With the opening of a dedicated new production facility last September, Suez and Cemex marked a milestone in a relationship that will see Suez supply the cement manufacturer with a sustainable alternative to fossil fuels for the next 25 years.
By output, the Cemex kiln at Rugby is among the biggest in the UK and, under the deal, Suez will supply up to 240,000 tonnes of solid recovered fuel (SRF) to the kiln every year – most of which is manufactured at the Suez facility adjacent to the Rugby kiln. The facility will produce up to 200,000 tonnes of SRF, made to a specification Cemex calls Climafuel, while the remaining 40,000 tonnes will be produced from Suez’s SRF plant in Landor Street, Birmingham.
Both companies agreed the 25-year contract – thought to be the longest running of its kind outside the PFI mechanism – in September 2012 and Suez began supplying Climafuel from Landor Street in January 2013.
Suez leased land opposite the kiln from Cemex to build the £18m standalone facility and construction began in February 2014, with commission and the formal launch occurring in 2015.
The specification of Climafuel is designed to give a consistently high calorific value of 17-21MJ/kg while ensuring that unwanted elements such as chlorine (found in plastics including PVC), metals and moisture, which could damage the kiln or degrade the quality of the cement products, are kept to a minimum or removed completely.
This is achieved at the SRF facility by analysing the composition of the end product in realtime as it rolls off the production line. This allows the plant to adjust the calibration of optical sorters automatically at the front end of the plant to balance the values, which is achieved by selecting or removing certain types of material.
Analyser monitoring end product’s chemical and calorific composition
At full capacity the cement plant will consume up to 40 tonnes of SRF every hour; Climafuel partly replaces the coal or petroleum coke traditionally used by the cement industry to power its kilns. It is not yet possible to run the kiln using SRF completely, but substitution rates are gradually increasing as SRF manufacturing and handling processes improve.
The main challenge posed to Suez is achieving a consistent specification for lots of critical values using an ever-changing and inconsistent input material. At present, around 70% of residual waste input material comes from industrial and commercial businesses across Northamptonshire, Warwickshire and the wider Midlands region. The remaining 30% is municipal residual waste from Northamptonshire County Council which would otherwise go to landfill.
The manufacturing process enables Suez to extract recyclable materials, such as plastics, card and metals, from general waste, which would otherwise be impossible using more traditional disposal solutions such as energy from waste or landfill.
The facility employs 55 people working across two shifts, and there are more than 12,000 deliveries of feedstock material a year and 8,500 deliveries of Climafuel to the cement plant.
Across its global cement operations in 2014, Cemex reduced its specific net CO2 emissions by around 23% compared with its 1990 baseline, mainly as a result of the increasing use of alternative fuel in its plants. More than 90% of Cemex’s active cement plants consume alternative fuels; nine of them have exceeded a 50% alternative fuel rate while five of those now exceed 65%.
Suez is investing considerably in infrastructure to produce sustainable industrial fuels in the UK, and the Suez group supplies 1.1 million tonnes of SRF worldwide. The process allows the company to extract recyclable materials that would otherwise have been lost, and provides Cemex with a sustainable, long-term alternative to fossil fuel. The use of such energy offers numerous advantages because it is sustainable, transportable, abundant and makes economic sense for all parties.
Suez also supplies Cemex facilities in Latvia and other European countries, which is how the partnership in the UK came about.
Such is the importance of the export market to Suez in the UK that it has invested nearly £20m in a large-scale, alternative fuel facility strategically located at the Port of Tilbury which is due to formally launch later this year. This plant is about creating the maximum opportunity to divert waste material from landfill, and enables it to export RDF grades to Europe and SRF to the rest of the world.
Andy Hill is market director for alternative fuels at Suez