A
B
Integrated Shell biomass gasi cation process
Integrated Shell biomass gasi cation process
Biomass residues*
Variety of feedstocks
Pre- treatment and drying
Pre- treatment and drying
Liquid gasi cation
Fast pyrolysis
Solids gasi cation
Milling
Torrefaction
*Biomass residues from industrial processes
Figure 5 Integrated Shell biomass gasification process with (a) fast pyrolysis and (b) torrefaction
into a fine, homogeneous powder suitable for the entrained-flow gasification of solids (see Figure 5b ). With similar properties to lignite, torrefied biomass can be used in commercially “ Solid and liquid gasification has the potential to unlock advantaged feeds and convert them into high-value, bio- based and circular fuels, chemicals, and plastics with attractive margins ” proven lignite gasification units. Moreover, lower unit technical costs make torrefaction more attractive for greenfield projects compared with the fast-pyrolysis route. Quick and cost-effective deployment today As demand for lower-carbon and more circular products grows, solid and liquid gasification has the potential to unlock advantaged feeds, such as low-value biomass residues and unsorted plastic waste, and convert them into high-value, bio-based and circular fuels, chemicals, and plastics with attractive margins. Using existing gasifiers with only minor adaptions and novel pre-conversion technologies, gasification can be a quick-to- deploy and cost-effective way for refiners to meet changing market preferences and align with increasing regulations on carbon emissions and circularity.
A key consideration is the characteristics of plastic-derived gasification feedstock produced by liquefaction, which differ slightly from fossil-based feeds. For example, Table 1 highlights differences in sulphur, halides, ash, and ash behaviour. While these differences are important, they can be managed with only minor adjustments to an existing gasifier and connected equipment. For example: • Reconfiguration of upstream feedstock system to deal with different fouling and cracking behaviour. • Change refractory material to withstand fluctuating slag composition. • Addition of slag removal system (proven system used in goal gasification). • Upgrade materials based on expected chloride levels. • Simplify wastewater and sour gas treatment (plastic waste is relatively poor in sulphur). Fast pyrolysis for woody biomass Fast pyrolysis converts woody biomass, such as waste wood from industrial processes, into pyrolysis oil suitable for gasification (see Figure 5a ). As part of the integrated Shell biomass gasification process, fast pyrolysis can be deployed in existing liquid/residue gasifiers with only minor adaptions to the feed system. Moreover, because fast pyrolysis is relatively simple and quick to deploy, it can contribute to a faster reduction in carbon intensity and the production of low-carbon products when used with existing gasifiers. Torrefaction for solid biomass, residue and unsorted waste materials Torrefaction converts a wide range of biomass and unsorted waste into a product with similar properties to lignite that can be easily ground
Harold Boerrigter Harold.Boerrigter@shell.com Sven Felske Sven.Felske@shell.com
www.decarbonisationtechnology.com
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