Existing methods such as the Diary Farmer's "Aerobic Plate Count" inhibitor test are not directly applicable to anaerobic biogas conditions, so a New Biogas Inhibition Test Method is badly needed.
A major biogas plant systems provider WELTEC BIOPOWER, has now recognised this need, and has set about developing a solution.
The Problem Which Needs Solving by a New Biogas Inhibition Test for Anaerobic Digestion Plants
Anaerobic digestion plant operators are regularly faced with a dilemma whether or not to accept a feedstock as a biogas plant substrate.
To be told the source of the material in detail is generally not enough to base a reasoned judgement on the applicability of adding that feedstock to an existing or new AD plant.
A knowledge of such information about a feedstock such as its pH, calorific value, alkalinity, heavy metals content, and ammonia concentration, will be useful.
But, it won't inform the plant operator of possible negative inhibitory effects,and biogas process interruptions, which in extreme cases might possibly occur to the extent that introducing a new feedstock could jeopardise the entire gas production of the digester.
For this to be made possible, a quick test needs to be developed by experienced water chemistry and biochemistry specialists.
This test needs to provide controlled conditions under which anaerobic biochemical activity can be measured, including biogas yield so that inhibitory factors due to chemicals and even some moulds in a feedstock, can be predicted in advance.
This is no easy task to accomplish, so watch this space and we will provide further information as more results of the research described below become available.
Now we suggest that you read the following WELTEC BIOPOWER PRESS RELEASE ON THIS SUBJECT WHICH WAS RELEASED IN MARCH THIS YEAR:
WELTEC BIOPOWER Develops Innovative Analysis Procedure for Biogas SubstratesTogether with renowned partners, the biological department of biogas specialist WELTEC BIOPOWER in Vechta, Germany, is developing a quick test for identifying inhibitors in biogas substrates.
Input mass may contain substances that prevent efficient biogas production. For example, a small amount of mould is sufficient to cause such an adverse effect in silage. Plus, high ammonia from high nitrogen content feeds, is a well-known inhibitor.
Heavy metals, such s copper and zinc can inhibit methanogens. Drugs and and also disinfectants, are also identified as inhibitors in slurry and manure. Even traces of these substances are detrimental to the bacteria in the digester and thus counterproductive to the digestion process.
|© Photo Hölzen - WELTEC BIOPOWER has run its lab in Vechta since 2009. In Vechta, the biologists and lab team can conduct all important analyses and regularly examine samples from more than 300 digesters.|
Therefore, it is absolutely necessary to identify such inhibitors before transferring the substances into the digester. Since December 2016, WELTEC is involved in a research project to establish a new procedure that will solve this problem.
The project is subsidised by the German Federal Ministry of Food and Agriculture (BMEL) via Fachagentur Nachwachsende Rohstoffe e.V. (Agency for renewable resources). In collaboration with HAWK, the Göttingen University of Applied Sciences and Art, WELTEC is developing a quick, reliable and inexpensive procedure for identifying inhibitors in input substances.
For this, various feedstocks are first examined in the WELTEC lab in Vechta and at HAWK in Göttingen with the help of the Ankom system.
This system delivers precise information on the gas production. Moreover, the change of the acid spectrum is monitored while deliberately adding inhibitors.
The resulting target curves will henceforth be compared with the gas production curves of substrates. This comparison is to reveal whether the substrate contains any inhibitors.
Previously, the aerobic four-plate inhibitor test used to be employed for identifying inhibitors.
|Together with renowned partners, the biological department of biogas specialist WELTEC BIOPOWER in Vechta, Germany, is developing a quick test for identifying inhibitors in biogas substrates.|
In this way, biogas plant operators will be able to determine the quality of their input materials precisely, speedily and inexpensively.
"The need and demand are on hand. Currently, there is no quick and reliable way to identify such potential process disruptions, though this would be vital to avoid unscheduled downtimes of biogas plants",explains Sabine Lampe, graduate biologist and supervisor of the research project at WELTEC BIOPOWER. This is what made WELTEC and HAWK initiate the project, in which the Fraunhofer UMSICHT Institute in Oberhausen and Berlin-based analytics specialist aokin are also involved.
"Based on this innovative procedure, biogas plant operators will be able to decide faster whether to buy offered silage or liquid manure or whether to use a certain batch of their own slurry",explains Sabine Lampe. She added that it would also be possible for substrate providers to use this quick test to furnish evidence of the quality of their product. WELTEC BIOPOWER GmbH · Zum Langenberg 2 · 49377 Vechta · Germany Phone: +49 4441 99978-0 · Fax: +49 4441 99978-8 · Internet: www.weltec-biopower.de