Brief Technology Description
Development of an internationally certified biogas testing facility is underway to provide industry with reliable data on the water reclamation and energy potential of their wastes and ensure that successful commercial projects can be developed based on reliable energy output estimates.
Next Steps Required
Deployment of anaerobic digesters at four different universities in South Africa to allow independent, standardised tests of any given sample to ensure reliability of results through round-robin testing, thus attaining certification and accreditation.
Postgraduate student in chemical engineering (research project opportunities)
Postdoctoral fellow/Research engineer
The facility will be operated under the auspices of Stellenbosch University (SU), one of the oldest universities in South Africa with world-wide recognition and research and innovation leader. Personnel and students are resident at the Dept. Process Engineering at SU, also recognised as a leader in training world-class chemical engineers.
Detailed Technology Description
Seventeen pilot scale biodigesters with 30 L capacity were commissioned at the Department of Process Engineering, Stellenbosch University, and are operated using reliable protocols for testing high moisture content solid and liquid waste streams for biogas production and water reclamation. Protocols were developed using paper sludge and fruit juice processing waste, with water from the primary clarifier at paper mills used as make-up water. The developed protocols involve a combination of BMP tests and subsequent anaerobic digestion in continuously fed reactors.
Businesses wishing to venture into or expanding biogas facilities, or utilise alternative waste streams for anaerobic digestion often faces the dilemma of uncertain process performance and biogas yield. Substantial risk is thus presented when basing investment decisions on uncertain process performance. Analysis of samples at pilot scale with short turnaround time would greatly mitigate this risk and aid capital budget decisions. Moreover, a database will be created where performance indicators of a range of waste streams will be easily accessible. The facility will be deployed at five universities nationwide, offering easy access to potential clients irrespective of geographic location. Round-robin testing between facilities will support reliability of results and will be internationally verified by German technology partners.
For a wet anaerobic digestion process, solid waste should be mixed with liquid to facilitate mixing to achieve uniform heat and mass transfer throughout the digester. Industry liquid waste streams can thus be used as make-up stream for solid wastes for biogas production. Such a process will not only reclaim water from solid wastes, but will also clean the industry waste water stream, which can be recycled as process water. The programme will be implemented through standardised waste processing and testing protocols using a range of different types of waste, which can be further used to populate a national database for water reclamation, biogas production potential and digestate analysis.
Testing and Demonstration Results
Experimental work using a bank of 17 anaerobic digesters at Stellenbosch University are underway with a Masters’ thesis anticipated in 2018. Further banks of reactors will be deployed in 2018, which would allow round-robin testing, verification of results and subsequent accreditation. Test results of selected feedstocks will be verified by an international organisation located in Germany.
Papers and Publications
The unique process development and improvement strategies applied for biogas production from fruit juice industry waste and paper industry waste will lead to articles published in international peer-review journals.
Existing products are not licenced at present and all technology forthcoming from the present research will be managed through the technology transfer office of Stellenbosch University.
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