19 th November 2008 Introduction to Accelerated Carbonation Robert Williams Carbon8 Systems Ltd www.c8s.co.uk

Objectives: - to use CO 2 gas as a resource - to utilise the latent reactivity of industrial wastes (and soil) to CO 2 for the: 1) pre-treatment of landfill waste 2) diversion of landfill waste via the production of engineering materials 3) manufacture of specialist products

Drivers: - Landfill directive - Sustainable waste management - Reduction in CO 2 emissions - Diminishing aggregate resources - Recycling of contaminated land

History: 7000 B.C First lime mortars used 27 B.C. [ Vitruvius ] writes at length about the conditioning of lime mortars (The 10 books of architecture) 79 [ Pliny ] further explores conditioning of lime mortars 1870 Setting accelerated by raised CO 2 level in curing environment 1925 [ Fuller ] conditioned fresh cement with CO 2 1970’s [ Berger et al .] carbonated calcium silicate materials 1980’s [ Redland ] accelerated curing of roof tiles DCR treatment for contaminated soil (organics) 1990’s [ Jones ] used of super critical CO 2 (SCCO 2 ) with composites [ Hills ] Treatment of hazardous waste 2006 [ Carbon8 ] Production of aggregates by carbonation 2008 [ Carbon8 ] Carbonated building materials

‘ Quirks’ of the carbonation reaction: C or CH-based CS -based CO 2 CO 2 Intra-grain reaction products Extra-grain reaction products Ca Ca Ca Ca Ca CO 2 CO 2 CO 2 CO 2

Early observations: 50 um

Carbonate-ability of thermal wastes

Influence of ACT on pH

Carbonation of contaminated soil

Trials in E. London, April 2008

Treatment of hazardous waste

Production of artificial aggregates Key considerations include: - choice/availability of active/suitable wastes - waste blends - process condition, e.g. CO 2 partial pressure - throughput - market need?

Key considerations include: - choice/availability of active/suitable wastes - waste blends - process condition, e.g. CO 2 partial pressure - throughput - market need?

Production of aggregates

Steel Wastewater Sludge Quarry Fines Bauxite Wood Ash Paper Ash Metal Dust

Aggregate structure

Aggregate properties

Full-scale scale plant ca 70,000kg/hr (soil/waste) Manufacture of light-weight or dense-weight aggregates (10,000 -50,000kg/hr) Manufacture of carbonated building materials, through: Optimisation of processes for specific applications Performance testing/certification of products Key industrial partnerships with Carbon8 Systems Next Stage of development for ACT

ACT is a developing technology Potential to recycle waste in carbonated products utilising greenhouse gas emissions Intermediate-scale manufacture of carbonated aggregates available shortly Optimisation of carbonation process for specific applications underway Wider opportunities for the application of carbonation technology Acceptance of technology by IChemE, Shell Springboard Challenge and Times HE outstanding innovation award successes Summary

Acknowledgements Shell/BP NISP RE-KTN/EPSRC Gallagher Aggregates Viridor Waste Management Waste Recycling Group E-on Carbon-Free Group Southern and Scottish