Residue hydrogen content

The Schwechat plant was operated with a stoichiometric synthesis gas in a long term test of 5000 hrs. The residual hydrogen content could be decreased to 2.2 vol % which resulted in a heating value of 950 Btu/scf when about 1 vol % nitrogen was present in the synthesis gas. 

If it is also desired to determine the amount of fused metal, the cross-section of the bead shall be measured on tracings or photographs of the fractured faces. These measurements are made after hot extraction if the residual hydrogen content is also to be assessed. 

Two methods are described for measuring the total or residual hydrogen contents of ferritic weld metal the residual hydrogen content is that proportion remaining after measuring of diffusible hydrogen as described above. 

Relationship between the residual aromatics content, the hydrogen partial pressure, and the chemical hydrogen consumption (for a SR gas oil). 

Industrial specifications for aHphatic tertiary amine oxides generally requite an amine oxide content of 20—50%. These products may contain as much as 5% unreacted amine, although normally less than 2% is present. Residual hydrogen peroxide content is usually less than 0.5%. The most common solvent systems employed are water and aqueous isopropyl alcohol, although some amine oxides are available ia aoapolar solveats. Specificatioas for iadividual products are available from the producers. 

Charcoal—sulfur processes need low ash hardwood charcoal, prepared at 400—500°C under controlled conditions. At the carbon disulfide plant site, the charcoal is calcined before use to expel water and residual hydrogen and oxygen compounds. This precalcination step minimises the undesirable formation of hydrogen sulfide and carbonyl sulfide. Although wood charcoal is preferred, other sources of carbon can be used including coal (30,31), lignite chars (32,33), and coke (34). Sulfur specifications are also important low ash content is necessary to minimise fouling of the process equipment. 

To accelerate the polymerization process, some water-soluble salts of heavy metals (Fe, Co, Ni, Pb) are added to the reaction system (0.01-1% with respect to the monomer mass). These additions facilitate the reaction heat removal and allow the reaction to be carried out at lower temperatures. To reduce the coagulate formation and deposits of polymers on the reactor walls, the additions of water-soluble salts (borates, phosphates, and silicates of alkali metals) are introduced into the reaction mixture. The residual monomer content in the emulsion can be decreased by hydrogenizing the double bond in the presence of catalysts (Raney Ni, and salts of Ru, Co, Fe, Pd, Pt, Ir, Ro, and Co on alumina). The same purpose can be achieved by adding amidase to the emulsion. 

One disadvantage of tough pitch coppers is the embrittlement that is liable to occur when they are heated in atmospheres containing hydrogen. For many purposes, therefore, and particularly where fabrication is involved, deoxidised coppers are preferred. The usual deoxidising agent is phosphorus, and specifications require residual phosphorus contents of between... 

For SNG manufacture, it is necessary to reduce the residual hydrogen to a minimum in order to achieve a high calorific value. This is best realized if the synthesis gas, instead of having a stoichiometric composition, contains a surplus of C02 which can be utilized to reduce the H2 content by the C02 methanation reaction to less than 1% according to equilibrium conditions. The surplus C02 must be removed at the end of the process sequence. It is, of course, also possible to operate a methanation plant with synthesis gas of stoichiometric composition then there is no need for a final C02 removal system. The residual H2 content will be higher, and therefore the heating value will be lower (cf. the two long term runs in Table II). 

Initial rates of oxidation were determined as described in Reference 1. Mass of residual coke was determined by ashing, and carbon and hydrogen content of the residual coke was determined by microanalysis. Because the relative error in the total heat produced by oxidation of the bitumen exceeded 50%, the heats were considered unreliable and are not reported here. 

As expected, both the bottoms products and the residues, where formed, have substantially higher carbon and lower oxygen contents than the original fractions, but whereas in the bottoms products the hydrogen contents have increased, in the residues they are reduced. The bottoms products, including that from the whole coal, are remarkably similar in composition to each other. Lkkewise the residues are similar in composition to each other. 

The above TGA and elemental analysis studies are consistent with Van Krevelen s two step model for polymer charring (2) in which a polymer first rapidly decomposes at 500°C to fuel gases and a primary char residue characterized by modestly high hydrogen content. On further heating above 550°C, this primary char is slowly converted in a second step to a nearly pure carbon residue by the loss of this hydrogen. 

Another coke formed in a FCC unit is occluded or residual coke. In a commercial unit this coke corresponds to coke formed on catalyst porosity and its content depends on textural properties of the catalyst (pore volume and pore size distribution) and the stripping system capacity in the reaction section. Finally on the FCC catalyst rests some high-molecular weight of nonvaporized hydrocarbons. These molecules do not vaporize or react at the reactor conditions and accumulate in the catalyst pores like a soft carbonaceous residue with high hydrogen content. 

Before TPO analysis it was necessary to Soxhlet extract the FCC samples to remove nonvaporized hydrocarbons and avoid their accumulation in the pores of the catalyst as carbonaceous residue with high hydrogen content. As a result, the interference during TPO analysis caused by the desorption and decomposition of these compounds at high temperatures was eliminated. In this study it was observed that this type of coke is directly related to the Conradson carbon content of the feedstock. 

It has been determined using ll,FNMR that some of the perfluoro ethers and other per-fluorocarbon compounds synthesized with this process have residual hydrogen remaining on the organic compound in concentrations below 3 parts per billion. To put that in perspective, in polytetrafluoroethylcne which is made from tctrafluorocthcne monomer, the hydrogen content is several parts per million. 

The elemental analyses of the products from the extraction of Bruceton coal are shown in Table III. The mineral matter was separated from the extract quite efficiently as shown by the ash content of the extracts and the insoluble residue. The elemental composition of all fractions was quite similar to that of the original coal. Only the hydrogen content varied to some extent, increasing with increased solubility. The elemental analysis of the products from the extraction of Ireland Mine coal was incomplete. 

The two analyses agreed well and showed that the tritium content of the residue decreased from 21.4 to 15.8%. The difference (5.6%) corresponds approximately to that fraction of the hydrogen content of coal which is present... 

Coal and Coal-Tar Hydrogenation. If paraffinic and olefinic liquids are extracted from solid fuel substances, the hydrogen content of the residual material is reduced even further, and the residues become more refractory. The yields of liquids so derivable are generally low, even when a significant fraction of the hydrogen is extractable. Thus production of fuel liquids from nonliquid fuel substances such as coal and coal tars may be enhanced only by the introduction of additional hydrogen in a synthesis process. The principal differences in the processes are from the modes in which hydrogen is introduced and the catalysts used. 

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