- Hydrogenation of aqueous mixtures of calcium carbonate and carbon dioxide using a water-soluble rhodium(I)-tertiary phosphine complex catalyst
-
Aqueous suspensions of calcium carbonate were hydrogenated to yield calcium formate under a gas phase containing both H2 and CO2. A rhodium(I)-complex of monosulfonated triphenylphosphine (mtppms), [RhCl(mtppms)3] was used as catalyst. Reaction temperatures were in the range of 20-70°C, total pressure 10-100 bar with an optimum p(CO 2):p(H2) ratio of 1:4. Due to the mobile bicarbonate-formate equilibrium, the highest available formate concentration is decreased with increasing temperature but increased with increasing pressure. Interestingly, at 50°C and 100 bar total pressure the yield of formate was 143% (based on CaCO3) which implies the formation of free formic acid in the reaction of CO2 from the gas phase. The dependence of the hydrogenation rate on the catalyst and ligand concentrations, as well as that of the decomposition of formate as a function of temperature were also studied. A mild method has been developed for the hydrogenation of calcium carbonate to calcium formate in aqueous suspensions under CO2 + H2 pressure catalyzed by [RhCl(mtppms)3] (mtppms = monosulfonated triphenylphosphine) at 20-70°C and 10-100 bar total pressure. In certain cases the yield of formate exceeded 100% (based on CaCO3) which implies the concomitant hydrogenation of carbon dioxide, too.
- Jószai, István,Joó, Ferenc
-
-
Read Online
- Eco-friendly upconversion of limestone into value-added calcium formate
-
Although CaCO3 is a naturally available, inexpensive, abundant and extensively used chemical in various industries, to date, most of its conversions liberate CO2 into the atmosphere, which accounts for about 5-6% of global anthropogenic CO2 emission. Herein, the first synthesis of calcium formate (CF) by hydrogenation of an aqueous mixture of CaCO3 and CO2 using a heterogeneous catalyst in an unconventional CO2 reducing manner is reported. The phosphine-based heterogenized Ru catalyst efficiently converts CaCO3 into CF with good selectivity (>99%) and is readily separated from the reaction product, resulting in promising recycling ability. Thus, this work provides a promising strategy for the design of green and sustainable conversion of carbonate minerals in industry.
- Gunasekar, Gunniya Hariyanandam,Padmanaban, Sudakar,Park, Hongjin,Yoon, Sungho
-
-
Read Online
- Eco-friendly and techno-economic conversion of CO2 into calcium formate, a valuable resource
-
The suppression of greenhouse gas emissions is being considered more important than ever, and consequently, the development of methods to produce useful CO2 conversion products with excellent techno-economic feasibility and high CO2 reduction capability is of interest. A continuous CO2 conversion system and a heterogenized hydrogenation catalyst can be used to develop a process for the efficient and selective production of Ca(HCO2)2, which has not been considered as a CO2 conversion product so far, from waste resources, including CaO. Techno-economic analysis of the entire process showed that the production cost of Ca(HCO2)2 was reduced by around 16% compared with the conventional process, indicating a high possibility of market penetration. Furthermore, the estimation of the global warming index of the process through a life-cycle assessment showed that the global warming index could be reduced by about 20% compared with that of existing Ca(HCO2)2 production processes.
- Lee, Chul-Jin,Yoon, Ha-Jun,Yoon, Hayoung,Yoon, Sungho,Yoon, Taeksang
-
p. 1738 - 1745
(2022/03/08)
-
- A a method of preparing calcium
-
The invention discloses a preparation method of calcium formate and belongs to the technical field of chemical synthesis. The preparation method of the calcium formate comprises the following steps: carrying out dust removal on semi-water gas, desulphurizing, compressing, carbonizing and recompressing to 3-5MPa to obtain feed gas, reacting with a calcium hydroxide turbid liquid in the presence of ammonia or amine to generate a calcium formate aqueous solution containing ammonium formate or amine formate, adding right amount of lime milk and carrying out a replacement reaction in a calcium formate aqueous solution concentrating process, so that calcium formate precipitate is obtained. The preparation method of the calcium formate has the advantages that a reaction accelerator volatile alkali is used in a process that the feed gas reacts with the calcium hydroxide turbid liquid, generation of formate ions in reaction between carbon monoxide and hydroxyl ions is sped up, and concentration of a formate solution generated by the reaction between the carbon monoxide and hydroxyl ions is greatly increased, so that energy consumption in a concentration process is reduced, and coproduction of calcium formate and sodium formate can be realized on the basis of the original synthetic ammonia production system.
- -
-
Paragraph 0022-0023
(2017/07/07)
-
- CO2-"Neutral" hydrogen storage based on bicarbonates and formates
-
Let the circle be unbroken! One ruthenium catalyst generated in situ facilitates the selective hydrogenation of bicarbonates and carbonates, as well as CO2 and base, to give formates and also the selective dehydrogenation of formates back to bicarbonates. The two reactions can be coupled, leading to a reversible hydrogen-storage system. dppm=1,2- bis(diphenylphosphino)methane. Copyright
- Boddien, Albert,Gaertner, Felix,Federsel, Christopher,Sponholz, Peter,Mellmann, Doerthe,Jackstell, Ralf,Junge, Henrik,Beller, Matthias
-
p. 6411 - 6414
(2011/08/05)
-
- A METHOD OF MAKING SALT
-
A method of making the salt of an acid, includes the steps of combining and mixing the acid and a base selected from the oxides, hydroxides and carbonates of sodium, potassium, calcium and magnesium, in a first reaction zone over a first period to produce a reaction mixture. The reaction mixture is transferred at the end of the first period from the first reaction zone to a second reaction zone the transferring step being carried out over a second period. Heat generated by reaction between the acid and the base in the second reaction zone drives off sufficient water to produce a product mixture containing less than about 8 % (m/m) water. The first period is between about 1 and 180 seconds and the second period is between about 2 and 60 seconds.
- -
-
Page/Page column 17
(2008/06/13)
-
- Synthesis of cement-containing nickel-copper catalytic systems using formic acid aqueous solutions
-
Regular trends in the formation of phase composition, structure, and mechanical strength of nickel-copper catalysts used for treatment of process and off-gases were considered in relation to the concentration (5.0-60.0 wt %) of formic acid aqueous solutions used in their preparation. The optimal conditions of the preparation process were determined.
- Efremov,Tesakova,Mamaeva,Golosman
-
p. 745 - 751
(2007/10/03)
-
- A study of the Ca(HCOO)2-Cu(HCOO)2-H2O system at 25°C
-
The Ca(HCOO)2-Cu(HCOO)2-H2O system was studied at 25°C by the isothermal method in a wide component concentration range. The crystallization areas of Ca(HCOO)2, Cu(HCOO)2 · 4H2O, and a binary compound, Ca2Cu(HCOO)6, were established. The structure of solid phases was confirmed by X-ray structural analysis and IR spectroscopy. The Ca2Cu(HCOO)6 crystal lattice prameters were refined, an IR spectrum was obtained, and its behavior under heating was studied.
- Fakeev,Orlova,Iskhakova,Zhadanov
-
p. 1523 - 1526
(2007/10/03)
-
- The Ca(HCOO)2-Mn(HCOO)2-H2O System at 25°C
-
The Ca(HCOO)2-Mn(HCOO)2-H2O system was studied at 25°C by the isothermic method in a wide concentration range. The system is a simple eutonic. Solid phases were identified by IR spectroscopy.
- Fakeev,Orlova,Zhadanov
-
p. 1320 - 1322
(2008/10/08)
-
- Method of producing calcium salts from biomass
-
Calcium salts, such as calcium acetate, calcium formate or calcium proprionate, are obtained from aqueous liquors derived from the pyrolysis of lignocellulosic biomass containing cellulose, hemicelluloses or starch. The above biomass is subjected to rapid pyrolysis to obtain a crude product containing an aqueous phase and an organic phase. The product obtained, preferably as the aqueous phase, is then distilled to produce a distillate containing at least one acid selected from acetic acid, formic acid and propionic acid as well as their esters and formaldehyde. An alkaline source of calcium is added to this distillate to adjust the pH to an alkaline level sufficient to hydrolyze the esters, cause at least partial oxidation of the formaldehyde and prevent volatilization of acetate, formate or propionate ions as acetic acid, formic acid or propionic acid respectively. This pH adjusted alkaline liquid is then subjected to a further distillation to remove water and volatile organic components and produce at least one of calcium acetate, calcium formate and calcium propionate as solid residue.
- -
-
-
- Process for the production of calcium formate
-
Calcium formate is produced in aqueous phase by reaction of calcium hydroxide with formaldehyde in the presence of hydrogen peroxide or by reaction of calcium peroxide with formaldehyde. The molar ratio of CaO or Ca(OH)2 to H2 CO to H2 O2 is 1 to 2 to 1-1.2 and the molar ratio of CaO2 to H2 CO is 1 to 2. Calcium formate is obtained in an almost substantially quantitative yield and in highly pure form. The process avoids the disadvantages of prior processes for the production of calcium formate from calcium hydroxide and formaldehyde.
- -
-
-
