Crescendo of activity in alternative fuel energy sector

If you’ll pardon the pun, activity is really heating up in the alternative fuel combustion market as a number of projects are commissioned this year. For Saxlund it’s a busy time and we are on schedule to deliver more than 13 alternative fuel handling solutions, supporting a variety of combustion and gasification projects in the UK alone. Most of these are now either waiting to be commissioned or already undergoing production trials.

Galliford Try Infrastructure, for example, appointed us back in 2016 to design and deliver the bulk fuel reception and handling technology for three waste wood gasification facilities in Barry, Boston and Hull, for the renewable energy company Biomass UK. All three projects are at an advanced stage, pending dry or wet commissioning, with project completion expected in the second half of 2017.

Galliford Try Barry Infrastructure Push floors
Galliford Try, Barry, Infrastructure Push floors

Other sites include the Tansterne Advanced Biomass Project in Hull for HRS Energy where the first of two fuel streams is already commissioned; fuel handling solutions for Bouygues Energies & Services at two waste-to-energy gasification plants, one at  Hoddesdon in Hertfordshire and the second in Belfast; a fuel reception and delivery solution for a pioneering green gas generation plant at Marston Gate in Swindon for Go Gree Fuels; three projects with Babcock & Wilcox Vølund A/S, for biomass powerplants at Templeborough in Sheffield, Margam in South Wales and in Teesside; and a fuel handling solution for M+W Group the lead contractor for the Surrey County Council SUEZ operated Eco Park,  at Charlton Lane in Shepperton.

Tansterne Advanced Biomass Project
Tansterne Advanced Biomass Project


Customers appointing Saxlund expect several things, but fundamentally they are looking for high availability, low maintenance solutions to ensure the plant achieves the projected output in terms of energy production, and in tandem with this the financial returns that shareholders are anticipating, without whom many of these projects would not be achievable. 

Engineers who have worked with biomass and other alternative fuels will appreciate the challenges and will, no doubt, have experienced some of the issues that these fundamentally difficult fuels can present.


Mouldering and stagnated fuel heaps and constant recourse to air lances and the like to remove obstructions and restore flow have plagued many sites over the years, with constant stoppages and downtime. As an engineering design house, we frequently find ourselves troubleshooting systems that aren’t delivering, either where the original design has been defective in some way, or where the finances haven’t allowed a sufficiently robust solution in the first place.

Maintenance, or more particularly planned preventative maintenance, is another area that sometimes doesn’t receive enough upfront consideration. While it might be tempting to push machinery fractionally beyond its operating window, unplanned maintenance shutdowns due to breakdowns are likely to be costlier to rectify with consequences to downstream processes and supply chain deliveries.

Tansterne Advanced Biomass Project in Hull Push Floor discharge conveyor

Fuel characteristics

Biomass and alternative fuels such as Refuse Derived Fuel (RDF), now on the increase in the UK, and Solid Recovered Fuel (SRF), share similar characteristics. They are typically non-free flowing, wet and liable to compact and will happily form bridges in silos and chutes. So the potential to disrupt downstream processes shouldn’t be underestimated.

Material characteristics can change too, delivery to delivery, and we frequently see over-optimistic expectations when it comes to feedstock quality and consistency.  Even a reasonably consistent input material like waste wood can throw-up surprises. One in ten truckloads for example may be largely or completely composed of fine dust. Others may be black and compacted having been stored too long.

RDF with mixed organic residues can be even more challenging. These factors may be outside your control and will test the capabilities of installed handling systems if the design is defective, resulting in poor or erratic material flow, stagnant product and costly periods of outage.

Future proofing

Over the lifetime of a plant, twenty-five years or more, its quite conceivable that fuel specifications will change too, or that you need to switch to a different fuel, say from biomass to RDF.  Planning for this at the design phase is also essential.

Returning to the fuel storage and handling projects in Barry, Boston and Hull for Galliford Try Infrastructure, future proofing the design specifically for this reason has been a key design focus from the outset.

Each site is similar with twin Saxlund Push Floor storage bunkers discharging waste wood into a conveying and screening system. This incorporates oversize material and ferrous metal removal and weighing systems before feeding fuel to twin gasifiers. At each site one of the Push Floors is designed to accept straightforward modifications to handle RDF, extending the operator’s fuel flexibly if supply pressures occur.   

Each system will provide on-site storage for approximately 600m3 of waste wood and is designed to discharge some 100,000 tonnes of fuel per annum.

Galliford Try Infrastructure, Boston, screening tower

Good design

Good design is clearly essential if you want a fuel feed solution that works from day one and is also reliable. The temptation to select cheaper ‘equivalent’ solutions will be attractive if CAPEX expenditure can be reduced, but it makes no sense if the result is higher operational costs to resolve fuel feed issues, with expensive manual interventions and costly fixes.

Design direction to provide sufficient fuel storage, plus reclaim and conveying systems, will also be dictated by site constraints and available space, factors that are sometimes overlooked at the early stages of project development.

Permitted vehicle movements for example including delivery hours and weekend working will also determine storage requirements and truck reception systems, and there may be environmental factors at play, including noise, dust and water run-off to consider.

Whether you are processing fuel onsite or relying on shipments from third parties, fuel cleanliness will also be important with a requirement for oversize and undersize screening and metal removal. Weighing and sampling might also be required to monitor quality and deliver fuel at precise rates to the combustion process. Together with reception systems, storage systems and reclaim conveyors, these are elements that need to work together seamlessly, and for the life of the facility. 

For Saxlund engineers key technologies for handling and storage revolve around activated surfaces and ‘first in, first out’ principles. This limits the opportunity for fuel to degrade and for most materials some form of Sliding-Frame or Push-Floor system is advisable. These make for dynamic rather than static storage and ensure that easily-compacted materials are kept on the move.

In general terms, a system design that favours vertical rather than inclined surfaces, broad rather than narrow channels and positive handling options such as screw-feeders and chain conveyors will minimise problems.

For most projects delivering the energy output required to make the plant viable will always be a major focus, but this shouldn’t ignore the fuel feed and handling aspects of a project. One is very much dependent on the other. Design features to overcome difficult fuel characteristics and to ensure full availability are clearly important.

Early engagement to allow a holistic approach is also beneficial and planning for changing fuel specifications, which may be outside your control, together with appropriate maintenance, must all be factored into the solution you choose. These are some of the reasons why clients select Saxlund International and with more than 60 years’ experience, we can ensure that bulk fuel handling solutions aren’t a weak link in your energy project too.

Is your fuel handling plagued by excessive manual intervention?

  • Biomass fuel feed – Avoiding failure

If you are currently operating or developing a biomass energy plant or gasification facility, then you’ll appreciate the importance of a reliable fuel feed and reception solution, to ensure long term plant viability and performance.

The same is true whether you are burning refuse derived fuels such as SRF, favoured in the cement sector, or RDF, and any number of alternative fuels from Municipal Solid Waste to Distiller’s Dried Spent Grain.

That said, the industry is littered with plant failures and facilities that simply haven’t achieved predicted energy outputs precisely because of fuel handling and storage issues. Why?

  • repeated interruptions in the fuel feed prevent the plant reaching peak efficiency or
  • excessive cost of unplanned manual intervention and troubleshooting, required to rectify issues, destroys the financial foundations and investment opportunity for the project.

Not only is this hugely costly but some plants may never reach their full potential or overrun extensively in time and cost just to get them operating at all.

The fuels we are talking about all have similar characteristics. They tend to be sticky, abrasive and cohesive with a tendency to compact and bridge. ‘Buyer Beware’ should be at the forefront of your thinking when considering a solution for your project as these properties can easily disrupt storage and conveying systems if the design is defective, resulting in poor or erratic material flow, with stagnant product and periods of prolonged outage.

Reception systems, storage and discharge, screening, reclaim conveyors, plus weighing and dosing systems, are all elements that need to work together seamlessly and for the life of the facility, twenty to twenty five years is typical.

So a full understanding of the handling and flow characteristics of the material involved becomes important, with a direct bearing on the engineering solution and long term plant reliability. Important considerations are:

  • Particle size
  • mass flow properties
  • density variations
  • moisture content
  • compressibility
  • engineering partner

Specialised in bulk material handling for more than 60 years Saxlund’s design approach focusses on activated surfaces and ‘first in, first out’ design principles. This limits the opportunity for fuel to degrade in the system, ensuring a continuous uninterrupted flow of product 24/7.

Today solutions are deployed across hundreds of sites in Northern Europe. Of the twenty or so biomass energy projects currently under construction in the UK, 13 have specified Saxlund fuel handling solutions incorporating either Saxlund Push Floor or Sliding Frame silos for fuel storage and discharge.

Bouygues Energies & Services, the company responsible for the engineering and construction of the UK’s largest waste-to-energy gasification plant currently underway at Hoddesdon in Hertfordshire, is just one example.

Plant longevity is another key factor. Slough Heat & Power, now owned and operated by SSE, and one of the UK’s largest dedicated biomass fired Combined Heat and Power (CHP) plants, for example has been operating since 2003 with Saxlund Push Floors feeding waste wood and recently installed a third Saxlund Push Floor fuel handling solution to feed additional combustion capacity with a 720m3 fuel reception area with live storage.

With over three years successful operation already completed RWE’s Markinch biomass power station in Fife is one of the largest of its type in the UK, burning over 450,000 tonnes of sustainable waste wood each year. Again the fuel storage and handling solution, developed by Saxlund, is a crucial element, designed to ensure uninterrupted operation 24/7. Read the full case study here.

As with all these projects the efficiency of the combustion process and energy conversion is clearly where much of the industry’s science and engineering is currently focussed, and rightly so. But a consistent uninterrupted fuel feed, when the material is typically sticky and difficult to handle, is just as crucial. Choosing the right engineering partner, plus a clear understanding of the material characteristics you are working with, will help to deliver maximum plant uptime, better reliability and improved confidence for all stakeholders.

You can find out more by visiting us online or visit us at RWM stand no 4D80. Why not call or email to book an appointment.

Why By-Products Are a Valuable Resource for The Food And Drinks Industry

 – Biomass handling in the food and drinks sector

Across Europe food and drink manufacturers have been piling into the bioenergy sector for some time, turning waste and production by-products into energy. Some are successfully producing sufficient energy – both heat and power – for their own needs, with surplus energy feeding back to the grid.

AD processes producing biogas from liquefied waste tend to dominate, but in some sectors dried production residues are also being used to fuel combustion plants, including fluidised bed boilers and gasification solutions.

Food waste is a valuable resource that should never end up in landfill

In the UK, we throw away some 14.8 million tonnes of food every year throughout the supply chain. This accounts for over 20 million tonnes of greenhouse gas emissions and 6.2 billion litres of water.

Around 40% of this food waste ends up in landfill where it produces harmful methane that has a Global Warming Potential (GWP) 21 times greater than carbon dioxide.

A significant change in the waste industry over the past few years has been the shift in mindset from waste to resource. Central to this shift is the waste hierarchy and landfill tax, which push waste materials higher up the value chain by increasing the cost of landfill and placing a greater importance on the principles of reduce, re-use, recycle and recover.

This is what the UK could look like in 2020 if we achieve zero food waste to landfill

  • Over 1.1 terawatt-hours of energy produced
  • Greenhouse gas emissions reduced by 27 million tonnes
  • £3.7 billion potential savings in the public sector
  • £12 billion saved by UK householders
  • £2 billion saved by UK PLC (retailers, manufacturers and caterers)

Coffee & Grain by-products are a perfect biofuel with a high calorific content

Coffee, or more correctly spent coffee grounds, are produced in vast quantities as a by-product of instant coffee manufacture. All those coffee pods and capsules that have brought new convenience to that morning coffee, once destined for landfill, is a perfect biofuel with a high calorific content.

Distillers Dried Spent Grain (DDSG) is another. It too is produced in huge quantities by an industry that produces millions of litres of spirits each year in the UK alone and is finding new uses as a biofuel in the drive for energy self-sufficiency. 

Resolving Sticky & cohesive material handling and storage problems

But these and other food and agricultural residues, such as palm kernels, make up a group of biomass products all with similar characteristics. The material is sticky, cohesive and non-free flowing with a tendency to compact and bridge.

For energy plant operators and developers, these properties can easily disrupt storage and conveying systems if plant design is defective, resulting in poor or erratic material flow, and periods of prolonged outage.  Excessive manual intervention and troubleshooting may be required especially at transfer points to remove blockages. This can be hugely costly and some plants may never reach their full potential.

Saxlund’s experience is ideally suited to resolving these material handling and storage problems. While the majority of bioenergy fuel handling projects we work on involve waste wood as the fuel – we are currently involved in 13 projects in the UK – we are also seeing an increase in projects within the food and drink sectors.

The ability to work with variations in the material composition

At one site in the UK for a major distillery business, a new fuel handling solution to feed Distillers Dried Spent Grain into an adjacent bio-energy plant is completing trials and testing. The system is based on the principles of activated and wiped surfaces, removing the opportunity for material to stick and build up in the system and restrict the flow.

The design involves a series of transport screws and elevating chain conveyors to transfer biomass cake 40 metres up and into an adjacent combustion plant. The standalone design ensures reliable 24/7 operation during production phases and is rated up to 30 tonnes per hour while ensuring additional handling system capacity for future expansion.

For this project Saxlund provided detailed consultancy with a number of design options, including live site trials for a section of the main elevating chain conveyor, to deliver proof of concept and project confidence.  The ability to work with variations in the material composition, including changes in moisture content, was a further design requirement.

Experienced solutions for the coffee drinks sector

Saxlund also has experience of handling coffee grain discharge solutions at a number of international coffee processing facilities. In the UK, for example, we recently completed the design and installation of a 150m3 capacity storage and discharge solution for handling spent coffee grounds used to fuel a fluidized-bed boiler.

Incorporating a welded stainless steel flat bottom silo, in place of conventional conical designs, with Saxlund Sliding Frame technology [click for more information here] at its base, the solution has been designed to provide an efficient and reliable storage and discharge system, with capacity to handle peaks in supply from freeze and spray dried production processes.

Measuring 12 metres high and four metres in diameter the silo sits on a base frame to allow vehicle access beneath the structure.  Pressed coffee grounds are pneumatically transferred to the top of the silo via separate blow lines while the reciprocating action of the Sliding Frame at the base of the silo continuously sweeps the material into a central trough which incorporates two separate screw conveyors to achieve the desired discharge option.

Unlike conical silos which rely entirely on gravity, the reciprocating action of the Saxlund sliding frame creates a ‘live base’ of material at the bottom of the silo to provide an entirely reliable and consistent discharge solution.

With both these projects, a full understanding of the flow characteristics of the material involved becomes important with a direct bearing on the engineering solution and long-term plant reliability. Particle size, mass flow properties, density variations, moisture content and compressibility are all important considerations. The composition of the biomass (or its source) may also change over time, and this needs to be factored into the system design to ensure a robust, enduring solution which can deliver an uninterrupted and consistent flow of material to ensure plant reliability.

As well as activated and wiped surfaces, Saxlund solutions also favour ‘first in, first out’ design principles, important where the calorific value of the material can degrade and for products that are likely to compact.

For more information on how we can help you optimise your existing biomass handling and storage systems or for turnkey engineering / visit … etc


Tel: +44(0) 2380 636330

Fax: +44(0) 2380 636343



UK data references:

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.

How Water Companies Save Up to £17,000K P/M

Increasing demands on water companies to meet environmental targets, reduce costly overheads and streamline operations have opened up further debate on alternative ways to be more profitable.

The UK Government and the Environmental Agency produced an evidence document in 2009 “transforming wastewater treatment to reduce carbon emissions”. The WFD (Water Framework Directive) set targets that good chemical status needs to be achieved by 2015.

So in 2016, today’s innovative water companies are shifting their focus from sewage disposal to energy generation.

Generating gas from sludge at large water treatment sites using anaerobic digestion and thermal hydrolysis infrastructures is a key part of the solution.

In a recent article in “Water and Waste Treatment Magazine” I discuss an effective solution that reduces costly overheads, transport logistics and processing waste. The in-depth article titled “Getting to grips with… sludge cake optimisation” covers and answers important areas such as:

  • What issues do water companies face from building new advanced digestion facilities?
  • Why do water companies need to transfer sludge between sites?
  • What methods are available for transporting it?
  • Why is sludge dewatering important?
  • How important is the quality of your sludge to you?
  • Why is the choice of storage systems important?
  • Why change from a hook lift container storage system?
  • What factors should be borne in mind when designing the Reception facilities on site?
  • How can costs of the process be reduced?
  • What’s the “transport system” cost / benefit?

See the full article here

In an article titled Sludge Management Water UK said: The recycling or disposal of sludge in a sustainable manner is a major challenge to the water industry”.  In a further statement they have said: “Many water companies have decided to increase renewable energy generation to offset the impacts of increased energy prices, to use their resources (e.g. sludge) as efficiently as possible”

The solution of dewatering of slurry and processing into cake reduces load volume representing 4:1 reduction in volume and enables a quicker turnaround of trucks, reducing transport and storage costs. This means 1 truck could be used instead of 4, typically the saving is around £10,000 to £17000 per month for a 100m3 truck loading silo.

If you would like to know more about how to reduce your cake handling costs and generate energy, please contact me on +44(0) 2380 636330

Your Name (required)

Your Email (required)

Your Telephone Number (required)


Your Message

CfD Causing Unfair And Unjustifiable Uncertainty

We believe combined heat and power (CHP) projects using UK waste wood should have a long-term beneficial role as part of the UK’s future energy mix, as is the case in Scandinavia and other parts of Europe. 

An abundance of raw materials for CHP plants

As an energy source, waste wood is not dependent on sun or wind and has the potential to provide consistent, sustainable, low-cost heat and power for industry and domestic use.  Not only that, but with 10 million tonnes of forest thinning’s, stumps and bark being wasted or transported overseas, recycling low-grade waste wood as a cheap energy source to power local CHP in the UK seems an obvious solution. 

CfD has a negative effect on investors confidence

However, as we move from Renewable Obligations to Contracts for Difference (CfD) investor confidence is suddenly faltering at the very time when biomass renewables in the UK seemed to be gaining ground. This is likely to have a damaging effect on the take-up of biomass EfW projects, especially the more beneficial small- to medium-size plants where local industries and communities can benefit.  This is a great shame, particularly when companies such as ours have been so successful in pioneering the technology to generate sustainable biomass energy which is already delivering returns on investment.

CfD process is “another reason not to”

The complexity, length and opaque nature of the CfD process is the root of the problem. Already this is sending a signal to potential investors who will be unwilling to invest time, energy and capital in planning potential biomass investments if the CfD process remains unsupportive. A bidding process that pitches biomass against alternative technologies in this way clearly needs re-evaluation.

CfD obscures the reality & benefits

The way that funding is split under CfDs into three pots is partly to blame. Biomass Energy with CHP for example shares Pot 2 for ‘Less Established Technologies’ with Offshore Wind. But experience so far however has seen the dominance of Offshore Wind completely denying awards to biomass schemes.  This seems ludicrous when waste wood is such an abundant resource in the UK.  It is a resource we are squandering, much of it being exported for the benefit of biomass projects in Northern Europe.

The data tells the story

The results from the first CfD auction were quite striking. Of the 27 contracts awarded, none were to Biomass Energy and only 5 were waste-related.  Of the Pot 2 allocation it was totally dominated by two Offshore Wind Projects totalling 1,162MWe. In addition there were three Advanced Conversion Technology (ACT) projects awarded totalling 62MWe. However, it meant that no CfD’s were awarded to Biomass CHP projects which were effectively squeezed from the Pot.  Albeit at an early stage, it appears that the current process favours big business and this is something we would like to see being re-evaluated to ensure an even playing field.

CfD postponement send the wrong message

Further doubts were sown in July when DECC announced the postponement of the next CfD auction round as this can create further uncertainty for investors. If the government believes that biomass energy solutions using waste wood and other renewables should play a part in a balanced and secure UK energy future then the CfD process should needs to be more supportive. 

Read my comment in MRW’s November issue full article…HERE

Matt Drew – Managing Director

If you would like to contact Saxlund International, please complete the form below or call us on Tel: +44(0) 2380 636330.

Your Name (required)

Your Email (required)

Your Telephone Number (required)


Your Message

Why New Cake Handling Systems Reduce Costs by 75%

The 20th European Biosolids & Organic Resources Conference is Europe’s foremost conference for the biosolids and biowaste industries and this year as well as reviewing sludge developments to date, will be exploring future solutions.

Due to my work with Utilities and Contractors in the Water Industry I was asked to demonstrate at the event some of the cost benefits Anglian and United Utilities are seeing from their innovative truck loading silos and sludge reception technology for digestion satellite and hubs, which is contributing to their overall gas generation model.


Innovative water companies are trying to be more efficient and cost effective and reduce their carbon emissions. Some are already changing their focus from water supply / waste treatment to energy generating. They are looking at the potential of sludge in a new way – as a possible source of profit rather than a cost. Why?

Instead of thinking of sludge as a cost centre and something to be disposed of, many water companies are deciding that generating gas from sludge at large water treatment sites (hubs) and transporting sludge from smaller treatment works (satellites) to hubs will be the model of the future. As part of sludge treatment improvement facilities, forward thinking water companies have Anaerobic Digestion and Thermal Hydrolysis infrastructure such as these already in operation:

Davy Hulme being fed by 7 satellites (Wigan, Preston, Hyndburn etc.) by United Utilities Colchester, Cliff Quay and Pyewipe being fed by more satellites (ie Thetford, Bedford, Marston, Dovercourt, Canwick) by Anglian Water’s

With UK population predicted to reach 71 million by 2030, there will inevitably be more sludge to deal with in large cities and towns. By treating this as an opportunity to generate energy rather than a problem, companies are building Anaerobic Digestion Plants and Thermal Hydrolysis infrastructure near large population centres and creating smaller satellite stations to store the sludge.

This pioneering method collects the sludge from the satellites, dewaters it and delivers it to the hubs for processing. Not only is the storage solution more efficient in construction, but in operation and efficiency also.


  • Energy creation instead of waste sludge disposal
  • No container rental costs
  • No requirement to regularly swap full containers
  • Fewer staff needed at all times, including bank holidays
  • By storing the sludge in new innovative ways, the plants become more flexible and the satellites capture more fuel (sludge). The solutions demonstrated focussed on the storage and discharge of Sludge, these included Truck Loading Silos, Truck Receptions Silos and Process Silos for Advanced Anaerobic Digestion.

To reduce costs further, Anglian and United Utilities chose to dewater the sludge to reduce the cost of transporting water so choosing “trailered cake @ 22%” Dry Solids instead of “tankered wet @ 6% solids.” This choice means they use 1 truck instead of 4, so saving costs of up to 75%.


  • Reducing haulage costs by 75%
  • Have more sludge available to process
  • Not hauling sludge borne water between locations
  • Saving fuel
  • Up to 4 fold reduction in CO2

How it works

Each storage unit is discharged by the same technology and features the same benefits. In each case, a Saxlund Sliding Frame mechanism is used to undercut the full section of the contents of the silo to prime a screw trough. Materials are discharged on a “first-in, first out” basis – important in handling materials with a shelf-life. Since the whole section is undercut, the pile section discharge is termed “mass-flow” (like laminar flow in a pipe) from the silo. This gives a homogenous discharge to the next process.

Where there is some dewatering requirement for the dilution of the sludge prior to the next process, the most efficient mix is controlled via the injection of final effluent in the pressure cavity of the Progressive Pump. Since the Progressive Cavity pump auger has already been primed by the action of the Sliding Frame and Saxlund Discharge Screw, a volumetric mix ratio between the Sludge and Final Effluent can be measured by comparison of revolutions between the Dilution and PC Pumps. This can otherwise be more random with the method of filling the inlet hopper of the PC pump with final effluent and expecting the PC Pump Auger to prime the PC Pump.

With 60 years’ experience in delivering BioEnergy projects across Europe, Saxlund holds patents on key technologies to improve feed and combustion efficiency which in turn reduce fuel costs and carbon emissions.

With its UK engineering and project management office based in Southampton, we are currently collaborating with Tier One and Tier Two water companies, consultants, contractors and investors, to deliver truck reception systems as Saxlund’s sliding frame technology, tested in hundreds of successful applications, is the only real solution for discharging sewage sludge silos at this size.

To learn how Saxlund technology could help you, please contact Mark Neal –

If you would like the presentation notes and slides, let me know your details below and I will send them straight to your inbox.

Your Name (required)

Your Email (required)

Your Telephone Number (required)


Your Message

Biomass Solutions, WfE and Bulk Materials Handling – RWM 2015 – Stand 4B33

Saxlund International is exhibiting at RWM 2015 on September 15th to 17th in halls 4/5 stand 4B33.

RWM is one of the biggest European events for companies researching & actioning the best solutions for resource efficiency and waste management.

Saxlund is a leading specialist in biomass combustion, Energy-from-Waste, alternative fuel systems for cement works and bulk materials handling solutions. We will be outlining our European-wide capabilities and the latest technologies we have deployed across a range of current and new projects.

These include small to mid-scale biomass fired CHP plants in the UK, Sweden, Estonia and Lithuania, energy from waste solutions in the cement industry, as well as new bulk materials handling solutions such as the new 3 million Euro contract to provide a state-of-the-art biomass multi-fuel handling system for a 40 MW green energy project in Margam, Port Talbot for Babcock & Wilcox Vølund, which is due for commissioning in 2016.

Saxlund’s involvement covers the design, manufacturing, delivery and commissioning of two fully automatic fuel handling systems, providing 100% redundancy, including  fuel reception, conveyor feed systems, mixing and fuel storage.

Due to begin production shortly, Saxlund will also be discussing experiences at the new 3.4MWe waste wood biomass CHP power station based at Twinwoods Business Park in Bedfordshire. Key components of the project include proven Saxlund fuel handling and push floor technology, conveyors, biomass combustion boiler and associated equipment feeding a Siemens turbine.

Managing Director Matt Drew says:

“The Renewable Heat Incentive offers a real window of opportunity in the UK for the development of small-scale, waste wood biomass plants, and we are busy collaborating with a number of new partners who see the value of consistent green base-load energy. There is increased interest across the board from energy producers, large business consumers and district heating groups for onsite CHP biomass power solutions. Appropriate technology, realistic project outcomes and the right investment partners remain essential, but at Saxlund the combination of our project management skills, our Combustion Centre of Competence and 100% success rate, put us in a uniquely strong position.”

With 60 years’ experience in delivering BioEnergy projects across Europe, the company holds patents on key technologies to improve feed and combustion efficiency which in turn reduce fuel costs and carbon emissions.

The Southampton-based company is currently collaborating with consultants, contractors and investors, to deliver biomass combustion solutions for combined heat and power (CHP) plants, district heating, electrical production and process steam for manufacturing. Solutions are capable of converting from 6,000 to 80,000 tonnes of waste wood per annum to produce renewable energy and heat, a fuel source that would otherwise be sent to landfill or exported.

To book your free tickets or find out more about RWM 2015 click here –  RWM 2015

Contact Saxlund  International and book an appointment to discuss waste management solutions at RWM 2015 here – Email:


How to deliver low cost energy to cities and municipalities

Delivering low cost energy

Energy security and rising electricity costs are big issues for cities and municipalities across Europe, especially for those that rely substantially on large energy producers and imported fossil fuels for their power generation. Recent falls in the cost of fossil fuels, on the back of declining oil prices, have given some temporary respite but already energy costs are rising.

Matt Drew, MD of Saxlund International says: “Renewables, driven in part by government and EU targets, are helping and as a consequence wind energy in particular has been growing in importance at both a local and national level. This has allowed some municipalities to take back an element of control. However renewables are only a small part of the solution and they aren’t right for everyone. Moreover, large subsidies frequently hide the true cost of the energy produced, nor are they a base load solution – if the wind doesn’t blow and the sun doesn’t shine you still need conventional solutions for generating power consistently.”

So what’s the solution for delivering low cost energy?

Well clearly there isn’t one single answer. But part of the jigsaw and one which is especially relevant to dense urban areas, where there is a high demand for both heating and electricity, is locally generated Combined Heat and Power (CHP). Sometimes referred to as co-generation, CHP integrates the production of electricity together with useable heat in one single, highly efficient process. Capturing waste heat in this way and deploying it for use in district heating and other processes makes CHP up to 80% more efficient than conventional power generation. It means energy costs can be reduced by as much as 20%.

That’s a significant reduction. If you combine CHP with biomass fuels, in particular sustainable timber and waste wood from forest harvesting, then the gains are doubly attractive. Fuel costs are significantly lower and it’s better for the environment. There’s the potential to cut CO2 emissions by some 90% compared to gas.

For parts of Northern & Eastern Europe where forestry is plentiful, the opportunity hasn’t gone unrecognised and local biomass energy solutions in the 2 to 5MW range providing Combined Heat and Power are starting to play an important role in delivering secure, affordable, green energy.

With two year’s successful operation behind them, a new CHP plant in Falköping municipality, Sweden, commissioned by Falbygdens Energi from Saxlund International, is a typical example. The plant supplies district heating and electricity, producing 2.4 MW of electricity and 10 MW of district heating, from locally sourced and sustainable forestry including bark and other forest residues as well as virgin timber.

Kaunas Municipality in Lithuania and the city of Tallin in Estonia will also benefit when new biomass CHP plants come on stream in 2016. Both make use of local renewable timber and follow a strategic partnership between Saxlund International and Axis Industries to deliver state-of-the-art biomass combustion solutions. The 5MW electric CHP plant for Danpower Baltic in Lithuania will be entirely fuelled by renewable timber, while the larger 21.4 MW electric solution in Tallin for energy company Utilitas will burn woodchip combined with 30% peat to deliver 20% of the municipality’s heat demand.

Small-scale biomass fired CHP solutions

There are a number of other reasons why small-scale biomass fired CHP solutions makes sense. They are easier to fund, with considerably less risk than much larger power stations, and quicker to design and build. Importantly the technology is robust and technically proven with dozens of examples especially in Scandinavia. At the scales we are talking about, between 5 and 10 MW electric, local fuel sources are easily managed without the supply chain issues and security of supply that much bigger plants will face.

Waste wood collection and processing

Moreover, the potential to use waste wood and Solid Recovered Fuel (SRF) means urban centres away from forested areas can also benefit, ticking the waste to energy boxes and diverting material from landfill. A typical CHP plant will convert for example between 6,000 to 80,000 tonnes of waste wood diverted from landfill and other low quality waste wood into 170,000MWhr of renewable thermal energy, each year. Importantly this isn’t diverting prime timber resources and it is also helping to create employment opportunities across Europe for waste wood collection and processing.

Saving waste from landfill in the UK

In the UK for example, the construction of a 3.4MW biomass CHP plant at Twinwoods Heat & Power in Bedfordshire, a privately operated power company, is nearing completion. Designed to produce over 27,000 MW hr of electricity and 8000 MW hr of district heating annually, the plant will burn approximately 40,000 tonnes of waste wood from commercial and domestic recycling centres each year, a fuel source that would otherwise be sent to landfill or exported.

Matt Drew says: “Selecting the right technology partner is crucial. The good news is that Saxlund has over 60 years’ experience and can supply everything required to deliver successful energy projects from the biomass combustion furnace, fuel handling solutions through to advanced flue gas treatment and heat recovery.”

To learn more please contact Saxlund International today on +44 (0) 2380 636330 or send your name and contact details to, to discuss how we can provide the right solution for your energy requirements.

Waste to Energy is Ready for Solid Investment in the UK?

The ever increasing debate around waste to energy vs historical landfill has been with us for several years. Governments around the world are focused on reducing the environmental impact that increased energy consumption creates.

The Department for Environment, Food & Rural affairs (Defra) quoted in their energy from waste guide in 2014:

Waste to energy has a poor historical image in the UK. Northern Europe is clearly ahead of the UK, but with the right technology, planning and people, we have all the opportunities to create a world class solution.

Waste to Energy – Risk vs Investment

WMW (Waste Management World) asked industry insiders for their thoughts on how projects can best secure finance. Saxlund International’s managing director Matt Drew shared his thoughts on where he thinks investors are digging their heels when it comes to creating the right environment for investment, read more here…

Industry investors are rarely “early adopters” of new technology, preferring proven technology that has historical proof.

Matt Drew says: It’s not that investors aren’t hungry to invest. We talk to almost as many investors as we do project owners. We know what works and what goes wrong.

Waste to Energy – Financing

Financing of energy from waste projects can be difficult with financial institutions, local authorities and waste companies all seeking to minimise their risks. This often leads to a reliance on long term contracts and steers projects towards proven technologies and companies, making it difficult for small companies or innovative technologies to break in.

Matt Drew says: The selected procurement method is important too.  EPC contracts ‘Engineer, Procure, Construct’ are popular because there is one “butt to kick” if things go wrong. Other contracting routes are available, which apportion risk over a number of parties and add construction management services to consult and advise. The benefits are lower costs, better process control, stronger collaboration and better results.

Waste to Energy the Growth of an Industry

The waste-to-energy market is set to grow at a rapid rate over the coming decade. The waste management industry’s rising goals for improved practices combined with the search for alternative energy sources are bringing transformational change to the waste to energy marketplace and opening up a new landscape of opportunities for waste conversion technologies and projects.

Saxlund International has over 50 years’ experience providing innovative solutions for Bulk Materials handling and Biomass Combustion. Using worldwide leading patented technology and practical experience in handling major projects, the company has constructed more than 3500 plants worldwide, all of which set new standards in terms of their technical performance and reliability. Indeed, a reputation has been established during this period for supplying solid and reliable equipment that performs as designed.

Matt Drew says: “We have experience of working for all of the major UK utilities and also working as part of a team collaborating directly with the end client on complex projects. As a UK contractor, we are also experienced working on NAECI Blue Book sites for major projects.

Is Waste to Energy Technology Ready for Solid Investment in the UK?

Saxlund International has the technology and infrastructure in place with a proven track record of sustainable growth in energy produced through waste to energy technology. Creating a reduced cost environment through combined solutions that give investors the confidence to finance the projects.

Contact Saxlund today on +44 (0) 2380 636330 for a solid solution that attracts the right investment.