Carbon dioxide after sulfurous compound

After shift conversion, carbon dioxide, residual carbon monoxide, and sulfur compounds (only present in the synthesis gas from partial oxidation) have to be removed as they are not only a useless ballast but, more importantly, can poison the ammonia synthesis catalyst. 

The ratio of hydrogen to carbon monoxide is controlled by shifting only part of the gas stream. After the shift, the carbon dioxide, which is formed in the gasifier and in the water gas reaction, and the sulfur compounds formed during gasification, are removed from the gas. 

A closed bottle of unused potassium dichromate-sulfuric acid mixture exploded after several months in storage [1]. Previous similar incidents were summarised, and the possibility of the bottle having burst from internal pressure of carbon dioxide arising from trace contamination by carbon compounds was advanced [1,2], Two further reports of incidents within 1 or 2 days of preparation of... 

Berzelius went further in his attempt to simplify the science. He joined the symbols of the elements to represent the simplest parts of compounds. Thus copper oxide was written CuO, and zinc sulfide ZnS. He had, at first, denoted the number of oxygen atoms by dots and the number of sulfur atoms by commas thus carbon dioxide was C and carbon disulfide was C. But he soon discarded these dots and commas, although for decades after, mineralogists utilized this method of writing the formulas of minerals. 

Decamethylsilicocene (1) reacts with carbon dioxide already under mild conditions. Surprisingly, the products obtained depend on the solvent used. Bubbling CO2 at room temperature for about 3 through a solution of 1 in pyridine led to the eight-membered cyclic compound 1 in about 65 % yield, whereas in toluene as solvent the spiro heterocyclic compound II was formed in about 70 % yield. 1 reacts with carbon oxysulfide already under very mild conditions A toluene solution of 1 was added to liquid COS at -78°C. The dithiadisiletane III was isolated in about 50 % yield after a reaction time of 2 at this temperature. Compound III, already known in the literature as the reaction product of 1 with sulfur [6], is poorly soluble in organic solvents. 

Methyl tetra-0-acetyl-/3-D-glucoside 942 Acetobromoglucose (8.6 g) is dissolved in anhydrous methanol (126 ml) and shaken at room temperature with dry, powdered silver carbonate (8.5 g). The evolution of carbon dioxide, which is initially rapid, slackens after about an hour, and the mixture is then shaken mechanically for about 6 h in a closed vessel. Insoluble material is then filtered off and washed well with ether, and the filtrate is treated with water and a small amount of barium carbonate, then filtered again and evaporated in an evacuated desiccator over sulfuric acid. The dry residue is shaken with water and repeatedly with ether. The united ethereal solutions are shaken with sodium carbonate solution and water and dried over sodium sulfate. Evaporation of the ether affords a nicely crystalline compound when this glycoside is recrystallized from methanol and then from light petroleum it has m.p. 104-105°, the yield being 3.75 g. 

Unfortunately, the H2 CO ratio is generally much less than 3 1, and therefore it has to be adjusted by the shift reaction in which carbon monoxide is oxidized to carbon dioxide with concomitant production of hydrogen (Reaction 2). After removal of CO2 and sulfur compounds, the... 

Purification of synthesis gas. The sulfur- and carbon-containing compounds in synthesis gas must be removed in order to avoid the poisoning of catalysts in the following processes. Sulfur and carbon containing compounds are absorbed by different solvents. The used solvents are regenerated by desorption and H2S (or element S) and carbon dioxide are recovered. The trace amounts of carbon monoxide and carbon dioxide which remained in synthesis gas is removed via the reaction of methanation or other methods. After a series of purifications, the content of carbon monoxide and carbon dioxide in the synthesis gas are on the levels of ppm (1 ppm = 1 ml m ). 

Ammonia is readily absorbed by potassium carbonate solutions. Sulfur dioxide and hydrogen cyanide, both acidic compounds, are also readily absorbed by hot carbonate solutions. After absorption, these compounds react further forming a variety of compounds, such as sulfates, thiosulfates, thiocyanates, polysulfides, and elemental sulfur, which accumulate in the solution. 

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