Production of synthesis gas

The term synthesis gas stands for a multitude of different gas mixtures consisting of H2, CO and N2, partially with traces of hydrocarbons, CO2 and Ar. Similarly high as the number of the different and technically relevant synthesis gases is the number of the practically applied production processes [5.16-5.18], 

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The technology of urea production is highly advanced. The raw materials requited ate ammonia and carbon dioxide. Invariably, urea plants ate located adjacent to ammonia production faciUties which conveniently furnish not only the ammonia but also the carbon dioxide, because carbon dioxide is a by-product of synthesis gas production and purification. The ammonia and carbon dioxide ate fed to a high pressure (up to 30 MPa (300 atm)) reactor at temperatures of about 200°C where ammonium carbamate [111-78-0] CH N202, urea, and water ate formed. 

Fig. 12. Production of synthesis gas in three-2one shaft reactor furnace (38).

The indirect liquefaction basehne design is for a plant of similar size. Unhke the direct hquefaction basehne, the design focuses on producing refined transportation fuels by use of Sheh gasification technology. Table 27-17 shows that the crude oil equivalent price is approximately 216/m ( 34/bbl). Additional technological advances in the production of synthesis gas, the Fischer-Tropsch synthesis, and product refining have the potential to reduce the cost to 171/m ( 27/bbl) (1993 US dollars), as shown in the second column of Table 27-17. 

The production of synthesis gas from methane and the major chemicals based on it are noted in Chapter 5. 

The first step in the production of synthesis gas is to treat natural gas to remove hydrogen sulfide. The purified gas is then mixed with steam and introduced to the first reactor (primary reformer). The reactor is constructed from vertical stainless steel tubes lined in a refractory furnace. The steam to natural gas ratio varies from 4-5 depending on natural gas composition (natural gas may contain ethane and heavier hydrocarbons) and the pressure used. 

In Europe naphtha is the preferred feedstock for the production of synthesis gas, which is used to synthesize methanol and ammonia (Chapter 4). Another important role for naphtha is its use as a feedstock for steam cracking units for light olefins production (Chapter 3). Heavy naphtha, on the other hand, is a major feedstock for catalytic reforming. The product reformate containing a high percentage of Ce-Cg aromatic hydrocarbons is used to make gasoline. Reformates are also extracted to separate the aromatics as intermediates for petrochemicals. 

Thus indeed CH4 oxidation in a SOFC with a Ni/YSZ anode results into partial oxidation and the production of synthesis gas, instead of generation of C02 and H20 as originally believed. The latter happens only at near-complete CH4 conversion. However the partial oxidation overall reaction (3.12) is not the result of a partial oxidation electrocatalyst but rather the result of the catalytic reactions (3.9) to (3.11) coupled with the electrocatalytic reaction (3.8). From a thermodynamic viewpoint the partial oxidation reaction (3.12) is at least as attractive as complete oxidation to C02 and H20. 

The production of synthesis gas from natural gas and coal is the basis of the 33 000000 tpa methanol production and is also used in the production of ammonia. After removal of sulfur impurities, methane and water are reacted over a nickel oxide on calcium aluminate catalyst at 730 °C and 30 bar pressure. The reaction is highly endothermic (210 kJmol ) (Equation 6.6). 

Very often, light gases such as methane that are liberated during oil production are flared. Why is this Is steam reforming of such gases an option Give a number of sources for the production of synthesis gas, and also a number of applications of synthesis gas. 

Several other important commercial processes need to be mentioned. They are (not necessarily in the order of importance) the low pressure methanol process, using a copper-containing catalyst which was introduced in 1972 the production of acetic add from methanol over RhI catalysts, which has cornered the market the methanol-to-gasoline processes (MTG) over ZSM-5 zeolite, which opened a new route to gasoline from syngas and ammoxidation of propene over mixed-oxide catalysts. In 1962, catalytic steam reforming for the production of synthesis gas and/or hydrogen over nickel potassium alumina catalysts was commercialized. 

The catalytic partial oxidation of methane for the production of synthesis gas is an interesting alternative to steam reforming which is currently practiced in industry [1]. Significant research efforts have been exerted worldwide in recent years to develop a viable process based on the partial oxidation route [2-9]. This process would offer many advantages over steam reforming, namely (a) the formation of a suitable H2/CO ratio for use in the Fischer-Tropsch synthesis network, (b) the requirement of less energy input due to its exothermic nature, (c) high activity and selectivity for synthesis gas formation. 

The production of synthesis gas based on heterogeneous catalytic reactions using 02 (air) as an oxidant is referred to as catalytic POx (CPO). Although the process is potentially able to process a wide range of hydrocarbon feedstocks, including heavy hydrocarbons, most of the information in the literature relates to the CPO of methane (or NG). The CPO of methane can be presented by the following equation ... 

Simplified schematics of a thermal plasma reformer for the production of synthesis gas from hydrocarbons. 1 = Anode, 2 = cathode, 3 = discharge, and 4 = insulator. 

Rostrup-Nielsen, J., Production of synthesis gas, Catal. Today, 18,305,1993. 

Gasior, S.J. et al., Production of synthesis gas and hydrogen by the steam iron process—Pilot-plant study of fluidized and free-falling beds, Bureau of Mines Report of Investigations, Pittsburgh, PA, 5911,49,1961. 

Three additional circles have been added at the left of Figure 1 to represent the additional components involved in the production of synthesis gas. These involve the light gases H2 and CO, with N2, 02 and Ar as minor components water and ammonia with amines as minor components and cresols and other organic components. These three additional types of components produce a total of 15 combinations of interactions between the various types of components or 12 additional interactions. Thus the additional work to be done could be as much as four to five times the amount already done on oil and gas components. 

The R D requirement exists solely in the production of synthesis gas from wood, since the catalytic production of methanol is well developed. The vertical shaft counter flow reactor developed by Union Carbide for municipal waste... 

Many organics also undergo oxidation of a noncombustion nature to form various commercial products. Such reactions are mostly catalytic and include production of synthesis gas, a mixture of CO and H2, conversion of ethylene to ethylene oxide, and cumene to phenol and acetone. 

A generalized scheme of the Sasol process is illustrated in Figure 1. The basic raw materials are coal, water and air. The plant is a complex operation consisting of many interlinked processes. This complexity is, however, not an important factor in the economics when it is borne in mind that the main cost is the production of synthesis gas, which accounts for over 50 % of the total. 

A flow reactor is used for the production of synthesis gas, CO + H2, by direct oxidation of methane and other hydrocarbons in the presence of steam. Preheated streams are mixed and react in a... 

Optimal operating conditions can be maintained over a wide range of flow rates and feed compositions. The high energy density that is generated reduces the chemical reaction time. This results in a short residence time for the reactants to be converted into products. A wide range of hydrocarbons can be used for the production of synthesis gas or hydrogen, with conversion of hydrocarbons close to 100%. 

Coal gasifiers are used for the production of synthesis gas however, any carbon source could be used. Biomass is receiving attention as a carbon source. 

The residue from the vacuum tower is sent to a high pressure slagging gasifier for production of synthesis gas. A portion of the synthesis gas goes through shift conversion and acid gas removal steps to produce pure hydrogen for the process. The... 

Raudaskoski R, et al. Catalytic activation of CO2 use of secondary CO2 for the production of synthesis gas and for methanol synthesis over copper-based zirconia-containing catalysts. Catal Today. 2009 144(3 4) 318-23. 

Nearly thirty years ago it was recognized that fuel for the process could just as well be coal, and work on process development for production of synthesis gas from coal was initiated. At that time,... 

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