Advanced mineral carbonation: An approach to accelerate CO\u3csub\u3e2\u3c/sub\u3e sequestration using steel production wastes and integrated fluidized bed reactor

© Springer Nature Switzerland AG 2019. Industrial pollution is the major source of global warming through emissions of greenhouse gases (GHG’s) like CO2, CH4, and NO2, causing noticeable increasing in the world’s temperature. Mineral carbonation is a method of carbon capture and storage (CCS) through which CO2 is sequestered with advantage of permanent sequestration and no need for post-storage surveillance and monitoring through stabilizing the reactive mineral wastes released from metal industries. This paper applied a simple and an inexpensive hydration process as a pre-treatment step for the carbonation of Ladle Furnace (LF) slag, one of the steel production by-products in UAE, followed by direct gas-solid carbonation in a new designed integrated fluidized bed reactor (FBR). About (10–15)% by weight of produced steel, alkaline solid residues were generated, based on the characteristics of the manufacturing process. The integrated FBR was designed to control the flow rate up to 50 l/min with step accuracy of 0.1 l/min, and temperature up to 200 °C through a double jacket electrical heater. Operating pressure can be adjusted up to 6 bars. All parameters are monitored by SCADA system. A mixture gas of 10% CO2, balanced with air, was used to perform the carbonation process and evaluation the carbonation efficiency as well. A gas analyzer installed at the outlet of FBR was used to measure unreacted CO2 gas after leaving the reactor, and calculate the amount of CO2 captured accordingly. Results of analytical techniques like TGA and XRD emphasized the sequestration of CO2 and show a high efficient carbonation process

Comparison Of Biochemical And Physiological Properties Of Nigerian Tomato Fruits Ripened Under Different Conditions

The growth in chronic diseases such as obesity, diabetes, various types of cancers and cardiovascular diseases is an argument in favour of promoting fruit and vegetable consumption in Africa, with the main obstacle being the purchasing power. The objective of this study was to investigate the respective impacts of ripening stages and techniques of ripening on tomato fruit quality in order to recommend which of the conditions of ripening is better for optimum benefit of the tomatoes. The physiological and biochemical changes in tomato fruits of two varieties (Ibadan-Local and Roma cultivars) ripened using two different techniques (field and ambient temperature ripening) were monitored; the differences in the mean values between the ripening methods are discussed at appropriate significance levels. The mean differences in percent total solids for tomato fruits between the two conditions of ripening are significant (P<0.05 at the breaker stage of Ibadan-local cultivar and P<0.01 for other stages in the two varieties). The differences are much higher at the pink to fully-red stages in tomatoes ripened under the ambient temperature. Except at light-red stage of Ibadan-local cultivar and breaker stage of Roma cultivar, the mean differences in pH values between the ripening methods are significant (P<0.05 at the breaker stage of Ibadan-local cultivar and at the light-red stage of Roma cultivar and P<0.01 for other stages in the two varieties).Mean differencesin percent titratable acidity (as citric acid) of the fruits under the two methods of ripening are also significant (P<0.05 at the breaker stage of Roma cultivar and P<0.01 for other stages in the two varieties) with exceptions at fully-red stage of the two varieties. However, high significant differences (P<0.01) exist between the mean values of reducing sugar, lycopene (but P<0.05 at breaker stage of Roma cultivars) and beta-carotene contents of the tomato fruits under the two conditions of ripening, with higher values obtained mostly in the field ripening method.About 69.2 g and 58.3 g of tomato fruits, ripened on the parent plants (field ripening), at light-red stage of Ibadan-local and Roma-type respectively, are recommended daily in accordance with average daily recommendation of 25.2 mg of lycopene per day in Canadian diet and from the study from Harvard School of Medicine. Equivalent quantities could only be reached by consuming higher quantities of tomatoes ripened at ambient temperature

A comprehensive review of sectorial contribution towards greenhouse gas emissions and progress in carbon capture and storage in Pakistan

The extreme amount of greenhouse gases (GHGs) being released into the atmosphere has proved to be a globally challenging phenomenon that leads to changes in the climate and global warming. The amount of GHGs in the atmosphere has escalated immensely, with a substantial growth of 5.8% in 2010; a similar increase was observed in Pakistan as well. In Pakistan, carbon dioxide (CO2) emissions stand at 54% of total GHG emissions whereas methane, nitrous oxide, carbon monoxide and volatile organic carbon contribute to emissions at 36%, 9%, 0.75% and 0.3%, respectively. One of the key reasons for climatic changes is GHG emission generation from human interventions and activities related to transportation, urban development, industrialization, energy sources, farming and agriculture, waste's improper management, land use and forestry. In 2011, Pakistan's entire GHG emissions were a whopping 347 Mt of CO2-eq, and by 2050, they are estimated to reach 4621 Mt CO2-eq. This review evaluates and assesses GHG emissions generating from various sectors in Pakistan, in a socio-scientific prospect that is caused by human activities and interventions in different economic sectors in Pakistan, endangering the environment across the country. Additionally, the review examines the current level of GHG emissions while accounting for China-Pakistan Economic Corridor-based emissions, abatement strategies including development of a state-of-the-art technique for carbon capture and storage/utilization technologies in Pakistan. (c) 2019 Society of Chemical Industry and John Wiley & Sons, Ltd

Nanocomposite sodalite/ceramic membrane for pre-combustion CO2 capture: synthesis and morphological characterization

Carbon capture and storage (CCS) is amongst the possible options to reduce CO2 emission. In the application of CCS, CO2 capture techniques such as adsorption and membrane system have been proposed due to less energy requirement and environmental benign than the absorption process. However, membrane system has drawbacks such as poor membrane reproducibility, scale-up difficulty and high cost of the membrane supports. In this study synthesis and characterization of nanocomposite sodalite (HS)/ceramic membrane via “pore-plugging” hydrothermal synthesis (PPH) protocol for pre-combustion CO2 capture is reported. The morphology and crystallinity of the as-prepared membranes were checked with scanning electron microscopy and X-ray diffraction. Surface chemistry of the membrane was examined with Fourier Transform Infrared spectroscopy. In nanocomposite architecture membranes, zeolite crystals are embedded within the pores of the supports instead of forming thin-film layers of the zeolite crystals on the surface of the supports. Compared to the conventional in situ direct hydrothermal synthesis, membranes obtained from PPH possess higher mechanical strength and thermal stability. In addition, defect control with nanocomposite architecture membranes is possible because the zeolite crystals are embedded within the pores of the support, thereby limiting the maximum defect size to the pore size of the support. Furthermore, the nanocomposite architecture nature of the membranes safeguards the membrane from shocks or abrasion that could promote formation of defects. The aforementioned advantages of the nanocomposite architecture membranes could be beneficial in developing high performance and cost-effective membrane materials for pre-combustion CO2 capture.</p