Low-Pressure Oxygen Distillation Without Auxiliary Vaporizers
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Solution Overview
Problem
The existing methods for producing low-pressure gaseous oxygen are costly due to the use of auxiliary vaporizers and associated complex equipment, which increases expenses and facility size.
Innovation Solution
The method eliminates auxiliary vaporizers by operating the lower pressure column at the oxygen delivery pressure, using two stacked reboilers driven by pressurized nitrogen and air, and incorporating a nitrogen or air turbine/booster to achieve efficient separation and production of low-pressure gaseous oxygen.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If auxiliary vaporizers are used to produce gaseous oxygen at pressure, then oxygen production capability is improved, but device complexity and capital expenditure increase
Solution Approach 1:
The patent extracts and eliminates the auxiliary vaporizer from the system by redesigning the process to operate the lower pressure column directly at delivery pressure, removing the need for separate vaporization equipment and associated complex piping and valves
Solution Approach 2:
The patent merges the function of the lower pressure column with the vaporization function by operating it directly at delivery pressure, combining what were previously separate functions into a single integrated system
2Productivity
If auxiliary vaporizers and boosting equipment are used, then oxygen production at pressure is achieved, but capital expenditure increases
Solution Approach 1:
The patent removes the auxiliary vaporizer and boosting equipment from the system, eliminating the capital expenditure associated with purchasing and installing this expensive equipment while maintaining oxygen production capability through column pressure optimization
Solution Approach 2:
The patent changes the operating pressure parameter of the lower pressure column to match the delivery pressure, eliminating the need for pressure boosting equipment and associated capital costs
3Productivity
If auxiliary vaporizers are used, then gaseous oxygen is produced, but facility size increases
Solution Approach 1:
The patent extracts the auxiliary vaporizer from the facility, eliminating the volume it occupied within the cold box and reducing the overall facility size while maintaining gaseous oxygen production capability
Solution Approach 2:
The patent combines the vaporization function into the lower pressure column operation, eliminating the need for separate vaporizer equipment and reducing the total volume required for the facility
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 simplifies the process, reduces capital expenditures, and maintains oxygen product quality while minimizing equipment size, achieving a 42% reduction in main condenser size and 2% reduction in auxiliary column size.
Implementation Method 1
cooling a compressed and purified air stream in a heat exchanger
Implementation Method 2
introducing the compressed and purified air stream to a first reboiler such that the compressed and purified air stream acts as a reboiling fluid
Implementation Method 3
an at least partially condensed air stream is formed
Implementation Method 4
HP column 40 is configured to operate under conditions effective to separate the air into nitrogen and oxygen
Implementation Method 5
nitrogen vapor rises towards the top and ultimately is condensed in the reboiler 41
Data Source
AI summary
A method for the production of low pressure gaseous oxygen includes providing a system of distillation columns and a heat exchanger, wherein the system of columns comprises a lower pressure column, a higher pressure column, an auxiliary column, the auxiliary column having a distillation section, a first reboiler, and a second reboiler, wherein the LP column and the HP column are thermally integrated via a top reboiler/condenser disposed on top of the HP column. A cooled air stream is rectified within the system of columns such that the auxiliary column produces a cold oxygen fluid that is then warmed in the heat exchanger to produce a low pressure oxygen product. The cooled air stream provides reboiling duty for the first reboiler prior to rectification within the system of columns, and a compressed nitrogen stream received from a cold end of the heat exchanger provides reboiling duty for the second reboiler.