Ethylene Process Heat Exchange Between De-ethanizer and C2 Splitter
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing methods for preparing ethylene require a refrigerant loop that is subjected to high energy loads, leading to inefficiencies and potential malfunctions, necessitating a reduction in the energy source used by the refrigerant loop.
Innovation Solution
Installing a heat exchanger between columns in the ethylene production process to enable direct heat exchange, with a pressure difference of 542.6 kPa (4.5 kgf/cm²) or more between the de-ethanizer column and the first C2 splitter, and maintaining an ethylene concentration of 70 to 80 mol% in the lower stream of the first C2 splitter for optimized heat exchange.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a refrigerant loop is connected with each column to cool the columns, then the columns can be operated at required temperatures, but the load on the refrigerant loop increases leading to higher energy consumption and potential malfunctions
Solution Approach 1:
The patent merges the cooling functions of multiple columns into a single shared refrigerant loop. Instead of connecting separate refrigerant loops to each column (de-ethanizer, acetylene converter, C2 splitters), a common refrigerant loop is used to cool all columns. This consolidation reduces the overall load on the refrigeration system, decreases energy consumption, and eliminates the malfunctions associated with multiple high-load refrigerant loops while maintaining required operating temperatures for all columns.
2Reliability
If high-pressure steam is provided to operate the refrigerant loop, then the refrigeration system can function, but the energy source requirement increases leading to higher operational costs
Solution Approach 1:
The patent combines multiple refrigerant loops into one shared system, thereby reducing the total high-pressure steam required to drive the refrigeration process. By consolidating the cooling demand of all columns into a single refrigerant loop, the energy source (high-pressure steam) requirement is significantly reduced while maintaining reliable operation of the refrigeration system.
3Ease of operation
If multiple separate refrigerant loops are used for each column, then each column can be independently cooled, but the system complexity and load on refrigeration system increases
Solution Approach 1:
The patent merges multiple separate refrigerant loops into a single integrated refrigeration system. Instead of having independent refrigerant loops for the de-ethanizer, acetylene converter, and C2 splitters, a common refrigerant loop serves all columns. This reduces system complexity and the burden on the refrigeration infrastructure while still allowing for effective cooling of all process columns through the shared refrigeration capacity.
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 the amount of refrigerant used, resulting in energy savings and improved energy efficiency by minimizing the load on the refrigerant loop and optimizing heat exchange conditions.
Implementation Method 1
a heat exchanger is installed between the de-ethanizer column and the first C2 splitter to perform direct heat exchange between processes
Implementation Method 2
enable direct heat exchange between the columns
Data Source
Figure 1
Figure 2
AI summary
Provided is a method for preparing ethylene with improved energy efficiency which can reduce energy due to direct heat exchange between processes. The method for preparing ethylene with improved energy efficiency includes providing a C2 compound isolated from a de-ethanizer column to an acetylene converter to convert acetylene of the C2 compound into ethylene and ethane; transferring the C2 compound containing ethylene and ethane converted from acetylene to a first C2 splitter to isolate and discharge a part of the ethylene; and transferring a lower stream containing remaining ethylene and ethane, which are not discharged from the first C2 splitter, to a second C2 splitter, to isolate and discharge the ethylene, and converting the remaining C2 compound containing ethane into ethylene to be recycled, wherein a heat exchanger is installed between the de-ethanizer column and the first C2 splitter to perform direct heat exchange between processes, a difference in pressure between the de-ethanizer column and the first C2 splitter to enable the heat exchange is 4.5 kgf/cm2 G or more, and a concentration of ethylene contained in the lower stream of the first C2 splitter is 70 to 80 mol%.