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Difference between revisions of "Pulping and fractionation"
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{{Infobox technology|Name=Pulping and fractionation|Category=[[Conversion]] ([[Conversion#Other_processes_and_technologies|Other processes and technologies]])|Feedstock=Woody biomass|Product=Pulp and lignin}} | |||
'''Pulping''' is a process that extracts fibrous material from biomass, most commonly as a precursor for paper making. The process is often combined with '''fractionation''' processes to separate and valorise lignin. Pulping and fractionation processes separate the fibrous cellulose and lignin from the other components and impurities in the biomass. Main processes are mechanical, chemical, and a combination of mechanical and chemical pulping in a hybrid pulping process. Mechanical pulping relies on physical separation methods without added chemicals. However, water can be added to reduce the damage to the fibres from friction. Chemical pulping uses chemicals to remove the lignin from the pulp, resulting in a higher quality pulp. Hybrid technologies use chemicals to soften the lignin before a physical separation results in a pulp that still contains a substantial amount of the lignin.<ref name=":0">{{Cite web|year=|title=PrintWiki, The Free Encyclopedia of Print|e-pub date=|date accessed=6-9-2021|url=http://printwiki.org/Pulping}}</ref> Finally, biological pulping uses biotechnology for the pulping process<ref name=":1">{{Cite journal|title=A review of the traditional pulping methods and the recent improvements in the pulping processes|year=2021-01-03|author=Drake Mboowa|journal=Biomass Conversion and Biorefinery|doi=10.1007/s13399-020-01243-6}}</ref>. | '''Pulping''' is a process that extracts fibrous material from biomass, most commonly as a precursor for paper making. The process is often combined with '''fractionation''' processes to separate and valorise lignin. Pulping and fractionation processes separate the fibrous cellulose and lignin from the other components and impurities in the biomass. Main processes are mechanical, chemical, and a combination of mechanical and chemical pulping in a hybrid pulping process. Mechanical pulping relies on physical separation methods without added chemicals. However, water can be added to reduce the damage to the fibres from friction. Chemical pulping uses chemicals to remove the lignin from the pulp, resulting in a higher quality pulp. Hybrid technologies use chemicals to soften the lignin before a physical separation results in a pulp that still contains a substantial amount of the lignin.<ref name=":0">{{Cite web|year=|title=PrintWiki, The Free Encyclopedia of Print|e-pub date=|date accessed=6-9-2021|url=http://printwiki.org/Pulping}}</ref> Finally, biological pulping uses biotechnology for the pulping process<ref name=":1">{{Cite journal|title=A review of the traditional pulping methods and the recent improvements in the pulping processes|year=2021-01-03|author=Drake Mboowa|journal=Biomass Conversion and Biorefinery|doi=10.1007/s13399-020-01243-6}}</ref>. | ||
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In this refiner process the biomass is preheated by impregnation of steam under pressure. The high temperature (115-155 °C) softens the lignin and helps in fibre separation. The refining takes place in two steps, the first at elevated pressure and temperature, around the glass transition temperature of lignin (140 °C), the second at atmospheric pressure and temperature. The resulting yields are high (>93%) and the pulp is characterised by its high strength.<ref name=":1" /> | In this refiner process the biomass is preheated by impregnation of steam under pressure. The high temperature (115-155 °C) softens the lignin and helps in fibre separation. The refining takes place in two steps, the first at elevated pressure and temperature, around the glass transition temperature of lignin (140 °C), the second at atmospheric pressure and temperature. The resulting yields are high (>93%) and the pulp is characterised by its high strength.<ref name=":1" /> | ||
====Groundwood==== | ====Groundwood==== | ||
Stone groundwood pulping is the oldest mechanical pulping method, where the biomass is pressed against a rotating grindstone. The grindstone breaks apart the biomass into thin fibres and fragments, which are washed away with a water stream. The friction results in an increased temperature, which helps the process. The product stream is scanned to remove the larger particles, then the water is removed to thicken the pulp. The process has high yields (about 95%), because most lignin remains in the product. Next to stone groundwood, there are also '''pressure groundwood''', where additional pressure is applied and '''thermal groundwood''', which sues elevated temperatures.<ref name=":1" /> | |||
Stone groundwood pulping is the oldest mechanical pulping method, where the biomass is pressed against a rotating grindstone. The grindstone breaks apart the biomass into thin fibres and fragments, which are washed away with a water stream. The friction results in an increased temperature, which helps the process. The product stream is scanned to remove the larger particles, then the water is removed to thicken the pulp. The process has high yields (about 95%), because most lignin remains in the product.<ref name=":1" /> | |||
===Biological pulping=== | ===Biological pulping=== | ||
Biological pulping takes advantage of natural methods to break down fibrous materials. For example, white-rot fungi can be used to soften and remove lignin.<ref name=":1" /> | Biological pulping takes advantage of natural methods to break down fibrous materials. For example, white-rot fungi can be used to soften and remove lignin.<ref name=":1" /> | ||
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===Valmet=== | ===Valmet=== | ||
Valmet is a developer and supplier of process technologies, automation and services for the pulp, paper and energy industries. The company has over 200 years of industrial history and was reborn through the demerger of the pulp, paper and power businesses from Metso Group. Valmet offers tailored technology solutions for softwood and hardwood kraft pulp production, as well as various mechanical pulping technologies. | Valmet is a developer and supplier of process technologies, automation and services for the pulp, paper and energy industries. The company has over 200 years of industrial history and was reborn through the demerger of the pulp, paper and power businesses from Metso Group. Valmet offers tailored technology solutions for softwood and hardwood kraft pulp production, as well as various mechanical pulping technologies. | ||
{{Infobox provider-pulping|Company=Valmet|Country=Finland|Technology name=Chemical and mechanical pulping|Webpage=https://www.valmet.com/|TRL=9|Technology category=Other processes|Feedstock=Hardwoods, softwoods, bamboo|Product=Pulp}} | |||
==Open access pilot and demo facility providers== | ==Open access pilot and demo facility providers== | ||
[https://biopilots4u.eu/database?field_technology_area_data_target_id=108&field_contact_address_value_country_code=All&field_scale_value=All&combine=&combine_1= Pilots4U Database (Pulping)] | [https://biopilots4u.eu/database?field_technology_area_data_target_id=108&field_contact_address_value_country_code=All&field_scale_value=All&combine=&combine_1= Pilots4U Database (Pulping)] | ||
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Currently no patents have been identified. | Currently no patents have been identified. | ||
==References== | ==References== | ||
<references /> | <references /> | ||