A Geo-Inspired Clinker for a Low Carbon Future

Strategic Energy Research Consortium (SERC)

Background

Cement production accounts for 8% of global CO2 emissions. These emissions come from the thermal decomposition of limestone and clay-rich rocks needed for the clinker chemistry (~70% of the emissions) and indirectly from the largely fossil energy used to drive the process (~30% of the emissions). The move to more efficient energy technologies and non-fossil fuel sources of energy can help reduce the emissions from the heating process, however, alternatives that can reduce the 70% fraction of CO2 emissions from the calcination of limestones are needed. During calcination, 38% of the weight of the rock, which is transported at considerable cost, is emitted as CO2. This makes the cement manufacturing process not only an environmental concern but also inefficient.

Project Goals

This project aims to engineer a low-emission cementitious clinker by utilizing an alternative raw material that doesn't rely on limestone as its primary resource. This alternative material comprises a blend of volcanic rocks, whose composition promotes the in-situ growth of interwoven fibers. These fibers bridge cracks and reinforce cement at both micro- and nanoscales. The objective is to create a novel design that matches the strength of Ordinary Portland Cement (OPC) while substantially reducing CO2 emissions, improving ductility, and reducing costs.
 

Approach

The researchers are  engineering a more sustainable clinker through a geomimetic approach — a technology inspired by geological processes. The work will formulate a binder that melds the best properties of Roman marine concrete which has survived millennia, and a fibrous concrete-like rock created by nature (figure 1), known to withstand harsh environments. The binder composition enables reduced emissions from the “upstream” of cement manufacturing while forming fibers embedded in geopolymers. The design of the mortar structure will be refined through characterization and synthesis of the nanoscale building blocks and testing the properties at the macroscopic scale. This approach combines the serviceability and sustainability of fiber-reinforced and hybrid cement microstructures.

Team Members

Tiziana Vanorio
Tiziana Vanorio is Associate Professor in Earth and Planetary Sciences, Stanford Doerr School of Sustainability. Her research focuses on studying the properties of rocks and geomaterials under harsh condition of stress and temperature, with emphasis on the physical and mechanical changes that result from solid-fluid chemical interaction. The applications of her research go from geological to engineered processes, including fluids in reservoirs and cementation of natural systems from pozzolanic activity and geopolymerization. Her group is pioneering the design of a geocement — a novel Nature-inspired ‘geomimetic’ cementitious binder that greatly minimizes carbon dioxide emissions and increases serviceability of cement sheath to maintain well integrity behind the casing.

Alberto Salleo
Alberto Salleo is a Professor of Materials Science and Engineering at Stanford University. His research focuses on novel materials and processing techniques for large-area and flexible electronic/photonic devices. He develops polymeric materials for electronics, bioelectronics, and biosensors and electrochemical devices for neuromorphic computing. Professor Salleo also conducts structure/property studies of polymeric semiconductors, nano-structured and amorphous materials in thin films, and advanced characterization techniques for soft matter. 

Matteo Cargnello
Matteo Cargnello is an Associate Professor of Chemical Engineering and Terman Faculty Fellow at Stanford University. His group research interests are in the preparation and use of uniform and tailored materials for heterogeneous catalysis and photocatalysis and the technological exploitation of nanoparticles and nanocrystals. Reactions of interest are related to sustainable energy generation and use, control of emissions of greenhouse gases, and better utilization of abundant building blocks (CO2, methane, biomass). Dr. Cargnello received his Ph.D. in Nanotechnology in 2012 at the University of Trieste (Italy) and he was then a post-doctoral scholar in the Chemistry Department at the University of Pennsylvania (Philadelphia) before joining the Faculty at Stanford.

Other Team Members:
Davide Geremia, Postdoctoral Scholar, Department of Geological Sciences, Stanford University
Jorge Osio-Norgaard, Postdoctoral Scholar, Chemical Engineering, Stanford University
Ahmed El Gamal, PhD student, Department of Geological Sciences, Stanford University
Andrew Ames Sleugh, Graduate student, Department of Materials Science and Engineering, Stanford University