FI20245517A1

FI20245517A1 - System for pretreatment of biomass

Info

Publication number: FI20245517A1
Application number: FI20245517A
Authority: FI
Inventors: Marina Ståhl; Juha Tamper; Sami Turunen; Vilho Nissinen; Isko Kajanto; Folke Örså; Christos Nitsos
Original assignee: Upm Kymmene Corp
Priority date: 2024-04-04
Filing date: 2024-04-23
Publication date: 2025-10-05
Also published as: WO2025209895A1

Abstract

A system (100) for pretreatment of biomass (4), wherein the system (100) comprises at least one of the following: a reactor, a conveyor (1), and/or a blowline (30). The system further comprises one or more transducers and/or vibrators (40) configured to be arranged on an outer surface (S1,S2,S3) of the at least one of the following: the reactor, the conveyor (1), and/or the blowline (30). The one or more transducers and/or vibrators (40) are configured to create sound or mechanical waves inside the at least one of the following: the reactor, the conveyor (1), and/or the blowline (30) for removing and/or minimizing build-ups. Also a method is disclosed.

Description

SYSTEM FOR PRETREATMENT OF BIOMASS

FIELD OF THE INVENTION

The present application relates generally to a system for pretreatment of biomass. More specifically, the present application relates to removing and/or min- imizing formation of build-ups in the system.

BACKGROUND OF THE INVENTION

A system for pretreatment of biomass may com- prise a reactor, a conveyor, and a blowline. However, especially at high temperatures build-ups may be formed on a surface of the reactor, the conveyor and the blow- line, which may require regular cleaning. It is im- portant to find solutions wherein forming of the build- ups could be minimized.

SUMMARY

This summary is provided to introduce a selec- tion of concepts in a simplified form that are further described below in the detailed description. This sum- mary is not intended to identify key features or essen- tial features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. The scope of protection sought for var- + ious embodiments of the present disclosure is set out

S by the independent claims. + The embodiments of the present disclosure pro- = vide ultrasonic and/or mechanical treatment for cleaning

N 30 and/or prevention of organic build up precipitate during

E pretreatment of biomass in a system comprising an eguip-

K ment. The equipment may comprise at least one of the lo following: a reactor, a conveyor, and/or a blowline. The

N system may also comprise one or more transducers and/or

N 35 vibrators arranged on an outer surface the equipment to create sound and/or mechanical waves inside the equipment for removing and/or minimizing build-ups. This way the equipment may stay cleaner and if cleaning is needed it may also be easier.

According to a first aspect a system for pre- treatment of biomass is disclosed. The system may com- prise at least one of the following: a reactor, a con- veyor, and/or a blowline; one or more transducers and/or vibrators configured to be arranged on an outer surface of the at least one of the following: the reactor, the conveyor, and/or the blowline, wherein the one or more transducers and/or vibrators may be configured to create sound or mechanical waves inside the at least one of the following: the reactor, the conveyor, and/or the blow- line for removing and/or minimizing build-ups. The con- veyor is, for example, a screw, a belt, or a pipe.

If pretreatment conditions are severe or a bi- omass stream is not moving forward, the biomass may stay in the reaction atmosphere for a long time, which may form hard, condensated, and carbonized material, for example build-ups onto the surface of an equipment. The eguipment may be blocked out and production may have to be stopped for cleaning regularly. However, one or more transducers and/or vibrators for removing and/or mini- mizing the build-ups may be installed and used even without stopping production lines and without making any changes to the equipment. This may extend cleaning in- tervals and reduce production interruptions.

N According to an embodiment of the first aspect,

N the one or more transducers and/or vibrators may be

S 30 ultrasonic devices or mechanical vibrators. The trans- = ducer 1s, for example, ultrasonic device. The vibrator

T is, for example, a mechanical vibrator or knocker. The * knocker may be a high frequency knocker or a hammer. The = one or more transducers and/or vibrators may be used for 3 35 facilitating material flow. Different transducers

S and/or vibrators may be used in the system. The one or more transducers and/or vibrators may be used during cleaning operation when the system is free of the pre- treated material with added cleaning liquid. The one or more transducers and/or vibrators may also be used dur- ing the pretreatment process without the additional cleaning liquid when the biomass is inside the equip- ment. The one or more transducers and/or vibrators may be easily attached on an outer surface of the equipment.

According to an embodiment of the first aspect, the one or more transducers and/or vibrators may be arranged at least one of the following: at a lower half of the reactor, at a second half of the conveyor, and/or a first half of the blowline. One or more transducers and/or vibrators may be placed anywhere along an outer surface of the equipment. One or more transducers and/or vibrators may be placed fixedly or removably along an outer surface of the equipment. However, the one or more transducers and/or vibrators may be attached to the most critical parts of the equipment, where most of the build-ups may occur. The build-ups may be formed most, for example, at the lower half of the reactor, at the second half of the conveyor, and/or at the first half of the blowline.

According to an embodiment of the first aspect, the system may further comprise at least one attachment part comprising a belt and the one or more transducers and/or vibrators configured to be attached onto the belt, wherein the at least one attachment part may be

N configured to be attached onto the at least one of the

N following: the reactor, the conveyor, and/or the blow-

S 30 line. The one or more transducers and/or vibrators may

O be attached to the belt fixedly or removably. This may

E speed up fastening, but also installation and mainte- * nance because there may be no need to permanently fix = anything to the surface of the equipment. The belt may 3 35 be used to attach the one or more transducers and/or < vibrators removably on the outer surface of the equip- ment. The belt may have a quick clamping system, which may allow the belt to be attached or removed. This way it may be easy to move the belt from one place to an- other.

According to an embodiment of the first aspect, the at least one transducer and/or vibrator may be con- figured to be attached onto the at least one of the following: the reactor, the conveyor, and/or the blow- line. In addition to this, it may be possible to attach also at least one attachment part comprising a belt and the one or more transducers and/or vibrators onto the at least one of the following: the reactor, the con- veyor, and/or the blowline. Thus, the eguipment may have the one or more transducers and/or vibrators, and/or one or more belts attached on it.

According to an embodiment of the first aspect, the at least one attachment part may be configured to be arranged at least one of the following: at the lower half of the reactor, at the second half of the conveyor, and/or the first half of the blowline. One or more at- tachment parts may be placed along an outer surface of the equipment. They may be attached to the most critical parts of the equipment, where most of the build-ups may occur.

According to an embodiment of the first aspect, the reactor 1s a hemihydrolysis reactor. The hemihy- drolysis reactor may operate at high temperatures, for example between 120°C to 250°C. At high temperatures it

N may be beneficial to use the transducers and/or vibra-

N tors to prevent forming of the build-ups inside the

S 30 equipment and to ensure that the biomass may be removed

Q effectively.

E According to an embodiment of the first aspect, - the at least one conveyor may be a hemihydrolysis reac- = tor and/or may be configured to be at least partly lo- 3 35 cated inside the hemihydrolysis reactor. When the at

S least one conveyor is the hemihydrolysis reactor, there is no need for a separate reactor. When the conveyor is configured to be at least partly located inside the hemihydrolysis reactor, hemihydrolysis started in the hemihydrolysis reactor may continue also in the con- veyor. 5 According to an embodiment of the first aspect, the at least one conveyor may comprise at least one screw, which may be a shafted conveyor screw or a shaft- less spiral. The transducers and/or vibrators may be used with different kind of conveyors.

According to an embodiment of the first aspect, the at least one of the following: the reactor, the conveyor, and/or the blowline may comprise at least one liquid inlet for adding liquid inside the at least one of the following: the reactor, the conveyor, and/or the blowline. The liquid may be pumped through the liquid inlet inside the equipment, which may help to clean the equipment from the build-ups and/or to prevent the build-ups to stick on them. The liquid inlet may be a nozzle.

According to an embodiment of the first aspect, the liquid is at least one of the following: water, alkali, base, acid, and/or organic solvent. This may allow use of different liquids.

According to an embodiment of the first aspect, the pretreated biomass may be configured to be removed from the at least one of the following: the reactor, the conveyor, and/or the blowline for cleaning; liquid may

N be configured to be pumped into the at least one of the

N following: the reactor, the conveyor, and/or the blow-

S 30 line; the sound and/or mechanical waves may be config- = ured to be emitted, by the one or more transducers and/or

E vibrators, to remove and/or minimize build-ups; and the - liquid and the build-ups may be configured to be removed = from the at least one of the following: the reactor, the 3 35 conveyor, and/or the blowline. When the liquid is added

S into the equipment, the liquid may be exposed to sound and/or mechanical waves, such as ultrasound waves or mechanically created waves, which may create liquid pressure pulsations and local temperature increase. It may also help to clean surfaces of the equipment.

According to an embodiment of the first aspect, temperature inside the at least one of the following: the reactor, the conveyor, and/or the blowline may be from 120°C to 250°C when the biomass is configured to be treated. In high temperatures the build-ups may es- pecially be formed on a surface and the transducers and/or vibrators may be used to remove them.

According to a second aspect a method for cleaning a system for pretreatment of biomass is dis- closed. The system may comprise at least one of the following: a reactor, a conveyor, and/or a blowline; and one or more transducers and/or vibrators, wherein the method may comprise arranging one or more transducers and/or vibrators on an outer surface of the at least one of the following: the reactor, the conveyor, and/or the blowline, and creating, by the one or more transducers or vibrators, sound and/or mechanical waves inside the at least one of the following: the reactor, the at least one conveyor, and/or the at least one blowline for re- moving and/or minimizing build-ups. When the one or more transducers and/or vibrators are installed on the sur- face of the equipment, they may be used even without stopping production lines and without making any changes to the equipment. This may extend cleaning intervals and

N reduce production interruptions.

N According to an embodiment of the second as-

S 30 pect, the method may further comprises removing the pre-

O treated biomass from the at least one of the following:

I the reactor, the conveyor, and/or the blowline for - cleaning; pumping liguid into the at least one of the = following: the reactor, the conveyor, and/or the blow- 3 35 line; emitting the sound and/or mechanical waves, by the < one or more transducers and/or vibrators, to remove and/or minimize build-ups; and removing the liquid and the build-ups from the at least one of the following: the reactor, the conveyor, and/or the blowline. When the liquid is added into the equipment, the liquid may be exposed to sound and/or mechanical waves, such as ul- trasound waves or mechanically created waves, which may create liquid pressure pulsations and may help to clean surfaces of the equipment.

According to an embodiment of the second as- pect, the one or more transducers and/or vibrators may emit the sound and/or mechanical waves continuously or intermittently.

According to an embodiment of the second as- pect, the time period for emitting sound waves may be 1 second to 10 minutes. Emitting sound and/or mechanical waves periodically may facilitate removal of the build- ups. Emitting the sound waves may be done by making short impulses for a short period of time. For example, every 1 to 10 minutes there may be 1 to 3 seconds pulse when the sound waves may be emitted. With mechanical treatment emitting of the mechanical waves may be done by making short impulses for a short period of time. For example, every 1 to 10 minutes there may be one or two knocks when the mechanical waves may be emitted. For example, mechanical waves may be emitted by knocking once every one or two minutes.

BRIEF DESCRIPTION OF THE DRAWINGS

S The accompanying drawings, which are included + to provide a further understanding of the invention and = 30 constitute a part of this specification, illustrate em-

N bodiments of the invention and together with the de-

E scription help to explain the principles of the inven-

K tion. In the drawings: lo Figure 1 schematically shows an example of a

N 35 system according to an embodiment;

N

Figure 2 schematically shows an example of a conveyor comprising a shafted conveyor screw according to an embodiment;

Figure 3 schematically shows an example of the conveyor comprising a shaftless spiral according to an embodiment; and

Figure 4 shows an example method according to an embodiment.

Like references are used to designate like parts in the accompanying drawings.

DETAILED DESCRIPTION

Reference will now be made in detail to embod- iments, examples of which are illustrated in the accom- panying drawings. The detailed description provided be- low in connection with the appended drawings is intended as a description of the present examples and is not intended to represent the only forms in which the pre- sent example may be constructed or utilized. The de- scription sets forth the functions of the example and the sequence of steps or operations for constructing and operating the example. However, the same or equivalent functions and sequences may be accomplished by different examples.

According to an example embodiment, a system for pretreatment of biomass comprises an equipment and + one or more transducers and/or vibrators. The equipment

S may be at least one of the following: a reactor, a + conveyor, and/or a blowline. During acid-catalyzed pro- = 30 cessing of the biomass, such as acid hydrolysis or au-

N tohydrolysis, unwanted dark-colored solid substances

E may be formed due to degradation of carbohydrates, ex-

K tractives and condensation of lignin. These substances, lo so called organic build-up precipitates, may have high

N 35 tendency to precipitate or accumulate on the surfaces

N of the equipment walls, pipes, and screws and may demand shutdowns of a process and manual cleaning of the equipment. Ultrasonic and/or mechanical treatment may be used for the cleaning and/or prevention of the build- up precipitate on the pretreatment equipment, for exam- ple, an acid hydrolysis reactor discharging screw.

Build-up formation may be a problem in the acidic pre- treatment processes as it may negatively effect on the equipment performance and eventually might even block the reactor, pipes or screws. Therefore, periodic and unplanned shutdowns may be required to perform demanding and costly inefficient cleaning operations. Shutting down operations to manually open up and clean process equipment may be a costly practice, so the method and system for cleaning equipment without long interruption of the process may increase production efficiency and its economic performance.

Mechanical and/or ultrasonic treatment, for example, once to three times per day or per week, may be proposed for cleaning of build-up formation when the reactor is emptied of the pretreated material and addi- tional cleaning liquid is added. A mechanical and/or ultrasonic treatment system may be installed without any changes to the production equipment. Mechanical and/or ultrasonic sources may be installed outside of the eguipment. The hemihydrolysis reactor and the discharge screw may be emptied prior cleaning. Then water or cleaning liguids or chemicals may be pumped into dis- charge screw and mechanical and/or ultrasonic treatment

N may be switched on for 10-60 min, for example. After

N that the solution may be removed from the system and the

S 30 process may be continued normally until next cleaning. = The mechanical and/or ultrasonic cleaning process may

T use sound and/or mechanical vibrations to agitate a so- * lution to aid in the removal of substances from sur- = faces. The sound waves in the liquid may produce micro- 3 35 scopic implosions of bubbles that collapse on contact < with surfaces, creating a vacuum-like scrubbing action dislodging substances from the surface of the reactor screw. If alkali instead of water may be used, better cleaning effect expected to be achieved during the treatment.

Additionally, the mechanical and/or ultrasonic system may be used without stopping of the production process to prevent formation of the build-up. However, efficiency of the treatment may be reduced due to lack of solvent/water in the system.

In this specification and claims a reactor may be a pretreatment reactor, a steam explosion reactor, hydrothermal treatment reactor, or a hemihydrolysis re- actor.

In this specification and claims the term pre- treated biomass refers to biomass particles and/or lig- nocellulose particles. Preferably the composition of the pretreated biomass comprises at least one of the fol- lowing: wood particles, lignocellulose, solid lignin, soluble lignin, carbohydrates, extractives, soluble sugar monomers, and/or sugar oligomers.

According to an embodiment, the pretreated bi- omass may be pretreated wood biomass. The pretreated wood biomass may be formed in a process where wood chips may be treated by impregnation followed by hemihydrol- ysis in the hemihydrolysis reactor using high tempera- ture, steam, and pressure. The wood chips may be hard- wood chips, such as beech, birch, ash, oak, maple, chestnut, willow, or poplar chips. The wood chips may

I also be any combination or mixture of these. The im-

N pregnation may be accomplished by treating the wood

S 30 chips with an impregnation liquid. The impregnation lig- = uid may be water or acidic liquid. Preferably the im-

E pregnation liquid is sulfuric acid. The impregnated wood * chips may be transferred to hemihydrolysis reactor where = the wood chips may be subjected to hemihydrolysis reac- 3 35 tion. The hemihydrolysis reaction may be carried out by < treating the impregnated wood chips with high tempera- ture steam. The temperature in the hemihydrolysis reactor may be from 120°C to 250°C, and the pressure may be 1 - 20 bar or 2 - 16 bar, for example. Temperature of the pretreated biomass in the hemihydrolysis reactor is, for example, 120°C to 250°C. More preferably tem- perature of the pretreated biomass in the hemihydrolysis reactor is, for example, 150°C to 220°C or 185°C to 195°C. Finally the pretreated wood biomass may be trans- ferred out of the hemihydrolysis reactor by the at least one conveyor to be treated further by steam explosion so that fibers may be separated.

According to an example embodiment, an ultra- sonic device exhibits phenomenon of ultrasonic cavita- tion, wherein bubbles within a liquid medium form, ex- pand, and collapse uncontrollably due to the influence of a sufficiently pressurized ultrasonic field. This cavitation effect may be categorized into two types: steady-state and transient. The steady-state cavitation may occur gradually under continuous high-frequency ul- trasonic conditions, with the liquid bubble expanding but remaining below a critical size. Throughout this process, micro-flow generated by the changing bubble volume may induce strong eddy currents in the surround- ing medium, while dissolved gas diffusion may contribute to a small current around the bubble. The transient cavitation, on the other hand, may arise from continuous low-freguency ultrasound, which may cause rapid bubble expansion until reaching a critical size, followed by

N energetic bursting. This form of cavitation may generate

N high shear stresses and temperatures. The dynamic pro-

S 30 cesses of bubble expansion, contraction, explosion, and = implosion within the fluid medium may create extreme

E conditions pivotal in ultrasonic effects. The ultra- - sound-induced cavitation may yield numerous microbub- = bles in aqueous solutions, whose collapse produces ac- 3 35 tive intermediates, which may result mechanical and < thermal effects, for example, blast waves, high temper- atures, micro-jets, and acoustic streaming.

An example of Figure 1 shows a system 100 for pretreatment of biomass 4. The system 100 may comprise at least one of the following: a reactor, a conveyor 1, and/or a blowline 30. The system 100 may also comprise one or more transducers 40 and/or vibrators 40 config- ured to be arranged on an outer surface Sl, S2, S3 of the at least one of the following: the reactor, the conveyor 1, and/or the blowline 30. The one or more transducers and/or vibrators 40 may create sound or me- chanical waves inside the at least one of the following: the reactor, the conveyor 1, and/or the blowline 30 for removing and/or minimizing build-ups.

According to an example embodiment the one or more transducers and/or vibrators 40 may be ultrasonic devices or mechanical vibrators. The transducer is, for example, an ultrasonic device. The vibrator is, for ex- ample, a mechanical vibrator or knocker. The one or more transducers and/or vibrators 40 may be used with clean- ing liquid and/or during the pretreatment process with- out the liquid when the biomass is inside the equipment.

According to an example embodiment, the one or more transducers and/or vibrators may be arranged at least one of the following: at a lower half 21 of the reactor, at a second half 22 of the conveyor 1, and/or a first half 23 of the blowline 30. One or more trans- ducers and/or vibrators 40 may be placed anywhere along an outer surface S1, S52, S3 of the equipment. One or

N more transducers and/or vibrators 40 may be placed fix-

N edly or removably along an outer surface S1, S2, 53 of

S 30 the equipment. However, the one or more transducers = and/or vibrators 40 may be attached to the most critical

T parts of the equipment, where most of the build-ups may - occur. The build-ups may be formed most, for example,

D at the lower half of the reactor 21, at the second half 3 35 22 of the conveyor 1, and/or at the first half 23 of the

S blowline 30.

According to an example embodiment, the system 100 may further comprise at least one attachment part 24 comprising a belt 25 and the one or more transducers and/or vibrators 40 configured to be attached onto the belt 25. The at least one attachment part 24 may be configured to be attached onto the at least one of the following: the reactor, the conveyor 1, and/or the blow- line 30. The one or more transducers and/or vibrators 40 may be attached to the belt 25 fixedly or removably.

The belt 25 may have a quick clamping system, which may allow the belt 25 to be attached or removed. As seen from Figure 1 in addition to the belt 25 there may be one or more transducers and/or vibrators 40 attached to the reactor, conveyor 1, and blowline 30.

According to an example embodiment, the at least one transducer and/or vibrator 40 may be config- ured to be attached onto the at least one of the fol- lowing: the reactor, the conveyor 1, and/or the blowline 30. In addition to this, it may be possible to attach also the one or more one attachment part 24 comprising a belt 25 and the one or more transducers and/or vibra- tors 40 onto the at least one of the following: the reactor, the conveyor 1, and/or the blowline 30. Thus, the equipment may have the one or more transducers and/or vibrators 40, and/or one or more belts 25 at- tached on it.

According to an example embodiment, the at

N least one attachment part 24 may be configured to be

N arranged at least one of the following: at the lower

S 30 half 21 of the reactor, at the second half 22 of the = conveyor 1, and/or the first half 23 of the blowline 30.

T One or more attachment parts 24 may be placed along an - outer surface S1,52,53 of the equipment. = According to an example embodiment, the reactor 3 35 is a hemihydrolysis reactor.

S According to an example embodiment, the at least one conveyor 1 is a hemihydrolysis reactor and/or is configured to be at least partly located inside the hemihydrolysis reactor.

According to an example embodiment, tempera- ture inside the at least one of the following: the re- actor, the conveyor 1, and/or the blowline 30 is from 120°C to 250°C when the biomass is configured to be treated.

The hemihydrolysis reactor may comprise a hem- ihydrolysis reactor vessel 9 and at least one conveyor 1. The at least one conveyor 1 may be located at least partly inside the hemihydrolysis reactor vessel 9. Hem- ihydrolysis reaction started in the hemihydrolysis re- actor vessel 9 may continue also in the at least one conveyor 1. The hemihydrolysis reactor is an area where conditions for hemihydrolysis reaction may be present.

In the system the hemihydrolysis reaction may happen inside the hemihydrolysis reactor, which means inside the hemihydrolysis reactor vessel 9 and/or inside the at least one conveyor. In the other words, the hemihy- drolysis reaction conditions of the hemihydrolysis ves- sel 9 may be prevailed in the conveyor 1. The hemihv- drolysis reaction may regulre high temperatures, for example, 120°C - 250°C, preferably 150°C — 220 °C, more preferably 185°C — 195°C. In addition to the high tem- perature, the hemihydrolvsis reaction may require steam, and pressure of 1 - 20 bar or 2 - 16 bar, for example.

Saturated steam pressure may correspond a saturated

N steam temperature inside the reactor.

N The term "hemihydrolysis” may refer to a treat-

S 30 ment in which the impregnated and/or pretreated biomass = is treated in a reactor, for example a hemihydrolysis

E reactor with steam having a temperature of 120°C - - 250°C, 150°C — 220°C, or 185°C — 195°C. The purpose of = the treatment is to degrade and solubilize the hemicel- 3 35 lulose contained in the biomass and to break down the

S biomass structure so that the ceilulose may get acces- sible for enzymes (cellulases) and may be converted to glucose in high vields in the next treatment step after the hemihvdrolysis.

According to an example embodiment, there is a valve 26 between a conveyor 1 and a blowline 30. The valve 26 may release pressure from the conveyor 1 to blowline 30. The valve 26 may discharge the material from pressurized zone to the blowline which may have lower pressure causing the material to defiberized. The blowline 30 may lead the material from the conveyor 1 through the valve 26 to a cyclone or tank.

According to an example embodiment, the at least one of the following: the reactor, the conveyor 1, and/or the blowline 30 comprise at least one liquid inlet 20 for adding liquid inside the at least one of the following: the reactor, the conveyor 1, and/or the blowline 30. The liguid inlet 20 may be a nozzle.

According to an example embodiment, the liquid is at least one of the following: water, alkali, base, acid, and/or organic solvent. Water may comprise chem- icals, for example, sodium hydroxide (NaOH).

According to an example embodiment, the pre- treated biomass may be configured to be removed from the at least one of the following: the reactor, the conveyor 1, and/or the blowline 30 for cleaning. After that, the liguid may be configured to be pumped into the at least one of the following: the reactor, the conveyor 1, and/or the blowline 30. The sound and/or mechanical

N waves may be configured to be emitted, by the one or

N more transducers and/or vibrators 40, to remove and/or

S 30 minimize build-ups. Finally, the liquid and the build- = ups may be configured to be removed from the at least

T one of the following: the reactor, the conveyor 1, * and/or the blowline 30. = According to an example embodiment, the one or 3 35 more transducers and/or vibrators emit the sound and/or < mechanical waves continuously or intermittently.

According to an example embodiment, the con- veyor 1 is a screw, a belt, or a pipe.

The conveyor 1 may comprise a cylindrical shell 2 and a conveyor screw 3a, 3c according to examples of

Figures 2 and 3. The conveyor may comprise one or more transducers and/or vibrators 40 configured to be ar- ranged on an outer surface S2. The conveyor may also comprise one or more attachment parts 24 configured to be arranged on an outer surface S2.

The at least one conveyor 1 may be configured to be located at a bottom part of the hemihydrolysis reactor vessel 9. The at least one conveyor 1 may be configured to be located at least partly inside the hemihydrolysis reactor vessel 9. The system may comprise a plurality of conveyors 1, which may or may not be the same type of conveyors. Pretreated biomass 4 may be fed into the hydrolysis reactor vessel 9 according to arrow 10 and treated with high temperature, added steam (ac- cording to arrow 11), and pressure. A temperature inside the cylindrical shell 2 and/or in the hydrolysis reactor vessel 9 is, for example, from 120°C to 250°C. More preferably the temperature inside the cylindrical shell and/or the hydrolysis reactor vessel 9 is, for example, from 150°C to 220°C. After the hydrolysis, the hydro- lyzed pretreated biomass 4 may be removed by the at least one conveyor 1. From the at least one conveyor 1 the biomass 4 may be led through the valve 26 to the

N blowline 30 and finally out according to arrow P.

N According to an example embodiment, composi-

S 30 tion of the pretreated biomass 4 in the hemihydrolysis

O reactor vessel 9 and/or in the at least one conveyor 1

E comprises biomass particles and/or lignocellulose par- - ticles. Preferably the composition of the pretreated = biomass is a mixture of wood particles, lignocellulose, 3 35 solid lignin, soluble lignin fragments, carbohydrates, < extractives, soluble sugar monomers, and sugar oligo- mers. The pretreated biomass may comprise bigger particles, for example, cooked and crushed wood parti- cles and soluble components.

The at least one conveyor 1 according to Fig- ures 2 and 3 may be used to remove the pretreated biomass 4 from the hydrolysis reactor 9 of Figure 1.

While the conveyor 1 in Figure 1 comprises only one conveyor screw 3a, 3c within the cylindrical shell 2, the number of the conveyor screws 3a, 3c within the cylindrical shell 2 should not be considered limiting on the current disclosure. For example, in some exam- ples, multiple conveyor screws 3a, 3c may be provided within the cylindrical shell 2.

According to an embodiment, a conveyor 1 for pretreated biomass 4 is disclosed. The conveyor 1 may comprise a cylindrical shell 2 comprising an inlet 5 for receiving the pretreated biomass 4 and an outlet € whereat pretreated biomass 4 passes out of the cylin- drical shell 2. The conveyor 1 may further comprise at least one conveyor screw 3a, 3c rotatably positioned in the cylindrical shell 2 to move the pretreated biomass 4 out of the cylindrical shell 2. The at least one conveyor screw 3a, 3c and/or the cylindrical shell 2 may be configured to be at least partly coated with a coating material and/or at least partly polished.

According to an embodiment, at least part of an outer screw surface 7 of the at least one conveyor screw 3a, 3c and/or at least part of an inner shell

N surface 8 of the cylindrical shell 2 is configured to

N be coated with the coating material having electrical

S 30 charge. The coating material having electrical charge = may be a positively surface charged material or nega-

E tively surface charged material. According to an embod- - iment, the coating material having electrical charge is ob polymer. 3 35 According to an embodiment, at least part of

S the outer screw surface 7 of the at least one conveyor screw 3a, 3c and/ or at least part of the inner shell surface 8 of the cylindrical shell 2 is configured to be coated with the coating material having low adhesion tendency. With a term "low adhesion tendency” is meant ability that prevents the build-ups to stick on the surface of the shaftless spiral 3a and/or the cylindri- cal shell 2. This kind of coating material may have low adsorption ability. The coating material having low ad- hesion tendency may be polymer, ceramic, enamel, or glass. Polymer may be configured to be selected from a family of fluoropolymers Or polyaryletherketones (PAEK) . Fluoropolymer is, for example, polytetrafluoro- ethylene (PTFE) or perfluoroalkoxy alkane (PFA).

According to an embodiment, the at least one conveyor screw 3a, 3c is a shafted conveyor screw 3c, or a shaftless spiral 3a. Figure 2 show an example of the shafted conveyor screw 3c and Figure 3 show example of the shaftless spiral 3a.

An example of Figure 2 shows a conveyor 1 com- prising a shafted conveyor screw 3c. The conveyor 1 may comprise a cylindrical shell 2 comprising an inlet 5 for receiving the pretreated biomass 4 from a bottom of the hemihydrolysis reactor 9, another process, or an outlet of another conveyor. The conveyor 1 may be hemihydrol- ysis reactor itself. In that situation, the hemihydrol- ysis reaction may happen in the at least one conveyor 1 and no separate hydrolysis reactor vessel 9 is needed.

The cylindrical shell 2 may also comprise and an outlet

N 6 whereat pretreated biomass 4 passes out of the cylin-

N drical shell 2. Entering the pretreated biomass 4 is

S 30 shown with an arrow I and passing out of the pretreated = biomass 4 is shown with an arrow O. The conveyor 1 may

T further comprise at least one shafted conveyor screw 3c * rotatably positioned in the cylindrical shell 2 to move = the pretreated biomass 4 out of the cylindrical shell 3 35 2. The shafted conveyor screw 3c may comprise a shaft

S 14 and at least one helical flight 15 extending from the shaft 14. The at least one shafted conveyor screw 3c may rotate within the the cylindrical shell 2 to move the pretreated biomass 4 within the cylindrical shell 2 from the inlet 5 to outlet 6. When the shafted conveyor screw 3c is used sticky products may adhere most on the shafted conveyor screw 3c at the location where the flight 15 meets the shaft 14, on the flight back side, and on the shaft 14. The conveyor may comprise one or more trans- ducers and/or vibrators 40 configured to be arranged on an outer surface S2. The conveyor may also comprise one or more attachment parts 24 configured to be arranged on an outer surface S52.

An example of Figure 3 shows a conveyor 1 comprising a shaftless spiral 3a. The conveyor 1 may comprise a cylindrical shell 2 comprising an inlet 5 for receiving the pretreated biomass 4. The conveyor 1 may receive the pretreated biomass 4 from the bottom of the hemihydrolysis reactor 9, an outlet 6 of another con- veyor 1, or from another process. The conveyor 1 may be hemihydrolysis reactor itself. In that situation, the hemihydrolysis reaction may happen in the at least one conveyor 1 and no separate hydrolysis reactor vessel 9 is needed. The cylindrical shell 2 may also comprise an outlet 6 whereat pretreated biomass 4 may pass out of the cylindrical shell 2. Entering and passing out of the pretreated biomass 4 are shown with arrows I and O. The conveyor 1 may further comprise at least one shaftless spiral 3a rotatably positioned in the cylindrical shell

N 2 to move the pretreated biomass 4 out of the cylindrical

N shell 2. The shaftless spiral 3a does not have any shaft,

S 30 wherein the pretreated biomass 4 could stick. The inlet = support member 12 supports the shaftless spiral 3a from

T an inlet part and an outlet support member 13 supports * the shaftless spiral 3a from an outlet part allowing = it to rotate. The at least one shaftless spiral 3a may 3 35 rotate within the the cylindrical shell 2 to move the

S pretreated biomass 4 within the cylindrical shell 2 from the inlet 5 to the outlet 6. The outer screw surface 7 may comprises all the sides of the shaftless spiral 3, 3b or is a jacket around the shaftless spiral 3, 3b.

While the conveyor 1 in Figure 1 illustrates only one conveyor screw 3a, 3c within the cylindrical shell 2, the number of the conveyor screw 3a, 3c in

Figures 2 and 3 within the cylindrical shell 2 should not be considered limiting on the current disclosure.

For example, in some examples, multiple conveyor screws 3a, 3c may be provided within the cylindrical shell 2.

When the conveyor has more than one conveyor screw 3a, 3c they may clean each other.

According to an embodiment, the at least one conveyor 1 and/or blowline 30 as described above may be used for moving pretreated biomass. The at least one conveyor 1 according to Figure 2 or 3 may be used in the system as described in the Figure 1. The at least one conveyor 1 according to Figure 2 or 3 may also be used as a hemihydrolysis reactor or part of the hemihydrol- ysis reactor.

Figure 4 illustrates an example of a method for cleaning a system 100 for pretreatment of biomass 4. The system 100 may comprise at least one of the following: a reactor, a conveyor 1, and/or a blowline 30. The system may further comprise one or more transducers and/or vi- brators 40.

At operation 400, the method may comprise ar- ranging the one or more transducers and/or vibrators 40

N on an outer surface S1 ,S2 , S3 of the at least one of

N the following: the reactor, the conveyor 1, and/or the

S 30 blowline 30. = At operation 610, the method may comprise cre-

T ating, by the one or more transducers or vibrators 40, * sound and/or mechanical waves inside the at least the following: the reactor, the at least one conveyor 3 35 1, and/or the at least one blowline 30 for removing

I and/or minimizing build-ups.

Further features of the method directly result from functionalities of, for example, the system 100.

Different variations of the method may be also applied, as described in connection with the various embodiments.

The system 100 may be configured to perform or cause performance of any aspect of the method described herein.

Any range or device value given herein may be extended or altered without losing the effect sought.

Also, any embodiment may be combined with another em- bodiment unless explicitly disallowed.

Although the subject matter has been described in language specific to structural features and/or acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as examples of implementing the claims and other equiv- alent features and acts are intended to be within the scope of the claims.

It will be understood that the benefits and advantages described above may relate to one embodiment or may relate to several embodiments. The embodiments are not limited to those that solve any or all of the stated problems or those that have any or all of the stated benefits and advantages. It will further be un- derstood that reference to 'an' item may refer to one

N or more of those items.

N The steps or operations of the methods de-

S 30 scribed herein may be carried out in any suitable order, = or simultaneously where appropriate. Additionally, in-

E dividual blocks may be deleted from any of the methods - without departing from the scope of the subject matter = described herein. Aspects of any of the embodiments de- 3 35 scribed above may be combined with aspects of any of the < other embodiments described to form further embodiments without losing the effect sought.

The term 'comprising' is used herein to mean including the method, blocks, or elements identified, but that such blocks or elements do not comprise an exclusive list and a method or apparatus may contain additional blocks or elements.

Although subjects may be referred to as ‘first, ‘second’, or ‘third’ subjects, this does not necessarily indicate any order or importance of the subjects. In- stead, such attributes may be used solely for the pur- pose of making a difference between subjects.

It will be understood that the above descrip- tion is given by way of example only and that various modifications may be made by those skilled in the art.

The above specification, examples and data provide a complete description of the structure and use of embod- iments. Although various embodiments have been described above with a certain degree of particularity, or with reference to one or more individual embodiments, those skilled in the art could make numerous alterations to the disclosed embodiments without departing from scope of this specification. <t

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Claims

1. A system (100) for pretreatment of biomass (4), wherein the system (100) comprises at least one of the following: a reactor, a conveyor (1), and/or a blowline (30); one or more transducers and/or vibrators (40) configured to be arranged on an outer surface (S1,52,53) of the at least one of the following: the reactor, the conveyor (1), and/or the blowline (30), wherein the one or more transducers and/or vibrators (40) are configured to create sound or mechanical waves inside the at least one of the following: the reactor, the conveyor (1), and/or the blowline (30) for removing and/or minimizing build-ups.

2. The system (100) according to claim 1, wherein the one or more transducers and/or vibrators (40) are ultrasonic devices or mechanical vibrators.

3. The system (100) according to claim 1 or 2, wherein the one or more transducers and/or vibrators (40) are arranged at least one of the following: at a lower half (21) of the reactor, at a second half (22) of the conveyor (1), and/or a first half (23) of the blowline (30).

+ 4. The system (100) according to any one of the S preceding claims, wherein the system (100) further com- + prises at least one attachment part (24) comprising a = 30 belt (25) and the one or more transducers and/or vibra- N tors (40) configured to be attached onto the belt (24), E wherein K the at least one attachment part (24) is con- lo figured to be attached onto the at least one of the N 35 following: the reactor, the conveyor (1), and/or the N blowline (30).

5. The system (100) according to claim 4, wherein the at least one attachment part (24) is con- figured to be arranged at least one of the following: at the lower half (21) of the reactor, at the second half (22) of the conveyor (1), and/or the first half (23) of the blowline (30).

6. The system (100) according to any one of the preceding claims, wherein the reactor is a hemihydrol- ysis reactor.

7. The system (100) according to any one of the preceding claims, wherein the at least one conveyor (1) is a hemihydrolysis reactor and/or is configured to be at least partly located inside the hemihydrolysis reac-

tor.

8. The system (100) according to any one of the preceding claims, wherein the at least one conveyor (1) comprises at least one screw (3a,3c), which is a shafted conveyor screw (3c) or a shaftless spiral (3a).

9. The system (100) according to any one of the preceding claims, wherein the at least one of the fol- lowing: the reactor, the conveyor (1), and/or the blow- line (30) comprises at least one liquid inlet (20) for adding liguid inside the at least one of the following: N the reactor, the conveyor (1), and/or the blowline (30). & 3 30

10. The system (100) according to any one of n the preceding claims, wherein the liguid is at least one N of the following: water, alkali, base, acid, and/or or- = ganic solvent. ~ 3 35

11. The system (100) according to any one of N the preceding claims, wherein N the pretreated biomass (4) is configured to be removed from the at least one of the following: the reactor, the conveyor (1), and/or the blowline (30) for cleaning; liquid is configured to be pumped into the at least one of the following: the reactor, the conveyor (1), and/or the blowline (30); the sound and/or mechanical waves are config- ured to be emitted, by the one or more transducers and/or vibrators (40), to remove and/or minimize build-ups; and the liquid and the build-ups are configured to be removed from the at least one of the following: the reactor, the conveyor (1), and/or the blowline (30).

12. The system (100) according to any one of the preceding claims, wherein temperature inside the at least one of the following: the reactor, the conveyor (1), and/or the blowline (30) is from 120°C to 250°C when the biomass (4) is configured to be treated.

13. A method for cleaning a system (100) for pretreatment of biomass (4), wherein the system (100) comprises at least one of the following: a reactor, a conveyor (1), and/or a blowline (30), wherein the method comprises: arranging one or more transducers and/or vi- N brators (40) on an outer surface (S1,S2,S3) of the at N least one of the following: the reactor, the conveyor S 30 (1), and/or the blowline (30), and = creating, by the one or more transducers or E vibrators (40), sound and/or mechanical waves inside - the at least one of the following: the reactor, the at = least one conveyor (1), and/or the at least one blowline 3 35 (30) for removing and/or minimizing build-ups. O N

14. The method according to claim 12, wherein the method further comprises: removing the pretreated biomass (4) from the at least one of the following: the reactor, the conveyor (1), and/or the blowline (30) for cleaning; pumping liquid into the at least one of the following: the reactor, the conveyor (1), and/or the blowline (30); emitting sound and/or mechanical waves, by the one or more transducers and/or vibrators (40), to remove and/or minimize build-ups; and removing the liquid and the build-ups from the at least one of the following: the reactor, the conveyor (1), and/or the blowline (30).

15. The method according to claim 14, wherein the one or more transducers and/or vibrators (40) emit the sound and/or mechanical waves continuously or in- termittently. <t N O N < ? O N I a a PP 0 0 + N O N