Biomass Pyrolysis Oil Deoxygenation via Esterification and Segmented Hydroprocessing
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Solution Overview
Problem
Biomass-derived pyrolysis oil has high oxygen content, leading to acidity and low energy density, which causes plugging and fouling in hydroprocessing reactors during deoxygenation, limiting its utilization as a biofuel.
Innovation Solution
The method involves treating biomass-derived pyrolysis oil to reduce solids, metals, and water content, followed by esterification and deoxygenation using catalysts under specific hydroprocessing conditions to produce low oxygen pyrolysis oil, preventing reactor plugging and improving processibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If deoxygenation is performed on biomass-derived pyrolysis oil, then oxygen content is reduced and energy density is improved, but reactor plugging and fouling occur due to acid-catalyzed polymerization
Solution Approach 1:
The patent applies preliminary action by removing solids, metals, and water from biomass-derived pyrolysis oil before deoxygenation treatment. This pre-treatment step prevents acid-catalyzed polymerization during subsequent deoxygenation by eliminating impurities that would otherwise cause reactor plugging and fouling, thereby maintaining reactor operability while enabling energy density improvement through deoxygenation.
Solution Approach 2:
The patent uses an intermediary approach by introducing esterification as a intermediate step between the raw pyrolysis oil and deoxygenation. The esterification process converts carboxylic acids into esters, reducing the acidity that catalyzes harmful polymerization reactions during deoxygenation, thus preventing reactor plugging while allowing effective oxygen removal.
2Quantity of substance
If conventional deoxygenation methods are used, then oxygen removal is achieved, but run duration is limited due to catalyst fouling and reactor plugging
Solution Approach 1:
The patent applies preliminary action by removing solids, metals, and water from biomass-derived pyrolysis oil before deoxygenation treatment. This pre-treatment step prevents acid-catalyzed polymerization during subsequent deoxygenation by eliminating impurities that would otherwise cause reactor plugging and fouling, thereby maintaining reactor operability while enabling energy density improvement through deoxygenation.
Solution Approach 2:
The patent converts the harmful effect of carboxylic acids (which cause acid-catalyzed polymerization and reactor plugging) into a beneficial process by using esterification. The carboxylic acids react with alcohols to form esters, transforming the problematic acidic components into less reactive ester compounds that do not promote polymerization, thus extending reactor run duration while maintaining effective oxygen removal.
3Ease of manufacture
If pyrolysis oil is processed without pre-treatment, then processing simplicity is maintained, but solids and metals cause catalyst fouling and reduce processibility
Solution Approach 1:
The patent applies segmentation by dividing the processing into distinct sequential steps: pre-treatment (solids removal, metal removal, water removal), esterification, and deoxygenation. This segmentation allows each step to address specific issues independently, making the overall complex process more manageable and controllable, thereby improving processibility while maintaining reasonable operational simplicity through standardized unit operations.
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 results in low oxygen biomass-derived pyrolysis oil that is more suitable for biofuel use, reducing reactor fouling and increasing run duration, thus enhancing the biofuel's energy density and processing efficiency.
Implementation Method 1
Fast pyrolysis is a process during which organic carbonaceous biomass feedstock, i.e., 'biomass', such as wood waste, agricultural waste, etc., is rapidly heated to between about 300° C. to about 900° C. in the absence of air using a pyrolysis reactor.
Implementation Method 2
the biomass-derived pyrolysis oil is esterified with an alcohol to produce an esterified biomass-derived pyrolysis oil
Implementation Method 3
deoxygenating the esterified biomass-derived pyrolysis oil in a hydroprocessing reactor to produce a low oxygen biomass-derived pyrolysis oil
Data Source
AI summary
Methods for producing low oxygen biomass-derived pyrolysis oil are provided. Starting biomass-derived pyrolysis oil is deoxygenated by exposing the biomass-derived oil to a first catalyst in the presence of hydrogen-containing gas at first hydroprocessing conditions to produce a partially deoxygenated biomass-derived pyrolysis oil. The first catalyst has a neutral catalyst support. The partially deoxygenated biomass-derived pyrolysis oil is exposed to a second catalyst in the presence of additional hydrogen-containing gas at second hydroprocessing conditions to produce a hydrocarbon product. The biomass-derived pyrolysis oil may be esterified prior to deoxygenation. A portion of the low oxygen biomass-derived pyrolysis oil is recycled.