BIOMASS AND Power from waste
Belvedere – an ornament for the garden of England?1 April 2010
The next few years will see a steep increase in the commissioning of large energy-from-waste and other biomass projects in Europe. Prominent among them will be Belvedere and Lostock EfW facilities in the UK.
After 17 years of battling with London local authorities and government planning regulations, a couple of false starts, two public enquiries and a long tussle with protest groups the giant Belvedere energy from waste plant in Kent, UK, will at the end of this year finally come to completion. When it does it will be the largest EfW plant in the UK, and maybe in the world: it will be capable of processing 670 000 tons of municipal waste a year and generating over 66 MW of exportable electricity. It will also keep off the road the transport of much waste, largely confining it to the river.
The plant has been designed to keep open the option of producing combined heat and power, if a demand for the heat is found. Consultants PB Power have been commissioned to look into the market for potential purchasers.
The boiler supplier is Austrian Energy & Environmental, while the steam turbine has been supplied by MAN Turbo. The project is owned by Cory Environmental, the largest lighterage company on the Thames with a long history of waste management on the river; Cory, through its project manager Riverside Resource Recovery Ltd (RRR), contracted with AE&E subsidiary Von Roll Inova to carry out the EPC contract. The RRR plant will be the second Von Roll Inova reference plant in one of Europe’s capitals, the other being the Issy Project in Paris.
The new facility will provide the borough of Bexley, on the borders of southeast London,
as well as other London boroughs, with a means of disposing of its non-recyclable waste in a
more environmentally-friendly manner. It, and London in general, will not in future have to depend so heavily on landfill. London has a serious waste problem, and because of the lack of waste treatment sites in the capital it currently exports just over 50% of its municipal solid waste to landfills in the countryside around the city. This position is not sustainable, as Londoners produce more and more non-recyclable waste. The Belvedere facility will help make the city more self-sufficient in managing its own waste.
Cory finally gave the go ahead in January 2008 to contractor Breheny to start construction of the main access road and piling works. In August 2008 a £120 million contract was awarded to Costain to design and construct the EfW facility’s main buildings. Also in the summer of 2008 work started on the riverside jetties, the first jetty piles being installed by the following spring.
The start of construction followed a year
of ground preparation work at the site, investigating the ecology, archaeology and toxicity of the area, which has been home to a chemicals plant in the past.
Cory is aiming to complete the plant by the end of 2010, and commission it during early 2011. The project is on a firm schedule, revolving around delivery of the turbines. This is necessitated by huge global demand at the moment for power-generating turbines.
The lead arrangers of the finance, which owing to conditions in the financial markets took a year to arrange, were Bank of Ireland, Barclays Capital and Calyon. Finance was provided by a term facility of around £465 million, of which £430m is the senior term loan, £25m a contingency facility and £10m a change of law facility.
The facility will use three lines to process about 29.8 tonnes per hour (see schematic on page 36). The AE&E boilers incorporate conventional mass burn moving grate technology, and are expected to have a combined thermal efficiency of about 27%. It is claimed that even without the effect of CHP on working efficiency, the facility would be the one of the most efficient energy-from-waste plants in the UK.
320 tonne/h of live steam from the boilers at 70 bar and 425 °C goes direct to the MAN Turbo 80 MW single casing axial exhaust steam turbine generator set. It is not preconditioned – part of the MAN contract was to adapted the ST generator set to the boiler output requirements.
Unusually, the 170 tonne ST could not be shipped in by road because the only available route lay across a bridge too weak to take the weight. Instead, a 1000 ton floating crane was hired and the turbine lifted directly onto the quayside at the incinerator site.
It cannot be said that the decision to approve Belvedere was a popular one. The plant, indeed the very idea of such a plant, has met bitter opposition from various London boroughs, in particular some of those that are contracted through WRWA to supply the waste and those that fear the drift of noxious gases, especially dioxins from burning plastic. Other fears include drifting toxic ash, the release of harmful chemicals into the water system and the unnecessary burning of recyclable waste in order to increase or keep up profit levels. Moreover, the energy saving case is far from proven, unless one believes it to be the only waste disposal option available. But recycling, which is claimed to be a net saver of energy, is frequently touted as a more viable option, and plants such as Belvedere tend to reduce the general will to recycle waste.
Once built, the facility at Belvedere will recover around 62 MWe from an average of 585 000 tonnes of waste each year, brought in by barges, while up to 85 000 tonnes of material can also be brought in by road each year under the planning consent.
At present, about two-thirds of the plant's capacity is booked up – mostly through Cory's 25-year contract with the Western Riverside Waste Authority (WRWA) which represents four central London boroughs. Cory is currently bidding for further contracts during the construction period of the plant.
To comply with the 1999 EU Landfill Directive the UK must meet stringent targets on the amount of biodegradable municipal waste that can be landfilled – no more than 75 % of that produced in 1995 by 2010 and 35 % by 2020. The mayor’s policy envisages zero landfill by 2031 and most sites accepting London’s municipal waste are expected to close by 2025. The policy alternative is incineration.
At Belvedere the flue gas goes through numerous cleaning processes to ensure it meets the requirements of the permit conditions (Table 1) as specified under the facility’s authorisation from the Environment Agency to comply with the Waste Incineration Directive. The by-product combustion ash is separated into various types, then taken off site to be recycled or disposed of.
Moving the waste
The bulk of the waste will be delivered from the four WRWA boroughs. Waste will also come from Cory’s contract with City of London. These two contracts form the anchor waste supply (about 60%) for the funding case. The remainder will come from other areas of London and from commercial waste contracts.
One of the major advantages of the RRR facility is that it is river served and should save more than 100 000 heavy goods vehicle movements a year on London's already congested highways. It has the added advantage for Cory of safeguarding its lighterage operations.
The company currently operates a fleet of seven tugs and 47 barges. Four new Shoalbuster 2208 tugs, designed to be used in shallow waters, have been commissioned for the RRR facility.
Waste will be delivered to the facility in sealed containers on barges, off-loaded by jetty cranes and taken to the tipping hall where it is bunkered. From the waste bunker it is loaded by grabs and placed into waste hoppers from where it is fed into the boilers and incinerated.