Cost Effective Use of Heat Recovery

1. Cost Effective Use of Heat Recovery Tony Cotton

2. Johnson Tiles • Formed in 1901 • One of the UK’s largest tile manufacturers • Up to late 1990’s – 3 sites in the Tunstall area • Operations consolidated onto one site in 2001 with £35m investment • Highly automated process consuming ~1,500 tonnes of raw materials per week • 4,500,000 m2 of tiles per annum

3. Why Save Energy? • Reduce the environmental impact of energy usage • Protect the world’s resources: • the UK consumes 8% of oil resources & 4% gas resources every year • To reduce our carbon footprint • To meet legal obligations of climate change legislation • Good business sense - to save money & improve profitability

4. Energy Use • 126 GWh of gas per annum • 21.5 GWh of electricity per annum • All firing by continuous gas roller-hearth kilns • All production is fast once-fired using gas • Slowest firing cycle is 1 hour & fastest ½ hour

5. The problem of waste heat “Surplus industrial heat should be better exploited. Industrial plants often generate large amounts of high quality heat as a by-product. A comprehensive heat strategy must include ways to ensure this heat is reused wherever possible. In some cases industrial firms can reuse heat in their own processes.” “The Heat is On”: CBI

6. Nothing new! • Waste heat has been used for decades! • Heat exchangers on tunnel kilns provided space heating • Exhaust gases preheated spray driers to save gas

7. Kiln Heat Recovery System • Retrofit on existing roller kiln in 2008 • Applicable to any continuous kiln • Heat exchanger in rapid cooling zone • Combined with heat extracted from slow & final cooling zones • Recovered heat ~200°C into gas burners as combustion air

8. Energy Savings • Since installation • Saved: >£83K of gas >4,000,000 kWh of gas (9% of the kiln’s gas) >750 tonnes of CO2 emissions Payback estimated ~3 years

9. Current Site Innovative use of waste heat: • Excess heat from kiln fan platform used for space heating • Warm cooling air used for two process driers • Ducted hot air to replace electric heating in canteen

10. Important Considerations • Use for heating is seasonal • New buildings require little space heating • Old buildings have high heat loss & need to consider insulation • Target heat recovery for use in 24/7 process • Minimise creation of airborne dust

11. Training & Communication • Involve the workforce • Continuous Improvement Teams • Energy CIT • Departmental Energy Champions • Encourage suggestions • Regular bulletins & posters • Newsletter to inform of improvements • Home energy-saving tips

12. Energy Performance

13. Carbon Footprint 2009 of CO2 reduction in 2009 30% Reduction of SEC in CCA 2,936 tonnes Down 7.8% on 2008 66% from gas consumption 33% from electricity consumption 1% from company road vehicles Note: Excludes deliveries & distribution Specific Energy Consumption 2000 4,519 kWh/tonne 2010 3,143 kWh/tonne

14. Future Opportunities • Evaluate CHP systems • Heat recovery as standard on kilns • Heat exchangers on kilns for space heating • Main kiln exhaust scrubbing to use heat in spray drier • New concept of kiln exhaust control

15. Questions FM 26818 EMS 40817 2008 2009 2010 www.johnson-tiles.com www.material-lab.co.uk