Adiabatic Reactor Olefin Conversion via Internal Heat Exchange
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing processes for preparing alkylamines by reacting olefins with ammonia over calcined zeolitic catalysts achieve low conversion rates, typically between 5 to 20%, even at optimal temperatures and pressures, due to exothermic reactions and equilibrium limitations.
Innovation Solution
The process involves diverting the reaction mixture at specific points within the reactor for indirect thermal contact with a lower alkylamine concentration to cool the reaction mixture, effectively reducing the reactor outlet temperature and increasing olefin conversion without altering the reactor's internal volume or requiring external cooling facilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If low temperatures are used to shift equilibrium toward alkylamine product, then conversion yield is improved, but reaction rate deteriorates
Solution Approach 1:
The reaction process is segmented into multiple stages with different temperature zones. The reactor is divided into a first reaction zone (lower temperature for equilibrium) and a second reaction zone (higher temperature for rate), allowing both low temperature benefits and high reaction rate to be achieved in different segments of the overall process.
Solution Approach 2:
Temperature parameters are changed along the reaction path. The process uses a temperature gradient where the temperature increases from the first reaction zone to the second reaction zone, optimizing both equilibrium position and reaction kinetics at different stages of the reaction.
2Productivity
If high pressures are used to improve equilibrium position, then conversion yield is improved, but equipment complexity and operating cost worsen
Solution Approach 1:
The pressure conditions are segmented into different zones. The first reaction zone operates at lower pressure while the second reaction zone operates at higher pressure, allowing the system to achieve high overall conversion without requiring the entire system to withstand high pressures, thus reducing equipment complexity.
3Device complexity
If adiabatic operation is used to simplify reactor design, then device complexity is reduced, but temperature control and selectivity worsen
Solution Approach 1:
The adiabatic reactor is segmented into multiple reaction zones with different temperature characteristics. Each zone maintains adiabatic conditions for simplicity, but the zones are arranged to create an overall temperature gradient that improves selectivity and conversion without requiring complex external temperature control systems.
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 olefin conversion by optimizing temperature distribution within the reactor, allowing for higher yields of alkylamines while maintaining reactor efficiency and simplicity.
Implementation Method 1
the reaction mixture comprising the starting olefin, ammonia and the corresponding alkylamine is taken off at one or more points and brought into indirect thermal contact with the reaction mixture at one or more points in the reactor unit having in each case a lower concentration of alkylamine
Implementation Method 2
The addition of ammonia onto olefins is exothermic; low temperatures are therefore advantageous for shifting the equilibrium in the direction of the desired alkylamine product
Implementation Method 3
process for preparing alkylamines by reacting olefins with ammonia under hydroaminating conditions over a calcined zeolitic catalyst
Data Source
AI summary
A process for preparing alkylamines by reacting olefins with ammonia under hydroaminating conditions over a calcined zeolitic catalyst in an adiabatically operated reactor unit, wherein the reaction mixture comprising the starting olefin, ammonia and the corresponding alkylamine is taken off at one or more points and brought into indirect thermal contact with the reaction mixture at one or more points in the reactor unit having in each case a lower concentration of alkylamine compared to the point from which the reaction mixture was taken off, is proposed.