newsletter on the right-hand side of this page.

All the best,

Eco_Catherine

ecocatherine@about-going-green.com

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