January 29, 2018 in the State Register of Inventions of the Russian Federation patent for invention No. 2642859 " Method for controlling the process of obtaining sulfur by the Claus method " is registered.
The patented by JSC "Giprogazoochistka" method can be used in the utilization of hydrogen sulphide in the oil, gas, oil refining industry, as well as non-ferrous metallurgy and is suitable for sulfur-producing plants of various types.
A key feature of the method consists in adjusting the stoichiometric ratio of the volume of combustion air to the volume of the acid gas supplied to the thermal stage in real time, depending on the composition of the initial acid gas and the Claus process waste gas, by changing the combustion air flow rate.
The technical task solved by the patented JSC "Giprogazoochistka" method is to increase the efficiency of sulfur recovery by optimizing the process of H2S to sulfur conversion, as well as to shorten the optimization time with the ability to manage the process both in a stationary process and under the conditions of a drastic change in consumption and the composition of the source gas.
Features of the method for controlling the process of sulfur production by the Claus method.
The combustion air flow is adjusted using a multiparametric sequential model calculated for the thermal stage and the catalytic conversion stage under various boundary conditions. This multiparameter model predicts the state of the information-measuring and control system. To construct the model, an analysis of physicochemical processes and the equations of nonequilibrium thermodynamics for both stages is made. Based on the analysis, Concentration of components, pressure and temperature of total process gas stream at the outlet from the thermal stage are calculated. The results of the calculations are used as input data for modelling the catalytic stage. Taking into account the concentrations of sulfur compounds in the Claus waste gases process, a functional that is part of the optimization criterion for process control and determines its achievement is built up. Based on this, the combustion air flow in real time is adjusted to achieve the optimisation criterion. In this case, supply of the main and balancing combustion air is calculated.
The model allows to choose for optimization only those components of the initial acid gas that significantly affect the rate of sulfur recovery, and the boundary conditions for the system of equations describing the model make it possible to reduce the number of calculation units and thereby reduce the calculation time and, as a consequence, the delay time. All this in general significantly increases the efficiency of sulfur recovery.