Carbon capture and storage using alkaline industrial wastes.

Geological evidence indicates that grounded ice sheets reached sea level at all latitudes during two long-lived Cryogenian (58 and ≥5 My) glaciations. Combined uranium-lead and rhenium-osmium dating suggests that the older (Sturtian) glacial onset and both terminations were globally synchronous. Geochemical data imply that CO2 was 102 PAL (present atmospheric level) at the younger termination, consistent with a global ice cover. Sturtian glaciation followed breakup of a tropical supercontinent, and its onset coincided with the equatorial emplacement of a large igneous province. Modeling shows that the small thermal inertia of a globally frozen surface reverses the annual mean tropical atmospheric circulation, producing an equatorial desert and net snow and frost accumulation elsewhere. Oceanic ice thickens, forming a sea glacier that flows gravitationally toward the equator, sustained by the hydrologic cycle and by basal freezing and melting. Tropical ice sheets flow faster as CO2 rises but lose mass and become sensitive to orbital changes. Equatorial dust accumulation engenders supraglacial oligotrophic meltwater ecosystems, favorable for cyanobacteria and certain eukaryotes. Meltwater flushing through cracks enables organic burial and submarine deposition of airborne volcanic ash. The subglacial ocean is turbulent and well mixed, in response to geothermal heating and heat loss through the ice cover, increasing with latitude. Terminal carbonate deposits, unique to Cryogenian glaciations, are products of intense weathering and ocean stratification. Whole-ocean warming and collapsing peripheral bulges allow marine coastal flooding to continue long after ice-sheet disappearance. The evolutionary legacy of Snowball Earth is perceptible in fossils and living organisms.

https://hal.archives-ouvertes.fr/hal-01765604/document

Snowball Earth climate dynamics and Cryogenian geology-geobiology

A review of research progress on CO2 capture, storage, and utilization in Chinese Academy of Sciences

A review of mineral carbonation technology in sequestration of CO2

We assess the literature on innovation and upscaling for negative emissions technologies (NETs) using a systematic and reproducible literature coding procedure. To structure our review, we employ the framework of sequential stages in the innovation process, with which we code each NETs article in innovation space. We find that while there is a growing body of innovation literature on NETs, 59% of the articles are focused on the earliest stages of the innovation process, 'research and development' (RD appealing to heterogeneous users, managing policy risk, as well as understanding and addressing public concerns are all crucial yet not well represented in the extant literature. Results from integrated assessment models show that while NETs play a key role in the second half of the 21st century for 1.5 °C and 2 °C scenarios, the major period of new NETs deployment is between 2030 and 2050. Given that the broader innovation literature consistently finds long time periods involved in scaling up and deploying novel technologies, there is an urgency to developing NETs that is largely unappreciated. This challenge is exacerbated by the thousands to millions of actors that potentially need to adopt these technologies for them to achieve planetary scale. This urgency is reflected neither in the Paris Agreement nor in most of the literature we review here. If NETs are to be deployed at the levels required to meet 1.5 °C and 2 °C targets, then important post-R&D issues will need to be addressed in the literature, including incentives for early deployment, niche markets, scale-up, demand, and—particularly if deployment is to be hastened—public acceptance.

https://iopscience.iop.org/article/10.1088/1748-9326/aabff4/pdf

Negative emissions—Part 3: Innovation and upscaling

Carbonation of natural brucite in H2O and diluted HCl is investigated at room temperature and moderate pCO2 to explore the products’ mineralogy and reaction kinetics. Results show nesquehonite is by far the dominant carbonate species formed, despite its poorer thermodynamic stability relative to magnesite and possibly hydromagnesite. Time-dependent measurements reveal carbonate formation within 30 min, regardless of the original acidity of the slurry. However, while the fraction of reacted brucite in H2O increases gradually over time and approaches unity (∼98%) at 2.5 h, it rises rapidly in HCl within the first hour and levels off thereafter, leaving a significant amount of brucite unreacted. Such behavior suggests that the initial quantity of Mg2+ affects the reaction kinetics. Fitting a pseudo first-order rate law to the data yields a higher rate constant for the HCl experiments. These observations may imply that the carbonation does not proceed through heterogeneous reaction between gaseous CO2 and sol...

Aqueous carbonation of natural brucite: relevance to CO2 sequestration.

Temperature dependence of basalt weathering

Continued obliquity pacing of East Asian summer precipitation after the mid-Pleistocene transition

Uranium isotopic constraints on the provenance of dust on the Chinese Loess Plateau

Eolian deposits of loess on the Chinese Loess Plateau are investigated to decipher the influence of sequentially changed monsoon climate on silicate weathering process. Detailed hydrochloric acid dissolution experiments are applied to establish a sensitive proxy for silicate weathering. Combined elemental and mineralogical studies show that the minerals which are susceptible to incipient chemical weathering can be totally dissolved in hot hydrochloric acid (80°C, 3mol/L) after 4h, while other stable minerals are nearly unaffected. Thus, the hydrochloric acid dissolvable fractions (ADF) of loess and paleosol are more sensitive than bulk samples in the weathering reaction. Since Mg is tend to be leached out from the ADF while Al is conserved during the incongruent weathering, Mg/Al ratio of the ADF (Mg/Al ADF ) could indicate the weathering intensities of the Mg-bearing minerals, mainly chlorite. The Mg/Al ADF of the modern soils on the Chinese Loess Plateau is closely correlated to the local precipitation amounts, suggests that the intensity of summer monsoon is a key factor in the weathering of Mg-silicate. The silicate weathering intensity of the loess-paleosol deposits of past 130Kyrs shows strong procession cycle of ∼ 23Kyrs coupled by glacial-interglacial variation. The ∼ 23Krys cycles are coherent to the variations of the intensity of summer monsoon, while the ∼ 100Kyrs glacial-interglacial variation may relates to the changes in winter monsoon. Phased intensification of East Asian summer monsoon, and thus enhanced silicate weathering and atmosphere CO 2 drawdown, in response to the uplift of Tibetan Plateau, may be another mechanism relating the late Cenozoic tectonics to global cooling.

Liang Zhao

Papers

Aqueous carbonation of natural brucite: relevance to CO2 sequestration.

Temperature dependence of basalt weathering

Continued obliquity pacing of East Asian summer precipitation after the mid-Pleistocene transition

Uranium isotopic constraints on the provenance of dust on the Chinese Loess Plateau

Response of silicate weathering to monsoon changes on the Chinese Loess Plateau