AD Trial

CLEAN Cowra is planning a trial in mid-March to demonstrate the practical efficacy of the Cowra biomass project. Information from this trial will inform how we set up a later event – a full scale implementation of the Anaerobic Digester (AD) plant. 

First step will be a temporary onsite laboratory test to establish data and ascertain the true value of the codigestion process from local feed stocks.

That initial trial will utilise a mobile laboratory-scale anaerobic digester deployed on the back of a semi-trailer. With this we will process feedstock from our various local biomass suppliers with a view to establishing the quality of the gas produced. The raw data will indicate the energy values generated by each type of biomass.

We’re calling it the ABC trial (aggregated biomass co-digestion), emphasising it’s a collected stream of biomass, co-digestion meaning that we use the interaction of the different biomass to get the different gestate. Considering we anticipate that a fully operational plant would produce up to 60% of Cowra’s energy needs, this will be an excellent reference for which local waste streams we should be sourcing.

The results of the event, run over 10 days, will give us good raw data, as opposed to the desktop analysis we used in the PFS. They’ll assess the gas production for heat, and potential of the process for creating commercial quantities of agricultural fertiliser, converting local resources to establish outputs of much increased value.

The trials will cost around $25,000.

The ABC trial will inform a later demonstration of the AD plant, to be developed in consultation with Cowra Council. It will utilise a more complex, permanent infrastructure installed in a covered lagoon at the Cowra Waste Water Treatment Plant (WWTP). It’s a larger scale implementation of the initial trial, converting waste streams in the pond into anaerobic digestion. It will also provide a proof of concept insofar as the values of electricity generation, in addition to the values provided by the initial trial.

All the studies that we’ve done, as well as the indications of the Industry Reference Panel, Sydney Water and Melbourne Water is that codigestion has a great value in terms of waste water processing. Indeed it is a mainstream industry in Europe, with 6,000 AD plants in Germany alone and the European Biogas Association citing massive growth in certain countries such as the UK, where the number of biogas plants has doubled in the year up to September 2016. 

There are direct benefits to local industry, agriculture and local government in utilising the energy extracted from this process.

These include reductions in environmental impacts for the infrastructure and materials we will be using. Currently our waste water treatment plant produces a certain amount of unpleasant odour. The anaerobic process will considerably reduce the odour component and reduce the impacts from their current disposal. It will also reduce methane emissions by burning it to produce electricity.

As the European experience has shown, utilising biomass as an energy source creates an industry around that process, so the resource recovery to energy conversion and the creation of fertiliser from by products are industries in themselves – creating social benefits and localised employment for small communities such as Cowra.