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Upscale and demonstration of a integrated novel microwave pre-treatment system for efficient production of biogas from anaerobic digestion of pig manure to create a sustainable waste management system

Periodic Reporting for period 2 - biowave (Upscale and demonstration of a integrated novel microwave pre-treatment system for efficient production of biogas from anaerobic digestion of pig manure to create a sustainable waste management system)

Reporting period: 2017-06-01 to 2018-07-31

Generating biogas from pig slurry on its own is a challenging proposition. The design of pig farms typically lend themselves to storing slurry in tanks under the pig housing or in large lagoons. In these storage tanks the slurry will often sit for weeks or months and will naturally digest and generate methane, carbon dioxide and other gases. In order to treat slurry in a biogas plant, developers and farms construct large anaerobic digestion plants and co-mix the slurry with other feedstocks. These can be food waste, energy crops or grass. The challenge that Biowave is addressing is developing a sustainable anaerobic digestion system that operate on slurry alone and generates a greater volume of biogas compared to conventional systems. The Biowave microwave unit treats slurry as part of the process. This enables greater availability of digestible organic matter which the anaerobic digestion process can convert to biogas more readily.
Pork is the most widely consumed meat product in the world and production is expected to increase by almost 40% in the next few decades. European pig farms produce over 1bn tonnes of methane rich manure per annum. In addition to this, pig farming emits around 700m tonnes of greenhouse gases per annum. Agriculture as whole emits 5bn tonnes, thus pig farming contributes about 13% of the overall Agriculture total. Novel and cost effective means for farmers to convert low value by-products such as slurry into renewable energy are important for society as a whole. The Biowave concept enables farmers to operate an anaerobic digester in a straightforward manner and generate increased biogas production which enables an attractive return on investment.
The overall objective is to scale the lab Biowave system to a commercially acceptable solution installed on a working farm. The microwave system treats 5-10 tonnes of slurry per day and has been fully integrated with a pilot scale anaerobic digester to enable full end to end system validation.
The project commenced in April 2016 with a partner meeting in Waterford, Ireland where the project coordinator Ashleigh Farms (Environmental) is based. The requirements for each work package were discussed i.e. who was responsible, who was the lead beneficiary, who were the contributing beneficiaries and sub-contractors, what was required and most importantly timescales agreed.
‘Formal’ technical meetings took place every three months where all beneficiaries and sub-contractors met. In addition to the formal technical meetings there have been a large number of bi-weekly and monthly meetings between the coordinator AFE and individual beneficiaries both in Ireland and the UK.

WP1 - The outline BioWave system has been specified. This specification can now be used to generate PFD and P&ID documentation, so that the system may be designed, component parts ordered and the prototype system built.
WP2 - The microwave system was modelled, designed, and manufactured.
WP3 – The AD unit was designed suitable for commercial validation and a complete Bill of Materials was produced itemizing: Item description, Material, Number required, Power, Supplier and any comments in the form of notes.
WP4 - The sensors have been chosen to support each of the sub-systems being monitored and are tailored to each of these systems, being an experimental unit this system has more sensors than a production unit would, in order to monitor the changes that are expected to be made to the operation of this system in order to optimise the system.
WP5 - The microwave system was built and tested in terms of microwave measurement, temperature regulation, endurance and pressure. All the tests gave satisfying results.
WP6 – The bespoke Anaerobic Digester was built and commissioned
WP7 - All planning and departmental approvals have been granted. The site was designed, prepared and completed for the test rig
WP8 - All commercialisation tasks including a fully developed business plan and dissemination and exploitation plan have been completed
WP9 - The project was managed from initiation right through to validation and completion.

The following deliverables were achieved:

D1.1 Requirements and specifications report

D2.1 CAD design of up-scaled rig

D2.2 Process flow diagram

D2.3 Production and Instrumentation Diagram

D2.4 System components ordered

D3.1 CAD design of AD system

D3.2 Process flow diagram

D3.3 Production and Instrumentation Diagram

D3.4 Bill of materials

D3.5 AD system components specified

D4.1 System sensor specification

D4.2 Microwave reactor and AD control algorithms specified and tested

D4.3 Conduct HAZOP

D5.1 Built microwave reactor with control software implemented

D5.2 Dry testing report

D5.3 Risk assessment report

D5.4 Standard operating procedures

D5.5 Construct containerised unit, carryout working trials, write operating and maintenance manual

D6.1 Built AD validation unit with installed control software

D6.2 Risk assessment report

D6.3 Standard operating procedures

D7.1 On site pig slurry treatment system

D7.2 Field trial report

D7.3 Optimised complete system

D8.1 Plan for dissemination and use of the technology

D8.2 Business plan

D9.1 Ethics requirements

As of end of the project a fully integrated pilot plant has been designed, manufactured, constructed and operated.
Biomethane analysis of the slurry treated by the Biowave microwave system has shown a considerable improvement in the production of biogas compared to untreated slurry of over 40%. This has validated that the Biowave microwave pretreatment technology is highly disruptive and has enormous commercial potential. It is a system that's applicable in a range of biogas production plants and the consortium are planning to execute new projects and commercial applications as a result.

The BIOWAVE project is a major advancement of microwave systems, including their control philosophy and general construction, for the on-farm biogas industry. Microwaves are starting to be utilised in bioeconomy and renewable energy industries as their advantages are now more properly understood and the Biowave project has demonstrated this at scale.

Socio-economic impacts include knowledge creation of renewable energy and biogas production within the local communities and the supply chain of the project partners, the realised potential to create a new market for farm-scale biogas plants using novel microwave treatment processes and a meaningful interest from regional and national development agencies on the Biowave concept.