Method for generating refrigeration for a carbon monoxide cold box
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Solution Overview
Problem
Conventional cryogenic carbon monoxide purification processes face efficiency penalties when designed to handle varying feedstock compositions, as they require large turbine flowrate ranges to accommodate rare feed compositions, leading to decreased overall efficiency.
Innovation Solution
The method involves varying the flow rate of cryogenic liquid, such as liquid nitrogen, based on the incoming feedstock composition to adjust refrigeration needs, allowing the turbine to operate efficiently across a wider range of feed compositions without increasing the turbine flowrate range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the expansion turbine is designed to handle a large range of feedstock compositions, then the adaptability of the process is improved, but the turbine efficiency deteriorates due to operating away from optimal flowrate
Solution Approach 1:
The invention dynamically adjusts the refrigeration system configuration based on feedstock composition. The expansion turbine operates at a fixed optimal design point, and refrigeration deficiency or excess is compensated by adding or removing cryogenic liquid nitrogen, allowing the system to adapt to varying feed compositions without moving the turbine from its optimal operating point
Solution Approach 2:
The invention changes the refrigeration parameter by varying the amount of liquid nitrogen added to the system. This allows the turbine to maintain a constant optimal flowrate while the overall refrigeration capacity is adjusted to match different feedstock compositions, resolving the contradiction between adaptability and efficiency
2Adaptability or versatility
If the turbine flowrate range is increased to accommodate rare feed compositions, then the adaptability is improved, but the overall plant efficiency deteriorates
Solution Approach 1:
The invention segments the refrigeration function into two independent components: the expansion turbine providing base refrigeration at optimal efficiency, and liquid nitrogen injection providing adjustable refrigeration capacity. This segmentation allows the turbine to operate at a fixed optimal flowrate while the liquid nitrogen makes up the difference, eliminating the need to design the turbine for rare feed compositions
3Temperature
If liquid nitrogen is added to meet refrigeration demands, then the refrigeration capacity is improved, but the process complexity increases
Solution Approach 1:
The invention introduces liquid nitrogen as an intermediary substance to bridge the gap between turbine-generated refrigeration and actual process requirements. The liquid nitrogen is injected at a strategic point in the process where it can efficiently absorb heat and provide the needed refrigeration capacity without fundamentally redesigning the existing turbine-based system
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 enhances the operational range of the cryogenic CO purification process by reducing the maximum turbine design flowrate, leading to improved overall plant efficiency with potential reductions of 5 to 20% in turbine design flow, while maintaining efficiency across varying feedstock compositions.
Implementation Method 1
cooling and partially condensing the syngas cold box feed stream
Implementation Method 2
cooling and partially condensing the syngas cold box feed stream in a heat exchanger
Implementation Method 3
at least partially vaporized in the heat exchanger
Implementation Method 4
addition of a cryogenic liquid (e.g. liquid nitrogen)
Data Source
AI summary
The present invention is directed to a method of separating carbon monoxide from syngas mixtures by cryogenic means where a partial condensation cycle is generally employed, and more specifically varying refrigeration generation based on income feed composition of the hydrocarbon feedstock being processed.