We are looking for Biomass Boiler solutions for a large scale Biomass Project at our largest student residence. The project is to abate 1,000 tCO2 annually. An option is for us to burn a local byproduct "Rape Meal"... Any experiences?
Emission and particulate issues
Boiler plant suitability
Yes, this is the type of initiative British Gas can support and would be more than willing to meet you to discuss your requirements further.
I have outlined an example case study below, where we worked with Jesus College, Cambridge to install a Biomass boiler as part of Cambridge University.
You also mention Rape Meal in your post but we actually find Miscanthus is a better pelleted solution. If you either google “Miscanthus” or look at jacksonenergy.co.uk you will see more information on this type of fuel source.
Like I mentioned earlier, I’m more than happy to chat through options and potential end to end solutions.
British Gas, Head of Renewable Heat
Jesus College, Cambridge, 100kW
Jesus College, a grade 1 historic listed building, is part of Cambridge University situated in the centre of Cambridge.
There are strict building regulations to consider, when re developing listed buildings. The college decided to develop a new common room, which would have required extensive modifications to comply with building regulations, at a considerable cost.
British Gas (through Econergy) designed and installed a 100kW KWB automatic wood pellet boiler system with a 1500 litre buffer tank. The installation meets all the colleges requirements for an efficient and clean source of space heating and hot water. As there are no fossil fuel Carbon Dioxide emissions, the system exceeds all current building regulations, without extensive and costly changes to the fabric of the building.
• Heat exchanger: upright, auto-cleaning tubular heat exchanger with special turbulators that remove fly ash and self clean the boiler tubes.
• Fire shutter: gas-tight, flashback-proof and tested.
• Firing system: auger-fed gasifier, ring-nozzle burner, high-temperature impact dome, turbulent burnout zone.
• Ash-removal system: automatic ash removal, ash compaction and filling-level monitoring.
• Fuel extractor: innovative conveying technology for individual requirements.
• KWB COMFORT 3: innovative, easy to use, fully automatic and unique.
• Stoker worm: stainless-steel thread with carbide coating.
• The fuel store is located in the adjacent room to the boiler room. This was built on site by building contractors to Econergy’s design
• The fuel store dimensions are 5.2 metres by 3.2 metres and can hold approximately 10 tonnes of pellets.
• The pellets are automatically feed into the boiler via the screw feed auger transfer system when required
• This transfer system takes the pellets through the wall into the next room and then into the boiler
• In March 2006, The Energy Crops Company made its first delivery of wood pellets to Jesus College. The fuel was shipped in a specialist powder and granular fuel vehicle. The handling system on this vehicle allows deliveries to be pumped into the college store with minimal product degradation
• The fuel is delivered in 10 tonne loads
• The boiler uses approximately 2.5 tonnes of pellets per month
• Deliveries are kept to a minimum (3 per annum) due to the large store
Pellets are produced from sawdust without synthetic additives. Pellets have a higher energy content then woodchip therefore smaller fuel stores can be used. Pellet deliveries are blown directly into storage from a pneumatic tanker along a flexible hose, and can be blown up to 30 metres. Pellets are an ideal fuel for fully automatic heating systems where there are space and access restrictions.
For the large scale biomass project at your largest student residence we wouldn’t recommend rape meal. We know of some successfully installed rape meal fuelled installations for farmers but we would be very wary of using it in non-farming installations, because of the high levels of ash, clinker and corrosion.
We would also have reservations regarding Miscanthus. Reliability of source of ‘feedstock’ and the fact that you will be limiting your choice of boiler as some manufacturers warranties will not cover the use of Miscanthus also needs to be considered.
Many schools, colleges, universities and other educational organisations could make savings on their heating fuel costs by replacing their current fossil fuelled system with a biomass boiler fuelled with wood. As long as wood is obtained from sustainable sources it is extremely ‘carbon lean’ leading to large savings in carbon dioxide emissions. Using locally sourced wood also stimulates the management of local woodland which helps improve biodiversity, increases rural employment and keeps revenue in the local economy.
In addition, housing a boiler at an educational establishment provides the opportunity for wider curriculum benefits giving a practical demonstration of a low carbon technology.
We recommend using wood pellets as they are the more common feedstock, more consistent against the alternatives and the space required for storing pellets is less than other feedstocks. Delivery is also much simpler, usually blown delivery. Wood chip is an alternative, especially if you produce your own or it is more readily available locally, but it has higher moisture content and is bulkier. If you have room for a large fuel store that will accept several tonnes of pellets at a time, delivered in bulk by tanker, you can keep the cost down to around £190 per tonne in most parts of the UK. You may also be able to find a local supplier.
Logs can be cheaper than pellets, but costs depend on the wood suppliers in your local area, as they cost a lot to transport. If you have room to store more than a year’s worth of logs you can save money by buying unseasoned logs and letting them season for a year. You can search for wood fuel suppliers in your area at the Log Pile website.
Choice of feedstock and boiler should ideally be looked at in an overall context of your specific requirements and objectives.
The savings in carbon dioxide emissions are very significant, especially if the premises have been insulated, which we always recommend before considering installing renewable energy systems. So you could save money from insulating, and then save the money from switching to wood heating too!
You may be also able to receive payments for the heat you produce from a wood boiler through the government’s Renewable Heat Incentive (RHI). This scheme should be launched in October 2012.
Does this sound like something you’d like to consider and hear more about? We’d be happy to talk to you or meet you to discuss the options