Hydropyrolysis Catalyst Separation in Fluidized Bed Reactors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current processes for converting biomass into hydrocarbons face challenges in achieving economically and technically feasible commercial-scale production, particularly in efficiently separating hydropyrolysis catalysts and char produced during the process.
Innovation Solution
A process involving a fluidized bed of hydropyrolysis catalyst, where biomass is contacted with hydrogen under specific conditions to produce partially deoxygenated pyrolysis liquids and char, with the catalyst and char separated based on their settling velocities, allowing the catalyst to remain in the bed and char to be entrained with products, using attrition-resistant catalysts and suitable reactor conditions to maintain catalyst activity and prevent contamination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a fluidized bed of hydropyrolysis catalyst is used to convert biomass into hydrocarbons, then the conversion efficiency and product yield are improved, but the separation between catalyst and char becomes difficult
Solution Approach 1:
The patent applies parameter changes by utilizing the difference in settling velocities between catalyst particles and char particles. By controlling the fluidization velocity and utilizing gravity settling, the system separates catalyst (higher settling velocity) from char (lower settling velocity) without additional complex separation equipment, thus resolving the contradiction between high conversion efficiency and separation difficulty
Solution Approach 2:
The patent segments the solid particles in the fluidized bed based on their different settling characteristics. Catalyst particles and char particles are separated into different phases within the reactor based on their velocity differences, allowing the catalyst to be retained and recycled while char is removed, thereby simplifying the separation process while maintaining high productivity
2Stability of the object's composition
If the fluidized bed operates at high velocity to maintain catalyst fluidization, then mixing and heat transfer are improved, but catalyst attrition increases
Solution Approach 1:
The patent applies dynamics by using a fluidized bed system where the catalyst particles are suspended and mixed dynamically through controlled gas or liquid flow. This dynamic fluidization ensures uniform heat and mass transfer throughout the bed while allowing the system to operate at optimal velocities that balance mixing efficiency with catalyst particle integrity, minimizing attrition through proper hydrodynamic control
3Reliability
If catalyst particles are retained in the bed to maintain activity, then catalytic conversion is improved, but product removal and char discharge become restricted
Solution Approach 1:
The patent resolves this contradiction by changing the velocity parameter of the fluidizing medium. By operating at a velocity range that is sufficient to keep catalyst particles suspended and active but not so high as to prevent product and char removal, the system achieves both catalyst retention and efficient product discharge. The differential settling velocities of catalyst and char allow simultaneous achievement of both goals
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 effectively converts biomass into valuable liquid hydrocarbon products like gasoline, diesel, and jet fuel, with improved catalyst retention and char separation, enhancing the economic and technical feasibility for commercial-scale production.
Implementation Method 1
the char has a settling velocity that is less than the exit bed velocity and hydropyrolysis catalyst has a settling velocity that is greater than the exit bed velocity
Implementation Method 2
the fresh hydropyrolysis catalyst attrits in the fluidized bed to form small catalyst particles
Implementation Method 3
contacting the biomass with hydrogen in the presence of a fluidized bed of hydropyrolysis catalyst under hydropyrolysis conditions
Data Source
AI summary
A process for converting biomass to products is described. Biomass is contacted with hydrogen in the presence of a fluidized bed of hydropyrolysis catalyst in a reactor vessel under hydropyrolysis conditions; and products and char are removed from the reactor vessel. The products leave the fluidized bed at an exit bed velocity, the char has a settling velocity that is less than the exit bed velocity and hydropyrolysis catalyst has a settling velocity that is greater than the exit bed velocity.