OGP Research » Enhanced Weathering

This research investigates geoengineering approaches to atmospheric carbon dioxide stabilisation, particularly enhancing silicate and carbonate weathering on human relevant timescales and ocean alkalinity modification through the addition of hydroxide or carbonate minerals.

Research led by Dr Phil Renforth:
 

Enhanced Weathering of Silicates

Over geological time, the weathering of silicate minerals on land to form limestone in the ocean is a natural climate stabilisation mechanism. We are investigating the potential of speeding this up by spreading crushed silicates onto the land surface. Weathering is enhanced in two ways 1) the surface area of the material is substantially enlarged by crushing and grinding which means that there is more material exposed to the environment. 2) Biological activity in soils naturally speeds up weathering as a way of extracting nutrients from minerals. Because there is large uncertainty in both of these areas, the feasibility of enhanced weathering is poorly understood.

Collaboration: Prof. Jens Hartmann (Universität Hamburg), Dr Joshua West (University of Southern California),


Mineral Comminution

Size reduction of rock requires a substantial amount of energy. The relationship between comminution and the geochemical properties of the crushed material is poorly understood. This relationship is critical to understanding the feasibility of enhanced weathering and ocean alkalinity enhancement. Therefore, we are developing a systematic approach through modelling and laboratory work to understand this relationship.

 Typical material flow path through comminution.  Modelled using JK SimMet.

Collaboration: Dr Neil Rowson (University of Birmingham)


Waste Silicate Carbonation

Analogous to their natural counterparts, the weathering of waste silicate material may be an important mechanism for drawing carbon dioxide out of the atmosphere. Understanding the geochemistry of this material could also inform the research on natural silicate weathering. Waste silicates are produced from a number of human processes including iron and steel manufacturing (slag), construction and demolition (concrete), cement manufacturing (cement kiln dust), coal combustion (fuel ash), and quarrying (quarry fines). The weathering of these materials in the environment may be able to offset some of the carbon emissions associated with manufacturing.

Collaboration: Prof. David Manning (Newcastle University), Dr Will Mayes (University of Hull), Dr Ian Burke (University of Leeds)

 

Publications:

Renforth, P., Manning, D.A.C. (2012) Passive Sequestration of Atmospheric CO2 through Coupled Plant-Mineral Reactions in Urban soils. Environmental Science and Technology. 

Renforth, P. (2012) The potential of enhanced weathering in the UK. International Journal of Greenhouse Gas Control. (10) pp 229-243

Renforth, P., Mayes, W.M., Jarvis, A.P., Burke, I.T., Manning, D.A.C. and Gruiz, K. (2012) Contaminant mobility and carbon sequestration downstream of the Ajka (Hungary) red mud spill: the effects of gypsum dosing. Science of the Total Environment (in press).

Renforth, P., Washbourne, C-L., Taylder J., Manning, D.A.C. (2011). Silicate production and availability for mineral carbonation. Environmental Science and Technology, 45, (6) pp 2035-2041

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