Wax-Coated Fischer-Tropsch Catalyst Activation
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Solution Overview
Problem
The Fischer-Tropsch process faces challenges with the generation and separation of catalyst fines during the activation of iron catalysts, particularly with smaller spray dried particles, which combust easily and create reactive dust, and the inefficiency of water removal in high-pressure synthesis gas activation, leading to undesirable re-oxidation and deactivation of the catalyst.
Innovation Solution
A method involving the wax coating and shaping of spray dried catalyst particles, followed by fluidization and activation in a two-phase system without a liquid medium, allowing for selective removal of fines and efficient water removal, and recycling of non-condensed gases to enhance the activation process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If iron catalyst is reduced in slurry phase with liquid medium, then catalyst activation is achieved, but catalyst breakage and fines generation increase
Solution Approach 1:
The invention changes the phase parameter of the activation medium from liquid (slurry phase) to gas (gas phase), eliminating the liquid medium that causes catalyst breakage and fines generation during reduction, while still achieving effective catalyst activation through gas-phase reducing conditions
Solution Approach 2:
The invention replaces the mechanical mixing and contact required in slurry-phase reduction with a gas-phase system where reducing gases diffuse and react with catalyst particles suspended in gas, eliminating mechanical stress and friction that cause catalyst breakage
2Ease of operation
If spray dried catalyst particles are removed from reduction reactor, then catalyst can be transported, but highly reactive catalyst dust is created
Solution Approach 1:
The invention maintains an inert or reducing gas atmosphere throughout the catalyst activation and transport process, preventing oxidation of the reduced catalyst particles and eliminating the formation of highly reactive catalyst dust by keeping the environment free of oxygen until the catalyst is ready for use
3Productivity
If activation is conducted at high pressure with synthesis gas, then catalyst activation efficiency improves, but water removal becomes inefficient leading to re-oxidation
Solution Approach 1:
The invention extracts and removes water produced during the activation reaction through condensation and separation systems, preventing water accumulation that would cause catalyst re-oxidation and deactivation, thereby maintaining catalyst stability while operating at high pressure for efficient activation
Solution Approach 2:
The invention implements a feedback control system where water removal efficiency is monitored and activation conditions are adjusted accordingly, ensuring that water is continuously removed from the system to prevent re-oxidation while maintaining optimal activation efficiency
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 stabilizes the catalyst, reduces fines generation, and prevents re-oxidation, enabling more efficient and stable Fischer-Tropsch synthesis by maintaining catalyst activity and extending reactor operation time.
Implementation Method 1
reducing the catalyst with synthesis gas (i.e. a gas comprising carbon monoxide and hydrogen), CO, or H2. The reduction process involves dissolving a reducing gas in the liquid medium whereby reducing-gas-saturated liquid enters the catalyst pores and surfaces to activate the catalyst
Implementation Method 2
The reduction process involves dissolving a reducing gas in the liquid medium whereby reducing-gas-saturated liquid enters the catalyst pores and surfaces to activate the catalyst
Implementation Method 3
fluidization and activation in a two-phase system
Data Source
AI summary
A method of preparing a spray dried catalyst by combining spray dried catalyst particles with wax so the spray dried catalyst particles are coated with wax, yielding wax coated catalyst particles, and shaping the wax coated catalyst to provide shaped wax coated catalyst. A method of activating Fischer-Tropsch catalyst particles containing oxides by contacting the catalyst particles with a reducing gas in an activation vessel to produce an activated catalyst, wherein contacting is performed in the absence of a liquid medium under activation conditions. A system for activating a Fischer-Tropsch catalyst containing an activation reactor configured to introduce an activation gas to a fixed or fluidized bed of the Fischer-Tropsch catalyst in the absence of a liquid medium and at least one separation device configured to separate a gas stream comprising entrained catalyst fines having an average particle size below a desired cutoff size from the activation reactor.