Continuous Hydrogen Sulphide Gas Treatment With Oxygen Feedback
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Solution Overview
Problem
Commercial biodesulfurization processes face instability and reduced selectivity for elemental sulfur due to variations in hydrogen sulfide content and interference from thiol compounds, leading to undesired sulfate formation and inefficiencies in redox potential control.
Innovation Solution
A continuous process that measures oxygen consumption in real-time to control oxygen supply in the biodesulfurization process, combined with feedback and feedforward control strategies, to maintain high selectivity for elemental sulfur formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If redox potential is used to control oxygen supply, then selectivity for sulfur formation is improved, but process stability deteriorates when hydrogen sulfide content varies
Solution Approach 1:
The patent implements a feedback control system where oxygen supply is continuously adjusted based on real-time measurement of oxygen consumption. The control unit monitors the actual oxygen consumption by the sulfide oxidizing bacteria and modulates the oxygen supply accordingly, creating a closed-loop system that adapts to varying hydrogen sulfide content and maintains process stability.
Solution Approach 2:
The patent replaces the electrochemical redox potential measurement system with an oxygen consumption measurement system. Instead of using redox electrodes that are sensitive to interfering substances like thiols, the system directly measures oxygen consumption through oxygen sensors, providing a more reliable and interference-free control parameter.
2Productivity
If oxygen supply is increased to maintain sulfur formation rate, then productivity is improved, but sulfate formation increases reducing selectivity
Solution Approach 1:
The feedback control system continuously monitors oxygen consumption and adjusts oxygen supply in real-time. When oxygen consumption increases (indicating higher sulfur formation activity), the system automatically increases oxygen supply to maintain the reaction rate, while preventing excessive oxygen accumulation that would lead to sulfate formation. This dynamic adjustment maintains optimal selectivity across varying production rates.
Solution Approach 2:
The system transitions from static oxygen supply control to dynamic control based on actual biological activity. The oxygen supply rate is continuously adapted to match the instantaneous oxygen consumption rate of the bacteria, allowing the system to maintain high productivity when bacterial activity is high while preventing sulfate formation when activity is low.
3Ease of operation
If redox potential control is used, then measurement simplicity is maintained, but measurement accuracy deteriorates due to thiol compound interference
Solution Approach 1:
The patent substitutes redox potential measurement with direct oxygen consumption measurement using oxygen sensors. This replacement eliminates the interference from thiol compounds and other substances that affect redox electrode readings, providing accurate measurements of the actual biological activity without being influenced by chemical interferences in the solution.
Solution Approach 2:
The system uses oxygen consumption as an intermediary parameter to indirectly measure bacterial activity. Instead of directly measuring redox potential which is affected by multiple factors including thiol compounds, the system measures oxygen consumption which directly correlates with bacterial metabolic activity and sulfur formation, providing a more specific and accurate control parameter.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The process achieves stable and efficient sulfur formation even with varying hydrogen sulfide supply and thiol compound presence, minimizing sulfate formation and maintaining high selectivity for elemental sulfur.
Implementation Method 1
the hydrogen sulphide comprising gas is contacted with an aqueous alkaline solution further comprising sulphide oxidising bacteria thereby obtaining a loaded aqueous solution comprising sulphide compounds and sulphide oxidising bacteria
Implementation Method 2
contacting the loaded aqueous solution with an oxygen comprising gas to regenerate the sulphide oxidising bacteria
Implementation Method 3
the consumption of oxygen in step (b) is measured and wherein the supply of oxygen in step (b) is controlled by the measured consumption of oxygen
Data Source
AI summary
The invention is directed to a continuous process to treat a hydrogen sulphide comprising gas comprising the following steps: (a) contacting the hydrogen sulphide comprising gas with an aqueous alkaline solution further comprising sulphide oxidising bacteria thereby obtaining a loaded aqueous solution comprising sulphide compounds and sulphide oxidising bacteria. (b) contacting the loaded aqueous solution with an oxygen comprising gas to regenerate the sulphide oxidising bacteria to obtain a liquid effluent comprising regenerated sulphide oxidising bacteria which is partly used as the aqueous alkaline solution in step (a). (c) separating elemental sulphur as prepared by the sulphide oxidising bacteria in steps (a) and (b) from the loaded aqueous solution of step (a) and/or from the liquid effluent of step (b) and wherein the consumption of oxygen in step (b) is measured and wherein the supply of oxygen in step (b) is controlled by the measured consumption of oxygen.