Hydrothermal Digestion Slurry Catalyst Retention
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Solution Overview
Problem
The efficient conversion of cellulosic biomass into fuel blends is hindered by issues such as thermal degradation of soluble carbohydrates, catalyst poisoning, and the need for high conversion percentages, which existing technologies have not adequately addressed, leading to energy inefficiencies and increased costs.
Innovation Solution
A method involving hydrothermal digestion with a slurry catalyst capable of activating molecular hydrogen, using a digestible filter aid to retain the catalyst and perform in situ catalytic reduction reactions, which stabilizes soluble carbohydrates and enhances energy efficiency by integrating heat and reducing the need for separate solvent recycling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If high temperature digestion is used to increase conversion rate, then productivity is improved, but thermal degradation of soluble carbohydrates increases
Solution Approach 1:
The patent applies preliminary action by adding the slurry catalyst before digestion to activate molecular hydrogen in advance, which then protects soluble carbohydrates from thermal degradation during high-temperature processing. The catalyst is introduced at the beginning of the digestion process to establish protective conditions before thermal stress occurs.
Solution Approach 2:
The slurry catalyst acts as an intermediary substance that facilitates the conversion process while protecting soluble carbohydrates from thermal degradation. It mediates between the high temperature conditions and the carbohydrate molecules, enabling high conversion rates without proportional increases in degradation.
2Manufacturing precision
If slurry catalyst is used to enable in situ catalytic reduction, then manufacturing precision is improved, but device complexity increases
Solution Approach 1:
The digestible filter aid performs self-service by automatically forming a filter cake that retains the slurry catalyst during digestion. The filter aid is consumed as part of the digestion process, and its decomposition products become part of the digestate, eliminating the need for separate catalyst recovery systems.
Solution Approach 2:
The patent applies discarding and recovering by using a digestible filter aid that is discarded during digestion while simultaneously recovering the slurry catalyst through the filter cake formation. The filter aid is intentionally consumed to achieve catalyst retention, and its loss is acceptable as it facilitates catalyst recovery.
3Reliability
If separate catalyst retention system is used, then reliability is improved, but device complexity increases
Solution Approach 1:
The patent merges the catalyst retention function with the existing digestion process by using the digestible filter aid that forms a filter cake during normal operation. The retention mechanism is combined with the filtration and digestion functions, eliminating the need for separate dedicated retention equipment.
Solution Approach 2:
The digestible filter aid serves multiple functions: it acts as a filter medium for catalyst retention, serves as part of the digestion substrate, and its decomposition contributes to the overall digestate composition. This multi-functionality reduces the need for separate specialized components.
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 allows for high-yield conversion of cellulosic biomass into stable reaction products, reducing thermal degradation and energy input, while maintaining catalyst effectiveness and minimizing operational costs through efficient catalyst distribution and retention.
Implementation Method 1
a slurry catalyst capable of activating molecular hydrogen and performing at least one in situ catalytic reduction reaction on the soluble carbohydrates
Implementation Method 2
forming a filter cake comprising a digestible filter aid on a solids retention mechanism configured to allow the liquor phase to pass therethrough; collecting at least a portion of the slurry catalyst on the filter cake
Implementation Method 3
distributing the slurry catalyst within the cellulosic biomass solids using upwardly directed fluid flow
Implementation Method 4
heating the cellulosic biomass solids in the hydrothermal digestion unit in the presence of the slurry catalyst, a digestion solvent, and molecular hydrogen, thereby forming a liquor phase comprising soluble carbohydrates
Implementation Method 5
heating the cellulosic biomass solids in the hydrothermal digestion unit... thereby forming a liquor phase comprising soluble carbohydrates
Implementation Method 6
performing a first catalytic reduction reaction on the soluble carbohydrates within the hydrothermal digestion unit, thereby at least partially forming a reaction product comprising a triol, a diol, a monohydric alcohol, or any combination thereof
Data Source
AI summary
Digesting cellulosic biomass in the presence of a slurry catalyst may reduce degradation product formation, but catalyst distribution and retention can be problematic. Digestion methods can comprise: providing cellulosic biomass solids and a slurry catalyst capable of activating molecular hydrogen in a digestion unit; providing a digestible filter aid in the digestion unit; distributing the slurry catalyst within the cellulosic biomass solids using fluid flow; retaining at least a portion of the slurry catalyst in a fixed location using the digestible filter aid; heating the cellulosic biomass solids in the presence of the slurry catalyst, a digestion solvent, and molecular hydrogen, thereby forming a liquor phase comprising soluble carbohydrates; and performing a catalytic reduction reaction on the soluble carbohydrates within the digestion unit, thereby at least partially forming a reaction product comprising a triol, a diol, a monohydric alcohol, or any combination thereof in the digestion unit.