The term ‘energy from waste’ (EfW) covers a wide variety of combustion processes that reclaim energy from a waste material feedstock.

It in particular refers to treatment processes that harness the calorific price in waste to generate electrical power or heat. This is then distributed with the rest of our “non-renewable” and “fossil fuel” derived energy.

Using energy which would have been lost if it had been placed in a landfill, EfW energy production methods also serve to cut back the volume and weight of the original waste which will go to landfill, leaving only a small residue that requires disposal. These plants, in the form of incineration plants, are actually capable of reducing the volume of waste by as much as ninety p.c. and the weight by seventy five percent The incineration process is actually just about the most efficient at this, and the ash that’s left may also be made excellent use of in construction materials recycling applications. This ability of incineration to reduce volume and mass, is not nowadays as effective as it once was, when emissions to atmosphere were less strongly regulated. This is due to the need for sophisticated methods to be used to clean up incinerator flue gases before they can be emitted, and the air pollution control systems which provide this function. The air pollution control systems most often used in incineration plants produce waste of their own, which needs further treatment or disposal in a specifically approved “hazardous waste” landfill site.

A number of alternative strategies to incineration have just recently been developed for recovering EfW, including combustion, gasification, pyrolysis and biological processes, e.g. anaerobic digestion and the extraction of landfill gases. The quest continues for better EfW processes which:

- avoid creating polluting gases and toxins in order to reduce the need for costly and energy consuming flue gas clean-up technology
- are highly effective in reducing the volume and mass of the residue
- if not particularly good at reducing volume and mass of the incoming waste, to provide a valuable non-toxic product (e.g. anaerobic digestion produces biogas and a fertilizer).

Despite much work having been done in developing alternative EWfW technologies to incineration the commonest kind of EfW is using incineration technology, and the majority of new capacity (e.g. in the UK) is being installed as incineration processes.

This means burning residual waste ( generally after separation for recycling and composting ) in furnaces and which incorporate a boiler and generator system to supply an electricity output from the steam produced. The heat may be exploited in district heating systems (known as CHP). The technology itself is really flexible, and can process mixed municipal wastes and other waste streams, including clinical and industrial wastes.

Other processes pelletise waste inputs for burning in a refuse derived fuel ( RDF ) plant. The UK Governing Body has outlined RDF as ‘turning the flamable portion of waste, e.g. paper and plastics, into a fuel which can on occasion be stored and transported, or immediately used on site to provide heat and / or power. RDF gives the operator the opportunity to store energy and choose to generate power when it is needed the most – a rare attribute among renewable energy processes.

A key development of EfW has been thru the development of environmental technology and regulation. During the last 20 years the emissions from EfW plants have been seriously reduced thru progressively tighter regulation and improved use of flue gas treatment technologies.

Throughout Europe the older generation of incineration plants have all been closed or upgraded to meet the 1996 EU emissions directive and the further reinforced EC Incineration Directive emission came into effect in 2004.

There are no longer any reasons to hold back any EfW plants due to concerns about gas emissions as the science surrounding what constitute emissions risk to human health are now well known, and the legislation has been set at a level which guarantees the health of all those who work in these plants, or live nearby. The idea of incineration, being simply to burn the materials until there is nothing left to combust has its limitations, especially when other processes can produce useful products, so many would like to see a bigger upatke of the alternative waste technologies, like including combustion, gasification, pyrolysis and biological processes.

Unfortunately, although there’s been a major level of interest in developing new plants which will utilize the ‘emerging ‘ technologies ( pyrolysis, gasification etc.), and basically thes are essential to help the all EU nations meet their duty to reduce their dependance on landfill dumping of waste. EfW plants that handle between ninety thousand and six hundred thousand tonnes of waste every year can produce between 6 and 40MW of electricity.

There was in 2004, enough capacity to provide 203MW of power from UK EfW facilities, which process has a grand total of just about 3,000,000 tons of community solid waste every year. Substantial extra capacity for the has been installed since then, and furthur plants are in the planning stage, with the result that installed capacity has more than doubled and with a similar increase in the power now being generated from previously landfill-dumped municipal industrial and commercial solid waste.

The reason that the more recently developed waste technologies are not being built in bigger numbers lies in their newness meaning that investors find it hard to take on-board the bigger risk from new processes, and which in a recessionary economic period might or might not, in unstable “immature” markets produce essential income from the sale of their products (e.g. compost or say “bio-char”).

All nations should do their utmost to gain as much value from our wastes as practical, instead of continuing historical dependence on landfilling, for the sake of minimising use of finite materials resources and avoiding groundwater pollution. After we have removed as many valuable materials from the waste as feasible, like paper, glass and plastics, the residual waste still contains valuable energy that will replace coal or oil burning.

The United Kingdom lags behind its Western european neighbors in recovering energy from waste, it is pleasant to note the accelerating number of energy from waste facilities now being built and further projects in the pipeline, will soon make the UK one of the leaders in EfW adoption.

Just when will our society realise that when everyone produces such large quantities of waste, the waste HAS to be processed and disposed of somehow, and somewhere, and that it is unreasonable to expect to send it out of the area in which the waste was created!

In our first case the Surrey County Council Energy from Waste (EfW) facility, which only received planning permission in October 2008, now looks set to face further delays after a successful challenge against its development by the local parish council. Surrey Waste Management’s proposal for the facility at the Clockhouse Brickworks site in Capel, Surrey, has suffered a myriad of set-backs and challenges since the original planning permission, granted as far back as 2002, was overturned.

An official judgment is expected to have been made by the end of February (after this issue has gone to press). The 100000 tonnes capacity facility was intended to be operational in 2012 as part of a PFI-funded deal between Sita subsidiary, Surrey Waste Management, and the county council.

Our second problem waste processing facility in Cornwall has been rejected and new plans must be drawn up, so the problem is really serious for the citizens of Cornwall. The following is an extract from the BBC News item highlighting the problem:

New county waste plans ‘needed’

An alternative strategy for dealing with Cornwall’s waste needs to be drawn up as soon as possible, a council scrutiny committee has ruled.

The call to Cornwall Council comes after plans by waste company Sita for an incinerator at St Dennis were refused two weeks ago.

Sita then withdrew proposals for a waste centre at Scorrier last week.

The council will decide whether to follow the recommendation for a waste plan after elections later in the year.

Cornwall Council’s Environment Policy and Development Scrutiny Committee recommended that a dedicated panel be set up to look at alternatives.

The committee’s chairman, independent councillor Mark Kaczmarek, said: “It is essential that Cornwall has a clear way forward to deal with its waste.

“Our remaining landfill is running out. Far too much time and money has been wasted over the last few years and no solution to Cornwall’s waste disposal has been created. Cornwall Council must make this issue a priority.”

The full council will decide whether to follow the recommendation for a waste plan after it holds its elections in June.

County councillors voted 20-to-one on 26 March against Sita’s bid to build a waste-to-energy incinerator in the county. Planning officials had advised the council to grant the application.

The £117m waste-to-energy plant would have handled all of Cornwall’s waste – an estimated 240,000 tonnes of waste a year which would, in turn, have generated power for thousands of homes across the county. More here.

MRW – Claire Churchard, 08 Jan 2009

Cheshire County Council has saved £2.1 million by reducing the waste it sends to landfill.

The council has been able to free-up the cash due to a forecast 20 per cent reduction in landfill use, equalling about 50,000 tonnes.

“There has been a significant fall in the amount of rubbish we are having to landfill,” said the council’s Environment Executive Member Andrew Needham.

“This reduction compared to last year’s figure has happened for two main reasons. Recycling at our household waste recycling centres has more than doubled to 65 per cent under our new contractor H W Martin. This new contract has seen a 50 per cent reduction in landfill from the HWRCs. There have also been further improvements in kerbside recycling undertaken by the district councils,” he said.

Cash to be used for roads

But the money will not go back into funding for recycling and waste services in the area because “recycling is a dead duck,” Needham told MRW. He explained that the authority had a surplus of recycled materials and said the income from recycling had reduced, adding that they were now paying for people to take it.

He said the council supported the findings of the recent IMechE reportwhich called for the Government to abandon its focus on recycling and concentrate on building more energy-from-waste plants.

“Politically, dealing with waste is not easy,” Needham said, “there are no votes in it.”

PFI project

The authority is currently evaluating bidders for its £1 billion, 25-year private finance initiative waste project, which could include mechanical biological treatment and EfW technologies.

Neeedham explained that the £2.1m will not go towards funding this scheme, which is due to finalise a preferred bidder early this year. He also explained that £2.1m was a small amount in comparison to the £1 billion needed for the PFI project. More here at MRW Magazine.

The Waster notes that currently the council like elsewhere in post credit-crunch recession Britain, has to pay for recycling materials to be taken away.