# Direct Selective Oxidation of Hydrogen Sulfide: Laboratory, Pilot and Industrial Tests
## 22 Facility for the Purification of Gases Caused by Blowing-off Sour Crude Oil
Unit for the Direct Oxidation of Hydrogen Sulfide as a Component of the Associated Petroleum Gas  
Another application for sour associated gas is as low-debit flows with a capacity of 1000 \(\mathrm{nm^{3}/h}\). On the one hand, these flows are environmental pollution sources and may be used with a compact method of purification for the autonomic regeneration of heat energy and electric power for travel heaters, the power supply for gas turbine units, etc. SMP specialists Neftegaz JSC, BIC, in collaboration with TatNIINentefemash JSC and VNIIUS JSC, developed a production unit to selectively remove hydrogen sulfide directly from APG (Figures 28 and 29) [160; 161; 162]. The unit has undergone a complete cycle of industrial tests and is ready for industrial application. The most important indicator of the process is its selectivity with respect to the hydrocarbon part of the purified gas. In this regard, a technique was developed to study the composition of the hydrocarbon part of the gas which is able to precisely identify individual components based on GC analysis. Figure 28: Flow-sheet diagram of the purification plant. Direct catalytic oxidation of hydrogen sulfide. Figure 29: Industrial APG purification plant by direct catalytic oxidation. The results are shown in Table 5.  
As shown in the given data, hydrocarbon components are preserved during gas purification, and the purified gas can be used to generate thermal and electrical energy with minimal damage to the environment. The preliminary results of techno economic analysis are given below (Table 6). For the sake of comparison, an existing Claus plant now in operation at the Minibay GPP was selected (See Figures 30 and 31). As shown in the data in Table 6, the installation using the direct oxidation process is significantly more compact, primarily due to the use of a reactor with a fluidized catalyst bed, where the actual target process is effectively combined with the simultaneous removal of excess heat. The required temperature of the direct oxidation process is adjusted by changing the flow rate of the coolant through a heat exchanger placed in the catalyst \begin{table}
\begin{tabular}{c c c c} \hline \hline \# & **Parameters** & **Direct Oxidation Unit** &
\begin{tabular}{c} **Three Stage Claus Unit** \\ **Minibay Gas Processing Plant** \\ \end{tabular} \\ \hline
1 & Acid gas (H\({}_{2}\)S+CO\({}_{2}\)) supply, nm\({}^{3}\)/h & 1050 & 1050 \\
2 & H\({}_{2}\)S content, \%vol. & 80 & 80 \\
3 & Air supply, nm\({}^{3}\)/h & 2000 & 2000 \\
4 & Sulfur production & 10.000 & 10.000 \\  & Annually, ton & Calculation & Direct data \\  & & Fluidized bed reactor: & Thermal stage furnace \\  & & Diameter = 1.5 m & Diameter = 2.5 m \\
5 & Dimensions of the main units & Height = 6 m & Length = 7 m \\  & & Fixed bed reactor & Catalytic converters (3 pieces) \\  & & Diameter = 2.5 m & Diameter = 2.5 m \\  & & Height = 6 m & Length = 4 m \\  & & Calculation & Direct data \\
6 & Catalyst load, ton & Fluidized bed reactor-2 &
\begin{tabular}{c} Direct data \\ Total: 18 \\ \end{tabular} \\
7 &
\begin{tabular}{c} Sulfur cost \\ Arbitrary units, estimation \\ \end{tabular} & 1 & 2.5 \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Comparison of the characteristics of the Claus Pant and a direct oxidation plant with the same capacities [163; 164].