CA1175820A - Utilization of cellulosic and lignocellulosic materials - Google Patents
Utilization of cellulosic and lignocellulosic materialsInfo
- Publication number
- CA1175820A CA1175820A CA000348089A CA348089A CA1175820A CA 1175820 A CA1175820 A CA 1175820A CA 000348089 A CA000348089 A CA 000348089A CA 348089 A CA348089 A CA 348089A CA 1175820 A CA1175820 A CA 1175820A
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- solids
- slurry
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E50/00—Technologies for the production of fuel of non-fossil origin
- Y02E50/10—Biofuels, e.g. bio-diesel
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- Preparation Of Compounds By Using Micro-Organisms (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
Method of converting lignocellulosic material to useful products such as ethanol, methanol, methane, organic acids and furfural, also producing best for use in the process and if feasible or advantageous for use outside the system;
such method comprising a two stage hydrolysis with a sensitization step between, followed by wet oxidation whereby the production of monosaccharides is maximized and their degradation is minimized; the products of hydrolysis (monosaccharides) and of wet oxidation of ligneous material left as residue from hydrolysis are converted. as by fermentation of monosaccharides, methanantion and processes of separation into useful end products such as ethanol, methane, methanol, organic acids and furfural; such method and system minimizing degradation to carbon dioxide, carbon monoxide and water and minimizing or eliminating the production of solid waste material.
Method of converting lignocellulosic material to useful products such as ethanol, methanol, methane, organic acids and furfural, also producing best for use in the process and if feasible or advantageous for use outside the system;
such method comprising a two stage hydrolysis with a sensitization step between, followed by wet oxidation whereby the production of monosaccharides is maximized and their degradation is minimized; the products of hydrolysis (monosaccharides) and of wet oxidation of ligneous material left as residue from hydrolysis are converted. as by fermentation of monosaccharides, methanantion and processes of separation into useful end products such as ethanol, methane, methanol, organic acids and furfural; such method and system minimizing degradation to carbon dioxide, carbon monoxide and water and minimizing or eliminating the production of solid waste material.
Description
~ 5~n ~ .
~` l 3This invention relates to the utilization of 4 cellulosic and lignocellulosic material to produce certain S chemicals such as ethanol and methane and to produce thermal 6 I energy which can be used within and/or outside the system.
3 ¦ The material which is subjected to the process of 9 ¦ the present invention includes all manner of cellulosic and 10 1 lignocellulosic materials such as, for example, softwoods, 11¦ hardwoods, agricultural residues such as straw and cotton 12¦ stalks, orchard trimmings and various other crops.
14¦ For convenience, such materials will be referred 15¦ herein from time to time as biQmass.
- 161 .
17 It is known that biomass may be converted by 18 ¦ hydrolysis and/or oxidation followed by fer~entation, etc.
19 ~ to useful products such as ethanol, acetic acid, methane, etc.
20 I Certain of such processes are described in a paper by 21~ Schaleger and Brink in TAPPI 61, No. 4, pages 65 to 68 (1978) 23 and in the literature cited in that paper.
r~
-
~` l 3This invention relates to the utilization of 4 cellulosic and lignocellulosic material to produce certain S chemicals such as ethanol and methane and to produce thermal 6 I energy which can be used within and/or outside the system.
3 ¦ The material which is subjected to the process of 9 ¦ the present invention includes all manner of cellulosic and 10 1 lignocellulosic materials such as, for example, softwoods, 11¦ hardwoods, agricultural residues such as straw and cotton 12¦ stalks, orchard trimmings and various other crops.
14¦ For convenience, such materials will be referred 15¦ herein from time to time as biQmass.
- 161 .
17 It is known that biomass may be converted by 18 ¦ hydrolysis and/or oxidation followed by fer~entation, etc.
19 ~ to useful products such as ethanol, acetic acid, methane, etc.
20 I Certain of such processes are described in a paper by 21~ Schaleger and Brink in TAPPI 61, No. 4, pages 65 to 68 (1978) 23 and in the literature cited in that paper.
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I ~ 1 7582() 1 It is an object of the present invention to provide 2 ¦ an integrated process whereby biomass material constituting 31 the raw feed material is subjected to a series of operations 4 I which result in hydrolysis of the cellulose and the hemi-S I celluloses and oxidation of the lignin and conversion of the 6 I hydrolytie products (monosaccharides) and oxidation products, to 7 useful chemicals such as ethanol, acetic acid and methane, such process optimizinc; the production of such end products ',' and resulting in thermal energy which can ~e used within and/or outside the process.
11 . .
12 ¦ The above and other objects of the invention will 131 be apparent from the ensuing description and the appended 14l claims.
16¦ Representative examples of biomass materials 17l susceptihle to the process of the present invention include 18 1 all manner of forest products including particularly material 19 which is otherwise waste such as saw mill residues, cull logs, products of thinning forests, sawdust, bark, etc.; it includes, 21 ll among forest products, softwoods, e.g. firs, pines, junipers, 221 cedar, Douglas firs and hemlock, hardwoods such as oak, 23 cottonwood and poplars, mountain mahogany, myrtles and 2~1 sac~ebrl1sh; aqricultural crop residues such as the straw residues o~ cereal grcl~Lns and the residues o~ other crops 26 I ,uch ~n ~:otLon orchnL~I trimmin~ls, oL~
I ~ 1 7582() 1 It is an object of the present invention to provide 2 ¦ an integrated process whereby biomass material constituting 31 the raw feed material is subjected to a series of operations 4 I which result in hydrolysis of the cellulose and the hemi-S I celluloses and oxidation of the lignin and conversion of the 6 I hydrolytie products (monosaccharides) and oxidation products, to 7 useful chemicals such as ethanol, acetic acid and methane, such process optimizinc; the production of such end products ',' and resulting in thermal energy which can ~e used within and/or outside the process.
11 . .
12 ¦ The above and other objects of the invention will 131 be apparent from the ensuing description and the appended 14l claims.
16¦ Representative examples of biomass materials 17l susceptihle to the process of the present invention include 18 1 all manner of forest products including particularly material 19 which is otherwise waste such as saw mill residues, cull logs, products of thinning forests, sawdust, bark, etc.; it includes, 21 ll among forest products, softwoods, e.g. firs, pines, junipers, 221 cedar, Douglas firs and hemlock, hardwoods such as oak, 23 cottonwood and poplars, mountain mahogany, myrtles and 2~1 sac~ebrl1sh; aqricultural crop residues such as the straw residues o~ cereal grcl~Lns and the residues o~ other crops 26 I ,uch ~n ~:otLon orchnL~I trimmin~ls, oL~
- 3 -~ ' " . . . : I
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~ l ~ ~
I ~ ! 7582() Certain embodiments of the invention are illustrated, 21 particularly for softwoods, by way of example in Figures l 3l and 2, Figure l being a simplified flow diagram and Figure 2 41 being a more detailed flow diagram. Figure 3 represents Sl preferred modification of Figure 2.
6I Referring no~ to Figure l, biomass material enters 7I the system at lO. By way of example this could be green wood 8j containins approximately equal quantities of lignocellulosic ql ~material (oven dry wood) and naturally occurring moisture.
10l This material in suitably comminuted form is introduced into ' a Eirst hydrolyzer or zone indicated by the reference numeral .
12 ll in which stage I hydrolysis is carried out. In this 13 hydrolysis unit the biomass materiai is subjected to an . Ii l4,i elevated temperature, for example, 140 to 220~C., preferably 15l about 160 to 180C. The pressure in the hydrolyzer is 16" autogenic being, for example, 75 psi gauge at 160C. (All 17,l temperatures are centigrade.) A recycle line 12 serves an 181'~ important Eunction in recycling sugars (hexoses) produced in ;~ 19 1l second stage hydrolysis. The obiect is to increase the 20 li concentration of sugars (hexoses) in an aqueous solution 21!, ~hich is routed to another part Oc the system. ~It is desirabl~
22, to ~eep the residence time in hydrolysis zonc Il as short as 231' possible consistent with ~ccompli.shinc; the desired hydxolysis.
2~l By way o~ e~ample in processing white fir at about 160C. the 25~ residence time in zone ll that qives a ma:~im~lm reduc;.ng SU~Jar 26 ! yield ~las 30 minutes and i.5 a lun~tiorl oE sever~l variables 27l including pli, paxticle size, mi~in~ eEficiency and species 2al . .
, j, _,~,, , .. l ~ ~
31 75~n 1 of plant material. Yn Table I below there is given 2 representative ranges of hemicelluloses, cellulose and 3 ligneous compositions of softwoods and hardwoods. It is
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~ l ~ ~
I ~ ! 7582() Certain embodiments of the invention are illustrated, 21 particularly for softwoods, by way of example in Figures l 3l and 2, Figure l being a simplified flow diagram and Figure 2 41 being a more detailed flow diagram. Figure 3 represents Sl preferred modification of Figure 2.
6I Referring no~ to Figure l, biomass material enters 7I the system at lO. By way of example this could be green wood 8j containins approximately equal quantities of lignocellulosic ql ~material (oven dry wood) and naturally occurring moisture.
10l This material in suitably comminuted form is introduced into ' a Eirst hydrolyzer or zone indicated by the reference numeral .
12 ll in which stage I hydrolysis is carried out. In this 13 hydrolysis unit the biomass materiai is subjected to an . Ii l4,i elevated temperature, for example, 140 to 220~C., preferably 15l about 160 to 180C. The pressure in the hydrolyzer is 16" autogenic being, for example, 75 psi gauge at 160C. (All 17,l temperatures are centigrade.) A recycle line 12 serves an 181'~ important Eunction in recycling sugars (hexoses) produced in ;~ 19 1l second stage hydrolysis. The obiect is to increase the 20 li concentration of sugars (hexoses) in an aqueous solution 21!, ~hich is routed to another part Oc the system. ~It is desirabl~
22, to ~eep the residence time in hydrolysis zonc Il as short as 231' possible consistent with ~ccompli.shinc; the desired hydxolysis.
2~l By way o~ e~ample in processing white fir at about 160C. the 25~ residence time in zone ll that qives a ma:~im~lm reduc;.ng SU~Jar 26 ! yield ~las 30 minutes and i.5 a lun~tiorl oE sever~l variables 27l including pli, paxticle size, mi~in~ eEficiency and species 2al . .
, j, _,~,, , .. l ~ ~
31 75~n 1 of plant material. Yn Table I below there is given 2 representative ranges of hemicelluloses, cellulose and 3 ligneous compositions of softwoods and hardwoods. It is
4 the hemicelluloses (galactoglucomannans and glucurono~ylans) sl and the rea~ily accessible amorphous l-egions of the c~llulosc 61 that are hydrolyzed in the first hydrolysis unit to simple 7 , sugars (hexoses and pentoses) which in turn are converted to 81 useful products such as ethanol, methane, methanol, acetic 91 acid and furfural.
T~BLE I .
~ 121 13 GymnospermsAngiosperms ~41 (Softwoods?( _ dwoods and Grasses) 15¦ Cellulose 42 + 3%43 + 3%
16¦ Galactoglucomannans 20 + 5~ 4 1- 2%
1 17 ¦ Glucurono~ylans12 ~ 3~ 27 + 7%
13 I Lignins30 -~ 53 25 + 5 20 ¦ The effluent product from hydrolyzer ll, which is 21 I in the form of a slurry, is introduced thlough line 13 into 22 ¦ a separator l~ whicll may be any of several well ~no~7n types 23 ¦ such as centrifucJes or filters that are preferably continuously 2~ ¦ opera~ cJ types and ~re capab.l.e of sep~rati.ng soli~s from 25 ¦ liqllids. (P~eEerellce i.s made ~hroucJhout to "lines" and to flow of m.ll:erial throu(;h "lines". In the preEerred practice 2~
29 .
33l . .
,,.
_ 5 _ .
~ ~ 75~2~!
1 of the invention there are in fact conduits through which 21 materials flow, preferably in a continuous manner. However, 31 the effluent from a given piece of equipment may be stored 4l and introduced into the next piecc of equipment as needed.) 51l The liquid leaves by way of line 15 and the solids by way of 61 line 16 A recycle line 17 is sho~n ~hich is primarily for 7I water as needed in the separator 14.
8 I .
9 I The slurry of solids separated in separator 14 is 10 , then introduced into a sensitizer unit 18. There are also introduced into the sensitizer unit ~ or air and acid 121 as needed through lines 19 and 20. The slurry of solids 13jl separated in separator 14,then passes through a refiner 16a 14 I which serves to refine the solids so as to make them quite l~ ¦ fine, incxease their surface area and make them more amenable l6~ in the ~e,ct step which is carried out in sensitizer 18. Air 17 I or oxygen and acid are introduced into sensitizer 18 as 18 I needed through lines 19 and 20, respectively. In the 19 , sensitizer 18 important variables are temperature, residence 201 time, pH, rate of oxygen introduction, degree of dispersion 21 of the oxy~en and the particle size of the lignocellulosic 22 ; material. These variables are interacting and are optimiæed 231 to ma:cimize production of reduciny sugars. A temperature,,in 24j the ran~3e oi 1~10 to 220C~, preferably 160 to ~00C., is 2511 m.lirlt~-lined in the sensi.ti~er unit 18 and the input of air is 26~ ~dml~ed ~t a pr~ssuro oE 50 ~o 400 p~i tb-ve n~togolic 2~ , ' , , 3211 ' ' ' ' ' . ' ' .
- 6 ' , , ~ ~ j :~ I ~ 7~82(~
~ `1 . . ~,,, 1 ¦ pressure of the system in a manner to give fine dispersion and 2 ¦ in an amount o~ 0.2 to 4.0 grams of oxygen per minute per kilogxam of biomass on an oven dried ~O.D.) basis. The acid 4¦ used m~y be ~ mineral acid or it may be an organic acid or acids produced in the process itself ~hich, being one or more 61 of the end products of the system, does not require removal 7 as a waste material but rather is a marketable end product.
8I F u r th e r, nitric acid may be an acid of preferance since ~' 91 it has the advantage that nitrogen compounds derived from the 10¦ nitric acid provide a nutrient for the fermentation step. By 3 11 way of example white fir ~ood of particle size minus -2 * 4, 12¦ after treatment in hydrolysis zone ll, was sensitized by 13¦ heating a slurry at pH 2.l and 170C. for 60 minutes while 41 sparging with air at a rate of l~0 gram of oxygen per minute , 15¦ per kilogram o~ o.D. pre-hydrolyzed wood. The sensitized G' 16l solids and accompanying li~uid are transferred through line 25 I7¦ to a stage II hydrolysls unit i6 in which a temperature in~
1 18¦ the range of~160~to 240C., preferably app7-oximately 180 19 ¦ to 220~C. i5 maintalned. Spent gas is removed through line 27~, ,r 20 ¦ such being rlitrogen, unconsumed oxygen, other constituents . I ~ . i,:
21 ¦ o~ the air and any gas, such as carbon dioxide and carbon~
22 ¦ monoxide, produced in the sensitizer.
. . . ~.
~ 7 - ~' ~
~ ~ ~ ~:
I ! 7 5 8 2 () . .
~`` ., 1 Heat necessary for the hydrolysis stages including 2 I sensitization may be supplied from a source external to the 3 ' system but preferably steam generated in the system itself is ` 4 ¦1 used as described hereinafter with reference to Figure 2. i~
S¦l Also the flow of materials is designed to optimize the use of 61' heat exchange in ord~r to minimize the steam requirements of 7 , the system. ~ ~;
8 ¦ ~;
9 The product of the stage II hydrolysis, which is in 101l the form of a slurry, proceeds by way of line 28 to a separator 29 which may~be similar to the separator l4. Water 1211 as needed for dlsplacement or other types of washing solids, i ;
1311 and for slurrying of solids in the operation of the separator i ~ 14 ¦¦ is provided through recycle line 30. The liquid effluent lSI~ (an aqueous solution of sugar~, ~oth hexoses and pentoses, ~ 16 ha~ing a concentration ty~pically of about l to 10% ol reducLng .'~1 17 1 sugars) leaves by way of line 12 as recycle material to go to 18 the stage I hydrolysis un1t. The separated solids ~in the , 19 form of a slurry) proceed~by way of line 31 to a wet oxidation step described hereina~ter.
21 ~
22~ An il~portant reature of the invention is the recycle ;' 23 o~ liquld material erom the separator 29 by way o~ line 12 to 24 the first hydrolysls unlt 11. The ~irst hydrolysis uni~
functions primarily to hydrolyze hemicelluloses, which are '~ 26¦ more readily hyclrolyzed than cellulose. Tlle hydrolyisis ;i 27 -31 .
32 ;
~ 1 7 5 ~ 2 ~) 1 products are hexoses and pentoses. Cellulose is hydrolyzed 2 I in unit 26 (aided by the pretreatment in sensitization unit 13), 3I the hydrolysis product being predominantly glucose. By reason 41 of the recycle throug}l line 12, the concentration of mono- ¦
51~ saccharides routed to other parts of the system through line 15 61, is considerably increased.
7,, 8~ As a preferred alternative, the recycle hydrolysis 9l may pass from line 12 to line 12a, through hydrolyzer 11 10' countercurrently to the biomass feed material passing through this hydrolyzer an~ our through line 12b to line 15.
The solid material is separated in separator 29 as 14l a washed slurry and passes by way of line 31 to a wet oxidizing 15 ¦1 unit 32 into ~hich air is delivered through line 33. The wet 16jl oxidation step carried out in the unit 32 may be, for example, 17l, that described in Brink U.S. Patent 3,562,319. The process i8ll is exothernic and a steam coil (not shown) may be provided to 19 1l heat boiler feed water and generate steam. Gas leaves the ~ 201l wet oxidation unit through line 42, such being unconsumecl 1 21 jl oxygen, other eomponents of the air and carbon monoxide and 22 1l carbon dio.cide procluced in the wet oxidation unit. The product 2~ll of wet oxic1ation, whlch is in the form of a slurry, leaves 2~1j throug}l a line 43 and ;s introduced into a .;ep~ration unit 2511 or units ~4 in which by a process or succession of processes 2hll such ~s solvent cxtractioll, etc. useful end products such as Ij . .
27 1 acetic acid, fonnic ac~d, furfural and rnethanol are scparated 28,1 arld may be further separated in fr~ctiona~ioll Ull.it or units 45.
29 ~
30~ . .
311 . ' , ~:
~ i 7~82~3 1 ~he principal function of the irst hydrolysis unit ll is to hydroly~e hemicelluloses to simple sugars 3 (he~oses such as glucose, mannose and c~alaetose and pentoses 4l such as xylose and arabinose) and to complete hydrolysis of oligomers introduced into this unit with hydrolysate from 6~ the second hydrolysis unit througll line 12 or lines 12 and 12a.
7 1l The hemicelluloses are the ~nost easily hydrolyzed constituents 8jl of lignocellulose. The proportions of he~oses and pentoses 9,~ depends upon the plant (biomass) material used as raw material lOj as indicated in Table I above. The function of the seeond stage hydrolysis unit 2~ is to hydroly~e the eellulose to .
1211 glucose and for that purpose a higher temperature and higher 13j'i acidity, i.e. higher hydrogen ion concentration, are needec.
141j The f~nction of the sensitizer unit 18 is to pre-eondition 15¦j the cellulose with the result, as ~e have discovered, of 16 I increasing greatly the rate of hydrolysis and substantially 17 incr~asing the yield of glucose. The unction of the wet 18 , pxidation unit 32 is to brea]c down -the lignin to water soluble 19 organie fragments. In each of the units 11 (first stage 20l~ hydrolysis), 18 (sensitization), 26 (second stage hydrolysis) 21¦~ and 32 (wet oxidation) the purpose is to convert a fraction ~2 li o the blomass to products ~hich can in turn be eonverted by 23~ metllods such as fe~rlnerltatioll, extraction, fractionation and ~l met:llclllation t:o usc-flll encl prod-lcts sucll as ethano1, ~cetie 2~ acid, forlllic acicl, furEural, methanol and rnethane. It is an 26~j object of the invellltion to so carry out the process that the 27ll yield o thesc elld procluets is higll, the concentration of ~ugc1rs 281 introduced into the fennentatioll step is high, and the production 291 of o~idative products such as C02, CO alld degradation produets 30i of ].ittle value are minimi~ed. To thaf: end in each of the ~, ~ ' , ' ' ''' .
- 10 ~
.;., . .. ~ , :
. ~ 17~2~) ~¦ units 11 19, 26 and 32 the residence time and temper~ture are 21 balanced so that end products of little or no value are I minimized. We have found that at the temperaturcs indicated 41I residence time of the biomass or partiallv conver~ed bion~ass
T~BLE I .
~ 121 13 GymnospermsAngiosperms ~41 (Softwoods?( _ dwoods and Grasses) 15¦ Cellulose 42 + 3%43 + 3%
16¦ Galactoglucomannans 20 + 5~ 4 1- 2%
1 17 ¦ Glucurono~ylans12 ~ 3~ 27 + 7%
13 I Lignins30 -~ 53 25 + 5 20 ¦ The effluent product from hydrolyzer ll, which is 21 I in the form of a slurry, is introduced thlough line 13 into 22 ¦ a separator l~ whicll may be any of several well ~no~7n types 23 ¦ such as centrifucJes or filters that are preferably continuously 2~ ¦ opera~ cJ types and ~re capab.l.e of sep~rati.ng soli~s from 25 ¦ liqllids. (P~eEerellce i.s made ~hroucJhout to "lines" and to flow of m.ll:erial throu(;h "lines". In the preEerred practice 2~
29 .
33l . .
,,.
_ 5 _ .
~ ~ 75~2~!
1 of the invention there are in fact conduits through which 21 materials flow, preferably in a continuous manner. However, 31 the effluent from a given piece of equipment may be stored 4l and introduced into the next piecc of equipment as needed.) 51l The liquid leaves by way of line 15 and the solids by way of 61 line 16 A recycle line 17 is sho~n ~hich is primarily for 7I water as needed in the separator 14.
8 I .
9 I The slurry of solids separated in separator 14 is 10 , then introduced into a sensitizer unit 18. There are also introduced into the sensitizer unit ~ or air and acid 121 as needed through lines 19 and 20. The slurry of solids 13jl separated in separator 14,then passes through a refiner 16a 14 I which serves to refine the solids so as to make them quite l~ ¦ fine, incxease their surface area and make them more amenable l6~ in the ~e,ct step which is carried out in sensitizer 18. Air 17 I or oxygen and acid are introduced into sensitizer 18 as 18 I needed through lines 19 and 20, respectively. In the 19 , sensitizer 18 important variables are temperature, residence 201 time, pH, rate of oxygen introduction, degree of dispersion 21 of the oxy~en and the particle size of the lignocellulosic 22 ; material. These variables are interacting and are optimiæed 231 to ma:cimize production of reduciny sugars. A temperature,,in 24j the ran~3e oi 1~10 to 220C~, preferably 160 to ~00C., is 2511 m.lirlt~-lined in the sensi.ti~er unit 18 and the input of air is 26~ ~dml~ed ~t a pr~ssuro oE 50 ~o 400 p~i tb-ve n~togolic 2~ , ' , , 3211 ' ' ' ' ' . ' ' .
- 6 ' , , ~ ~ j :~ I ~ 7~82(~
~ `1 . . ~,,, 1 ¦ pressure of the system in a manner to give fine dispersion and 2 ¦ in an amount o~ 0.2 to 4.0 grams of oxygen per minute per kilogxam of biomass on an oven dried ~O.D.) basis. The acid 4¦ used m~y be ~ mineral acid or it may be an organic acid or acids produced in the process itself ~hich, being one or more 61 of the end products of the system, does not require removal 7 as a waste material but rather is a marketable end product.
8I F u r th e r, nitric acid may be an acid of preferance since ~' 91 it has the advantage that nitrogen compounds derived from the 10¦ nitric acid provide a nutrient for the fermentation step. By 3 11 way of example white fir ~ood of particle size minus -2 * 4, 12¦ after treatment in hydrolysis zone ll, was sensitized by 13¦ heating a slurry at pH 2.l and 170C. for 60 minutes while 41 sparging with air at a rate of l~0 gram of oxygen per minute , 15¦ per kilogram o~ o.D. pre-hydrolyzed wood. The sensitized G' 16l solids and accompanying li~uid are transferred through line 25 I7¦ to a stage II hydrolysls unit i6 in which a temperature in~
1 18¦ the range of~160~to 240C., preferably app7-oximately 180 19 ¦ to 220~C. i5 maintalned. Spent gas is removed through line 27~, ,r 20 ¦ such being rlitrogen, unconsumed oxygen, other constituents . I ~ . i,:
21 ¦ o~ the air and any gas, such as carbon dioxide and carbon~
22 ¦ monoxide, produced in the sensitizer.
. . . ~.
~ 7 - ~' ~
~ ~ ~ ~:
I ! 7 5 8 2 () . .
~`` ., 1 Heat necessary for the hydrolysis stages including 2 I sensitization may be supplied from a source external to the 3 ' system but preferably steam generated in the system itself is ` 4 ¦1 used as described hereinafter with reference to Figure 2. i~
S¦l Also the flow of materials is designed to optimize the use of 61' heat exchange in ord~r to minimize the steam requirements of 7 , the system. ~ ~;
8 ¦ ~;
9 The product of the stage II hydrolysis, which is in 101l the form of a slurry, proceeds by way of line 28 to a separator 29 which may~be similar to the separator l4. Water 1211 as needed for dlsplacement or other types of washing solids, i ;
1311 and for slurrying of solids in the operation of the separator i ~ 14 ¦¦ is provided through recycle line 30. The liquid effluent lSI~ (an aqueous solution of sugar~, ~oth hexoses and pentoses, ~ 16 ha~ing a concentration ty~pically of about l to 10% ol reducLng .'~1 17 1 sugars) leaves by way of line 12 as recycle material to go to 18 the stage I hydrolysis un1t. The separated solids ~in the , 19 form of a slurry) proceed~by way of line 31 to a wet oxidation step described hereina~ter.
21 ~
22~ An il~portant reature of the invention is the recycle ;' 23 o~ liquld material erom the separator 29 by way o~ line 12 to 24 the first hydrolysls unlt 11. The ~irst hydrolysis uni~
functions primarily to hydrolyze hemicelluloses, which are '~ 26¦ more readily hyclrolyzed than cellulose. Tlle hydrolyisis ;i 27 -31 .
32 ;
~ 1 7 5 ~ 2 ~) 1 products are hexoses and pentoses. Cellulose is hydrolyzed 2 I in unit 26 (aided by the pretreatment in sensitization unit 13), 3I the hydrolysis product being predominantly glucose. By reason 41 of the recycle throug}l line 12, the concentration of mono- ¦
51~ saccharides routed to other parts of the system through line 15 61, is considerably increased.
7,, 8~ As a preferred alternative, the recycle hydrolysis 9l may pass from line 12 to line 12a, through hydrolyzer 11 10' countercurrently to the biomass feed material passing through this hydrolyzer an~ our through line 12b to line 15.
The solid material is separated in separator 29 as 14l a washed slurry and passes by way of line 31 to a wet oxidizing 15 ¦1 unit 32 into ~hich air is delivered through line 33. The wet 16jl oxidation step carried out in the unit 32 may be, for example, 17l, that described in Brink U.S. Patent 3,562,319. The process i8ll is exothernic and a steam coil (not shown) may be provided to 19 1l heat boiler feed water and generate steam. Gas leaves the ~ 201l wet oxidation unit through line 42, such being unconsumecl 1 21 jl oxygen, other eomponents of the air and carbon monoxide and 22 1l carbon dio.cide procluced in the wet oxidation unit. The product 2~ll of wet oxic1ation, whlch is in the form of a slurry, leaves 2~1j throug}l a line 43 and ;s introduced into a .;ep~ration unit 2511 or units ~4 in which by a process or succession of processes 2hll such ~s solvent cxtractioll, etc. useful end products such as Ij . .
27 1 acetic acid, fonnic ac~d, furfural and rnethanol are scparated 28,1 arld may be further separated in fr~ctiona~ioll Ull.it or units 45.
29 ~
30~ . .
311 . ' , ~:
~ i 7~82~3 1 ~he principal function of the irst hydrolysis unit ll is to hydroly~e hemicelluloses to simple sugars 3 (he~oses such as glucose, mannose and c~alaetose and pentoses 4l such as xylose and arabinose) and to complete hydrolysis of oligomers introduced into this unit with hydrolysate from 6~ the second hydrolysis unit througll line 12 or lines 12 and 12a.
7 1l The hemicelluloses are the ~nost easily hydrolyzed constituents 8jl of lignocellulose. The proportions of he~oses and pentoses 9,~ depends upon the plant (biomass) material used as raw material lOj as indicated in Table I above. The function of the seeond stage hydrolysis unit 2~ is to hydroly~e the eellulose to .
1211 glucose and for that purpose a higher temperature and higher 13j'i acidity, i.e. higher hydrogen ion concentration, are needec.
141j The f~nction of the sensitizer unit 18 is to pre-eondition 15¦j the cellulose with the result, as ~e have discovered, of 16 I increasing greatly the rate of hydrolysis and substantially 17 incr~asing the yield of glucose. The unction of the wet 18 , pxidation unit 32 is to brea]c down -the lignin to water soluble 19 organie fragments. In each of the units 11 (first stage 20l~ hydrolysis), 18 (sensitization), 26 (second stage hydrolysis) 21¦~ and 32 (wet oxidation) the purpose is to convert a fraction ~2 li o the blomass to products ~hich can in turn be eonverted by 23~ metllods such as fe~rlnerltatioll, extraction, fractionation and ~l met:llclllation t:o usc-flll encl prod-lcts sucll as ethano1, ~cetie 2~ acid, forlllic acicl, furEural, methanol and rnethane. It is an 26~j object of the invellltion to so carry out the process that the 27ll yield o thesc elld procluets is higll, the concentration of ~ugc1rs 281 introduced into the fennentatioll step is high, and the production 291 of o~idative products such as C02, CO alld degradation produets 30i of ].ittle value are minimi~ed. To thaf: end in each of the ~, ~ ' , ' ' ''' .
- 10 ~
.;., . .. ~ , :
. ~ 17~2~) ~¦ units 11 19, 26 and 32 the residence time and temper~ture are 21 balanced so that end products of little or no value are I minimized. We have found that at the temperaturcs indicated 41I residence time of the biomass or partiallv conver~ed bion~ass
5 I should be as short as possibl~ generally not more that about
6 30 minutes and frequently much less.
7 I .
8 I The first stage hydrolysis the sensitization and
9 I the second stage hydrolysis are shown as being carried ou-t in separate pieces of equipment. IIowever they may be caxried ll I out in a continuous tube.
13 ¦ The circulation of solids out of wet o~idation unit 32 14 throug~ lines 43 76 and 79 is optimized to maximize production 15I of acetic acid and other organic products.
16~
17 Reverting now to the separation of a liquid phase l8¦ ~a solution of sugars) from the hydrolysis sensitization part lq of the system the liquid leaviny separator 14 through line 15 is routed to a liquid extraction unit 47 The extract is 21 routed by line 48 to the Liquid extraction unit 44 mentioned 22 above, ln whicIl acicls etc. are e~tracted and a~-e then 23 separated as described above. Solvellt: for these extractions 24 enters througll line 49. The raffirIate rrom unlt 47 passes by way of line S0 to fermentation unit 5l into which necessary 2O~ acld;tives such ag yC!aSt~ nutrients and/or bases to neutralize 27I the aqueous medium to a desired pll for fermelltation are 28 I introduced through line 52. Solvent extraction in unlt ~7 29 ~ removes substances SUCII as furfural which ~ould interfere 31 ~ h fermentation in UIIit 510 -' . '' . ' .
- ].1 - ' :
' !
~ 1 7 ~ 8 2 ~
Excess yeas~ and o~her solids (if any) leave fermentation uni~ 51 by line 53 and CO2 by line 54. The solids may be used as cattle feed, for example. The clarified liquid or beer leaves u~it 51 through line 55 to Eractionation unit 60.
Ethanol, e.g. 95% ethanol leaves the system through line 64 as one of the end products. The still bottoms from rectification unit 6Q pass by way of line 62 to methanation unit 63.
Methanation may be carried out by any of several well known processes resulting in CO2 and methane which leave by way of line 64a and may be separated. Liquid containing some solids lea~es methanation unit 63 through line 65 and is separated, in separator 66, into commercially pure water (i.e. water which can be used in the system~ and a dilute slurry of solids that `~ have passed through the system without being solubilized and/or have been produced-in the system as yeast or bacteria in the biochemical processing steps. Part of the water is recycled through lines 17 and 30 as described above and part is removed from the syste~ through line 68. Make-up water is added as ~- needed at any convenient point in the system, preferably as wash water to separator 29. The dilute slurry passes through line 75 and is recycled to wet oxidation unit 32. Raffinate from liquid extraction unit 44 passes by way of line 76 to separator 77 where aqueous solution is separated and passed to methanation unit 63 through line 78 and a dilute slurry is separated and passed to wet oxidation unit 32 by way of line 79.
pc/cb , . . .
~ ~s - . 1 ~3 i .1 75 :' I
I
. .
1 ¦ Tlle procedure described above with reference to 2 ¦ Figure 1 is applicahle to both .softwoods and hardwoods.
l30wever, when the raw feed material is a hardwood, i.e.
4 , angiospenns having low proportion of hemicelluloses which S contain hexoses, the hydrolysates from first and second stage 6 hydrolyses may be processed separately. For example, the 71 hydrolysate passing from separator 14 through line 15 ~which 81 is rich in pentoses) may be processed to recover furfural, 9 ~ hile the hydrolysate in line 12 (which is rich in glucose)
13 ¦ The circulation of solids out of wet o~idation unit 32 14 throug~ lines 43 76 and 79 is optimized to maximize production 15I of acetic acid and other organic products.
16~
17 Reverting now to the separation of a liquid phase l8¦ ~a solution of sugars) from the hydrolysis sensitization part lq of the system the liquid leaviny separator 14 through line 15 is routed to a liquid extraction unit 47 The extract is 21 routed by line 48 to the Liquid extraction unit 44 mentioned 22 above, ln whicIl acicls etc. are e~tracted and a~-e then 23 separated as described above. Solvellt: for these extractions 24 enters througll line 49. The raffirIate rrom unlt 47 passes by way of line S0 to fermentation unit 5l into which necessary 2O~ acld;tives such ag yC!aSt~ nutrients and/or bases to neutralize 27I the aqueous medium to a desired pll for fermelltation are 28 I introduced through line 52. Solvent extraction in unlt ~7 29 ~ removes substances SUCII as furfural which ~ould interfere 31 ~ h fermentation in UIIit 510 -' . '' . ' .
- ].1 - ' :
' !
~ 1 7 ~ 8 2 ~
Excess yeas~ and o~her solids (if any) leave fermentation uni~ 51 by line 53 and CO2 by line 54. The solids may be used as cattle feed, for example. The clarified liquid or beer leaves u~it 51 through line 55 to Eractionation unit 60.
Ethanol, e.g. 95% ethanol leaves the system through line 64 as one of the end products. The still bottoms from rectification unit 6Q pass by way of line 62 to methanation unit 63.
Methanation may be carried out by any of several well known processes resulting in CO2 and methane which leave by way of line 64a and may be separated. Liquid containing some solids lea~es methanation unit 63 through line 65 and is separated, in separator 66, into commercially pure water (i.e. water which can be used in the system~ and a dilute slurry of solids that `~ have passed through the system without being solubilized and/or have been produced-in the system as yeast or bacteria in the biochemical processing steps. Part of the water is recycled through lines 17 and 30 as described above and part is removed from the syste~ through line 68. Make-up water is added as ~- needed at any convenient point in the system, preferably as wash water to separator 29. The dilute slurry passes through line 75 and is recycled to wet oxidation unit 32. Raffinate from liquid extraction unit 44 passes by way of line 76 to separator 77 where aqueous solution is separated and passed to methanation unit 63 through line 78 and a dilute slurry is separated and passed to wet oxidation unit 32 by way of line 79.
pc/cb , . . .
~ ~s - . 1 ~3 i .1 75 :' I
I
. .
1 ¦ Tlle procedure described above with reference to 2 ¦ Figure 1 is applicahle to both .softwoods and hardwoods.
l30wever, when the raw feed material is a hardwood, i.e.
4 , angiospenns having low proportion of hemicelluloses which S contain hexoses, the hydrolysates from first and second stage 6 hydrolyses may be processed separately. For example, the 71 hydrolysate passing from separator 14 through line 15 ~which 81 is rich in pentoses) may be processed to recover furfural, 9 ~ hile the hydrolysate in line 12 (which is rich in glucose)
10~ may be subjected to fermentation. However, as explained elsewhere in this specification, the hexose rich hydrolysate .
12 and the pentose rich hydrolysate may be combined (as they 13¦ are in Figure 1) and subjected to simultaneous fermentation 14 (after suitable processing to remove substances which 15¦ interfere with fe~nentation) to ethanol, employing a suitable 16 I mixture of micro-organisms, or the combined hydrolysa1:es may 17¦ be subjected to sequential fermentation of hexoses and 18 pentoses. Alternately, solids in the slurry of streams 75, 19 ¦ having nutritive value can be separated for appropriate 20 ¦ utili~ation with separated water used as described above.
`21 23 :
27 ' ~
31 t /, ,.
32 ~
i! ' ' S ` .
- 12a -~, , , . . . . .
~:: : :~ ~ : :
i~ 1 7 ~ ) ~ , .
¦~ l Referring llOW to Figure 2, biomass, for example, 2 green wood from trees or saw mill residues in suitably 3 comminuted form enters the system at 100 and is received in 4 a storage hopper 101. The comminuted wood then proceeds along , the path 102 to a first hydrolyzer 103. This is the same hydrolyzer as shown at 11 in Figure 1 and the temperature `~i 7 and residence time are as described in connection with that 8 figure. Hydrolysate solution also enters the hydrolyzer 103 9 through the line 104 and recycle wash water tlirough the line 6 i 10 104a. The effluent leaves the hydrolyzer through line 105 ll and passes through a heat exchanger 106. Typically, in the 12 ¦ case of wood from trees, this effluent will consist of an 13¦ aqueous phase having dissolved therein approximately 30 to 35%
14¦ of the dry weight of the wood, the remaining 65 to 70~i being 151 solids. The~effluent slurry leaves the heat exchancJer 106 16j twhere it is cooled somewhat below the temperature prevailing 17 in hydroly~er 103) through line 107 and is introduced into i 18 ¦ a separator 108~which serves to separate liquid phase from 19 solids. In this instance and in others like it, the separated 20 liquid, apart from traces of solids is entirely a liquid ;~
21 phase containing dissolved solids~ The separated "sollds" ~ , i~i 22 I are actually a slurry of undissolved solids and liquid, the , ~ ~ .
23 ¦ liquid being the same as the separated liquid phase. As is ,!:' ' 24 ¦ well ~nown, the "solids" must contain a large proportion oP
1 25 ¦ liquid to be amen~ble to pumpiny through pipes and otherwise ~: 26 ¦ handling.
` 27 `~ 2~ ~' 31 ~
32 .
!~
~ ~758~n I The liquid leaves by line 109 and the solids by 2 I line 110. The separator 108 may be of conventional variety 3 ' such as, for example, one or more centrifuges. The solids 4' leaving through line 110 will typically consist of about ~O
S to 85~ aqueous phase and 40 to 15% solids, and is introduced 6 into a separator-washer 111. Two strearns of water frorn a 7 recycle stream referred to hereinafter are introduced into 8 I the separator-washer 111 through lines 116 and 117. The 9 I separator-washer 111 may be of well known construction, e.g.
a washing centrifuge or drum filter. The portion of the water introduced through line 116 serves to displace and remove, .
12l through line 118, a major proportion of the sugar content of 13j the aqueous phase introduced through line 110. This solution, 141 after passing through a heat exchanger 119, passes into line lS 1 104a for recycling to the first hydrolyzer 103. Water intro-16 duced in line 117 dilutes the washed solids in 111 to a l7 ! transportable slurry carried in line 120. ~ slurry of solids 18 passes by way of line 120 through heat exchanger 106 to an 19 ~ agitator 121 and then into sensitizer 122 into which air or 20 I oxygen is introduced through line 123 from a source 123a. The 2l I function of the agitator~ is to provide an intimate 22 i dispersion of air, solids and liquid which then passes by 231 way of linc 12~ into sensitizer 122, ~Ihich corresponds to the 24 sensitizer 1t3 in Figure 1 and in wllich the conditions of 251 tempcrature a~ld tirnc of re~sidence are as described above in 26 I con!lectioll Wittl Figure 1. Acid as needed to control pEI in 27 I the sensltizer 122 and in the secolld stage hydrolyzer 135 28 (see belo~) enters throuyh line 130a directly lnto line 131 29 , and also by way of line 130b to a~3itat.or 121.
30 I "
3l 3~
~ 14 -_ ! ;`
.
~, .
: - -f~ ~7582(~ ~
l I Spent gas (largely nitrogen, carbon dioxide and 2 other, minor components of air) is vented from the sensitizer 3¦ through line 130 to the atmosphere or if desired to any 4¦ desired ~crubber before ventillg to the atmosphere. A slurry 5 I of solids and aqueous liquid leave the sensitizer 122 through 6 line 131 ~nd a cellulose hydrolyzer agitator 132 to a heat 7 ! exchanger 133 where it is heated to the temperature of hydrolysis ` 8 i and then proceeds by way of line 134 to a second (cellulose) 1 9 j hydrolyser 135 corresponding to the second hydrolyzer 26 in lOI Figure l and in WhiC}I temperature and time of residence are -llll as described in connection with Figure 1. As explained above, .
12ll in this hydrolyzer the cellulose is substantially broken down 13l into glucose. To the extent that cellulose is hydrolyzed to 14 j oligomers, these are further hydrolyzed to glucose by virtue lS of being recycled through line 104 to hydrolyzer 103. A
l6 slurry (an aqueous solution of glucose and solids, largely 17 lignin) passes by way of line 136 through a heat exchanger 137 18 into a separator 1380 A portion, typically about 70 to 903 19 of the aqueous phase ~a solution of glucose) passes by way of ~ 20 line 139 through heat exchanger 137 to line 104 for recycling.
:: 21 1l (As described about in connection with Figure 1, this 22 ll recycle hydrolysate may be passed through hydrolyzer 103 ~3 ll counterc~uI rently to the hiomass ~eed material.) ~ slurry of 2~, sol.ids (largely lignill) and aqueous phase passes through line 140 lnto 5eparator-washer 1.4]. into which two streams 2261 f water enter by way of lines 142 and 143. The wasll stream 28 ' 29 ~ .
32 .
. i - .l5 -., ' i': ' ''`~ , .
~ 17~82n entering through line 142 carries wi-th it a major portion of the aqueous phase which displaces the major part of the hydrolysate remaining ~ith the insoluble ligneous residue.
The displaced solution then passes by way of line 144 to line 104. The water entering through line 143 serves to dilute the slurry of solids and contained liquid so that it can be readily passed through line 145 to join another stream (described hereinbelow) to a line 147, by means of junction 146, then through heat exchanger 148 and line 149 into wet oxidation ~ 10 unit 150. Wet oxidati.on unit 150 is the same unit as shown at : 32 in Figure 1 and the conditions prevailing therein as regards temperature, time of residence, etc~ are as described in connection with Figure 1~ The wet oxidation reactions which occur in unit 150 are exothermic and generate steam in steam coil 155 which passes in part through line 156 for use in the system as described hereinafter. Depending upon the degree of hydrolysis of polysaccharides effected, it would be possihle to generate an excess of steam which would then be e~ported.
Spent gas from the wet oxidation unit 150 leaves through line 158 and joins the stream of spent gas leaving the system through line. 130 for venting or scrubbing and venting as described above.
A liquid with. a controlled amount of solids contained in it passes from unit 150 by way of line 159 through heat exchanger 148 to liquid extraction unit 160. Line 159a recycles liquor to wet oxidation unit 150 to optimize oxidation of solids.
The extract from unit 160 passes through line 161 to e~llipment generally designated as 162 and which may consist of several pieces of equipment, pc/~
~ I ~ 7~82~) ~ `
1 I e.g~ for stearn stripping, for fractionation in a fractionating 21 colurnn, for precipitation, etc. to produce products such as 3l indicated. The raffinate from unit 160 leaves through line 163, ¦
4 then passes througll a heat exchanger 164 and by way of line 165 5¦ to separat:or 166 wherein the controlled amount of solids 6 remaining in the liquid (with a suitable quantity of liquid 7 to act as a carrier) passes through line 167 and join strearn 8 1 145. Boiler feed wat~r is shown entering the system through 9 I line 170 and heat exchanger 16-~ to steam coil 155 in wet ~ol oxidation unit lSOo
12 and the pentose rich hydrolysate may be combined (as they 13¦ are in Figure 1) and subjected to simultaneous fermentation 14 (after suitable processing to remove substances which 15¦ interfere with fe~nentation) to ethanol, employing a suitable 16 I mixture of micro-organisms, or the combined hydrolysa1:es may 17¦ be subjected to sequential fermentation of hexoses and 18 pentoses. Alternately, solids in the slurry of streams 75, 19 ¦ having nutritive value can be separated for appropriate 20 ¦ utili~ation with separated water used as described above.
`21 23 :
27 ' ~
31 t /, ,.
32 ~
i! ' ' S ` .
- 12a -~, , , . . . . .
~:: : :~ ~ : :
i~ 1 7 ~ ) ~ , .
¦~ l Referring llOW to Figure 2, biomass, for example, 2 green wood from trees or saw mill residues in suitably 3 comminuted form enters the system at 100 and is received in 4 a storage hopper 101. The comminuted wood then proceeds along , the path 102 to a first hydrolyzer 103. This is the same hydrolyzer as shown at 11 in Figure 1 and the temperature `~i 7 and residence time are as described in connection with that 8 figure. Hydrolysate solution also enters the hydrolyzer 103 9 through the line 104 and recycle wash water tlirough the line 6 i 10 104a. The effluent leaves the hydrolyzer through line 105 ll and passes through a heat exchanger 106. Typically, in the 12 ¦ case of wood from trees, this effluent will consist of an 13¦ aqueous phase having dissolved therein approximately 30 to 35%
14¦ of the dry weight of the wood, the remaining 65 to 70~i being 151 solids. The~effluent slurry leaves the heat exchancJer 106 16j twhere it is cooled somewhat below the temperature prevailing 17 in hydroly~er 103) through line 107 and is introduced into i 18 ¦ a separator 108~which serves to separate liquid phase from 19 solids. In this instance and in others like it, the separated 20 liquid, apart from traces of solids is entirely a liquid ;~
21 phase containing dissolved solids~ The separated "sollds" ~ , i~i 22 I are actually a slurry of undissolved solids and liquid, the , ~ ~ .
23 ¦ liquid being the same as the separated liquid phase. As is ,!:' ' 24 ¦ well ~nown, the "solids" must contain a large proportion oP
1 25 ¦ liquid to be amen~ble to pumpiny through pipes and otherwise ~: 26 ¦ handling.
` 27 `~ 2~ ~' 31 ~
32 .
!~
~ ~758~n I The liquid leaves by line 109 and the solids by 2 I line 110. The separator 108 may be of conventional variety 3 ' such as, for example, one or more centrifuges. The solids 4' leaving through line 110 will typically consist of about ~O
S to 85~ aqueous phase and 40 to 15% solids, and is introduced 6 into a separator-washer 111. Two strearns of water frorn a 7 recycle stream referred to hereinafter are introduced into 8 I the separator-washer 111 through lines 116 and 117. The 9 I separator-washer 111 may be of well known construction, e.g.
a washing centrifuge or drum filter. The portion of the water introduced through line 116 serves to displace and remove, .
12l through line 118, a major proportion of the sugar content of 13j the aqueous phase introduced through line 110. This solution, 141 after passing through a heat exchanger 119, passes into line lS 1 104a for recycling to the first hydrolyzer 103. Water intro-16 duced in line 117 dilutes the washed solids in 111 to a l7 ! transportable slurry carried in line 120. ~ slurry of solids 18 passes by way of line 120 through heat exchanger 106 to an 19 ~ agitator 121 and then into sensitizer 122 into which air or 20 I oxygen is introduced through line 123 from a source 123a. The 2l I function of the agitator~ is to provide an intimate 22 i dispersion of air, solids and liquid which then passes by 231 way of linc 12~ into sensitizer 122, ~Ihich corresponds to the 24 sensitizer 1t3 in Figure 1 and in wllich the conditions of 251 tempcrature a~ld tirnc of re~sidence are as described above in 26 I con!lectioll Wittl Figure 1. Acid as needed to control pEI in 27 I the sensltizer 122 and in the secolld stage hydrolyzer 135 28 (see belo~) enters throuyh line 130a directly lnto line 131 29 , and also by way of line 130b to a~3itat.or 121.
30 I "
3l 3~
~ 14 -_ ! ;`
.
~, .
: - -f~ ~7582(~ ~
l I Spent gas (largely nitrogen, carbon dioxide and 2 other, minor components of air) is vented from the sensitizer 3¦ through line 130 to the atmosphere or if desired to any 4¦ desired ~crubber before ventillg to the atmosphere. A slurry 5 I of solids and aqueous liquid leave the sensitizer 122 through 6 line 131 ~nd a cellulose hydrolyzer agitator 132 to a heat 7 ! exchanger 133 where it is heated to the temperature of hydrolysis ` 8 i and then proceeds by way of line 134 to a second (cellulose) 1 9 j hydrolyser 135 corresponding to the second hydrolyzer 26 in lOI Figure l and in WhiC}I temperature and time of residence are -llll as described in connection with Figure 1. As explained above, .
12ll in this hydrolyzer the cellulose is substantially broken down 13l into glucose. To the extent that cellulose is hydrolyzed to 14 j oligomers, these are further hydrolyzed to glucose by virtue lS of being recycled through line 104 to hydrolyzer 103. A
l6 slurry (an aqueous solution of glucose and solids, largely 17 lignin) passes by way of line 136 through a heat exchanger 137 18 into a separator 1380 A portion, typically about 70 to 903 19 of the aqueous phase ~a solution of glucose) passes by way of ~ 20 line 139 through heat exchanger 137 to line 104 for recycling.
:: 21 1l (As described about in connection with Figure 1, this 22 ll recycle hydrolysate may be passed through hydrolyzer 103 ~3 ll counterc~uI rently to the hiomass ~eed material.) ~ slurry of 2~, sol.ids (largely lignill) and aqueous phase passes through line 140 lnto 5eparator-washer 1.4]. into which two streams 2261 f water enter by way of lines 142 and 143. The wasll stream 28 ' 29 ~ .
32 .
. i - .l5 -., ' i': ' ''`~ , .
~ 17~82n entering through line 142 carries wi-th it a major portion of the aqueous phase which displaces the major part of the hydrolysate remaining ~ith the insoluble ligneous residue.
The displaced solution then passes by way of line 144 to line 104. The water entering through line 143 serves to dilute the slurry of solids and contained liquid so that it can be readily passed through line 145 to join another stream (described hereinbelow) to a line 147, by means of junction 146, then through heat exchanger 148 and line 149 into wet oxidation ~ 10 unit 150. Wet oxidati.on unit 150 is the same unit as shown at : 32 in Figure 1 and the conditions prevailing therein as regards temperature, time of residence, etc~ are as described in connection with Figure 1~ The wet oxidation reactions which occur in unit 150 are exothermic and generate steam in steam coil 155 which passes in part through line 156 for use in the system as described hereinafter. Depending upon the degree of hydrolysis of polysaccharides effected, it would be possihle to generate an excess of steam which would then be e~ported.
Spent gas from the wet oxidation unit 150 leaves through line 158 and joins the stream of spent gas leaving the system through line. 130 for venting or scrubbing and venting as described above.
A liquid with. a controlled amount of solids contained in it passes from unit 150 by way of line 159 through heat exchanger 148 to liquid extraction unit 160. Line 159a recycles liquor to wet oxidation unit 150 to optimize oxidation of solids.
The extract from unit 160 passes through line 161 to e~llipment generally designated as 162 and which may consist of several pieces of equipment, pc/~
~ I ~ 7~82~) ~ `
1 I e.g~ for stearn stripping, for fractionation in a fractionating 21 colurnn, for precipitation, etc. to produce products such as 3l indicated. The raffinate from unit 160 leaves through line 163, ¦
4 then passes througll a heat exchanger 164 and by way of line 165 5¦ to separat:or 166 wherein the controlled amount of solids 6 remaining in the liquid (with a suitable quantity of liquid 7 to act as a carrier) passes through line 167 and join strearn 8 1 145. Boiler feed wat~r is shown entering the system through 9 I line 170 and heat exchanger 16-~ to steam coil 155 in wet ~ol oxidation unit lSOo
11 I . ~
12¦ Reverting no~ to the aqueous solution leaving
13¦ separator 108 through line 109, this solution enters liquid
14¦ extraction unit ~80 and passes countercurrently to solvent
15¦ entering throuqh line 181, the extract leaving through line
16 182 to liquid extraction unit 160 wilere it serves as the
17 extraction mediurn. The purpose of extraction in unit 180 is
18 to eliminate from the solution of fcrTnentable sugars those
19 solutes which would interfere with fermentation, e.g. furfural
20 ¦ and/or to remove organic acids. The purified aqueous solution
21 ~ of sugars passes through line 183 to fermenting unit 184,
22 ~hich is supplied throuc3h line 185 ~ith yeast or other suitabl~
23 I mic-ro-organism and any nutrient media and base to acl~u;t for
24 pll required for alcoholic ferlnentation. Gas (carbon dioxide) leaves through line 196 and the fermented rnaterial ~beer) 26 throuqh line 187 ancl hezlt exchanqer 188 to rectifying colurnns 27 189. Steam is supplied to col-unn 1.89 through line 191 and 228 conclénsate leaves through line 192.
'''' .
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~ 7582n ~
.' I
lj The distillate, for e~ample, 190 proof ethanol leaves through line 190 as an end product and the still bottoms leave 3 I through line 200 and pass through heat exchanger 188 to 4 methanation unit 201 whel-ein the pentoses are converted to methane and CO2 which leave through line 202. The gaseous 6l, mixture may be used as fuel or the methane and carbon dioxide 71, may be separatedO Liquid, which for the most part is simply 8ll waste water but which may contain a certain amount of solids, 9! leaves methanation unit 201 through line 204 and passes to a separator 205 which separates any remnant of solids. These -11l solids leave through line 206 and are returned to wet .
1211 oxidation unit 150. The water leaving separator 205 passes 13!l through line 207 and is recycled to the system through lines 14 1 116 and 117 ~to separator ~ ) and lines 142 and 143 (to 16 separator ~t~.17 Make-up water (if needed) may be added to the 18¦ system at any convenient point, e.g. by introducing it into 19 ¦ line 117 and/or line 143. Water is removed from the system through line 207a to prevent build-up of solutes.
221 .
, 231 2'11 ; ,. .
' `,;'6~ ~ ~
~ ~7~2n 1 Referring now to Figure 3, this is a flow diagram , 2 of a modification of the flo~ diagram of Figure 2 centering 3 about the first stage hydrolysis unit (numbered 103 as in 4 Figure 2) and illustrating a different, and preferred method of recycling the hydrolysate from the second stage hydrolysis~
6 Wherever in Figure 3 a line is interrup-ted (the interruption 7 being indicated by a zis-zag terminus), it is to be understood 8 I that such line connects to other equipment (not shown in 9 ¦ Figure 3) as in Figure 2.
10 I .
11¦ Lignocellulosic raw material suitably comminuted, 12¦ enters frorn hopper 101 and passes through a continuous feed ~31 device 220. This may be a screw type feed or a rotary feed.
14¦ The material passes into Eirst stage hydrolyzer 103 and passes 15¦ downwardly countercurrently to up-coming liquid described 16 hereinafter. (The arrangement need not be vertical; e.g.
17¦ it may be horizontal, but a vertical arrangement is convenient.) 13¦ The partially hydrolyzed material (solid and liquid) passes l9¦ through line 221 and a refiner 222 to line 223, then throuyh heat exchanger 119 to agitator 121 thence to sensitizer 122.
21¦ Hydrolysate solution from second stage hydrolysis unit 135 22¦ (see ~lgure 2) pass~s throu~h line 104 to a point near the 231 bottorn of hyclrolyxer unit 103 and, as inclicated hy curved 241 arrows it is distriblltec1 about the circumference o~ the
'''' .
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~ 7582n ~
.' I
lj The distillate, for e~ample, 190 proof ethanol leaves through line 190 as an end product and the still bottoms leave 3 I through line 200 and pass through heat exchanger 188 to 4 methanation unit 201 whel-ein the pentoses are converted to methane and CO2 which leave through line 202. The gaseous 6l, mixture may be used as fuel or the methane and carbon dioxide 71, may be separatedO Liquid, which for the most part is simply 8ll waste water but which may contain a certain amount of solids, 9! leaves methanation unit 201 through line 204 and passes to a separator 205 which separates any remnant of solids. These -11l solids leave through line 206 and are returned to wet .
1211 oxidation unit 150. The water leaving separator 205 passes 13!l through line 207 and is recycled to the system through lines 14 1 116 and 117 ~to separator ~ ) and lines 142 and 143 (to 16 separator ~t~.17 Make-up water (if needed) may be added to the 18¦ system at any convenient point, e.g. by introducing it into 19 ¦ line 117 and/or line 143. Water is removed from the system through line 207a to prevent build-up of solutes.
221 .
, 231 2'11 ; ,. .
' `,;'6~ ~ ~
~ ~7~2n 1 Referring now to Figure 3, this is a flow diagram , 2 of a modification of the flo~ diagram of Figure 2 centering 3 about the first stage hydrolysis unit (numbered 103 as in 4 Figure 2) and illustrating a different, and preferred method of recycling the hydrolysate from the second stage hydrolysis~
6 Wherever in Figure 3 a line is interrup-ted (the interruption 7 being indicated by a zis-zag terminus), it is to be understood 8 I that such line connects to other equipment (not shown in 9 ¦ Figure 3) as in Figure 2.
10 I .
11¦ Lignocellulosic raw material suitably comminuted, 12¦ enters frorn hopper 101 and passes through a continuous feed ~31 device 220. This may be a screw type feed or a rotary feed.
14¦ The material passes into Eirst stage hydrolyzer 103 and passes 15¦ downwardly countercurrently to up-coming liquid described 16 hereinafter. (The arrangement need not be vertical; e.g.
17¦ it may be horizontal, but a vertical arrangement is convenient.) 13¦ The partially hydrolyzed material (solid and liquid) passes l9¦ through line 221 and a refiner 222 to line 223, then throuyh heat exchanger 119 to agitator 121 thence to sensitizer 122.
21¦ Hydrolysate solution from second stage hydrolysis unit 135 22¦ (see ~lgure 2) pass~s throu~h line 104 to a point near the 231 bottorn of hyclrolyxer unit 103 and, as inclicated hy curved 241 arrows it is distriblltec1 about the circumference o~ the
25 ¦ down~al-dly moving, partially hydrolyzed oass of solids and 27~ move, ~p~,rdly ~l~d oountor~rlontly to th~ solids. ~/ash ,~ . ' ' .
~ - 13a ~
': . ' ' '; ,, ! _ . .
, ~ . ~ 2.175~20 ~
l water from line 207 (see Figure 2) is split into two streams 224 2 ¦ and 225 (which correspond to lines 117 and 116, respectively 3 j in Pigure 2). That portion of the wash water entering through 4 ¦ line 225 pass~s through heat exchanger 226, then th~ough 5 I line 227 into the bottom portion of hydrolyzer 103 below the 6 ¦ level where the hydrolysate enters through line 104. As in ; ' the case of the hydrolysate a distributor is employed and ll 8 I the liquid moves upwardly, joining the hydrolysate, counter- ¦~
¦~ ¦. currently to the down-coming solids. Recycle ~ash water entering 10¦ through line 224 passes into the bottom of hydrolyzer 103 where par, of it moves upwardly to join the other stre~-n counter-12 currently to the down coming solids and part passes from the 13 I h~drolyzer 103 with -the solids through line 221. A connecting `~ 14 line 228 connects line 227 with line 224. The portion of wash water thus entering through line 228 is heated ~y steam 16 in heat exchanger 226. By proportioning the streams 224 and 17 228, the temperature of the liquid entering the bottom of the 1 hydrolyzer unit 103 can be adjusted. Steam enters heat exchanger 119 from line 156, then passes through heat ; 20 exchanger 226 and connects to line 191. Steam as needed, 21¦ generated within the system or from outside the system, may 22¦ be introduced as neecled, e.g. into line 156 and/or heat 231 e~chan~er 119.
' ' 2,~1 . : .
251 . .
~ - 13a ~
': . ' ' '; ,, ! _ . .
, ~ . ~ 2.175~20 ~
l water from line 207 (see Figure 2) is split into two streams 224 2 ¦ and 225 (which correspond to lines 117 and 116, respectively 3 j in Pigure 2). That portion of the wash water entering through 4 ¦ line 225 pass~s through heat exchanger 226, then th~ough 5 I line 227 into the bottom portion of hydrolyzer 103 below the 6 ¦ level where the hydrolysate enters through line 104. As in ; ' the case of the hydrolysate a distributor is employed and ll 8 I the liquid moves upwardly, joining the hydrolysate, counter- ¦~
¦~ ¦. currently to the down-coming solids. Recycle ~ash water entering 10¦ through line 224 passes into the bottom of hydrolyzer 103 where par, of it moves upwardly to join the other stre~-n counter-12 currently to the down coming solids and part passes from the 13 I h~drolyzer 103 with -the solids through line 221. A connecting `~ 14 line 228 connects line 227 with line 224. The portion of wash water thus entering through line 228 is heated ~y steam 16 in heat exchanger 226. By proportioning the streams 224 and 17 228, the temperature of the liquid entering the bottom of the 1 hydrolyzer unit 103 can be adjusted. Steam enters heat exchanger 119 from line 156, then passes through heat ; 20 exchanger 226 and connects to line 191. Steam as needed, 21¦ generated within the system or from outside the system, may 22¦ be introduced as neecled, e.g. into line 156 and/or heat 231 e~chan~er 119.
' ' 2,~1 . : .
251 . .
26~
2,73 ' 291 . . ' , ' I , ~ 30 I ~
~ 1 ~ '' r - 18b -,, ~ .
~ - ~
I ! 7 5 8 2 (1 1¦ Effluent liquid from the top oE hydrolyzer 103 passes 2 ¦ by way of line 229 and part is recycled by line 230 and feed 31 device 220 to l-ydrolyzer 103 and another part passes by way 4j of line 231 to liquid extraction unit 1800 .~ I
6 ~ By reason of the modification of Figure 3 certain 7 advantages are achievedO The down-coming partially hydrolyzed 8 solids in the biomass are washed and sugars are extracted;
9 the washing liquid [streams 104, 227 and 224 (in part)] are 10l cooled, giving up their heat to the solids; and the dissolved ~ sugars passing up with the combined streams are subjected .
12 j to high temperatures for a short time, which minimizes 18 ! degradation. i}eat in streams 104, 227 and 224 is adjusted .
~ to optimi7e t mper~ture for hydrolysis.
25~ ~
2~ . . .
32 . .
. - 18c -'. . ' ' ' - . . . ~ ' ' . :
; ` -.
~1 7582n .
1 GENER~L DISC~SSlON OP THE SYSTEM
3 The system thus described and illustrated comprises 4 an hydrolysis-sensitization sub-system, a wet oxidation sub-~ system and ~ Eermentation-methanation sub-system and certain 6 ¦ recovery stepsO In the hydrolysis-sensitization sub-system, ' primary hydrolytic operations are performed which break down 8 I high molecular weight polysaccharides (cellulose) and lower molecular weight polysaccharides (hemicelluloses)` into 10 1 monosaccharides (hexoses and pentoses) by a process of depolymerization. In the ~et oxidation sub-system a more .
12~, drastic oxidative attack (yet sufficiently mild to minimize 13 ! production of carbon dioxide, carbon monoxide and water) is 14 performed on the structure of lignin to break it down into 15 ¦ low molecular weight organic substances of commercial value ~ such as organic acids (typically acetic acid and formic acid), 17 furfural and methanol while minimizing production of CO2, 18 CO and 112O. The fermentation-methanation phase is described 19 I above with particular reEerence to fermentation of hexoses 20 ¦ to ethanol and the conversion of pentoses by methanation to 21 methane. However, by using a suitable mixture of micro-22 ¦ orgallisms both hexoses and pentoses in admixture may be 23 fermented to ethanol or hexoses may be fermented to ethanol 24 ¦ with suitable micro-organisms and pentoses may then be 25 ¦ fermented to ethanol separately by other micro-oryanisms.
26 ~150, pentoses can be sub~ected to dehydration to produce
2,73 ' 291 . . ' , ' I , ~ 30 I ~
~ 1 ~ '' r - 18b -,, ~ .
~ - ~
I ! 7 5 8 2 (1 1¦ Effluent liquid from the top oE hydrolyzer 103 passes 2 ¦ by way of line 229 and part is recycled by line 230 and feed 31 device 220 to l-ydrolyzer 103 and another part passes by way 4j of line 231 to liquid extraction unit 1800 .~ I
6 ~ By reason of the modification of Figure 3 certain 7 advantages are achievedO The down-coming partially hydrolyzed 8 solids in the biomass are washed and sugars are extracted;
9 the washing liquid [streams 104, 227 and 224 (in part)] are 10l cooled, giving up their heat to the solids; and the dissolved ~ sugars passing up with the combined streams are subjected .
12 j to high temperatures for a short time, which minimizes 18 ! degradation. i}eat in streams 104, 227 and 224 is adjusted .
~ to optimi7e t mper~ture for hydrolysis.
25~ ~
2~ . . .
32 . .
. - 18c -'. . ' ' ' - . . . ~ ' ' . :
; ` -.
~1 7582n .
1 GENER~L DISC~SSlON OP THE SYSTEM
3 The system thus described and illustrated comprises 4 an hydrolysis-sensitization sub-system, a wet oxidation sub-~ system and ~ Eermentation-methanation sub-system and certain 6 ¦ recovery stepsO In the hydrolysis-sensitization sub-system, ' primary hydrolytic operations are performed which break down 8 I high molecular weight polysaccharides (cellulose) and lower molecular weight polysaccharides (hemicelluloses)` into 10 1 monosaccharides (hexoses and pentoses) by a process of depolymerization. In the ~et oxidation sub-system a more .
12~, drastic oxidative attack (yet sufficiently mild to minimize 13 ! production of carbon dioxide, carbon monoxide and water) is 14 performed on the structure of lignin to break it down into 15 ¦ low molecular weight organic substances of commercial value ~ such as organic acids (typically acetic acid and formic acid), 17 furfural and methanol while minimizing production of CO2, 18 CO and 112O. The fermentation-methanation phase is described 19 I above with particular reEerence to fermentation of hexoses 20 ¦ to ethanol and the conversion of pentoses by methanation to 21 methane. However, by using a suitable mixture of micro-22 ¦ orgallisms both hexoses and pentoses in admixture may be 23 fermented to ethanol or hexoses may be fermented to ethanol 24 ¦ with suitable micro-organisms and pentoses may then be 25 ¦ fermented to ethanol separately by other micro-oryanisms.
26 ~150, pentoses can be sub~ected to dehydration to produce
27 furEural. In the recovery steps, the desired end products
28 are recovered by recti.fication, solvent extraction, et~.
3 :
31 ~
32 ,'`
' - 19'; . . .
. ,.,, , _ . .,,., !' .. .. - - - - .- -.
" ~ .
i~ l ~ -I ~ 7~82~) 1 1 I In connection with these sub-systems and steps, the 2 , following observations will be helpful, reference being to 3 Figure 1.
4i 5l Stage I H~drolysis in Unit 11. The conditions 6l are not as severe as in the sensitization unit 18 and in 7I the second stage hydrolyzer Ullit 2~. For e~ample, a 8I temperature of 140 to 220r~C., preferably about 160 to 180C., 9 is employed. A pH of 1.5 to 3.0 (preferably 2.0 to 3.0) lOi; and autogenous pressure, such as 75 psi gauge at 160C. are employecl. Residence time is sufficient to accomplish the 12j intended purpose of depolymerization of hemicelluloses to ~- 13l sugars yet to minimize degradation of these sugars. A
14 1l residence time preferahly not exceeding 40 minutes is sufficient and would be decreased to a shorter time as i 161, temperature is increased. Glucose solution, which includes 17 ¦ oligomers, produced in stelge II hydrolysis is recycled to 18 ¦ the first stage hydrolysis unit to maximize the concentration 19 j of monosaccharides leaving separator 14 by line 15.
20l Countercurrent flow is preferred as described above with 21ll reference to Figure 3. Representative concentrations of 22 1I recycle (line 12) and effluent (]ine 15) streams are optimized 231j in the rancJe of 2 to 12 perceni: monosaccharicles in line 15 24 !~ and 1 to 10 percent monosaccharides in line 12 -to maximize 25~1 yield of hexose sugars. Thi.s provides a high concentration 26~' of monosaccharide in the strearn going to ferment~tion 27 ¦ unit 51.
~8
3 :
31 ~
32 ,'`
' - 19'; . . .
. ,.,, , _ . .,,., !' .. .. - - - - .- -.
" ~ .
i~ l ~ -I ~ 7~82~) 1 1 I In connection with these sub-systems and steps, the 2 , following observations will be helpful, reference being to 3 Figure 1.
4i 5l Stage I H~drolysis in Unit 11. The conditions 6l are not as severe as in the sensitization unit 18 and in 7I the second stage hydrolyzer Ullit 2~. For e~ample, a 8I temperature of 140 to 220r~C., preferably about 160 to 180C., 9 is employed. A pH of 1.5 to 3.0 (preferably 2.0 to 3.0) lOi; and autogenous pressure, such as 75 psi gauge at 160C. are employecl. Residence time is sufficient to accomplish the 12j intended purpose of depolymerization of hemicelluloses to ~- 13l sugars yet to minimize degradation of these sugars. A
14 1l residence time preferahly not exceeding 40 minutes is sufficient and would be decreased to a shorter time as i 161, temperature is increased. Glucose solution, which includes 17 ¦ oligomers, produced in stelge II hydrolysis is recycled to 18 ¦ the first stage hydrolysis unit to maximize the concentration 19 j of monosaccharides leaving separator 14 by line 15.
20l Countercurrent flow is preferred as described above with 21ll reference to Figure 3. Representative concentrations of 22 1I recycle (line 12) and effluent (]ine 15) streams are optimized 231j in the rancJe of 2 to 12 perceni: monosaccharicles in line 15 24 !~ and 1 to 10 percent monosaccharides in line 12 -to maximize 25~1 yield of hexose sugars. Thi.s provides a high concentration 26~' of monosaccharide in the strearn going to ferment~tion 27 ¦ unit 51.
~8
29 3l .
32 , . ~' , '~ '' . , .
- 20 - , :. .: : ~
~ .
i I ~ 7~82(~
' I .
11 Sensitization Skep in Unit 18. The conditions of 2l pH (1.0 to 3.0, preferably about 1.0 to 2.0~, temperature 3 ' (preferably about 160 to 200c.) and total pressure 41' (autogenous pressure plus pressure of air) are more severe than in the hydrolysis unit 11. Limited and controlled 6l o~:idation is carried outO Suitable rates of introduction 7 1! are0.2 to 4.0 grams of o~ygen per minute per kilogram of O.D.
8l raw material and depend upon the variables and amount of oxygen to be absorbed. The added acid may be a mineral acid 10l such as nitric, sulfuric or hydrochloric acid; an acid salt such as ferric nitrate or ferric chloride or a mixture of 12 ll acid and acid salt or an organic acid such as acetic acid, 13 ll formic acid, oxalic acid generated in the process. The 14 ¦1 acid is added to adjust pl~. By using an organic acid 15ll generated in the process, recovery problems are simplified 16l since the added organic acid is separated along with end 17 ¦ products of the system. If nitric acid is employed, it 18¦ will provide the nitrogen required as a nutrient medium for 19 the fermentation step or steps. It is believed that in this 20 ~ sensitization step a mild attack occurs on the cellulose 21 structure which renders it more amenable to hydrolytic ¦~
22, cleavage in Stage II hydrolysis. In any event, it has been 23 I observed that the second stage hydrolysis in unit 26 proceeds 24 I at a considerably faster rate, that it can be accomplished at a lowcr acidity (higher pll) and that a higher yield of 26 I reducing sugars results than would result in the absence of 27 . .
29 . . :
31 . .
~2 .
:. ~
:
: : :
.~ . ~ ~
~ ~75~2n , ' 1 the sensitization step. In the hydrolysis of cellulose, 2 I acidity and an elevated temperature provide the desired 3 ~ hydrolysis ~nd also produce the compe~ing degradatioll of monosaccharides. By enabling the second stage hydrolysis Sj to be carried out under milder conditions (higher pH and 61 lower temperature) the sensi-tizing step promotes the production 7 I of sugar and minimizes the deyradation of sugars.
9 I Step II Hydrolvsis. This is carried out at a 10 , relatively high acidity (pll about l.0 to 3.0, preferably about 11' l.0 to 2.0) and at a higher temperature (about 160 to 2~0C., preferably about 180 to 220C.) and at corresponding autogenous 13 I pressure. These conditions are sufficiently severe to 14 I accomplish the desired hydrolysis of cellulose to glucose.
15 1 As pointed out, it is the object to maximize separation of 16 I hydrolysate from the ligneous residue by removal of as much 17 ¦ hydrolysate as possible and then use countercurrent washing 18 ¦ with the slurry wash being recycled to hydrolysis unit ll 19 I and the washed residue being slurried in a water stream which goes to wet oxidation unit 32.
23~
2sl 2~ ' .
31 I ' 32 ' ~' .
?
' - 22 -. ,_ . , ' ,' , ~` . ` I ! 7~5 8 2 () ~'1 ':
l ¦ Wet Oxidation. This is an exothermic process which 2 may be used to generate steam for use as a source of heat in 3 the process (heat exchangers are shown in Figure 2). When 4 compressed air is used to supply oxygen, the hot gas leaving unit 32 (or 150 in Figure 2) may be expanded through a gas 6 I turbine to produce power. The conditions of temperature, 7 pressure and o~ygen partial pressure are such as to result 8 in substantially complete breakdown of lignin into simple 9 products including commercially valuable products such as 10~ organic acids, methanol, etc. but such as to minimize ll conversion to carbon dioxide, carbon monoxide and water,or ¦`
12¦ the products of breakdown of lignin may be converted to 13l methane. Generally speaking, the procedures described in 14 Brink U.S. Patent 3,582,369 may be used.
16 Among the advantages of this system the following 17 may be mentioned. The concentrations and yield of mono-18 saccharides leaving the hydrolysis-oxidation through line lS
19 are maximized and the time required for overall hydrolysis is reduced. Little or no solids leave the system to present 21 disposal problems. The production of ethanol, methane ancl 22 other useful organic compounds is accomplished. The wet 23 oxidation step i5 exothermic and the system as a ~hole can 2~ be made independent of an external energy source. The s.ystem can be designed to prod~ce suf~icient thermal en~rgy to 2h operate the system with the possihility of providing surplus 27 energy for outside use.
2~ `
. .
",~
~ 2 (!
1 The manner in which the wet oxidation step is carried 2 I out can be adjusted to maximize the production of heat or to 3 maximize the production of useful organic materials such as 4 I methane, methanol, organic acids and Eurfural. By using more 51l o~.ygen, a greater amount of heat is generated and a lesser 6 ¦ amount of organic products of value is produced. Conversely 7 I by employing milder conditions, e.g. less oxygen, less heat 8 j and more useful OrgaQiC products result. The recycle of 9 ~ solids to the wet oxidation unit also influences heat 10 , production; the more solids recycled, the greater the 11 production of organic productsO By maximizing oxidation, .
12 a temperature of 2Z0C. or higher and greater heat production 13 result. By conducting wet oxidation to achieve temperatures 14 of 180 to 220Co r less heat and more useful organic compounds 15 I result.
17 ~ The following specific example, although based on 18 I laboratory work and lacking, therefore, the advantageous 19 ~ continuity of a commercial process will serve further to 20 ¦ illustrate the hydrolysis-sensitization sub-system of the 23~ proce~s.
.2~1 . , ' .
291 . . .
.
31 ;
', ' , ~ 2~ ~
, ~ ~ I j .
1~175~20 l Example 21!
3 ¦1 A. Stage I Hydrol~sis (Pre-~yd Iysis)~ White fir 4~ woocl comn~inuted to -2-~4 mesll ~as used. 4.0 Kilograrns 5; (O.D. basis) were used containing 0.5 kilogram water. The 6l wood was slurried in 35.5 kilograms of water and brought to 7i pH 3.0 with nitric acid. This slurry was stirred in a closed 8 1l reaction vessel and brought to 160Co in 10 minutes and held 9f~ at that ternperature ~or 30 minutes. I`his produced a solution lOI containing 1.16% reducing sugars, pH = 2.54 with, of course;
llij undissolved solids. The slurry was cooled to room temperature .
121 and was separated by filtration and water washinc3 to give a 13 li ligrlocellulosic residue of 2.85 kg (O.D. basis) or 6.4 kg 14l (wet basis)~ (In commercial practice a separation would be lSI made of hydrolysate (monosaccharide derived from hemicelluloses), 16 recycle hydrolysate ~ould be employed, and a combined 17l hydrolysate would be routed to Eermentation.) l91 B. Sensitization. 4.0 Xilograms (O.D. basis) of :, I _ . .
20 ¦ washed, pre-hydrolyzed residue such as produced in A and 3.2 kg 2ll of wash water are slurried with water to give 24.4 kcJ. which 22 1 is brought to p~ 2.45 by 72% nitric acic~ and is heated to 23~ :l70aC. in a closed vcsscl in about 10 niinutes and llelcl at 2~ such telnperature wi.th ayitation Eor 60 minutes with sparginy 25I¦ with air at the rate of 1.01 gram per miIlutc of oxygen per 26 kg oE O.D. wood. q'he total pres.surc was maintainecl at 17.58 27 kg/sq. cm, the auto(Jenous steam pr~ssure beiny calculated as 2~ 7.04 ky/sq. cm.
.. ' ' .
~ - 25 - I
~'11 .. , ~ ' ~
. ~ ~
~ ~7~i3~) l C. Stage II Hydrol~sis. Stirring of the slurry resulting from B was continued, hydrolysis was initiated by 31 terminating the introduction of ai.r and increasing the 4~ temperature to 19~C. in three rninutes and releasing off gas Sll to stabilize the pressure at about 24 kg/sqO cm. The 6 ll temperature was maintained at 195 - 205C. for 35 minutes at 7 ¦I which time a maximum sugar content was obtained in the aqueous phase. The increased rate of hydrolysis in this 91 stage resulting from sensitization step B was calculated to lO¦ be about four times the rate in the absence of step B.
111 .
12¦ It will therefore be apparent that a novel and 13¦ advantageous method and system have been provided for the l~¦ conversion of lignocellulosic material to useEul products lS¦ with a minimum of degradation to waste products, whether 16 ¦ gaseous, liquid or solid and with a minimum input or no inp~t Oe the mal eDergy from an external source .
222 . ' 23 .
~5 .
27 . .
2~ .
32 .
,,,. .
- 26 -- . .
, ~ : .
32 , . ~' , '~ '' . , .
- 20 - , :. .: : ~
~ .
i I ~ 7~82(~
' I .
11 Sensitization Skep in Unit 18. The conditions of 2l pH (1.0 to 3.0, preferably about 1.0 to 2.0~, temperature 3 ' (preferably about 160 to 200c.) and total pressure 41' (autogenous pressure plus pressure of air) are more severe than in the hydrolysis unit 11. Limited and controlled 6l o~:idation is carried outO Suitable rates of introduction 7 1! are0.2 to 4.0 grams of o~ygen per minute per kilogram of O.D.
8l raw material and depend upon the variables and amount of oxygen to be absorbed. The added acid may be a mineral acid 10l such as nitric, sulfuric or hydrochloric acid; an acid salt such as ferric nitrate or ferric chloride or a mixture of 12 ll acid and acid salt or an organic acid such as acetic acid, 13 ll formic acid, oxalic acid generated in the process. The 14 ¦1 acid is added to adjust pl~. By using an organic acid 15ll generated in the process, recovery problems are simplified 16l since the added organic acid is separated along with end 17 ¦ products of the system. If nitric acid is employed, it 18¦ will provide the nitrogen required as a nutrient medium for 19 the fermentation step or steps. It is believed that in this 20 ~ sensitization step a mild attack occurs on the cellulose 21 structure which renders it more amenable to hydrolytic ¦~
22, cleavage in Stage II hydrolysis. In any event, it has been 23 I observed that the second stage hydrolysis in unit 26 proceeds 24 I at a considerably faster rate, that it can be accomplished at a lowcr acidity (higher pll) and that a higher yield of 26 I reducing sugars results than would result in the absence of 27 . .
29 . . :
31 . .
~2 .
:. ~
:
: : :
.~ . ~ ~
~ ~75~2n , ' 1 the sensitization step. In the hydrolysis of cellulose, 2 I acidity and an elevated temperature provide the desired 3 ~ hydrolysis ~nd also produce the compe~ing degradatioll of monosaccharides. By enabling the second stage hydrolysis Sj to be carried out under milder conditions (higher pH and 61 lower temperature) the sensi-tizing step promotes the production 7 I of sugar and minimizes the deyradation of sugars.
9 I Step II Hydrolvsis. This is carried out at a 10 , relatively high acidity (pll about l.0 to 3.0, preferably about 11' l.0 to 2.0) and at a higher temperature (about 160 to 2~0C., preferably about 180 to 220C.) and at corresponding autogenous 13 I pressure. These conditions are sufficiently severe to 14 I accomplish the desired hydrolysis of cellulose to glucose.
15 1 As pointed out, it is the object to maximize separation of 16 I hydrolysate from the ligneous residue by removal of as much 17 ¦ hydrolysate as possible and then use countercurrent washing 18 ¦ with the slurry wash being recycled to hydrolysis unit ll 19 I and the washed residue being slurried in a water stream which goes to wet oxidation unit 32.
23~
2sl 2~ ' .
31 I ' 32 ' ~' .
?
' - 22 -. ,_ . , ' ,' , ~` . ` I ! 7~5 8 2 () ~'1 ':
l ¦ Wet Oxidation. This is an exothermic process which 2 may be used to generate steam for use as a source of heat in 3 the process (heat exchangers are shown in Figure 2). When 4 compressed air is used to supply oxygen, the hot gas leaving unit 32 (or 150 in Figure 2) may be expanded through a gas 6 I turbine to produce power. The conditions of temperature, 7 pressure and o~ygen partial pressure are such as to result 8 in substantially complete breakdown of lignin into simple 9 products including commercially valuable products such as 10~ organic acids, methanol, etc. but such as to minimize ll conversion to carbon dioxide, carbon monoxide and water,or ¦`
12¦ the products of breakdown of lignin may be converted to 13l methane. Generally speaking, the procedures described in 14 Brink U.S. Patent 3,582,369 may be used.
16 Among the advantages of this system the following 17 may be mentioned. The concentrations and yield of mono-18 saccharides leaving the hydrolysis-oxidation through line lS
19 are maximized and the time required for overall hydrolysis is reduced. Little or no solids leave the system to present 21 disposal problems. The production of ethanol, methane ancl 22 other useful organic compounds is accomplished. The wet 23 oxidation step i5 exothermic and the system as a ~hole can 2~ be made independent of an external energy source. The s.ystem can be designed to prod~ce suf~icient thermal en~rgy to 2h operate the system with the possihility of providing surplus 27 energy for outside use.
2~ `
. .
",~
~ 2 (!
1 The manner in which the wet oxidation step is carried 2 I out can be adjusted to maximize the production of heat or to 3 maximize the production of useful organic materials such as 4 I methane, methanol, organic acids and Eurfural. By using more 51l o~.ygen, a greater amount of heat is generated and a lesser 6 ¦ amount of organic products of value is produced. Conversely 7 I by employing milder conditions, e.g. less oxygen, less heat 8 j and more useful OrgaQiC products result. The recycle of 9 ~ solids to the wet oxidation unit also influences heat 10 , production; the more solids recycled, the greater the 11 production of organic productsO By maximizing oxidation, .
12 a temperature of 2Z0C. or higher and greater heat production 13 result. By conducting wet oxidation to achieve temperatures 14 of 180 to 220Co r less heat and more useful organic compounds 15 I result.
17 ~ The following specific example, although based on 18 I laboratory work and lacking, therefore, the advantageous 19 ~ continuity of a commercial process will serve further to 20 ¦ illustrate the hydrolysis-sensitization sub-system of the 23~ proce~s.
.2~1 . , ' .
291 . . .
.
31 ;
', ' , ~ 2~ ~
, ~ ~ I j .
1~175~20 l Example 21!
3 ¦1 A. Stage I Hydrol~sis (Pre-~yd Iysis)~ White fir 4~ woocl comn~inuted to -2-~4 mesll ~as used. 4.0 Kilograrns 5; (O.D. basis) were used containing 0.5 kilogram water. The 6l wood was slurried in 35.5 kilograms of water and brought to 7i pH 3.0 with nitric acid. This slurry was stirred in a closed 8 1l reaction vessel and brought to 160Co in 10 minutes and held 9f~ at that ternperature ~or 30 minutes. I`his produced a solution lOI containing 1.16% reducing sugars, pH = 2.54 with, of course;
llij undissolved solids. The slurry was cooled to room temperature .
121 and was separated by filtration and water washinc3 to give a 13 li ligrlocellulosic residue of 2.85 kg (O.D. basis) or 6.4 kg 14l (wet basis)~ (In commercial practice a separation would be lSI made of hydrolysate (monosaccharide derived from hemicelluloses), 16 recycle hydrolysate ~ould be employed, and a combined 17l hydrolysate would be routed to Eermentation.) l91 B. Sensitization. 4.0 Xilograms (O.D. basis) of :, I _ . .
20 ¦ washed, pre-hydrolyzed residue such as produced in A and 3.2 kg 2ll of wash water are slurried with water to give 24.4 kcJ. which 22 1 is brought to p~ 2.45 by 72% nitric acic~ and is heated to 23~ :l70aC. in a closed vcsscl in about 10 niinutes and llelcl at 2~ such telnperature wi.th ayitation Eor 60 minutes with sparginy 25I¦ with air at the rate of 1.01 gram per miIlutc of oxygen per 26 kg oE O.D. wood. q'he total pres.surc was maintainecl at 17.58 27 kg/sq. cm, the auto(Jenous steam pr~ssure beiny calculated as 2~ 7.04 ky/sq. cm.
.. ' ' .
~ - 25 - I
~'11 .. , ~ ' ~
. ~ ~
~ ~7~i3~) l C. Stage II Hydrol~sis. Stirring of the slurry resulting from B was continued, hydrolysis was initiated by 31 terminating the introduction of ai.r and increasing the 4~ temperature to 19~C. in three rninutes and releasing off gas Sll to stabilize the pressure at about 24 kg/sqO cm. The 6 ll temperature was maintained at 195 - 205C. for 35 minutes at 7 ¦I which time a maximum sugar content was obtained in the aqueous phase. The increased rate of hydrolysis in this 91 stage resulting from sensitization step B was calculated to lO¦ be about four times the rate in the absence of step B.
111 .
12¦ It will therefore be apparent that a novel and 13¦ advantageous method and system have been provided for the l~¦ conversion of lignocellulosic material to useEul products lS¦ with a minimum of degradation to waste products, whether 16 ¦ gaseous, liquid or solid and with a minimum input or no inp~t Oe the mal eDergy from an external source .
222 . ' 23 .
~5 .
27 . .
2~ .
32 .
,,,. .
- 26 -- . .
, ~ : .
Claims (18)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A method of hydrolyzing lignocellulosic material containing hemicellulose, cellulose and lignin which comprises the following steps:
(a) subjecting such material to a first stage hydrolysis step in an aqueous medium and in comminuted form at a temperature and a pressure chosen to effect primarily depolymerization of hemicellulose without major depolymeri-zation of cellulose to glucose, such step resulting in a slurry in which the liquid aqueous phase contains dissolved monosaccharides resulting from depolymerization of hemicel-lulose and a solid phase containing cellulose and lignin;
(b) separating from the product of step (a) at least a portion of such liquid aqueous phase;
(c) also separating from the product of step (a) the solid phase;
(d) subjecting the separated solid phase in the form of an aqueous slurry to a second stage hydrolysis step under conditions such that at least a major portion of the cellulose is depolymerized, such step resulting in a liquid aqueous phase containing dissolved therein the soluble de-polymerization products of cellulose, such conditions being chosen to minimize the degradation of the depolymerization products of cellulose;
(e) separating from the product of step (d) at least a major portion of such liquid aqueous phase, and (f) also separating from such product the undis-solved solids;
the various steps (a) through (f) being carried out under conditions to minimize the loss of heat from the system and to minimize the times of exposure of solutions resulting from steps (a) and (d) to elevated temperature.
(a) subjecting such material to a first stage hydrolysis step in an aqueous medium and in comminuted form at a temperature and a pressure chosen to effect primarily depolymerization of hemicellulose without major depolymeri-zation of cellulose to glucose, such step resulting in a slurry in which the liquid aqueous phase contains dissolved monosaccharides resulting from depolymerization of hemicel-lulose and a solid phase containing cellulose and lignin;
(b) separating from the product of step (a) at least a portion of such liquid aqueous phase;
(c) also separating from the product of step (a) the solid phase;
(d) subjecting the separated solid phase in the form of an aqueous slurry to a second stage hydrolysis step under conditions such that at least a major portion of the cellulose is depolymerized, such step resulting in a liquid aqueous phase containing dissolved therein the soluble de-polymerization products of cellulose, such conditions being chosen to minimize the degradation of the depolymerization products of cellulose;
(e) separating from the product of step (d) at least a major portion of such liquid aqueous phase, and (f) also separating from such product the undis-solved solids;
the various steps (a) through (f) being carried out under conditions to minimize the loss of heat from the system and to minimize the times of exposure of solutions resulting from steps (a) and (d) to elevated temperature.
2. The method of claim 1 wherein step (a) is carried out by continuous passage of lignocellulosic material through a first hydrolysis zone and wherein liquid aqueous phase from step (e) is caused to pass continuously and countercurrently through such zone in contact with the ligno-cellulosic material.
3. The method of claim 1 wherein the solids separated in step (f) are subjected in the form of a slurry to contact with molecular oxygen at an elevated temperature to cause at least a substantial part of the solids to be oxidized to low molecular weight organic products.
4. The method of claim 3 wherein the conditions under which oxidation of lignin is carried out are such as to minimize oxidation and degradation of the lignin to carbon dixoide, carbon monoxide and water and to maximize the production of organic compounds having commercial value.
5. The method of claim 1 wherein the liquid separated in step (h) is subjected to a step to remove solutes which interfere with fermentation of glucose to ethanol, the glucose in the thus purified liquid is fermented, ethanol is recovered by rectification and the residue from such rectification is subjected to methanation.
6. The method of claim 1 wherein the aqueous slurry of step (d) is first caused to undergo indirect heat exchange with the product of step (a) to cool such product and heat such slurry before it is subjected to the second stage hydrolysis step.
7. The method of claim l wherein at least a por-tion of the liquid aqueous phase of step (e) is recycled to step (a).
8. The method of claim l wherein the undissolved solids resulting from step (a) are subjected to attrition before they are subjected to second stage hydrolysis.
9. The method of claim 1 wherein the solids separated in step (c) are washed with water to displace liquid aqueous phase resulting from step (a) and which remains with the separated solids ! a further quantity of water is added to the washed solids to form a slurry and such slurry is subjected to step (d).
10. The method of claim 9 wherein prior to step (d) such slurry of solids and water is caused to pass through a heat exchanger countercurrently to the product of step (a) to cool such product and to heat the slurry by indirect heat exchange.
11. The method of claim 1 wherein the solids separated in step (f) are washed to displace accompanying liquid aqueous phase resulting from step (d) and the washed solids are formed into a slurry with added water.
12. The method of claim 11 wherein said slurry is subjected to oxidation by molecular oxygen under con-ditions to break down the lignin to soluble organic pro-ducts and resulting in a solution of such products.
13. The method of claim 12 wherein such solution is caused to undergo indirect, countercurrent heat exchange with incoming slurry to heat the slurry and cool the solution.
14. The method of claim 1 wherein the solid phase separated in step (c) is subjected to attrition to reduce the particle size and predispose the solid phase to hydrolytic action in step (d).
15. A method of producing low molecular weight organic materials of commercial value from lignocellulosic raw material which comprises the following steps:
(a) subjecting the lignocellulosic material to hydrolysis under conditions whereby the more readily cleaved polysaccharide components are depolymerized to soluble products and leaving an insoluble residue of more difficultly cleaved polysaccharides and ligneous material;
(b) separating the liquid phase from the product of step (a);
(c) separating the solids resulting from step (a) and subjecting the thus separated solids in admixture with water to more severe hydrolytic action to depolymerize cellulose and to convert a major portion of the cellulose to glucose;
(d) separating the liquid resulting from step (c) and recycling it to step (a);
(e) separating the solids resulting from step (c) and subjecting them in admixture with water to oxidative action to break down the lignin to low molecular weight organic materials;
(f) subjecting the liquid separated in step (b) to fermentation to produce ethanol;
(g) separating from the product of step (f) the ethanol from a higher boiling fraction;
(h) subjecting said higher boiling fraction to methanation to produce methane; and (i) so conducting steps (a) through (h) as to minimize the degradation of monosaccharides produced by hydrolysis, to maximize the production of ethanol and methane, to minimize the production of carbon dioxide and carbon monoxide and to minimize the residue of insoluble solids.
(a) subjecting the lignocellulosic material to hydrolysis under conditions whereby the more readily cleaved polysaccharide components are depolymerized to soluble products and leaving an insoluble residue of more difficultly cleaved polysaccharides and ligneous material;
(b) separating the liquid phase from the product of step (a);
(c) separating the solids resulting from step (a) and subjecting the thus separated solids in admixture with water to more severe hydrolytic action to depolymerize cellulose and to convert a major portion of the cellulose to glucose;
(d) separating the liquid resulting from step (c) and recycling it to step (a);
(e) separating the solids resulting from step (c) and subjecting them in admixture with water to oxidative action to break down the lignin to low molecular weight organic materials;
(f) subjecting the liquid separated in step (b) to fermentation to produce ethanol;
(g) separating from the product of step (f) the ethanol from a higher boiling fraction;
(h) subjecting said higher boiling fraction to methanation to produce methane; and (i) so conducting steps (a) through (h) as to minimize the degradation of monosaccharides produced by hydrolysis, to maximize the production of ethanol and methane, to minimize the production of carbon dioxide and carbon monoxide and to minimize the residue of insoluble solids.
16. The method of claim 15 wherein solids subjected to step (c) are first subjected to oxidative treatment to modify the cellulose and predispose it to depolymerization.
17. A process of producing useful products from the still bottoms resulting from distillation of a slurry of an aqueous solution of ethanol and undissolved organic solids which comprises separating such still bottoms, subjecting the separated still bottoms to methanation to produce methane and carbon dioxide, separating from such methanation step a slurry of undissolved organic solids and subjecting such separated slurry to oxidation by contact with molecular oxygen at an elevated temperature thereby breaking down at least a portion of such undissolved solids into soluble organic materials and separating from such oxidation step a solution of such soluble organic materials.
18. The process of claim 17 wherein any undissolved solids resulting from oxidation are recycled to the oxidation step.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US2333879A | 1979-03-23 | 1979-03-23 | |
| US023,338 | 1979-03-23 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1175820A true CA1175820A (en) | 1984-10-09 |
Family
ID=21814512
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000348089A Expired CA1175820A (en) | 1979-03-23 | 1980-03-21 | Utilization of cellulosic and lignocellulosic materials |
Country Status (4)
| Country | Link |
|---|---|
| JP (1) | JPS55127999A (en) |
| AU (1) | AU550028B2 (en) |
| CA (1) | CA1175820A (en) |
| NZ (1) | NZ193139A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2008095349A1 (en) * | 2007-02-01 | 2008-08-14 | China Fuel (Huaibei) Bioenergy Technology Development Co. Ltd. | Liquid fuel production process from cellulose biomass |
| CN109776461A (en) * | 2019-02-26 | 2019-05-21 | 东北农业大学 | A kind of co-production for producing furfural and methane product with stalk |
| US10612059B2 (en) | 2015-04-10 | 2020-04-07 | Comet Biorefining Inc. | Methods and compositions for the treatment of cellulosic biomass and products produced thereby |
| US10633461B2 (en) | 2018-05-10 | 2020-04-28 | Comet Biorefining Inc. | Compositions comprising glucose and hemicellulose and their use |
| CN113173997A (en) * | 2021-03-12 | 2021-07-27 | 广西大学 | Preparation method of alpha-pinene-based bagasse nanocellulose with drug slow-release performance |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4384897A (en) * | 1981-11-23 | 1983-05-24 | The Regents Of The University Of California | Method of treating biomass material |
| JP6177563B2 (en) * | 2013-01-31 | 2017-08-09 | 日本製紙株式会社 | Prehydrolyzate treatment system |
| JP6177535B2 (en) * | 2013-01-31 | 2017-08-09 | 日本製紙株式会社 | Prehydrolyzate treatment system |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5339261A (en) * | 1976-09-22 | 1978-04-11 | Anshiyutaruto Gemasu | Method and apparatus for continuous hydrolysis of pentoseecontaining substances |
| JPS5953040B2 (en) * | 1977-03-09 | 1984-12-22 | 味の素株式会社 | Manufacturing method of sugar solution |
| CH609092A5 (en) * | 1977-04-01 | 1979-02-15 | Battelle Memorial Institute |
-
1980
- 1980-03-17 NZ NZ193139A patent/NZ193139A/en unknown
- 1980-03-21 AU AU56725/80A patent/AU550028B2/en not_active Ceased
- 1980-03-21 CA CA000348089A patent/CA1175820A/en not_active Expired
- 1980-03-22 JP JP3580080A patent/JPS55127999A/en active Pending
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2008095349A1 (en) * | 2007-02-01 | 2008-08-14 | China Fuel (Huaibei) Bioenergy Technology Development Co. Ltd. | Liquid fuel production process from cellulose biomass |
| US8618341B2 (en) | 2007-02-01 | 2013-12-31 | China Fuel (Huaibei) Bioenergy Technology Development Co. Ltd | Process of producing liquid fuel from cellulosic biomass |
| US10612059B2 (en) | 2015-04-10 | 2020-04-07 | Comet Biorefining Inc. | Methods and compositions for the treatment of cellulosic biomass and products produced thereby |
| US11692211B2 (en) | 2015-04-10 | 2023-07-04 | Comet Biorefining Inc. | Methods and compositions for the treatment of cellulosic biomass and products produced thereby |
| US10633461B2 (en) | 2018-05-10 | 2020-04-28 | Comet Biorefining Inc. | Compositions comprising glucose and hemicellulose and their use |
| US11525016B2 (en) | 2018-05-10 | 2022-12-13 | Comet Biorefining Inc. | Compositions comprising glucose and hemicellulose and their use |
| CN109776461A (en) * | 2019-02-26 | 2019-05-21 | 东北农业大学 | A kind of co-production for producing furfural and methane product with stalk |
| CN113173997A (en) * | 2021-03-12 | 2021-07-27 | 广西大学 | Preparation method of alpha-pinene-based bagasse nanocellulose with drug slow-release performance |
| CN113173997B (en) * | 2021-03-12 | 2022-08-09 | 广西大学 | Preparation method of alpha-pinene-based bagasse nanocellulose with drug slow-release performance |
Also Published As
| Publication number | Publication date |
|---|---|
| NZ193139A (en) | 1982-05-25 |
| JPS55127999A (en) | 1980-10-03 |
| AU5672580A (en) | 1980-09-25 |
| AU550028B2 (en) | 1986-02-27 |
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