In anaerobic fermentation the end product is methane which can be captured for cooking heating and electrical generation. Anaerobic is a condition where oxygen is very limited. In anaerobic fermentation the condition is maintained in a closed container with lots of solid saturating a slurry. Methane as such can be renewal resource from sanitary waste and manures for example.

In aerobid fermentation the end product is carbon dioxide rather than methane.  The aerobic condition is maintained in composting by turning piles of materials which have enough coarse material that they can aerate. 

Anaerobic fermentation by products can have issues with residue toxic materials. In stabilized aerobic composting these issues are taken care of by the composting process. The residues of anaerobic fermentation would be destined for aerobic composting to make them ready of amendment use for plant productions. 

Maintaining of aerobic conditions in composting prevent the anaerobic products which can be harmful for plant growth and generate foul smells not appreciated by residents surrounding the facilties.  Turning of compost piles allows the maintainence of aerobic conditions as well as combining proper ratios of C and N and materials which have the right textures for aeration. 

A simple test for maturity of aerobic compost is the saturation of test material with water and sealing it in a ziplock plastic bag if after 2 days the material generates no foul smell the compost is stabilized and ready for plant use. This simple test is called the stink bag test. Generally anything that smells bad is not good for crop or plant amendment. 

Raw manures can have issues related to their direct use with the right composting or anaerobic fermentation and composting waste with some noxious nature are transformed into valuable inputs and their issues with disposal are greatly minimized by the 80 to 90% consumption of the organic materials. This is criitical for our soil fertility and environmental issues related to synthetic nitrogen and use of raw manures which can contaminate our water systems through the eutrophication which results from excess soluble products in the water which ends in robs water of oxygen needed for fishery health and best recreational use. 

In anaerobic fermentation the end product is methane which can be captured for cooking heating and electrical generation. Anaerobic is a condition where oxygen is very limited. In anaerobic fermentation the condition is maintained in a closed container with lots of solid saturating a slurry. Methane as such can be renewal resource from sanitary waste and manures for example.

In aerobid fermentation the end product is carbon dioxide rather than methane.  The aerobic condition is maintained in composting by turning piles of materials which have enough coarse material that they can aerate. 

Anaerobic fermentation by products can have issues with residue toxic materials. In stabilized aerobic composting these issues are taken care of by the composting process. The residues of anaerobic fermentation would be destined for aerobic composting to make them ready of amendment use for plant productions. 

Maintaining of aerobic conditions in composting prevent the anaerobic products which can be harmful for plant growth and generate foul smells not appreciated by residents surrounding the facilties.  Turning of compost piles allows the maintainence of aerobic conditions as well as combining proper ratios of C and N and materials which have the right textures for aeration. 

A simple test for maturity of aerobic compost is the saturation of test material with water and sealing it in a ziplock plastic bag if after 2 days the material generates no foul smell the compost is stabilized and ready for plant use. This simple test is called the stink bag test. Generally anything that smells bad is not good for crop or plant amendment. 

Raw manures can have issues related to their direct use with the right composting or anaerobic fermentation and composting waste with some noxious nature are transformed into valuable inputs and their issues with disposal are greatly minimized by the 80 to 90% consumption of the organic materials. This is criitical for our soil fertility and environmental issues related to synthetic nitrogen and use of raw manures which can contaminate our water systems through the eutrophication which results from excess soluble products in the water which ends in robs water of oxygen needed for fishery health and best recreational use. 

Aerobic composting is decomposition of organic matter using microorganisms that require oxygen. The microbes responsible for composting are naturally occurring and live in the moisture surrounding organic matter. Oxygen from the air diffuses in to the moisture and is taken up by the microbes.

Anaerobic composting requires an entirely different set of organisms and conditions than does aerobic composting. The anaerobic process, which is essentially putrefaction (sorry, but there it is), produces a very acidic environment similar to that in the stomach. Hence the term “digester” used to describe anaerobic processes and to distinguish them from aerobic composting. Actually, the stomach still holds the prize for acidic environments. The pH in an anaerobic digester might dip as low as four but that in the stomach is between one and two.

AEROBIC COMPOSTING VS ANAEROBIC COMPOSTING

HotRot units use continuous aerobic composting technology to turn putrescible organic wastes into compost, a renewable resource. So what do we mean by aerobic composting and why do we prefer this over anaerobic composting technology?

AEROBIC COMPOSTING

Aerobic composting is decomposition of organic matter using microorganisms that require oxygen.  The microbes responsible for composting are naturally occurring and live in the moisture surrounding organic matter. Oxygen from the air diffuses in to the moisture and is taken up by the microbes. As aerobic digestion takes place the by-products are heat, water and carbon dioxide (CO2). While CO2 can be classified as a greenhouse gas it’s evolution from the composting process is not counted in emissions. Additionally, CO2 is only 1/20th as harmful to the environment as methane (the main by-product of anaerobic degradation).

The heat produced in aerobic composting is sufficient to kill harmful bacteria and pathogens as these organisms are not adapted to these environmental conditions. It also helps support the growth of beneficial bacteria species including psychrophilic, mesophilic, and thermophilic bacteria which thrive at the higher temperature levels.

From start to finish, the HotRot in-vessel aerobic composting process takes only 8-10 days. No leachate is produced as any surplus moisture is extracted as water vapour which can be condensed and used for watering nearby vegetation.

ANAEROBIC COMPOSTING

Anaerobic composting is decomposition that occurs using microorganisms that no not require oxygen to survive. In an anaerobic system the majority of the chemical energy contained within the starting material is released as methane. The process is characterised by very strong odours and only a small amount of heat is generated meaning decomposition takes much longer and doesn’t reach sufficient temperatures to safely kill plant pathogens, weed and seeds. To overcome these limitations external (artificial) heat is normally added.

As the material is broken down by anaerobic digestion, it creates a sludge-like material that is even more difficult to break down. This material, digestate, typically requires aerobic composting to complete the stabilization process.

Aerobic composting is the principle at work in above ground composting environments — whether it takes place in a free standing pile or in a container that provides air circulation, such as a bin with open sides or a tumbler with aeration holes.

As long as plenty of air is available, aerobic decomposers work faster and more efficiently than their anaerobic counterparts, providing you with finished compost on a faster timetable. However, as organisms deplete the supply of oxygen from the existing spaces and pores between bits of organic matter, the decomposition process slows.

Anaerobic organisms work without oxygen, so most anaerobic takes place underground in pits or trenches. Basically, you dig a hole, fill it with organic matter, and seal it with a layer of soil. Anaerobic decomposers get right to work, with no need for fresh O2.

Anaerobic organisms work at slower rates than their aerobic counterparts, and it’s impossible to monitor their progress without digging into the hole and poking around. Anaerobic organisms exude smelly gas as a byproduct of their exertions. And because of the colder conditions, weed seeds and plant pathogens aren’t destroyed.

The major difference one can observe in the composting methods is the end products and their stability in the environment. Nuisance to the surroundings is another point to be noted.

I am affraid that there does not exist anaerobic composting at all. Please have a look at the following "composting (compost) definitions":

Composting is a form of waste disposal where organic waste decomposes naturally under oxygen-rich conditions. (http://study.com/academy/lesson/what-is-composting-definition-and-examples.html)

Composting of waste is an aerobic (in the presence of air) method of decomposing solid wastes. (https://en.wikipedia.org/wiki/Compost)

Composting is a natural biological process, carried out under controlled aerobic conditions (requires oxygen). (http://www.ecochem.com/t_compost_faq2.html)

Composting is the aerobic bio-degradation of organic materials under controlled conditions, resulting in a rich humus-like material.

Let’s now talk about the key parts of that definition. Firstly, composting involves ‘aerobic’ processes, which means simply that it requires oxygen to proceed properly. While ‘anaerobic’ (without oxygen) regions can (and will) develop in a compost pile/bin, our aim is to keep the system as aerated as possible. (http://www.compostguy.com/composting/composting-defined/)

Composting is the biological decomposition and stabilization of organic substrates, under conditions that allow development of thermophilic temperatures as a result of biologically produced heat, to produce a final product that is stable, free of pathogens and plant seeds, and can be beneficially applied to land. Thus, copmposting is a form of waste stabilization, but one that requires special conditions of moisture and aeration to produce thermophilic temperatures. The latter are generally considered to be above about 113 oF (45 oC) (Roger T. Haug. The Practical Handbook of Kompost Engineering, Lewis Publishers, 1993 (https://books.google.cz/books?id=MX_jbemODmAC&pg=PA1&lpg=PA1&dq=official+composting+definition&source=bl&ots=Wd2Kopffl9&sig=cKfPqEeltmko2rQgA4ERKri-HGk&hl=en&sa=X&ved=0ahUKEwjBiZ3xrsTSAhXJLhoKHfi4BmMQ6AEIQDAG#v=onepage&q=official%20composting%20definition&f=false))

All of them strictly talk about aerobic condition or oxygen presence.

Regards

Vit 

 Mr.Vit Mateju,interesting point/ question raised.In India we have two popular methods of composting-Indore method(developed originally by Albert Howard and Y.D.Wad,1924-1931) and Bangalore method( developed by C.N.Acharya,1939).The former method is aerobic and the latter one is anaerobic.The Bangalore method (anaerobic) is adopted by Central and state Governments in India for the safe composting of night soil and refuge.Though the Bangalore method is called anaerobic method,initially for a few days it is aerobic.The anerobic decomposition is slow process and takes 4-6 months to completeThe composting is carried out in pit.The refuse and night soil are put in alternate layers in the pit and the pit is covered,creating anaerobic conditions.In this method pathogens are killed effectively and foul smell is controlled.The following two references will provide detailed information.

shodhganga.inflibnet.ac.in/bitstream/10603/110226/5/05_chapter 1.pdf

Composting Sanitary disposal andreclamation of organic waste by Harold B.Gotaas World Health Organization Geneva 1956 

http://www.fastonline.org/CD3WD_40/JF/413/05-166.pdf

Interested

In a village concept the anaerobic decomposition of manures can generate natural gas for clean cooking eliminating the dangerous combustion by other sources within the home setting causing largely unnecessary health issues.

By then recovering the anaerobic residue it is captured in Indore conventional above ground aerobic composting.

I believe for developing world situations this is best agricultural solution. By the way the advantage of aerobic composting is the reduction and concentration of materials and their added value making them more healthful and easier to return to gardens and fields.

As biochar systems can be used as ways of harvesting renewable energy to a grid of energy the biochar can be used for acid soil depleted areas both in compost mixtures and/or directly to depleted gardens and field.

I do not believe either anaerobic or aerobic are off per se but a better result can be had by working these in tandem and viewing the material and its disposition as part of system.

Smell: anaerobic condition produce stinky gasses and by-products. Aerobic process produce mainly odorless gasses.

By-products: Anaerobic process produces Methane instead of carbon dioxide in case of aerobic.

Heat: Aerobic process produces heat as the bacteria consumes oxygen. This kills any pathogen and weed seeds when composting. This is not the case in anaerobic composting.

Time: it take more time to decompose the organic matter through anaerobic process. The oxygen and heat expedite the decaying in aerobic process.

Uses: The cattle manure is decomposed anaerobically to produce methane that is used for combustion purpose. The compost, manure and compost tea is made through aerobic method that produce useful nutrients and microbes for plants.

Ref: is anaerobic composting harmful? link: https://www.leaffin.com/anaerobic-compost-tea-aeration-pump/