Glasgow climate pact: a step on the way towards a lower carbon dioxide world

Geoffrey Hammond at the University of Bath and Marcus Newborough of ITM Power review what happened at the UN climate change conference in Glasgow last year, and what the resulting ‘Glasgow climate pact’ means for global warming and climate change.

The Effect of Bacteria on Early Age Strength of CEM I and CEM II Cementitious Composites

Despite being associated with lower carbon emissions, CEM II cementitious materials exhibit reduced early age strength compared to that of CEM I. Several studies have demonstrated early age strength improvements by incorporating bacterial cells in concrete. In this study, live vegetative bacteria and dead bacteria killed in two different ways were used to explore whether changes in strength are related to the bacteria’s viability or their surface morphology. Compressive and flexural strength tests were performed at mortars with and without bacteria for both CEM I and CEM II cement. Their microstructure, porosity and mineralogy were also examined. No net strength gain was recorded for either CEM I or CEM II bacterial mortars compared to non-bacterial controls, although changes in the porosity were reported. It is proposed that two phenomena, one causing strength-reduction and one causing strength-gain, took place in the bacterial specimens, simultaneously. It is suggested that each phenomenon is dependent on the alkalinity of the cement matrix, which differs between CEM I and CEM II mortars at early age. Nevertheless, in neither case could it be recommended that the addition of bacteria is an effective way of increasing the early age strength of mortars.

Water Stabilization of Clay Bricks with Improved Tannin and Iron Mixes

Weak water resistance is a big obstacle for clay materials to overcome in modern construction industry. Compared to the hydraulic stabilized additives, bio-additives have a lower carbon footprint and have been used in many vernacular construction techniques to immobilize clay. In this work, the traditional recipes of tannin and iron have been revisited, in particular, the question of pH and iron solubility has been explored. Oak tannin and FeCl3 were chosen and their influence on the properties of clay materials in terms of rheological properties, compressive strength, and water resistance were characterized in the lab. Based on the results, tannin can reduce the yield stress of paste while with the addition of FeCl3, the yield stress of tannin dispersed pastes increased to a value similar to the reference sample but lower than the value contain only FeCl3. The increase was attributed to the complex reaction between tannin and Fe3+. The iron-tannin complexes can also increase the samples’ strength and water resistance. Although the complexes did not change the hydrophilic properties of the samples’ surface, they prevent the ingression of water. These results are very promising as they allow the production of a fluid earth material that is water-resistant. This opens a wide range of application potentials and can help to mainstream earth materials in construction.

Evaluation of Bio-Based Earth Engineered Mortars for Low Energy and Carbon Buildings in Tropical and Subtropical Climates

Improving the thermal performance of low-income housing in developing countries, located in tropical and subtropical regions, is one of the main challenges of the building sector. The use of mortars as building cladding is a current practice in many developing countries. Bio-based (such as bamboo particles) and earth materials have shown interesting potential for improving some thermal properties of covering mortars. In addition, bio-based earth mortars can have a lower carbon footprint than conventional mortars (typically made of cement or cement with lime) used in the building sector. The aim of this study is the evaluation of the life cycle GHG emissions of different mixtures of an engineered bio-based earth mortar mixed with bamboo particles, earth, and different cementitious materials (Portland cement, hydrated lime, metakaolin, and fly ash) and water. Four mixtures are evaluated: without bamboo particles, with 3%, 6%, and 9% of bamboo particles in volume. The thermal energy performance and carbon footprint of these mortars are evaluated. From physical tests carried out in the laboratory, thermal energy simulations are carried out in DesignBuilder software considering a case study of a social housing project in Brazil, evaluating tropical and subtropical climates. Finally, the carbon footprint was performed, using the Life Cycle Assessment (LCA) methodology considering a cradle-to-gate scope. When compared with two conventional mortars (made of cement and hydrated lime), the bio-based earth mortar presents better thermal energy performance and a lower carbon footprint. We can conclude that there is a potential to improve the thermal energy performance in low-income housing and, at the same time, to reduce the mortar carbon footprint. This mortar can be produced where bamboo and cementitious materials are available, which is the case in several developing countries that are expected to have a substantial housing demand for new buildings in the coming years.

Effect of Different Acids on Rice Husk Calcination and Extraction of Bio-Silica

Silica is an essential material which has many applications in various fields such as construction, catalyst, optical fibers and raw material of metallurgical industry. This work observed the recent trends in silica extraction from agro and natural wastes for high-tech applications. Hence, this work approached in new way for the bio-silica extraction from waste rice husk using HCl, H2SO4 and CH3COOH for the calcination. The results revealed that the effect of pH on ash nature and silica purity. The purity of silica was differed based on metal ions, rice husk ash color and non-combusted carbon. The results were compared with treatment in absence of acid ash using FT-IR, SEM, EDAX and XRD analysis to measure the effect of pH on the bio-silica purity. This work observed the lower carbon content in acid treated ash when compare to water washed rice husk.

Remote Cementing Enabled with Automation Drives Reliability, Consistency and Efficiency; A Case History from Norwegian Continental Shelf

Cementing is the fundamental first step and foundation for well construction. The traditional "let's go, mix it, pump it and bump it" cannot be the standard for the current and future offshore cementing operations. As oil and gas operators continue to push the envelope for both innovation and efficiency in well construction operations, to drive energy transition, lower carbon footprint, service providers continue to look for ways to "do more, with less". The latest innovation is redefining offshore cementing operations with a powerful combination of field-proven expertise, equipment, processes, and software. Remote Cementing Operations, the first of its kind in the industry, offers real- time and remote-operation capabilities, controls, and diagnostics of offshore cementing units. While conventional operations would typically involve a cement specialist working in an adjacent room on the rig, Remote Cementing Operations allows all cementing procedures to be controlled offsite by a cementing SME (Subject Matter Expert) from a Remote Operations Center (ROC), miles away from the offshore rig simplifying the operations, minimize errors and improve reliability. As the industry moves forward with a goal to lower carbon footprint, remote cementing enabled by automation will play a key role to implement innovative technologies that will help operators accomplish zonal isolation today and in the future while improving reliability, consistency and driving efficiency. The new implemented process thus results in reduced costs, risks, and non-productive time (NPT) with fewer personnel on-board (POB)—all without sacrificing quality, safety, and performance. A recent success case study is presented, where in an entire offshore well all the cementing operations have been mixed and pumped flawlessly from the ROC in one of the NCS (Norwegian Continental Shelf) rigs. This work explores the relationship between the process of planning, execution and troubleshooting remotely when performing cement operations. By analyzing and reviewing different previous experiences on remote operations, the authors developed a more comprehensive decision support system for remote cementing operations.

Metrics for Assessing the Economic Impacts of Power Sector Climate and Clean Electricity Policies

Modeling tools are increasingly used to inform and evaluate proposed power sector climate and clean electricity policies such as renewable portfolio and clean electricity standards, carbon pricing, emissions caps, and tax incentives. However, claims about economic and environmental impacts often lack transparency and may be based on incomplete metrics that can obscure differences in policy design. This paper examines model-based metrics used to assess the economic efficiency impacts of prospective electric sector policies. The appropriateness of alternative metrics varies by context, model, audience, and application, depending on the prioritization of comprehensiveness, measurability, transparency, and credible precision. This paper provides guidance for the modeling community on calculating and communicating cost metrics and for consumers of model outputs on interpreting these economic indicators. Using an illustrative example of clean electricity standards in the U.S. power sector, model outputs highlight strengths and limitations of different cost metrics. Transformations of power systems with lower-carbon resources and zero-marginal-cost generation may entail shifts in when and where system costs are incurred, and given how these changes may not be appropriated reflected in metrics that were commonly reported in the past such as wholesale energy prices, showing a decomposition of system costs across standard reporting categories could be a more robust reporting practice. Ultimately, providing better metrics is only one element in a portfolio of transparency-related practices, and although it is insufficient by itself, such reporting can help to move dialogues in more productive directions and encourage better modeling practices.

High-Volume Fly Ash-Based Cementitious Composites as Sustainable Materials: An Overview of Recent Advances

High-volume fly ash (HVFA) cementitious composites (paste, grout, mortar, and concrete) have been widely investigated as a class of sustainable materials due to their lower carbon footprint and often better life cycle performance than conventional Portland cement mixtures. Recent years have seen increased research in HVFA-based materials, and the potential of this type of mixtures in engineering applications has significantly improved. In this context, this work reviews the renewed knowledge of HVFA mixtures, focusing on the relevant papers published over the last decade. The effects of replacing cement with a HVFA binder on the fresh properties, mechanical properties, durability performance, and environmental impact of HVFA cementitious composites are explored. Measures that can compensate for the main drawbacks that limit the wider application of HVFA mixtures are discussed in detail. At last, we summarize the research needs and remaining challenges of HVFA cementitious composites.

LUCEFIN C60 (1.0601), C60E (1.1221), C60R (1.1223)

Lucefin C60, C60E, and C60R are high-carbon, non-alloy steels that are used in the normalized, cold worked, or quenched and tempered condition. C60E and C60R may also be flame or induction hardened. C60, C60E, and C60R are used for applications where the higher carbon is needed to improve wear characteristics and where strength levels required are higher than those attainable with the lower carbon grades. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on forming, heat treating, machining, and joining. Filing Code: CS-213. Producer or source: Lucefin S.p.A.