Teaming with APP & National Grid to reduce the carbon footprint of fuel
Dr David Deegan, the Chief Technical Officer of Tetronics International gives the low down and an engineer’s perspective on the latest exciting Tetronics project
Tetronics is currently providing clean plasma technology to the world’s first commercial plant to produce biomethane from household waste. The plant will process 10,000 tonnes per annum of refuse derived fuel and waste wood to produce 22GWh per annum of grid quality natural gas energy, enough to heat 1,500 homes or fuel 75 heavy goods vehicles. This project will provide a reference facility, operating under commercial conditions to enable the financing of large scale commercial projects.
The project is being delivered by our sister company, Advanced Plasma Power alongside its core partners National Grid Gas Distribution, and Progressive Energy. The partners are also joined by consortium partners Wales and West Utilities and CNG Services.
Playing our part to help reduce the carbon footprint
There has been a lot of public debate on climate change, waste management and energy security. Often the subjects are considered in isolation and, as is often the case, when examined in detail appear to be significantly linked under the umbrella of sustainability:
- Climate change – this is all about CO2 emissions and decarbonising the economies of the world to reverse, or at least stall, the impacts of global warming. However, most emphasis has been on the carbon footprint of electrical power and not more generally of fuel based energy sources.
- Waste management – landfill disposal of waste fails to valorise the intrinsic energy and material value of waste and its ability to offsetting virgin fuel or material equivalents. Modern waste management regimes, inclusive of Energy Recovery Facilities (ERFs) or incinerators compliment recycling and meet part of this requirement; but their efficiency, material valorisation and secondary waste profiles are questionable.
- Energy security – As natural source become more dispersed, complex to access, prices escalate and national boundaries and politics inhibit transfer movement; in this context waste must be seen as an opportunity and not as a problem.
The complete solution to the waste dilemma and energy trilemma
The project, sponsored by the Department for Transport (DfT), Ofgem and National Grid (NG), represents an enabling reference plant for a technology that has the potential to significantly address the environmental impacts of heating, transport fuels and waste management and to reduce climate change impacts outside of the electrical power arena. It focusses on the other two main energy requirements of the UK, i.e. natural gas for heating most UK homes (23 million customers) and fuel for transportation. In this way, it could support the sustainable mobility of the UK and avoid house-holds slipping into energy poverty; with a solution that complements existing national infrastructure and policy.
In summary, the project combines the use of a residual (after recycling) waste derived fuel, in a two-stage thermal gasification process that produces a syngas which is cleaned and transformed into a natural gas equivalent, using proprietary catalyst technology. The natural gas equivalent is known as SNG or substitute natural gas and is a compatible with domestic heating appliances and transport fuel requirements.
How plasma plays a vital role
The work of Tetronics’ delivery team focuses on the heart of this innovative two-stage thermal process – the engineering, procurement and manufacturing of a plasma energised conversion vessel. This converter process vessel is required to do the following:
- Process or polish syngas to increase its quality
- Minimise energy consumption and manual intervention whilst polishing the gas
- Vitrify the inorganic dust and flyash removed from the syngas to form a glass-ceramic product called Plasmarok®
- Safely containing the process that occurs in a sealed, flammable, high temperature, bright and dynamic process environment
- Maximise annual process availability profiles in continuous operation and therefore minimise scheduled and periodic maintenance demands
- Undertake the process with remote operation via plc or computer control, with real time and condition based monitoring diagnostics
This is an example of plasma being used very selectively to maximise benefits and efficiencies to valorise or convert waste to fuel; which is counter to the typical and often wrong default position which is assumed with respect to the technology. To achieve all of the process requirements simultaneously Tetronics’ engineers have relied on the company’s decades of experience and employed some of the most advanced computer aided modelling to inform the design with the results having been validated by pilot plant operation.
The models include multiple fluid phase fields, electrohydrodynamics (EHD), mass and heat transfer routines/balances and chemical reaction considerations. This is all complemented by good old know-how and fundamental engineering. This together is then transformed into detailed equipment specifications. The long-established and extensive Tetronics’ supply chain is then used to make this a physical reality.
Tetronics is proud to be teaming with Advanced Plasma Power and National Grid and to be part of this pioneering UK based project which is expected to be ready for commissioning in the last quarter of 2017.