New Energy-from-Waste Plant in the UK

by the CADDET UK National Team

Introduction

The total waste arising from the city of Birmingham is more than 800,000 tonnes/year, of which Birmingham City Council (BCC) collects about 450,000 tonnes/year. Until recently, this waste was disposed of by incineration and landfill. But today, the UK's second modern energy-from-waste (EfW) facility, at Tyseley in Birmingham, processes 350,000 tonnes/year of the city's waste, continuing BCC's long-standing tradition of waste disposal by combustion at the site.

The Tyseley site is 4.5 km from the city centre and has been used since 1926 for waste incineration. The first plant had two furnaces, each capable of handling 2.5 tonnes/hour of refuse. These raised steam in boilers for electricity production via two 100 kW generators. The electricity produced was used to power the plant and charge the batteries of the electric-powered collection vehicles and clinker trucks.

In 1976 a replacement plant was built at Tyseley, capable of processing 150,000 tonnes/year of waste. A small amount of heat was recovered for the plant and offices, but there were no boilers or power generation.

After December 1996, the existing incinerator could not meet the UK's new, more stringent emissions limits. At that time, BCC was also faced with the closure of a landfill site which had been handling about half of Birmingham's waste, and the failure of a local reclamation plant, which was in receivership.

In view of these issues, BCC embarked on a major study to consider its future waste management options and decided to opt for long-term self-sufficiency by means of a new EfW plant, and to maintain the existing transfer stations and public waste disposal facilities.

Tyseley energy-from-waste plant.

The Waste Disposal Contract

Since January 1994, BCC's waste disposal service has been carried out by Tyseley Waste Disposal (TWD) Ltd. TWD, a joint-venture company between BCC and Onyx Aurora Ltd, won the 25-year waste disposal contract against competition from 17 consortia representing 47 international companies.

When the contract started, the physical assets and employees of BCC's waste disposal service transferred to TWD, and the company became responsible for the operation of five civic amenity sites, two transfer stations of 120,000 and 150,000 tonnes capacity, a fleet of nearly 40 vehicles used for transfer activities, and the old incinerator at Tyseley.

A key requirement of the contract was for TWD to design, build, finance and bring into operation a new 350,000 tonnes/year EfW plant by 1 December 1996, when the new emissions standards would come into effect and the old plant would have to close.

The contract also required TWD to try to secure an electricity supply contract under the UK's Non-Fossil Fuel Obligation (NFFO). A 15-year NFFO contract was awarded and a proportion of the financial benefits go back to BCC.

Fast-Track Project

Tyseley, with its central location between the two transfer stations, was the obvious place to site the new plant, since it had enough space alongside the old plant (which had to remain in operation during the construction period). A comprehensive environmental statement was prepared to accompany the planning application and detailed consultation with residents' associations, local government organisations and environmental groups began in July 1993. The formal application was submitted in November 1993 and an information centre was opened on the site for interested parties to visit. Planning permission for the project was granted in February 1994.

The fast-track nature of the project is demonstrated by the mere 26 months between the ground-breaking ceremony, conducted on the cleared site in June 1994, and the first introduction of waste into the furnaces in August 1996. The plant effectively went into full operation in September 1996, when a three-month reliability test started. This allowed the early closure of the old incinerator, also in September 1996.

The new facility is now in full commercial operation and can comfortably meet the new environmental standards. Recent extractive tests have shown particulate levels below 1 mg/m3, a vast improvement on the old generation of plants, and much cleaner than a conventional fossil-fuel power station.

Schematic of the Tyseley plant.

Plant Description

The new facility uses well-established mass-burn EfW technology for the combustion of 350,000 tonnes/year of municipal solid waste. The waste is delivered to the plant via a new access road and is fed into two streams, each processing 23.5 tonnes/hour. Two Steinmüller reciprocating grates provide heat to the boiler which produces steam at 40 bar and 400°C. The steam passes to a single multi-stage condensing steam turbine, which drives a four-pole generator at 1,500 rpm. This provides 25 MW of electricity at 11 kV, which is converted to 132 kV by a transformer for export to the National Grid. The plant also recovers 16,000 tonnes/year of ferrous metal for recycling.

Modern pollution abatement equipment, comprising semi-dry acid gas scrubbers, activated carbon injection and fabric filters, ensures that operation of the plant meets the new emission limits. Clean gases are discharged through an 80 m stack, again in accordance with the new regulations.

During the construction phase, it was decided to sink a borehole to meet much of the process water requirements of the new plant. In fact, this was completed early enough to feed the high water demand of the old plant for its last year of operation.

A separate, small incinerator is provided for the treatment of clinical waste on site. The untreated flue gases from this plant are taken to the main plant's air pollution control system and treated to the same emission levels.

The new facility is connected to the grid by a 1.2 km cable which is routed under an adjacent canal, through a railway embankment, and across the environmentally-sensitive neighbouring land of a local charitable trust.

Capital Costs

The total project cost, including grid connection, capitalised interest and other project development costs, is estimated to be around £95 million (1994 prices, where £ is the UK pound).

For more information contact the CADDET UK National Team in Oxfordshire.

The CADDET Renewable Energy Newsletter is a quarterly magazine published by the CADDET Centre for Renewable Energy at ETSU, UK.

The articles published in the Newsletter reflect the opinions of the authors. They do not necessarily reflect the official view of CADDET.

Enquiries concerning the Newsletter should be addressed to
Pauline Toole, Editor, CADDET Centre for Renewable Energy, ETSU, Harwell, Oxfordshire OX11 0RA, United Kingdom. Tel: +44 1235 432968, Fax: +44 1235 433595.