Two-Stage Quenching Separates Hydrocarbons Before Fractionation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional quenching systems for oxygenate-to-olefin synthesis processes face inefficiencies due to the lack of dedicated hydrocarbon-water phase separation, leading to repeated separation of hydrocarbons in downstream fractionation, increased energy consumption, and higher investment costs, as well as the risk of hydrocarbon deposits and blockages.
Innovation Solution
A two-stage quenching process with separate quench water circuits operating at different temperatures, where phase separation is relocated to the cooler quench circuit, minimizing hydrocarbon condensation in the first stage and optimizing separation conditions to avoid repeated fractionation and reduce equipment size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If conventional quenching systems are used without dedicated phase separation, then the process is simpler, but hydrocarbons are repeatedly separated in downstream fractionation leading to increased energy consumption
Solution Approach 1:
The invention performs hydrocarbon-water phase separation in the quench system before the product stream enters downstream fractionation units. By separating hydrocarbons early in the process, the invention prevents repeated separation operations in subsequent fractionation columns, thereby reducing energy consumption without requiring fundamentally new equipment
Solution Approach 2:
The invention extracts the phase separation function from the downstream fractionation system and places it within the quench system. This extraction of the separation function allows the fractionation units to focus solely on their primary separation tasks, reducing redundant processing and energy waste
2Productivity
If phase separation is performed in the hot quench circuit, then separation occurs earlier in the process, but hydrocarbon solubility in hot water reduces separation efficiency
Solution Approach 1:
The invention divides the quench system into two separate temperature zones: a hot quench circuit for initial cooling and a cold quench circuit for phase separation. This segmentation allows each circuit to operate at optimal temperatures for its specific function, with the cold circuit providing better hydrocarbon-water separation efficiency
Solution Approach 2:
The invention introduces a cold quench circuit as an intermediary between the hot quench circuit and the phase separation process. This cold circuit acts as a mediator that receives the hot quench effluent, cools it further, and provides optimal conditions for hydrocarbon-water separation without directly interfering with the hot quench operation
3Quantity of substance
If larger fractionation equipment is used to handle hydrocarbon separation, then separation capacity is increased, but investment costs increase
Solution Approach 1:
By performing phase separation in the quench system before downstream processing, the invention removes a significant portion of hydrocarbons early in the process. This preliminary separation reduces the quantity of hydrocarbons that subsequent fractionation equipment must handle, allowing for smaller, more cost-effective separation units
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 hydrocarbon-water separation efficiency, reduces equipment volume and energy consumption, and prevents hydrocarbon deposits, resulting in lower investment costs and improved process efficiency.
Implementation Method 1
direct heat exchange with a fluid, usually liquid, quench medium, such as water
Implementation Method 2
The majority of the water contained in the product stream and supplied with the quench medium is condensed in the first quench stage
Implementation Method 3
In this phase separator 130, the comparatively cold, hydrocarbon-rich second quench fraction is mixed with the relatively warm, water-rich first quench fraction. This leads to partial evaporation (flashing) of the more volatile components
Data Source
Figure 1
Figure 2
AI summary
The invention relates to a method for quenching a fluid product stream containing water and hydrocarbons from a synthesis reactor, and to a quench system for carrying out such a method. According to the invention, a two-stage quench system is used, which has separate circuits for the water-containing quench media. The quench system is operated such that a quench fraction consisting largely of water is obtained in the first quench stage. The separation of the hydrocarbons, on the other hand, is largely transferred to a phase separator located in the second quench stage. A small partial stream of the quench medium from the first quench stage is transferred to the second quench stage, so that excess water can be removed from the quench system via the phase separator of the second quench stage.