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Petroleum Migration and Accumulation
Published in Muhammad Abdul Quddus, Petroleum Science and Technology, 2021
Highly soluble limestone is known as ‘karsts limestone’. Limestone is highly soluble in warm water in the presence of carbonic acid (H2CO3). Dissolved carbon dioxide gas in water forms carbonic acid. The dissolved karsts limestone is precipitated out under proper conditions. Karsts limestone, after precipitation and settling, forms reservoir rock of excellent porosity and permeability.
Dissolved Matter
Published in Paul N. Cheremisinoff, Handbook of Water and Wastewater Treatment Technology, 2019
When carbon dioxide dissolves in water, it forms, to a certain extent, a weakly dissociated acid—carbonic acid. (Ionization constant for the first hydrogen, at 18°C, is 3 × 10−7; and for the second hydrogen, at 25°C, is 6 × 10−11.) If the water is free from all traces of alkali, and is saturated with carbon dioxide—about 1450 ppm at 77°F—the pH value is approximately 3.8. This low pH would not be found in natural waters; except for waters containing free mineral acidity or exactly neutral waters, there is some bicarbonate alkalinity always present. Pure distilled water in equilibrium with the carbon dioxide content of the atmosphere will have a pH of about 5.7. Trace of alkalinity will raise this figure, so that most distilled waters in glass vessels will have pH values of around 6.4.
Production and Purification of Biogas From Biodegradable Waste
Published in C. S. P. Rao, G. Amba Prasad Rao, N. Selvaraj, P. S. C. Bose, V. P. Chandramohan, Mechanical Engineering for Sustainable Development, 2019
P. Sai Chaitanya, T. V. S. Siva, K. Simhadri
After the hydrogen sulfide was removed by the steel wool, the raw biogas passes into the water scrubbing unit for further purification. When carbon dioxide is dissolved in water, carbonic acid is formed. It is a weak acid. Complete separation of CO2 can improve the heating value of the gas by about 80% on a volume basis and nearly 225% on weight basis. Methane burns faster than biogas and hence will yield a higher specific output and thermal efficiency compared to biogas as engine fuel. Moreover, the absence of CO2 in the gas will enable an additional volume of air to be inducted into the engine cylinder, thereby improving the volumetric efficiency of the engine. It, therefore, seems very attractive to find means of separating biogas into methane and CO2, which can serve the dual purpose of improving the quality of combustion as well as obtaining CO2 as a commercial by-product.
Low-temperature synthesis of SrCrO4 nanorod particles from strontium sulfate
Published in Journal of Dispersion Science and Technology, 2020
SrCO3 was observed in the product phase, although no carbonation agent was added to the system. This is because the CO2 gas in the air acts as a carbonator when dissolved in water/solution medium. First, the CO2 gas enters the solution phase, whereupon it becomes soluble and then carboxylic acid, a polybasic acid, forms. Carbonic acid, which is a weak acid with two steps of ionization in the aqueous solution, forms bicarbonate in the first step and carbonate ions in the second step. However, the formation of these species strongly depends on the pH of the solution. Initially, when the medium is acidic, the concentration of carbonic acid decreases over time with the addition of sodium hydroxide and ends at approximately pH= 9. At this point, the concentration of bicarbonate ions reaches its maximum value. Finally, at about pH > 11, all of the bicarbonate ions turn into carbonate ions. Some of the free Sr2+ ions in the solution are precipitated as SrCO3 (Ksp: 5.6x1010 for SrCO3).[29]
Performance of an amide-based inhibitor derived from coffee bagasse oil as corrosion inhibitor for X70 steel in CO2-saturated brine
Published in Green Chemistry Letters and Reviews, 2019
N.B. Gomez-Guzman, D.M. Martinez de la Escalera, J. Porcayo-Calderon, J.G. Gonzalez-Rodriguez, L. Martinez-Gomez
The corrosion of carbon steel due to dissolved carbon dioxide (CO2) is commonly known as “sweet corrosion” and it is a serious problem in the different stages of hydrocarbon transport (1). It is known that CO2 when dissolved in water promotes the formation of carbonic acid (H2CO3). In this way, the carbonic acid reacts with the carbon steel causing its degradation and assisting in the formation of cracks which can evolve to fractures (2). This is a serious problem because the rupture of the hydrocarbon transport lines causes great economic and material losses, as well as damage to the environment.
Real-time colorimetric detection of dissolved carbon dioxide using pH-sensitive indicator based on anthocyanin and PVA coated green iron oxide nanoparticles at room temperature
Published in Inorganic and Nano-Metal Chemistry, 2022
Derya Aksu Demirezen, Dilek Demirezen Yılmaz
The operation of the pH-based colorimetric sensing in this study can be summarized as follows: CO2 diffusing into the PVA-gIONPs-ATH indicator solution causes a reaction that changes the pH value by producing carbonic acid. This change in pH induces a color change. pH change is proportional to the amount of carbon dioxide gas that had infiltrated into the indicator solution. The hydroxide is donated by PVA molecules at the surface of iron oxide nanoparticles. Simultaneously, the pH of the indicator solution increases by the end of CO2 gas and reaches the initial state.