Biogas production, composting or something else?
Handling organic waste material is challenging. The traditional methods cover both anaerobic and aerobic process types which both have their pros and cons. Alongside these methods, treatment in Ecolution aerobic bioreactor has been developed to give a cost-efficient alternative, that is an easy and quick way to reduce the amount of organic waste, producing only a nutrient-rich product without any further waste streams.
Find out about processing methods
Common for the biological treatment of organic fractions is the functioning of microbes. Whether anaerobic or aerobic microbes are used in the process depends on the desired product. While digestion can provide biogas and electricity from it, composting can produce nutrients for cultivation, i.e. compost, land improvement and fertilizers.
Treatment is based on microbial metabolism
Whereas aerobic microbes require oxygen, anaerobic microbes do not tolerate oxygen. In digestion, microbial metabolism produces methane and carbon dioxide, a combination of gases that is called biogas. When biogas is produced, a residue of digestion is formed as a waste stream, which requires further treatment. Without any treatment, the use of the sludge in arable farming is not without its problems.
It is not possible to produce energy in aerobic processing, but the investment is also smaller. On the other hand, when composting process is not optimized, air and its oxygen are not evenly distributed, which creates anaerobic pockets in which anaerobic microbes begin to function, producing the methane uncontrollably. Extensive composting areas increase the challenge of aeration and process control.
Ecolution bioreactor combines the benefits of digestion and composting
Tiina Piira, process expert at Chemitec Consulting Oy and a member of the Board of Directors of Ecolution Oy, is convinced of the benefits of the Ecolution bioreactor.
“Bioreactor combines the benefits of digestion and composting”
- There is a lot of information available on organic fraction processing methods, but the problem often is that the composition of the feed is not sufficiently known to choose the processing method, says Piira of the general problem of customers. Only feedstocks suitable for each process should be fed into the digestion and aerobic processes. According to Tiina Piira, the mass that does not decompose while processing reduces the yield and causes problems after treatment.
- Occasionally, unsuitable organic distributions, such as materials containing large quantities of lignin, are tried to be fed into the digester. They do not process and even act as inhibiters , i.e. hinder the normal functioning of the process. In addition, a biogas plant is a large investment and therefore the profitability should always be carefully assessed.
- The Ecolution bioreactor combines the benefits of digestion and composting. The cost of the reactor is considerably lower than that of a biogas plant, so its choice is justified when energy production is not desirable. It’s a method much faster than composing and produces organic land improver.
- According to Piira, in addition to the solid fraction formed in the Ecolution bioreactor, both gaseous carbon dioxide and process water can be utilised in greenhouse cultivation.
- Maximum synergy benefit is achieved when organic matter is handled safely and in a controlled manner close to where it was created and the products are utilised in local farming.
Tiina Piira,
Process Specialist at Chemitec Consulting Ltd.
Contact details
Chemitec Consulting
Tietäjäntie 2
02130 Espoo
+358 50 585 2627
info(at)chemitec.fi