Rich gas process

Description Gas feedstock is compressed (if required), desulfurized (1) and sent to the optional saturator (2) where some process steam is generated. The saturator is used where maximum water recovery is important. Further process steam is added, and the mixture is preheated and sent to the pre-reformer (3), using the Catalytic-Rich-Gas process. Steam raised in the methanol converter is added, along with available C02, and the partially reformed mixture is preheated and sent to the reformer (4). High-grade heat in the reformed gas is recovered as high-pressure steam (5), boiler feedwater preheat, and for reboil heat in the distillation system (6). The high-pressure steam is used to drive the main compressors in the plant. 

The above reactions proceed also in the so-called rich-gas processes of British Gas and Lurgi/BASF, which convert naphtha with steam in autothermal reactions in a vessel filled with a special nickel-containing catalyst. It was formerly successfully used for town gas production from naphtha. This reaction may also used as pre-reformer ahead of a conventional tubular steam reforming furnace to convert higher hydrocarbons at low temperature and low S/C ratio into a methane reach gas which can than be reformed in the primary reformer with a standard methane reforming catalyst instead of an alkalized catalyst (Section 4.1.1.3.1). 

CRG process (catalytic rich gas process) A catalytic process used to produce fuel gas ftom naphtha, which is a light petroleum distillate. The naphtha is reacted with steam over a nickel-based catalyst at a temperamre of up to 650 C and pressure of 70 bar to produce a gas mixmre that is rich in me ane. Other gases in the product include carbon dioxide, carbon monoxide, and trace amounts of hydrocarbons. The process was superseded in the UKbythe discovery of North Sea gas. 

Ammonium thiosulfate, stable as a solution, is produced ia the form of a 56—60% solution from ammonia and soHd sulfur or an H2S-rich gas stream or both soHd sulfur and H2S gas streams (68). As a result of avadabihty, only development of solutions for processing x-ray and color film and prints has been encouraged. The evolution of automatic processors to develop and print color reinforced the trend toward use of solutions. Most x-ray laboratories and automatic film and print processors require almost immediate results. 

Cryogenic processes using turboexpanders facilitate high levels of ethylene recovery from refinery gas while producing byproducts of hydrogen- and methane-rich gas. In a cryogenic process, most of the ethylene and almost all of the heavier components are liquified and ethylene is separated from this liquid. 

The Claus process consists of partial combustion of the hydrogen sulfide-rich gas stream (with one-third the stoichiometric quantity of air) and then reacting the resulting sulfur dioxide and unbumed hydrogen sulfide in the presence of a bauxite catalyst to produce elemental sulfur. Refer to the process flow diagram in Figure 7. 

Another objective of gas processing is to lower the Btu content of the gas by extracting heavier components to meet a maximum allowable heating limit set by a gas sales contract. If the gas is too rich in heavier components, the gas will not work properly in burners that are designed for lower heating values. A common maximum limit is 1100 Btu per SCF. Thus, if the gas is rich in propane and heavier components it may have to be processed to lower the heating value, even in cases where it may not be economical to do so. 

The rich gas from the absorption operation is usually stripped of the desirable components and recycled back to the absorber (Figure 8-57). The stripping medium may be steam or a dry or inert gas (methane, nitrogen, carbon oxides—hydrogen, etc.). This depends upon the process application of the various components. 

As a constituent of synthesis gas, hydrogen is a precursor for ammonia, methanol, Oxo alcohols, and hydrocarbons from Fischer Tropsch processes. The direct use of hydrogen as a clean fuel for automobiles and buses is currently being evaluated compared to fuel cell vehicles that use hydrocarbon fuels which are converted through on-board reformers to a hydrogen-rich gas. Direct use of H2 provides greater efficiency and environmental benefits. ... 

Once a significant amount of molecular hydrogen is produced, a rich gas-phase chemistry ensues.24 Ion-molecule processes are initiated in the interiors of dense clouds mainly via cosmic ray ionization, the most important reaction being,... 

To test if dilution of the products of CNO burning may explain the difference in abundance pattern with evolved giants and a possible excess in 12 C visible in N-rich stars (see left panel of Fig. 4), we use simple models in the plane [C/N] vs [O/N] (right panel of Fig. 4). Starting from the approximate composition of N-poor stars, the trend for different fractions of gas processed in the complete CNO-cycle (solid line) reproduces fairly well the data, albeit it predict too low C abundances for N-rich dwarfs. Pollution from RGB stars with composition N-rich from very deep mixing (complete CNO and Na enrichment involved, dotted line) reproduces also rather well the data, apart for N-rich dwarfs. On the other hand, the N-poor case, typical of the chemical composition of field RGB stars, is a very poor match (dashed line). Moreover, in this case, the model would predict C-poor, Na-poor stars, whereas no one is observed among over 40 dwarfs/subgiants in the 3 clusters. 

The a-process Could the low [a/Fe] and low [Y/Eu] ratios in dSph stars be related by the a-process The a-process (or a-rich freeze out) occurs when a neutron-rich, a-rich gas is out of nuclear statistical equilibrium and is thought to be important in the formation of 44Ca (Woosley Weaver 1995), 48Ti (Naka-... 

There are different process configuration concepts where FBs form the heart of the technology for the hydrogen-rich gas production. The following recently developed gasification reactor technology can be especially mentioned in this respect 44... 

Because the synthesis gas produced from coal is generally relatively poor in hydrogen, a typical CO H2 ratio being ca. 1 1, and because, as can be seen from Eqs. (14) and (15), a hydrogen-rich gas is required for the production of hydrocarbons and chemicals, a hydrogen enrichment step is usually necessary for the Fischer-Tropsch process. 

CRG [Catalytic Rich Gas] A process for making town gas and rich gas from light petroleum distillate (naphtha). The naphtha is reacted with steam over a nickel-alumina catalyst yielding a gas mixture rich in methane. Developed by British Gas and used in the United Kingdom in the 1960s, but abandoned there after the discovery of North Sea gas. In 1977,13 plants were operating in the United States. 

Koppers-Totzek A coal gasification process using an entrained bed. The coal is finely ground and injected in a jet of steam and oxygen into a circular vessel maintained at 1,500°C. Reaction is complete within one second. The ash is removed as a molten slag. The process was invented by F. Totzek at Heinrich Koppers, Essen, and further developed by Koppers Company in Louisiana, MO, under contract with the U.S. Bureau of Mines. The first commercial operation was at Oulu, Finland, in 1952 by 1979, 53 units had been built. Most of the plants are operated to produce a hydrogen-rich gas for use in ammonia synthesis. Developed by Lurgi. See also PRENFLO. 

Recatro A process for making gas from liquid fuels and other gaseous hydrocarbons by catalytic conversion into rich gas, followed by catalytic steam reforming. Developed by BASF and Lurgi. 

---