Water feedstock

Thus, while water is an indispensable ingredient for the organic cycle (Equations (2) and (3)), a high concentration of water causes the major loss of one of the feedstocks. Water is also made in situ from methanol and acetic acid together with methyl acetate. In addition to water, HI is the cause of by-product formation ... 

The production of hydrogen electrolytically, using clean solar power or other forms of renewable energy is essentially pollution-free. The feedstock, water, is composed of hydrogen and oxygem Hydrogen production or distribution would produce no CO. ... 

HES [Feedstock (Water, Coal, Oil, Gas, Biomass) Electric Energy (Nuclear PP, Renewable PP, Fossil PP), H2 Production (Electrolysis, Reforming, Gasification) H2Utilisation (Fuel Cell, Gas Turbine, Internal Combustion Engine)]... 

First, a hydrocarbon or a carboneous feedstock, water and air are converted to synthesis gas consisting of hydrogen and nitrogen in a 3 to 1 volumetric ratio. The second step in the process is ammonia synthesis according to the following well-known reaction ... 

It is interesting to note that the GS process, which has one of the smallest separation factors of those shown, appears to be the most practical large-scale industrial process. That is because the kinetics of the exchange are favorable, even in the absence of a catalyst. That factor, combined with the further advantage that an abundant and cheap feedstock (water) is employed, and that the process is nonparasitic (i.e., not coupled to a large-scale production plant for some chemical commodity), accounts for the dominance of the GS method. 

Feedstocks come mainly from catalytic cracking. The catalyst system is sensitive to contaminants such as dienes and acetylenes or polar compounds such as water, oxygenates, basic nitrogen, organic sulfur, and chlorinated compounds, which usually require upstream treatment. 

Anhydrous Acetic Acid. In the manufacture of acetic acid by direct oxidation of a petroleum-based feedstock, solvent extraction has been used to separate acetic acid [64-19-7] from the aqueous reaction Hquor containing significant quantities of formic and propionic acids. Isoamyl acetate [123-92-2] is used as solvent to extract nearly all the acetic acid, and some water, from the aqueous feed (236). The extract is then dehydrated by azeotropic distillation using isoamyl acetate as water entrainer (see DISTILLATION, AZEOTROPIC AND EXTRACTIVE). It is claimed that the extraction step in this process affords substantial savings in plant capital investment and operating cost (see Acetic acid and derivatives). A detailed description of various extraction processes is available (237). 

Friedel-Crafts (Lewis) acids have been shown to be much more effective in the initiation of cationic polymerization when in the presence of a cocatalyst such as water, alkyl haUdes, and protic acids. Virtually all feedstocks used in the synthesis of hydrocarbon resins contain at least traces of water, which serves as a cocatalyst. The accepted mechanism for the activation of boron trifluoride in the presence of water is shown in equation 1 (10). Other Lewis acids are activated by similar mechanisms. In a more general sense, water may be replaced by any appropriate electron-donating species (eg, ether, alcohol, alkyl haUde) to generate a cationic intermediate and a Lewis acid complex counterion. 

The carbon black (soot) produced in the partial combustion and electrical discharge processes is of rather small particle si2e and contains substantial amounts of higher (mostly aromatic) hydrocarbons which may render it hydrophobic, sticky, and difficult to remove by filtration. Electrostatic units, combined with water scmbbers, moving coke beds, and bag filters, are used for the removal of soot. The recovery is illustrated by the BASF separation and purification system (23). The bulk of the carbon in the reactor effluent is removed by a water scmbber (quencher). Residual carbon clean-up is by electrostatic filtering in the case of methane feedstock, and by coke particles if the feed is naphtha. Carbon in the quench water is concentrated by flotation, then burned. 

The water—carbon slurry formed in the quench vessel is separated from the gas stream and flows to the carbon recovery system needed for environmental reasons and for better thermal efficiency. The recovered carbon is recycled to the reactor dispersed in the feedstock. If the fresh feed does not have too high an ash content, 100% of the carbon formed can be recycled to extinction. 

When the recycle soot in the feedstock is too viscous to be pumped at temperatures below 93°C, the water—carbon slurry is first contacted with naphtha carbon—naphtha agglomerates are removed from the water slurry and mixed with additional naphtha. The resultant carbon—naphtha mixture is combined with the hot gasification feedstock which may be as viscous as deasphalter pitch. The feedstock carbon—naphtha mixture is heated and flashed, and then fed to a naphtha stripper where naphtha is recovered for recycle to the carbon—water separation step. The carbon remains dispersed in the hot feedstock leaving the bottom of the naphtha stripper column and is recycled to the gasification reactor. 

These reactions show that the synthesis gas stoichiometry is dependent on both the nature of the feedstock as well as the generation process. Reactions 4 and 5, together with the water gas shift reaction 3, serve to independently determine the equiUbrium composition of the synthesis gas. 

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