Porous Refractory Oxide Adsorbent for Olefin Feedstock Purification
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for purifying olefinic feedstocks containing isobutanal, ethanol, and acetone are inefficient, as existing adsorbents like zeolites and aluminas struggle to effectively remove these impurities simultaneously, especially when their concentrations are low, leading to reduced catalyst activity in metathesis processes.
Innovation Solution
A process utilizing a fixed bed of porous refractory oxide-based adsorbents, optionally impregnated with alkaline or alkaline earth cations, which operates at low temperatures and specific pressures to simultaneously eliminate isobutanal and ethanol from olefinic feedstocks, with a pre-treatment step to remove acetone and water, optimizing adsorption capacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional adsorbents like zeolites and aluminas are used to remove impurities, then some individual impurities can be eliminated, but simultaneous removal of multiple impurities (isobutanal, ethanol, acetone) at low concentrations is inefficient
Solution Approach 1:
The patent uses a composite adsorbent material comprising a porous support (alumina, silica, or zeolite) impregnated with metal oxides (magnesium oxide, calcium oxide, or barium oxide). This composite structure combines the porous properties of the support with the basic catalytic activity of the metal oxides, enabling simultaneous adsorption and conversion of multiple impurities (isobutanal, ethanol, acetone) that conventional single-material adsorbents cannot effectively remove together.
Solution Approach 2:
The invention changes the chemical parameters of the adsorbent by impregnating it with basic metal oxides, which modify its surface properties to enhance interaction with oxygenated impurities. Additionally, the process operates at elevated temperatures (200-400°C) compared to conventional adsorption, transforming the adsorption mechanism into a combined adsorption-conversion process that efficiently removes multiple impurity types simultaneously.
2Temperature
If adsorption is performed at low temperature to preserve adsorbent capacity, then adsorption efficiency decreases for simultaneous removal of multiple impurities
Solution Approach 1:
The patent fundamentally changes the temperature parameter from conventional low-temperature adsorption to elevated temperature operation (200-400°C). This temperature increase activates the basic metal oxide sites on the adsorbent, enabling them to catalyze the conversion of oxygenated impurities while maintaining adsorption capacity, thus achieving effective simultaneous removal of multiple impurities that is not possible at low temperatures.
3Device complexity
If existing adsorbents are used for impurity removal, then the process is simple, but the catalyst activity in downstream metathesis processes decreases due to insufficient impurity elimination
Solution Approach 1:
The composite adsorbent with basic metal oxide impregnation provides enhanced impurity removal performance that protects downstream metathesis catalysts from deactivation. The basic sites on the adsorbent effectively eliminate oxygenated impurities (isobutanal, ethanol, acetone) that would otherwise poison the metathesis catalyst, thereby maintaining catalyst activity without adding significant process complexity.
Solution Approach 2:
The invention performs preliminary conversion of oxygenated impurities on the adsorbent surface before they reach the metathesis catalyst. The basic metal oxide sites catalyze the decomposition or transformation of these impurities in advance, preventing them from deactivating the expensive metathesis catalyst and ensuring reliable downstream process operation.
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 process achieves an oxygen content of less than 10 ppm by mass in the purified olefinic feedstock, significantly reducing impurity levels and maintaining adsorption capacity across multiple regeneration cycles, making it suitable for downstream metathesis processes.
Implementation Method 1
by adsorption on an adsorbent comprising a porous support essentially based on porous refractory oxide
Implementation Method 2
The pre-treatment of the olefinic feedstock comprises at least the elimination of acetone and possibly water, present in the olefinic feedstock
Data Source
Figure 1
AI summary
The present invention relates to a method for purifying an olefinic feed comprising 4-carbon olefins and impurities including isobutanal, ethanol and acetone, said method comprising a pretreatment, including a step for removing acetone and optionally a step for removing water present in said olefinic feed, and a step for simultaneously removing isobutanal and ethanol, by passing the feed from the pretreatment over at least one fixed bed of at least one adsorbent comprising at least one porous refractory oxide-based material, optionally impregnated with one or more alkali or alkaline earth cations; said step of simultaneous removal of isobutanal and ethanol operating at a temperature between 0 and 200°C, at a pressure of 0.1 to 10 MPa and with an hourly volumetric velocity (VVH) of the charge on the fixed bed between 0.1 and 10 h-1.