Proposals
Currently, the city council diverts more than 46 per cent of
household waste from landfill. Green bin
contents, such as cardboard, paper, steel tins and aluminium cans,
are sent for recycling and brown bin garden waste is processed into
a compost-type material. However, this is not
enough to meet the UK government's Landfill Trading Allowance
Scheme, which is designed to meet the UK's obligations under the EU
Landfill Directive.
A cross-party waste and recycling working group of councillors
and council officers has been investigating options for future
waste recycling, treatment and disposal, with the aim of
eliminating the city's need for landfill.
The group has proposed that recycling rates are raised above
65 per cent through better education of the public and
business people; by expanding existing recycling
facilities; and by adding kitchen waste and
glass to the household kerbside collections.
The council has conducted a thorough investigation into the
many ways that waste disposal could happen in the future. It has
looked at all the issues including the technology involved, the
expected cost, environmental factors, possible locations for a
facility, plus any associated benefits. It has commissioned
independent advice and analyses to examine all the variables to
provide an informed proposal.
Below is a brief outline of the key points and more
information will be published online as it becomes available.
The council is planning to build a modern energy-from-waste
facility to deal with waste disposal. This will meet stringent new
EU regulations and will be able to provide heat and power to local
industry.
Three types of technology were identified as possible ways to
manage the waste issue:
- Mechanical biological treatment (MBT) with anaerobic
digestion and gasification. This process has three key
stages:
- Separation: the mixed waste is mechanically separated to get some extra recyclable materials out
- Digestion: the rest of the waste is digested in an air-free environment. This produces methane, which can be used to produce energy, and a residue
- Gasification: the residue is treated in a gasifier to
produce more energy.
- Mechanical biological treatment (MBT) with aerobic
digestion and gasification. This process also has three
stages:
- Separation: the mixed waste is mechanically separated to get some extra recyclable materials out
- Composting: the rest of the waste is composted in air. This method doesn't produce any methane, but it does still produce a residue
- Gasification: the residue is treated in a gasifier to produce
energy
- Energy from waste (EfW). This process has two
stages:
- Energy recovery: the waste is treated to produce energy
- Material recovery: extra materials such as metals are recovered from the residue
Comparing types of technology is difficult as they are all used in different ways, in differently sized plants and using different systems which don't compare like for like. However, having considered all the options, the council is proposing that an energy-from-waste facility represents the best choice. This would be in the form of an energy-from-waste plant which provides energy that would be used to offset the cost, provide heat to local businesses and schools, uses tested technology and operates in a clean and reliable way.