Biomass Hydropyrolysis Catalyst Sulfurization for Water Tolerance
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Solution Overview
Problem
Conventional methods for converting biomass into liquid hydrocarbon fuels face challenges due to the detrimental effects of water on catalyst stability and the difficulty in upgrading bio-oils to high-quality, fungible fuels, particularly in maintaining long-term stability and achieving milder process conditions.
Innovation Solution
A process involving hydropyrolysis and hydroconversion of biomass-containing or biomass-derived feedstocks using catalyst compositions prepared by combining porous supports with catalytically active metals from Group VI and VIII of the Periodic Table, with volatile content reduction steps conducted in the presence of sulfur-containing compounds, avoiding calcination temperatures to enhance catalyst stability and activity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If conventional pyrolysis is used to convert biomass into liquid bio-oil, then liquid fuel production is achieved, but the product has high oxygen content, low heating value, and poor stability making it difficult to upgrade to high-quality fuels
Solution Approach 1:
The patent applies parameter changes by conducting hydropyrolysis at elevated pressures (5-15 MPa) and temperatures (300-500°C) in the presence of hydrogen, which fundamentally changes the product composition compared to conventional atmospheric pyrolysis. This results in a hydrogen-rich, low-oxygen liquid product with superior stability and heating value that requires minimal upgrading
Solution Approach 2:
The patent uses hydrogen as an intermediary substance during hydropyrolysis and subsequent hydroconversion. The hydrogen acts as a mediator that removes oxygen from the biomass-derived liquid through hydrodeoxygenation, converting high-oxygen bio-oil into low-oxygen hydrocarbon fuel with improved quality and stability
2Quantity of substance
If conventional hydrotreating catalysts are used for hydro-deoxygenation of biomass-derived feedstocks, then oxygen removal is achieved, but catalyst stability deteriorates due to water production and long-term exposure to water
Solution Approach 1:
The patent employs composite catalyst systems combining metal sulfides (CoMoS or NiMoS) supported on alumina. This composite structure provides both high hydrodeoxygenation activity and enhanced water tolerance. The sulfided metal phase on alumina support creates a synergistic effect that maintains catalyst stability in the presence of water while achieving efficient oxygen removal
Solution Approach 2:
The patent applies preliminary sulfurization treatment to the catalyst before use in hydroconversion. By pre-sulfiding the metal catalyst with compounds like dimethyl disulfide or carbon disulfide, the catalyst is prepared in advance to resist deactivation by water, ensuring both high oxygen removal efficiency and long-term stability during the hydroconversion process
3Power
If high-temperature calcination is applied to catalyst preparation, then catalyst activity is improved, but catalyst stability deteriorates due to water exposure during subsequent hydroconversion
Solution Approach 1:
The patent inverts the conventional catalyst preparation sequence by applying sulfurization before or instead of high-temperature calcination. Rather than calcining the catalyst to high temperatures and then sulfiding it, the method uses mild thermal treatment followed by sulfurization, creating a catalyst that is both active and water-stable without requiring extreme calcination temperatures that compromise stability
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 high-yielding conversion of biomass to liquid hydrocarbons with reduced oxygen content, improving product quality and catalyst resilience, allowing for milder process conditions and broader applicability to various biomass feedstocks.
Implementation Method 1
reducing the volatile content of the catalyst precursor in one or more steps, wherein at least one volatile content reduction step is performed in the presence of one or more sulfur containing compounds
Implementation Method 2
at least one volatile content reduction step is performed in the presence of one or more sulfur containing compounds
Implementation Method 3
contacting the biomass-containing feedstock and/or biomass-derived feedstock with a first hydropyrolysis catalyst composition and molecular hydrogen in a first hydropyrolysis reactor vessel
Implementation Method 4
combining a porous support with one or more catalytically active metals selected from Group VI and Group VIII of the Periodic Table
Data Source
AI summary
The present invention provides a process for producing liquid hydrocarbon products from a biomass, biomass containing and/or biomass-derived feedstock, said process comprising the steps of: a) contacting the feedstock with a first hydropyrolysis catalyst composition and molecular hydrogen in a first hydropyrolysis reactor vessel at a temperature in the range of from 350 to 600° C. and a pressure in the range of from 0.50 to 7.50 MPa, to produce a product stream comprising partially deoxygenated hydropyrolysis product, H2O, H2, CO2, CO, C1-C3 gases, char and catalyst fines; b) removing said char and catalyst fines from said product stream; c) hydroconverting said partially deoxygenated hydropyrolysis product in a hydroconversion reactor vessel in the presence of one or more hydroconversion catalyst compositions and of the H2O, CO2, CO, H2, and C1-C3 gas generated in step a), to produce a vapour phase product comprising substantially fully deoxygenated hydrocarbon product, H2O, CO, CO2, and C1-C3 gases, wherein one or more of the first hydropyrolysis catalyst composition and the hydroconversion catalyst composition is prepared by a process comprising combining a porous support with one or more catalytically active metals selected from Group VI and Group VIII of the Periodic Table, thereby forming a catalyst precursor having a volatile content, and reducing the volatile content of the catalyst precursor in one or more steps, wherein at least one volatile content reduction step is performed in the presence of one or more sulfur containing compounds; and wherein the catalyst precursor does not reach calcining temperatures prior to said at least one combined volatile content reduction-sulfurizing step.