Compact Cryogenic Gas Processing for C3 Recovery With Lower Energy
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current cryogenic expansion processes for recovering propylene, propane, and heavier hydrocarbons from natural gas streams are energy-intensive and require extensive equipment, leading to high capital and operating costs, as well as potential environmental emissions from piping leaks.
Innovation Solution
A compact processing arrangement that combines multiple equipment items into a single housing, reducing the need for interconnecting piping and flanged connections, and employs a heat and mass transfer system for efficient cooling and separation, thereby lowering energy consumption and capital costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If traditional cryogenic expansion processes are used, then hydrocarbon recovery is achieved, but energy consumption is high and equipment complexity increases
Solution Approach 1:
The patent combines multiple equipment items (heat exchangers, separators, expansion machines, distillation columns) into a single integrated processing assembly. This merging eliminates the need for extensive interconnecting piping and flanged connections, reducing both equipment complexity and energy losses from leaks while maintaining effective hydrocarbon recovery through integrated heat and mass transfer operations.
2Object-affected harmful factors
If extensive piping and flanged connections are used, then equipment functionality is maintained, but environmental emissions increase due to potential leaks
Solution Approach 1:
By integrating multiple process functions into a single processing assembly with internal heat and mass transfer means, the patent eliminates extensive external piping and flanged connections. This integration directly reduces potential leak points where hydrocarbon emissions could escape to the environment, while maintaining all necessary process functionalities within the sealed assembly.
3Ease of manufacture
If multiple separate equipment items are used, then process functionality is achieved, but capital costs increase
Solution Approach 1:
The patent consolidates multiple separate equipment items into a single integrated processing assembly, reducing the total number of components that need to be manufactured, installed, and maintained. This merging reduces capital costs while ensuring process functionality through carefully designed internal heat and mass transfer mechanisms that replicate the functions of the separate equipment in a more efficient, integrated configuration.
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 achieves C3 recoveries exceeding 99.6% with complete rejection of C2 components, while reducing energy requirements and environmental emissions, and allows for 100% separation of C2 components from C3 and heavier components at lower energy costs, particularly effective at higher pressures and colder temperatures.
Implementation Method 1
The heat and mass transfer means provides heat exchange between the vapor portion of stream 32 and distillation liquid stream 43
Implementation Method 2
Stream 35 is expanded to slightly above the operating pressure (approximately 383 psia) of deethanizing section 115d by expansion valve 12, cooling stream 35a
Implementation Method 3
The machine 13 expands the vapor substantially isentropically to the operating pressure (approximately 380 psia) of absorbing section 115c, with the work expansion cooling the expanded stream 34a
Implementation Method 4
The trays and/or packing in deethanizing section 115d provide the necessary contact between the vapors rising upward and cold liquid falling downward
Implementation Method 5
The vapor portion of expanded stream 34a rises upward through the absorbing means in absorbing section 115c to be contacted with the cold liquid falling downward to condense and absorb most of the C3 components and heavier components
Data Source
AI summary
A process and an apparatus are disclosed for a compact processing assembly to recover propane, propylene, and heavier hydrocarbon components from a hydrocarbon gas stream. The gas stream is cooled, expanded to lower pressure, and fed to an absorbing means. A first distillation liquid stream from the absorbing means is fed to a mass transfer means. A first distillation vapor stream from the mass transfer means is cooled to partially condense it, forming a residual vapor stream and a condensed stream. The condensed stream is supplied as the top feed to the absorbing means. A second distillation vapor stream from the absorbing means is heated by cooling the first distillation vapor stream, combined with the residual vapor stream, and heated by cooling the gas stream. A second distillation liquid stream from the mass transfer means is heated in a heat and mass transfer means to strip out its volatile components.