Evaluation of pressure and temperature effects on hydropyrolysis of pine sawdust: pyrolysate composition and kinetics studies

Abstract

<p>Kinetics and product distribution from high pressure hydropyrolysis of biomass using Py-GC/MS and Py-FTIR.</p>

A Review of Recent Advances in Biomass Pyrolysis

“…156 Generally, high pressure is more desirable for catalytic hydropyrolysis to ensure the quantity and quality of bio-oil product. Venkatesan et al 157 showed that more hydrocarbons were generated under high hydrogen pressures than under low hydrogen pressures in the catalytic hydropyrolysis process of pine sawdust. Stummann et al 158 reported a threshold pressure value at which the content of oxygen in liquid bio-oil increased dramatically.…”

The interplay between ternary molten carbonate and biomaterials during pressurized slow pyrolysis

“…Pressurised pyrolysis is another pathway to increase the occurrence of secondary reactions for conversion of condensable volatiles to biochar and biogas, as opposed to bio-oil, 15,25,26 this is particularly the case in slow pyrolysis which supports long residence time for sample treatment. Thus, comparing previous findings exclusively in slow pyrolysis studies aiming biochar preparation/modification will be considered here.…”

One-Step Hydropyrolysis and Hydrotreating Tandem Reactions of Miscanthus × giganteus Using Ni Impregnated ZSM-5/MCM-41 Composites

“…The massive energy needs of our modern society and the depletion of fossil fuels are calling for renewable energy resources. − Biomass is a widely available resource that is considered as one of the few possible resources of renewable carbon and can be used for clean liquid fuels production, such as biogasoline and biodiesel. − The thermochemical technologies of biomass conversion, including torrefaction, liquefaction, pyrolysis, and gasification, have drawn great attention in recent years . Biomass pyrolysis operates at inert atmosphere and high temperature and leads to the production of liquid fuels (bio-oil) and two byproducts, namely, biochar and noncondensable gases .…”

“…Hydropyrolysis involves the presence of hydrogen, which differs from the inert atmosphere of pyrolysis . CFHP leads to more deoxygenated fuels and less coke compared to CFP. , CFHP is an exothermic reaction, which is one of the most important advantages of CFHP compared to CFP, which is endothermic. ,, Another crucial advantage of CFHP over CFP is that the former removes oxygen more likely via dehydration reactions followed by hydrogenation and hydrodeoxygenation reactions rather than decarboxylation or decarbonylation reactions, thus minimizing the carbon loss during the process. ,, The concept of hydropyrolysis was first proposed for the conversion of coal and later applied for biomass . CFHP of biomass did not receive considerable attention until approximately 10 years ago .…”

“…Compared to in situ CFP, it leads to a lower coke and higher liquid yield, with higher selectivity to hydrocarbons. , The noncatalytic fast hydropyrolysis with ex situ hydrotreating can be regarded as in situ hydrodeoxygenation (HDO), where the raw bio-oil is upgraded after it is vaporized. Vapor phase catalytic upgrading right after hydropyrolysis is beneficial over traditional HDO, because it can avoid secondary reactions during condensation and revaporization of the pyrolyzate. , Compared to in situ CFHP, the two-step noncatalytic hydropyrolysis followed by ex situ hydrotreatment allows for independent control of hydropyrolysis and catalytic upgrading at their respective optimal conditions. , The two-step in situ CFHP followed by ex situ hydrotreatment is a combination of the second and third configurations and allows for independent control of the two steps and complete deoxygenation and hydrogenation of the bio-oil compounds, thus producing gasoline and diesel range fuels. , …”