Selective Molybdenum Removal via Water-Organic Emulsion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing processes for selective removal of molybdenum from solutions containing molybdenum and vanadium face challenges such as decomposition, instability, and handling difficulties due to the sticky nature of molybdenum xanthates, which hinder their use as catalyst precursors in catalytic hydrotreatment processes.
Innovation Solution
A process involving the formation of a water-organic emulsion by adding an organic solvent to the solution, followed by the addition of an alkaline metal xanthate to create a stable molybdenum xanthate complex that remains in the organic phase, reducing contact with water and decomposition, and allowing for easier separation and handling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If molybdenum xanthate is formed in aqueous solution, then molybdenum can be selectively removed from solution, but the molybdenum xanthate decomposes rapidly and becomes unstable
Solution Approach 1:
The patent introduces an organic solvent as an intermediary medium to form a water-organic emulsion. This emulsion acts as a mediator that allows molybdenum xanthate to be formed and stabilized in a biphasic system, reducing its direct contact with water and preventing rapid decomposition while maintaining selective removal capability
Solution Approach 2:
The patent changes the physical-chemical parameters of the system by creating a biphasic water-organic emulsion environment. This parameter change modifies the stability characteristics of molybdenum xanthate, allowing it to remain stable in the organic phase while still enabling selective precipitation and removal of molybdenum from the aqueous phase
2Productivity
If molybdenum xanthate is precipitated in conventional processes, then molybdenum removal is achieved, but the product becomes sticky and difficult to handle
Solution Approach 1:
The organic solvent acts as an intermediary that modifies the physical properties of the precipitated molybdenum xanthate. By forming the product in the organic phase of the emulsion, the xanthate maintains a non-sticky, easily handleable form while still achieving complete molybdenum removal from the aqueous phase
Solution Approach 2:
The patent applies local quality by creating different phases with different properties within the same system. The molybdenum xanthate forms in the organic phase with desirable handling characteristics, while the aqueous phase maintains the selective precipitation function, allowing the product to have both high removal efficiency and ease of handling
3Productivity
If xanthates with higher extractive capacity are used, then molybdenum extraction efficiency increases, but selectivity decreases
Solution Approach 1:
The patent changes the physical environment parameter by introducing the organic solvent and creating a biphasic emulsion system. This parameter change allows the use of xanthates with higher extractive capacity while maintaining selectivity, as the emulsion environment modulates the interaction between xanthate and metal ions, enabling efficient and selective molybdenum removal
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
The process achieves a stable form of molybdenum xanthate suitable for use as a catalyst precursor, reducing decomposition and adhesion issues, and enabling direct use in catalytic hydrotreatment reactors.
Implementation Method 1
adding at least one organic solvent to the solution and stirring continuously so as to create a water-organic emulsion
Implementation Method 2
adding to the water-organic emulsion at least one alkaline metal xanthate ... so as to form a complex with molybdenum
Implementation Method 3
interrupting the stirring so as to allow the separation of the aqueous phase from the organic phase
Data Source
AI summary
The present invention relates to a process for selectively removing molybdenum from a solution which contains molybdenum, said process comprising the following steps: bringing the solution to an acid pH lower than or equal to 3, preferably lower than or equal to 2, even more preferably lower than or equal to 0.5, by the addition of an inorganic acid; adding at least one organic solvent, preferably toluene or xylene, to the solution and stirring continuously so as to create a water-organic emulsion; adding to the water-organic emulsion at least one alkaline metal xanthate having the general formula MeRX, wherein R is a linear or branched alkyl group having a number of carbon atoms higher than or equal to 2, Me is an alkaline metal selected from Li, Na, K, Rb, Cs and Fr, and X is the xanthate group, so as to form a complex with molybdenum wherein the molar ratio molybdenum/alkaline metal xanthate ranges from 1/6 to 1/2, keeping the emulsion at an acid pH by the addition of an inorganic acid, and interrupting the stirring so as to allow the separation of the aqueous phase from the organic phase. The linear or branched alkyl group R preferably has a number of carbon atoms higher than or equal to 2 and lower than or equal to 12. A reductant is optionally added to the starting solution which comprises Mo and V.