SPARG-process

Nitrogen in the Wine Industry. Part I. Sparging Process, Air Reduction... 

The SPARG (Sulfur Passivated Reforming) principle (ref. 3) allows operation below the carbon limit curve. It was demonstrated (ref. 4) that carbon-free operation could be obtained above a certain sulfur coverage at conditions which would otherwise result in carbon formation. Sulfur passivated reforming as practiced in the Topsoe SPARG process (ref. 5) solves the problem of carbon formation by "ensemble control" which means that the sites for carbon formation are blocked while sufficient sites for the reforming reactions are maintained. This effect is obtained by adding sulfur to the process feed. 

It is obvious that operation on the left side of the carbon limit curve in Fig. 2 results in more economic conditions (lower steam and C02-addition for a given H,/C0 ratio). Operation on mixtures of C02 and methane without steam is also possible. The conventional processes are limited by the carbon limit curve. Conditions for the SPARG process which have been demonstrated in a full size monotube process demonstration unit are listed in Table 1. 

With the requirement for a direct production of, e.g., a H2/C0 = 1.0 gas, the SPARG process shows to be superior to conventional reforming. H2/C0 = 1 can be obtained with C02/CH = 1.5 and HgO/CH = 0.7. Without sulfur present, operation is possible with both ratios being ca. 2, which results in a larger reformer. On the other hand, the CH leakage at given pressure is smaller, which is advantageous if the cold box is replaced by other separation systems. 

Autothermal reforming with oxygen and steam (ref. 6) is an alternative to the SPARG process. By combined partial oxidation and steam reforming of the hydrocarbon, it is possible to achieve low H2/C0 ratios without the addition of C02. 

The SPARG process is preferred when cheap C02 is available, whereas autothermal reforming requires cheap oxygen to be competitive. Two-step reforming (ref. 6) i.e., tubular reforming with autothermal reforming as a second step, may be a favorable solution in some cases, for instance, for the TIGAS process (ref. 7). 

The elimination of carbon formation by controlled sulfur poisoning is utilized in the Topsoe SPARG process for C02-reforaiingM M. The process operates at conditions for which thermodynamics predict carbon formation. 

The SPARG process is essentially the same as a conventional steam methane reformer except for the addition of sulfur to the catalyst [9]. An important feature, however, is a prereformer to convert heavy hydrocarbons in the natural gas to methane to prevent them from cracking under the extremely low steam to carbon conditions of the reformer [10]. 

Spandex, 129, 148, 205, 230, 264 SPARG process, 57 Spec 107Acars, 117, 118 Standard Oil of New Jersey, 43 Standardized liquid storage, 114 Stanford Research Institute (SRI), 194... 

Biodegradation is different from the other removal mechanisms that act on subsurface contamination during the air sparging process. While other mechanisms act to transfer the con-... 

Monitoring of air sparging systems installed at different sites provided valuable information on the air sparging process, partieularly the radius or zone of influence and contaminant... 

The principle of equilibrated gas is no law of nature. It is possible to break the thermodynamic limit. This can be done by using noble metals [396] or by using a sulphur passivated catalyst as practiced in the SPARG process [390] (refer to Section 5.5). Examples are shown in Figure 2.18. 

The scale-up from fundamental studies to pilot testing led to the introduction of the SPARG process to industry [503],... 

The blockage of sites for carbon nucleation was the idea of the SPARG process (refer to Section 5.5), with chemisorbed sulphur passivating the ensembles for nucleation of carbon. 

In the SPARG process, there is a competition between sulphur and carbon for the sites required for nucleation of carbon and the growth of graphene islands above the critical size, as reflected by the reaction... 

Limit C is a result of controlled sulphur passivation of the reforming catalyst as practiced in the SPARG process (see section 2.6.2). 

A less expensive solution for large scale applications is the use of a partly sulphur poisoned catalyst on which the sulphur blocks the nickel sites for nucleation of carbon. This is the basis of the SPARG-process. 

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