Partial Oxidation Process Using CO2 Transport Gas
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Solution Overview
Problem
Partial oxidation processes for producing synthesis gas from solid carbonaceous feeds often result in varying quality due to disturbances and inert compounds like nitrogen, making precise control of the oxygen-to-carbon ratio challenging, which affects the yield and composition of the synthesis gas.
Innovation Solution
A process that involves using a CO2-rich gas to partially oxidize fine particulate solid carbonaceous feeds in a pressurized gasification reactor with a membrane wall, where the CO2 to carbon feed weight ratio is controlled to minimize oxygen consumption and inert compounds, and the oxygen-to-carbon ratio is adjusted based on real-time steam flow measurements to optimize synthesis gas production.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a partial oxidation process is used to produce synthesis gas from solid carbonaceous feeds, then synthesis gas is obtained, but the quality varies due to disturbances and inert compounds like nitrogen
Solution Approach 1:
The patent uses a CO2-rich gas environment (≥80 mol% CO2) as the transport and reaction medium instead of air or nitrogen-based atmospheres. This inert CO2 environment prevents contamination with nitrogen and other inert compounds, while still allowing the partial oxidation reaction to proceed. The CO2 atmosphere is maintained throughout the gasification process, ensuring high purity synthesis gas without nitrogen dilution.
Solution Approach 2:
The patent changes the compositional parameter of the gas atmosphere from traditional air or nitrogen-based to CO2-rich (≥80 mol%). This parameter change fundamentally alters the reaction environment, eliminating nitrogen contamination while maintaining appropriate oxidation conditions. The CO2 concentration is controlled as a key parameter to ensure both inertness and reaction efficiency.
2Measurement precision
If the oxygen-to-carbon ratio is controlled using traditional methods (e.g., measuring methane concentration), then control is achieved, but the signal is not sharp making control less accurate
Solution Approach 1:
The patent implements a feedback control system where the CO2 concentration in the product gas is continuously measured and used to adjust the steam flow rate. This closed-loop feedback ensures accurate maintenance of the oxygen-to-carbon ratio by dynamically responding to process variations. The CO2 measurement provides a sharp, reliable signal for control adjustment.
Solution Approach 2:
The patent replaces traditional control methods (such as infrared methane measurement) with CO2 concentration measurement-based control. This substitution provides a sharper, more reliable control signal because CO2 is the dominant gas component and its concentration directly reflects the oxidation state, enabling more precise O/C ratio control compared to methane-based methods.
3Adaptability or versatility
If coal with varying H2O content is used as carbonaceous stream, then process variations occur, but this results in altered process conditions and varying synthesis gas composition
Solution Approach 1:
The patent uses feedback control where steam flow rate is continuously adjusted based on measured CO2 concentration in the product gas. This automatic feedback compensates for variations in coal moisture content and composition, maintaining stable synthesis gas composition despite feedstock variations. The system adapts to different coal types by dynamically adjusting operating parameters.
Solution Approach 2:
The patent employs a universal CO2-rich gasification process that can handle various carbonaceous feeds (coal, biomass, petroleum coke) with different moisture contents and compositions. The CO2-based reaction environment and feedback-controlled steam injection provide a universal solution that maintains stable synthesis gas composition across different feedstock types, making the process versatile and adaptable.
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 significantly reduces inert compounds like nitrogen in the synthesis gas, allows for precise control of the oxygen-to-carbon ratio, and enhances the long-term yield of synthesis gas by maintaining optimal process conditions.
Implementation Method 1
a solid carbonaceous feed is partially oxidized
Implementation Method 2
the conduits are cooled by evaporation of water to steam inside the conduits
Data Source
AI summary
The invention is directed to a process for preparing a mixture comprising of CO and H2 by operating a partial oxidation process of a solid carbonaceous feed. The process comprises at least the steps of: (a) supplying the solid carbonaceous feed and an oxygen-containing stream to a burner, wherein a CO2 containing transport gas is used to transport the solid carbonaceous feed to the burner; (b) partially oxidising the carbonaceous feed in the burner wherein a gaseous stream at least comprising CO and H2 is being discharged from said burner into a reaction zone, wherein the temperature in the reaction zone is between 1200 to 1800 °C and wherein said reaction zone is at least partly bounded by a wall or walls comprised of conduits in which conduits steam is prepared by evaporation of water resulting in a flow of steam being discharged from said reaction zone; (c) monitoring the conditions in the reaction zone by continually or periodically measuring the rate of the steam flow and using said flow rate as input to adjust the O/C ratio in step (a).