Co-processing H2S and CO2 in Electrolyzer

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Solution Overview

Problem

Current methods for processing hydrogen sulfide (H2S) and carbon dioxide (CO2) separately are inefficient and energy-intensive, leading to higher overhead costs and inefficiencies, as CO2 is often discarded or further processed without reacting in conventional treatments.

Innovation Solution

A method for co-processing H2S and CO2 in an electrolyzer with a solid electrolyte, where H2S is split into protons and elemental sulfur at the anode, and these protons are used to hydrogenate CO2 at the cathode, producing valuable chemicals like methane or methanol, while also generating electricity in a fuel cell configuration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If H2S and CO2 are processed separately using conventional methods, then each compound can be treated independently, but energy consumption increases and processing efficiency decreases

Engineering Contradiction:
Improveenergy consumptionVSAvoidprocessing efficiency
Core Design Contradiction:
Use of energy by moving objectVSProductivity

Solution Approach 1:

The patent combines separate H2S and CO2 processing operations into a single electrochemical cell where H2S is oxidized at the anode and CO2 is reduced at the cathode simultaneously. This merging of operations eliminates the need for separate processing units and reduces overall energy consumption while maintaining high processing efficiency for both compounds.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The electrochemical cell serves multiple functions simultaneously: it oxidizes H2S to elemental sulfur, reduces CO2 to valuable chemicals, and generates electricity through the electrochemical reactions. This multi-functionality resolves the contradiction by achieving efficient processing of both compounds in a single system that delivers multiple benefits.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Loss of substance

If CO2 is discarded or further processed without reacting in conventional treatments, then processing simplicity is maintained, but resource utilization decreases and overhead costs increase

Engineering Contradiction:
Improveresource utilizationVSAvoidprocessing complexity
Core Design Contradiction:
Loss of substanceVSDevice complexity

Solution Approach 1:

The patent converts CO2, which is typically discarded or requires complex further processing, into valuable chemicals through electrochemical reduction. By treating CO2 as a resource rather than waste, the system improves resource utilization without significantly increasing processing complexity, as the electrochemical reduction occurs simultaneously with H2S oxidation in the same cell.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

3Quantity of substance

If H2S is split into protons and elemental sulfur, then valuable products are produced, but energy consumption increases

Engineering Contradiction:
Improveproduct yieldVSAvoidenergy consumption
Core Design Contradiction:
Quantity of substanceVSUse of energy by moving object

Solution Approach 1:

The electrochemical cell uses the energy released from H2S oxidation at the anode to drive the CO2 reduction at the cathode. The system is largely self-sufficient, with the exergonic H2S oxidation providing the driving force for the endergonic CO2 reduction, thereby minimizing external energy input while maximizing product yield from both compounds.

Inventive Principle:
Principle #25Self-service

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

This approach reduces energy consumption and reaction units required, increasing conversion efficiency and producing valuable chemicals from both H2S and CO2, thereby addressing the inefficiencies of separate processing methods.

Implementation Method 1

splitting H2S of the first gas stream into protons and elemental sulfur at the anode

Methodology Applied
Scientific EffectElectrochemical oxidation: Oxidation

Implementation Method 2

transferring the protons split from the H2S of the first gas stream from the anode across the electrolyte to the cathode

Methodology Applied
Scientific EffectIon conduction: Conduction (electrical)

Implementation Method 3

hydrogenating the CO2 from the second gas stream with the protons that were transferred from the anode

Methodology Applied
Scientific EffectElectrochemical reduction: Reduction

Implementation Method 4

electrochemically oxidizing the protons transferred from the anode across the electrolyte to the cathode with the oxygen of the second gas stream

Methodology Applied
Scientific EffectElectrochemical oxidation: Oxidation

Data Source

PatentEP3283669B1Methods for co-processing carbon dioxides and hydrogen sulfide
Publication Date: 2022.02.23 SAUDI ARABIAN OIL CO
  • EP3283669B1 patent drawingFigure 1
  • EP3283669B1 patent drawingFigure 2A~2B
  • EP3283669B1 patent drawingFigure 3

AI summary

A method for co-processing H2S and CO2 in an electrolyzer includes feeding a first gas stream having H2S to an anode and feeding a second gas stream having CO2 to a cathode. The H2S is split into hydrogen ions and elemental sulfur. The hydrogen ions are transferred from the anode to the cathode, and the CO2 is hydrogenated with the transferred hydrogen ions. A method for producing electricity in a fuel cell includes feeding a first gas stream having H2S and CO to an anode, and feeding a second gas stream having oxygen to a cathode. The H2S and CO forms hydrogen ions and carbonyl sulfide. The hydrogen ions are transferred from the anode to the cathode. The transferred hydrogen is oxidized with the oxygen of the second gas stream, and electricity formed from the oxidation is collected.