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The Secret Recipe for Efficient Energy From Waste Delivery

Challenging the status quo of conventional fossil fuel power stations.

The four crucial factors governing success for Energy from Waste (EFW) and biomass combustion projects continue to revolve around:

  • location
  • technology
  • fuel supply
  • investment

Ground Breaking Technology Will Win the Smart Money

Despite the challenge of what can be ground breaking technology, at least in its application to residual waste, the ever increasing interest in EFW projects appears undaunted.

This is because the environmental and financial returns stack up extremely well and it’s an excellent alternative to other intermittent renewable energy sources such as wind or solar.

Waste wood biomass and residual waste from domestic and commercial sources are certainly plentiful in the UK and  there is a trend to move away from large mass-incineration to smaller, more sustainable plants fueled by local recycling operations. There are a consistently growing number of EFW  projects in the pipeline and under construction, and smaller Combined Heat and Power (CHP) schemes. Saxlund, for example, is involved with a number of projects in the UK including Margam in Port Talbot, Templeborough in Sheffield and Port Clarence in Teesside. [Link to press releases]

Fixing Weak Links Can Be Costly and Time Consuming

Attention is starting to shift to less common Advanced Thermal Treatments (ATT) such as gasification or pyrolysis. While this technology has been around for many years, its application to municipal / residual waste as a feedstock is somewhat more challenging. You only have to look at one of UK’s largest advanced plasma gasification projects in the Tees Valley, known as TV1, which has been struggling recently with technical difficulties. At this scale, 1,000 tonnes per day, you would expect some initial teething issues as it’s the first of its size and type in the country. However there are a number of smaller, simpler ATT projects under construction in the UK based on previously proven technology.

Four Steps to Clean Energy at The Grid

Whatever the technology involved, the basic process remains the same:

    • A reception system to receive the fuel whether biomass, RDF, or another waste derived fuel, and then feed it to the combustion process. This may include systems including weighing, screening for oversize and ferrous and non-ferrous metal removal.
  • The selected thermal treatment, to release the energy from the fuel, the most challenging aspect (especially with gasification)
  • Conversion of the energy to produce electricity, heat and derived fuels
  • Emissions clean up

Enabling Optimum Plant Performance

While significant project attention is focused on the technicalities of the selected thermal process and the energy conversion technology to which it is linked, there is a real danger if front end systems for fuel handling aren’t as robust as the end point technology.

It’s understandable given the focus is on ensuring the chosen thermal process will deliver the efficiencies and energy output required to make the plant viable. However, if the design process fails to identify material handling efficiency it will have a direct bearing on whether the plant reaches its full potential.

Reducing Human Intervention in The Feed Process

Waste derived fuels and biomass are non-free-flowing with a tendency to bridge and compact. It means the flow can easily clog and block, disrupting dependent processes often with far reaching consequences, up and down the supply chain. Indeed, some plants may never reach their full performance or overrun extensively in time and cost just to get them operating at all.

Disruption or poor consistency in the fuel delivery will inevitably lead to costly plant shut downs, so it is important that the material handling aspects are treated as part of the whole project and not a separate add on once everything else has been decided. Automated ‘first in first out’ storage principles are also vital, an area where Saxlund continues to lead the industry.

Proven Technology with Efficient Results

Saxlund has been engineering successful material handling solutions for biomass combustion and EfW over many years.  Our goal is to deliver the lowest cost of ownership for the lifetime of the plant and to design out premature failure. To ensure bulk material handling isn’t the weak link in your energy project, read my article in Materials Recycling World [link to MRW article] or contact us for further information.