Residual partial oxidation

Feedstock (process) Natural gas (steam reforming) Vacuum residue (partial oxidation) Coal (partial oxidation)... 

Here again, this is not a refining process, properly speaking. Partial oxidation is one of the processes for the ultimate conversion of heavy residues, asphalts, coke and even coal. 

The needs for hydrogen being considerably accentuated, the introduction of partial oxidation of at least a part of the ultimate residues is foreseen, in spite of its high cost. 

Flame or Partial Combustion Processes. In the combustion or flame processes, the necessary energy is imparted to the feedstock by the partial combustion of the hydrocarbon feed (one-stage process), or by the combustion of residual gas, or any other suitable fuel, and subsequent injection of the cracking stock into the hot combustion gases (two-stage process). A detailed discussion of the kinetics for the pyrolysis of methane for the production of acetylene by partial oxidation, and some conclusions as to reaction mechanism have been given (12). 

Noncatalytic partial oxidation of residual fuel oil accounts for the remainder of world methanol production. Shell and Texaco ate the predominant hcensors for partial oxidation technology (16) the two differ principally in the mechanical details of mixing the feedstock and oxidant, in waste heat recovery, and in soHds management. 

Heavy Hydrocarbon-Based Partial Oxidation Processes. Two major partial oxidation processes are commercially available, the SheU process (38) and the Texaco process (39). Operating conditions in the gas generator vary from 1200°C to 1370°C and from 3100 kPa to 8270 kPa (450—1200 psig). Generally, heavy oils are the hydrocarbon feeds however, the process can also accommodate feeds from natural gas to residual oils. 

Residuals Produced Typical residuals resulting from oxidation are partial oxidation products (e.g., chlorinated organics) and inorganic salts (e.g., NaCl, Mn02). Additional treatment may be required to permit disposal. 

There are different sources for obtaining synthesis gas. It can be produced by steam reforming or partial oxidation of any hydrocarbon ranging from natural gas (methane) to heavy petroleum residues. It can also... 

Andco-Torrax A process for making a fuel gas by the partial oxidation of organic wastes in a vertical shaft furnace. The residue is removed as a liquid slag from the base of the furnace. 

Mond A process for recovering sulfur from the residues from the Leblanc process. The sulfur is partially oxidized to thiosulfate and converted to elemental sulfur by adding hydrochloric acid. This process recovers only half the sulfur it was supplanted by the Chance process. Invented by L. Mond and operated by the Netham Chemical Company at Bristol from 1868 to 1888. 

Gasification coupled with water-gas shift is the most widely practiced process route for biomass to hydrogen. Thermal, steam, and partial oxidation gasification technologies are under development. Feedstocks include both dedicated crops and agricultural and forest product residues of hardwood, softwood, and herbaceous species. 

To extract boron from the sample a 50g sample of air-dried soil was boiled under reflux with 100ml of water for lOmin. After partial cooling, the extract was filtered through an 18.5cm Whatman No. 3 filter paper into a conical beaker and a 40ml aliquot of the filtrate transferred to a silica beaker. The solution was taken to dryness and the residue was oxidized twice with 10ml of 6% hydrogen peroxide solution. The residue was then diluted to 50ml. 

The catalytic conversion of heavy hydrocarbons, such as heavy oil or sulphurous organic residues, from the oil industry via steam reforming is not feasible because solid carbon starts to be deposited at temperatures above 800 °C, which renders the catalyst inactive in a short period of time and, furthermore, blocks the gas flow in the reactor. Heavy hydrocarbons are, therefore, converted to hydrogen using partial oxidation (POX). Note that in refineries the term gasification is more commonly used partial oxidation is the scientific terminology. 

Partial oxidation is mainly used in refineries, since the raw materials, i.e., refining residues, are available here at low cost. As far as the hydrogen produced is concerned, it can be assumed that this is primarily used by the refineries themselves, since the availability of lighter crudes is decreasing and hydrogen is being increasingly used to process heavier oils.9... 

Gasification is the conversion by partial oxidation at elevated temperature of a carbonaceous feedstock into a gaseous energy carrier consisting of permanent, noncondensable gases. Ideally, the process produces only a non-condensable gas and an ash residue. However, since gasification processes are carried out far from equilibrium, tars (condensable organic material) are produced and the ash resi-... 

The partial oxidation method is normally used for heavier feedstocks, everything from naphtha to residual fuel, in those places where natural gas or light hydrocarbons (ethane, propane, or butane) are not readily available. 

This most widely used black pigment is also in the top 50 chemicals. About 4.0 billion lb of carbon black were made in 2001. Commercial value was 1.4 billion at 35C/lb, but 93% of this is used for reinforcement of elastomers. Only 7% is used in paints and inks. Carbon black is made by the partial oxidation of residual hydrocarbons from crude oil. See Chapter 6, Section 7.2. The hydrocarbons are usually the heavy by-product residues from petroleum cracking, ideally high in aromatic content and low in sulfur and ash, bp around 260°C. 

Oxidation by molecular oxygen most likely occurs via a radical mechanism 10-13 and the reaction rates are generally slow unless traces of metal ions are present which are known to drastically affect the reaction rate 14 thus making control of the air-oxidation reaction rather difficult. The rates can also be significantly enhanced by adding charcoal to induce a surface-assisted catalysis of the intramolecular disulfide bond formation 15 Nonetheless the difficult control of this oxidation procedure can lead to partial oxidation of Met and Trp residues when peptides are exposed for longer periods of time to air oxygen 16 ... 

Hydrochloric Acid for removing basic tars Na Hydroxide for acidic tars Benzene for hydrocarbon residues Acetone for partially oxidized tars... 

In another study (Watwood, White Dahm, 1991), benzene mineralization occurred in soils incubated under an inert gas for 4 weeks. No attempt was made to remove residual oxygen from these soils and the possibility exists that benzene mineralization may have been linked to the consumption of oxygen. Alternately, it may have been that benzene was partially oxidized by microorganisms and the resulting product was amenable to anaerobic decay. An earlier study (Van Beelen Van Keulen, 1990) showed an extremely rapid rate of benzene mineralization 2% mineralized in 1 h and 5% in 7 days. No samples were taken between 1 and 7 days and further benzene mineralization was not observed. 

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