Biomass Pyrolysis Oil Feedstocks for Phenolic ... - ACS Publications

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Chapter 11 Biomass Pyrolysis Oil Feedstocks for Phenolic Adhesives H e l e n a C h u m , James D i e b o l d , J o h n Scahill, D a v i d Johnson, and Stuart Black Solar Energy Research Institute Golden, CO 80401

H e r b e r t Schroeder

R o l a n d E. K r e i b i c h

Colorado State University

4201 South 344th Street

Fort Collins, CO 80523

A u b u r n , W A 98001

Fast p y r o l y s i s o f pine sawdust i n a s m a l l v o r t e x reactor o p e r a t i n g at 10 to 20 kg/h a n d 480 t o 520 ° C produces h i g h y i e l d s o f pri mary p y r o l y s i s oils (over 5 5 % b y weight o n a d r y basis). T h e v o r t e x reactor t r a n s m i t s very h i g h heat fluxes t o the s a w d u s t , c a u s i n g pri marily d e p o l y m e r i z a t i o n o f the constituent p o l y m e r s i n t o m o n o m e r s a n d oligomers. A p r e l i m i n a r y scheme separates t h e r a w oils i n t o a c a r b o h y d r a t e - d e r i v e d aqueous f r a c t i o n a n d a p h e n o l i c - r i c h e t h y l a c etate (EA) soluble f r a c t i o n . T h e EA f r a c t i o n is washed w i t h water a n d w i t h aqueous s o d i u m b i c a r b o n a t e t o remove acids y i e l d i n g 2 0 % t o 2 5 % o f the feed as phenols a n d neutrals (P/N) in t h e EA s o l u t i o n . A f t e r ΕA e v a p o r a t i o n , a novolak f o r m u l a t i o n with 5 0 % p h e n o l a n d 5 0 % o f the P/N f r a c t i o n was successfully p r e p a r e d . G e l times for t h e P/N fractions s u i t a b l y prepared are i n t e r m e d i a t e between resorcinol a n d t r a d i t i o n a l phenol-formaldehyde resins. P r e l i m i n a r y p r o j e c t e d a m o r t i z e d p r o d u c t i o n costs for the P/N f r a c t i o n are 10(16) cents per p o u n d for a 1,000(250) tons per d a y p l a n t ( $ 1 0 / d r y t o n feedstock, 1 5 % interest w i t h 20-year a m o r t i z a t i o n ) . P y r o l y s i s o f biomass is k n o w n t o produce a c o m p l e x m i x t u r e o f p h e n o l i c c o m p o u n d s , w h i c h are derived p r i m a r i l y f r o m the l i g n i n f r a c t i o n o f t h e biomass (1-4)- E l d e r a n d Soltes (5, 6) have investigated a p h e n o l i c f r a c t i o n o b t a i n e d f r o m p y r o l y s i s oils m a d e i n a n u p draft gasifier b y T E C H A I R as a source o f p h e n o l i c adhesives; a phenolics f r a c t i o n was separated b y s o l u b i l i t y differences o f o i l fractions based o n s o l u b i l i t y o f acids i n aqueous b i c a r b o n a t e s o l u t i o n s a n d 0097-6156/89/0385-0135$06.00A)

c

1989 American Chemical Society

In Adhesives from Renewable Resources; Hemingway, R., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 1989.


136

ADHESIVES F R O M RENEWABLE RESOURCES

s o l u b i l i t y o f the phenolics f r a c t i o n i n aqueous a l k a l i s o l u t i o n . A d h e s i v e f o r m u l a t i o n s were p r e l i m i n a r i l y tested, a n d the effect o f a few m e t a l ions (such as b a r i u m ) o n the gel t i m e s of adhesives was m e a s u r e d . T h e f o r m u l a t i o n s tested m e t w i t h l i m i t e d success. These results suggested t h a t these oils w o u l d have to be c h e m i c a l l y m o d i f i e d t o be a f u l l replacement for p h e n o l or c o u l d be c o n s i d ered as s i m p l e extenders for p e t r o l e u m - d e r i v e d p h e n o l . R u s s e l l a n d R e i n m a t h ( 7 ) have e m p l o y e d a s i m i l a r f r a c t i o n a t i o n m e t h o d o n oils f r o m high-pressure b i o m a s s l i q u e f a c t i o n (8). A l i m i t e d a m o u n t o f adhesive t e s t i n g was c a r r i e d o u t , a n d a few b o n d e d w o o d specimens were s h o w n t o have tensile strengths s u p e r i o r t o the adhesive b o n d o f a c o m m e r c i a l b i r c h veneer (9). T h i s chapter describes the i n i t i a l results of c o n v e r t i n g waste sawdust i n t o phenolics t h r o u g h fast p y r o l y s i s e m p l o y i n g a v o r t e x reactor a n d a very fast heat transfer t o d e p o l y m e r i z e b i o m a s s i n t o m o n o m e r i c a n d o l i g o m e r i c c o m p o n e n t s . T h e p y r o l y s i s m e t h o d a n d the c h e m i c a l f r a c t i o n a t i o n e m p l o y e d t o isolate the p h e n o l i c - r i c h f r a c t i o n used i n the subsequent adhesive gel t e s t i n g are d e s c r i b e d . R e s u l t s o f a n e c o n o m i c e v a l u a t i o n o f the process are presented as w e l l as the c h a r a c t e r i z a t i o n o f the p h e n o l i c - r i c h m a t e r i a l . A n o v o l a k a n d a resol were successfully p r e p a r e d w i t h these c o m p o u n d s . Experimental

Methodology

P r i m a r y P y r o l y s i s V a p o r G e n e r a t i o n i n t h e V o r t e x R e a c t o r (10). T h e p y r o l y s i s reactor used t o generate the p y r o l y s i s oils is s h o w n s c h e m a t i c a l l y i n F i g u r e 1. C o a r s e softwood sawdust ( < 5 m m ) was metered by a screw feeder i n t o the e n t r a i n e d s o l i d s / g a s flow f r o m the e x i t o f the recycle l o o p . T h e I D o f the 300 series stainless steel recycle l o o p was 11 m m . N i t r o g e n was used as the carrier gas r a t h e r t h a n s t e a m . T h e e n t r a i n e d particles flowed t o the n i t r o g e n ejector where t h e y were accelerated b y the supersonic j e t t o velocities over 100 m / s . T h e fastm o v i n g e n t r a i n e d solids flow t h e n entered t a n g e n t i a l l y i n t o the v o r t e x reactor. Inside the v o r t e x reactor, the b i o m a s s particles were centrifuged to the w a l l a n d were forced i n t o a n a b n o r m a l l y t i g h t h e l i c a l p a t h t h r o u g h the reactor. A s the p a r t i c l e s s l i d a n d b o u n c e d o n the w a l l , they were i n excellent t h e r m a l contact w i t h the e x t e r n a l l y heated w a l l m a i n t a i n e d at 625 ° C . U n d e r these c o n d i t i o n s , the p a r t i c l e surface is very r a p i d l y heated t o a b o u t 450 ° C , where p y r o l y s i s to oils is f a v o r e d . T h e d i a m e t e r o f the v o r t e x t u b e reactor was 13 c m , a n d i t s l e n g t h was 70 c m . A 5 - c m - d i a m e t e r , a x i a l e x i t t u b e p r o t r u d e d i n t o t h e aft e n d of the v o r t e x reactor, w h i c h served t o encourage p a r t i a l l y p y r o l y z e d feedstock a n d large char p a r t i c l e s t o enter the recycle l o o p . T h e feedstock was recycled u n t i l i t was f u l l y p y r o l y z e d , w h i c h allowed a d e c o u p l i n g o f the t i m e r e q u i r e d t o p y r o l y z e the feedstock p a r t i c l e s a n d the gaseous residence t i m e . T h e a b i l i t y of the carrier gas ejector t o create a pressure differential across the recycle l o o p d e t e r m i n e d the rate o f gas flow i n the recycle l o o p . T h e pressure o f the s y s t e m was a d j u s t e d t o m a i n t a i n the feed hopper at a b o u t 250 P a above a t m o s p h e r i c pressure ( 2 . 5 - c m water c o l u m n ) b y r e s t r i c t i n g the flow o u t o f the s y s t e m . T h e


11.

C H U M E T AL.

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Biomass Pyrolysis Oil Feedstocks


char was r e m o v e d i n a hot cyclone. T y p i c a l t h r o u g h p u t for t h i s reactor is 10 t o 20 k g o f sawdust per h o u r w i t h 1- t o 2 - k g carrier gas per k i l o g r a m o f s a w d u s t . O i l C o l l e c t i o n . T h e p y r o l y s i s oils were collected i n a series o f condensers followed b y a coalescing filter t o remove r e s i d u a l aerosols, as s h o w n i n F i g u r e 2. T h e first condenser was a c y c l o n i c condenser 37 c m i n d i a m e t e r w i t h a 4 5 - c m - h i g h c y l i n d r i c a l section. T h e t a n g e n t i a l e n t r y was a r o u n d 5-cm t u b e . T h i s cyclone was w r a p p e d w i t h copper t u b i n g , t h r o u g h w h i c h c h i l l e d water c i r c u l a t e d at a b o u t 20 ° C . T h e c o o l i n g coils were e x t e r n a l l y i r r i g a t e d w i t h water t o transfer the heat f r o m the cyclone w a l l t o the c o o l i n g w a t e r . Inside a n d o u t s i d e the a x i a l o u t l e t o f the cyclone condenser were a d d i t i o n a l c o o l i n g coils. T h e p i p e c o n n e c t i n g the first a n d second condenser was also w r a p p e d w i t h a c h i l l e d water c o o l i n g c o i l a n d a d r a i n was p r o v i d e d for condensate. T h e second condenser consisted of a v e r t i c a l v o r t e x t u b e h a v i n g a 7.5-cm d i a m e t e r w i t h a r e c t a n g u l a r entrance m a d e f r o m a 1.7-cm I D t u b e a n d w i t h the a x i a l o u t l e t near the t a n g e n t i a l entrance. T h e v o r t e x t u b e condenser was cooled b y refrigerated g l y c o l at 2 ° C , w h i c h was c i r c u l a t e d t h r o u g h a copper t u b e w r a p p e d a r o u n d the O D . T h e t h i r d condenser was a 2 0 - L glass c a r b o y i m m e r s e d i n a d r y ice a n d p r o p a n o l b a t h . T h e e n t e r i n g gases were t a n g e n t i a l l y directed o n t o the I D of the carboy. T h e gas a n d aerosol s t r e a m t h e n passed t o the coalescing filter to remove the aerosols. E x c e p t for the glass carboy, the o i l c o l l e c t i o n s y s t e m was stainless steel, since the oils have been s h o w n t o be corrosive t o i r o n a n d z i n c (galvanized i r o n ) . F r a c t i o n a t i o n o f P y r o l y s i s O i l s . P y r o l y s i s o i l o b t a i n e d f r o m the v o r t e x re actor was f r a c t i o n a t e d a c c o r d i n g to the scheme s h o w n i n F i g u r e 3. W h o l e o i l (1 kg) was dissolved i n e t h y l acetate ( E A ) o n a 1:1 ( w / w ) basis. T h e o i l was t h e n v a c u u m filtered t h r o u g h filter paper t o remove fine c h a r . U p o n s t a n d i n g , the E A / p y r o l y s i s o i l separated i n t o t w o p h a s e s - a n o r g a n i c r i c h , E A - s o l u b l e phase a n d a n E A - i n s o l u b l e phase. M o s t of the water f o r m e d d u r i n g p y r o l y s i s is c o n t a i n e d i n the E A - i n s o l u b l e phase. T h e E A - s o l u b l e p o r t i o n o f the o i l was washed w i t h water (2 χ 75 m L ) t o remove the r e m a i n i n g w a t e r - s o l u b l e derived products. T h e E A - s o l u b l e phase was t h e n e x t r a c t e d w i t h N a H C 0 ( 5 % w / w , 10 χ 200 m L ) a n d the aqueous layer saved for i s o l a t i o n of the o r g a n i c acids f r a c t i o n . T h e solvent was r e m o v e d f r o m the r e m a i n i n g E A - s o l u b l e f r a c t i o n , w h i c h c o n t a i n e d the p h e n o l i c a n d n e u t r a l s ( P / N ) f r a c t i o n s , o n a r o t o e v a p o r a t o r u n t i l n o Ε A d i s t i l l e d over. T h e Ε A was not d r i e d p r i o r t o e v a p o r a t i o n , b u t r a t h e r , water was azeotroped d u r i n g the d i s t i l l a t i o n . F i n a l water contents of each f r a c t i o n were 0.5 t o 1.0% b y weight. 3

T h e o r g a n i c acids f r a c t i o n was i s o l a t e d b y a c i d i f y i n g the aqueous layer ( p H 2) w i t h 5 0 % H3PO4, s a t u r a t i n g the s o l u t i o n w i t h N a C l , a n d e x t r a c t i n g the o r g a n i c layer w i t h fresh E A . Solvent was removed b y r o t o e v a p o r a t i o n . T h e water-soluble a n d E A - i n s o l u b l e fractions were also i s o l a t e d b y r o t o e v a p o r a t i o n .



138


F i g u r e 1. S c h e m a t i c o f v o r t e x reactor for fast p y r o l y s i s .

Pyrolysis Gases Coalescing Filter

Pyrolysis Vapors 400 C

Cyclone Condenser

Dry Ice/ Propanol Vortex Condenser

F i g u r e 2. S c h e m a t i c o f p y r o l y s i s o i l c o n d e n s a t i o n t r a i n .


11.

C H U M ET AL.

Methods

of

139


Analysis.

Water

Content

of Fractions.

A

chromatographic

m e t h o d was e m p l o y e d u s i n g a glass c o l u m n (6 ft χ 0.2 m m I D ) p a c k e d w i t h P o r a p a k Q S . T h e c h r o m a t o g r a p h s used were a V a r i a n 3700 or a H e w l e t t P a c k a r d 5880. W a t e r contents were also d e t e r m i n e d b y the K a r l F i s h e r m e t h o d b y H u f f m a n Laboratories, Golden, Colorado. Total Carboxyl employed

S c h u e r c h (11)


and Phenolic

Hydroxyl

Content.

were m o d i f i c a t i o n s o f the procedure for l i g n i n t o t a l p h e n o l i c content.

Conductimetric titrations

described by

Sarkanen and

Spectroscopic determinations

o n t h e p h e n o l i c s a n d n e u t r a l s f r a c t i o n s were c a r r i e d o u t u s i n g the J E O L F X - 9 0 0 F o u r i e r T r a n s f o r m N M R s p e c t r o m e t e r a n d the N i c o l e t 5 S X C F o u r i e r T r a n s f o r m I n f r a r e d S p e c t r o m e t e r . I n a d d i t i o n , the s o l i d state C P / M A S

1 3

C - N M R spectra

were o b t a i n e d b y the R e g i o n a l N M R C e n t e r at C o l o r a d o S t a t e U n i v e r s i t y u s i n g c o n d i t i o n s d e s c r i b e d i n B r y s o n et a l . High

Performance

Size

Exclusion

(12). Chromatography.

The Hewlett-Packard

1090 l i q u i d c h r o m a t o g r a p h was used w i t h the H P 1040 d i o d e a r r a y or H P 1 0 3 7 A refractive i n d e x ( a n d H P 3392 i n t e g r a t o r ) detectors.

A fifty Â (5 m m , 300

χ 7 m m ) P o l y m e r L a b o r a t o r i e s P L gel ( p o l y s t y r e n e - d i v i n y l b e n z e n e c o p o l y m e r gel) c o l u m n was used a n d s t a n d a r d s were as d e s c r i b e d i n C h u m et a l .

(13).

T e t r a h y d r o f u r a n s o l u t i o n s o f o i l a n d o i l f r a c t i o n s were a n a l y z e d . Molecular-Β

earn M ass-Spectrometry.

T h i s p r o c e d u r e was c a r r i e d o u t

e q u i p m e n t d e s c r i b e d by E v a n s a n d M i l n e (14)·

on

P y r o l y s i s o f the o i l s (or frac

t i o n s ) was p e r f o r m e d u n d e r c o n t r o l l e d c o n d i t i o n s a n d followed i n r e a l t i m e b y a free-jet, m o l e c u l a r b e a m M S . P y r o l y s i s p r o d u c t s a n d f r a g m e n t a t i o n ions were detected. A d h e s i v e T e s t i n g . A l l gel t i m e s o f the adhesive resins were d e t e r m i n e d u s i n g a s t i r r i n g a p p a r a t u s , w h i c h consisted of a 1 5 0 - m m l o n g , 2 5 - m m O D d i s p o s a b l e b o r o s i l i c a t e test t u b e t o w h i c h a t o t a l o f 5.0-g of resin p l u s a n y a d d i t i o n a l c o m p o n e n t was a d d e d . T h e v o l u m e i n the test t u b e was s u c h t h a t a p p r o x i m a t e l y 15 m m above the o u t s i d e b o t t o m e n d was filled w i t h m a t e r i a l . A 6 - m m glass r o d w i t h a f i r e - p o l i s h e d , c i r c u l a r t i p was fastened t o be p a r a l l e l t o a second 6 - m m glass r o d u s i n g two m i n i a t u r e ( 8 - m m w i d e ) w o r m - d r i v e hose c l a m p s . T h e second glass r o d was i n s e r t e d i n t o the chuck o f a low t o r q u e s t i r r i n g m o t o r . W i t h t h i s a r r a n g e m e n t , a t h i c k c y l i n d r i c a l p a t h was s t i r r e d t h a t averaged o n l y 2.5 m m f r o m the test t u b e w a l l , w i t h the result t h a t the s t i r r i n g r o d d i d not f o r m a hole i n the g e l l i n g r e s i n .

O n c e the s t i r r i n g was b e g u n , a p r e h e a t e d ,

m a g n e t i c a l l y s t i r r e d m o l t e n w a x b a t h was r a i s e d r a p i d l y s u c h t h a t t h e lower 40 m m o f the test t u b e was s u b m e r g e d . G e l t i m e s were f r o m i n i t i a l submergence of the test t u b e i n t o the w a x b a t h u n t i l the s t i r r i n g was s t o p p e d b y the g e l l i n g r e s i n . T h e s t i r r e r power s e t t i n g was kept c o n s t a n t , a n d a l l resin gel t i m e s were c o m p a r e d w i t h t h a t for fresh C a s c o p h e n 313 ( B o r d e n C h e m i c a l s l i q u i d p h e n o l f o r m a l d e h y d e resol w i t h 4 0 % s o l i d fillers used w i t h 2 . 5 % N a O H t o have a p H o f 11) d e t e r m i n e d at the same b a t h t e m p e r a t u r e . G e l t i m e s at the same b a t h t e m p e r a t u r e were r e p r o d u c i b l e w i t h i n 1 0 % o f each o t h e r a n d were often m u c h closer together. W h e n the gel t i m e was less t h a n 6 m i n u t e s , i t was r e d e t e r m i n e d


140


at a lower t e m p e r a t u r e because there were i n d i c a t i o n s t h a t , at v e r y s h o r t gel t i m e s , the rate o f heat transfer became the d e t e r m i n i n g f a c t o r . N o v o l a k s were p r e p a r e d u s i n g a p h e n o l - t o - f o r m a l d e h y d e m o l a r r a t i o o f 4:1 w i t h 5 m o l e percent o f H S 0 a d d e d as a c a t a l y s t . T y p i c a l l y , 47 g l i q u i d p h e n o l ( 9 1 . 7 % assay), 3 g p a r a f o r m a l d e h y d e , a n d 30 m L water p l u s the r e q u i r e d a c i d c a t a l y s t were a d d e d t o a three-neck, 2 5 0 - m L r o u n d b o t t o m flask. T h e flask was f i t t e d w i t h a reflux condenser a n d s t i r r e r . T h e m i x t u r e was refluxed for 2 t o 4 h o u r s w i t h the o i l b a t h at 115 ° C ; t h e n , the m i x t u r e was n e u t r a l i z e d w i t h 5 0 % ( w / w ) N a O H a n d the excess p h e n o l removed b y s t e a m d i s t i l l a t i o n for 5 t o 6 h o u r s . T h e r e m a i n i n g viscous o i l y residue was washed r e p e a t e d l y w i t h b o i l i n g water. A n o v o l a k w i t h the P / N f r a c t i o n was p r e p a r e d as described above w i t h 1:1 b y v o l u m e p h e n o l a n d P / N f r a c t i o n a n d h a l f o f the a m o u n t of f o r m a l d e h y d e . Initial wood-gluing testing w i t h this novolak indicates wood failure rather t h a n glueline f a i l u r e .


2

4

T o prepare m a t e r i a l for gel t e s t i n g , 2 moles o f p a r a f o r m a l d e h y d e were a d d e d per m o l e o f p h e n o l i c h y d r o x y l . T h e p H was v a r i e d b y a d d i n g aqueous 5 0 % ( w / w ) N a O H dropwise w i t h r a p i d s t i r r i n g . A l l o f t h i s was done i n the disposable b o r o s i l i c a t e test t u b e . T o t a l a m o u n t o f a l l r e s i n f o r m u l a t i o n i n the test t u b e was always a d j u s t e d t o 5.0 g. T h e p y r o l y s i s oils were u s u a l l y s o l u b i l i z e d first b y a d d i n g sufficient N a O H . Results and Discussion F a s t P y r o l y s i s G l o b a l R e a c t i o n s . T h e p y r o l y s i s o f b i o m a s s occurs t h r o u g h a large n u m b e r o f reactions t h a t c a n be g r o u p e d i n t o : 1) d e h y d r a t i o n reactions t h a t f o r m c h a r , w a t e r , a n d a s m a l l a m o u n t o f c a r b o n oxides; a n d 2) d e p o l y m e r i z a t i o n reactions t h a t f o r m m o n o m e r fragments, m o n o m e r s , a n d o l i g o m e r s , w h i c h are o f interest for p h e n o l i c adhesive p r o d u c t i o n . H o w e v e r , as s h o w n i n F i g u r e 4, the p o l y m e r fragments are very reactive, a n d they q u i t e r e a d i l y u n dergo secondary reactions t o f o r m gases a n d m o r e stable o r g a n i c c o m p o u n d s (e.g., p o l y c y c l i c a r o m a t i c t a r s ) . A t low t e m p e r a t u r e s , the d e h y d r a t i o n reactions t h a t favor char f o r m a t i o n are faster t h a n t h e d e p o l y m e r i z a t i o n reactions t h a t f o r m p r i m a r y p y r o l y s i s o i l v a p o r s . However, the d e p o l y m e r i z a t i o n reactions are s t r o n g l y favored at elevated t e m p e r a t u r e s . C o n s e q u e n t l y , i t is necessary t o q u i c k l y heat the b i o m a s s p a r t i c l e s to elevated t e m p e r a t u r e s ( > 4 0 0 ° C ) to m a x i m i z e the p y r o l y s i s o i l y i e l d s a n d t h e n t o r a p i d l y c o o l the p r o d u c t v a p o r s . T h i s r a p i d h e a t i n g requires a large heat flux be p r o v i d e d t o the b i o m a s s s u r face, w h i c h c o n v e n t i o n a l l y w o u l d be achieved by u s i n g very h i g h t e m p e r a t u r e s . However, t h e presence o f the h i g h t e m p e r a t u r e s has the u n d e s i r a b l e effect of excessively h e a t i n g the o i l vapors t o cause some o f t h e m t o decompose t o gases (15). A n a l t e r n a t e m e t h o d o f s u p p l y i n g the large heat fluxes is to use a heat transfer m e c h a n i s m t h a t has a r e l a t i v e l y large heat transfer coefficient. F o r a c h i e v i n g these heat transfer p h e n o m e n a i n a c h e m i c a l reactor, a n e x t e r n a l l y heated v o r t e x t u b e was selected (16). T h e advantage o f t h i s reactor s y s t e m


11.

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141

Biomass Pyrolysis Oil Feedstock


#79, 15% water, pH 2.8 Whole Oil I DiMotw In EtOAc/FIIter

—•Char: 3%

ι

EtOAc Insol: 29%

I

EtOAc Sol: 71% —Water -NaHC0

WS: 37% A: 7%

3

— Evaporate

P/N: 26%

Figure 3. Pine sawdust pyrolysis o i l fractionation scheme. Yields are on a dry basis.

Secondary Tare

Macropolymerlc Blomaee Solids

Monomerlc Primary Vapors

Ollgomerlc Liquids Macropolymer Char Solids • H 0• C0 2

X

Secondary Gaeee

F i g u r e 4. B i o m a s s p y r o l y s i s g l o b a l m e c h a n i s m .


142


is the h i g h y i e l d s of p y r o l y s i s oils a n d the h i g h heat transfer possible f r o m the w a l l t o the b i o m a s s , w h i c h translates t o a r e l a t i v e l y s m a l l reactor w i t h a h i g h


throughput

(10).

O i l C o l l e c t i o n . T a b l e I shows the t e m p e r a t u r e of the process s t r e a m as i t passed t h r o u g h the heat exchangers, as w e l l as the a m o u n t a n d m o i s t u r e content of condensate collected at each l o c a t i o n . F o r R u n 83, t h i s o i l c o l l e c t i o n t r a i n d e m o n s t r a t e d a wet o i l recovery of 6 7 % of the d r y feedstock for a mass closure of 9 4 % . T h e wet o i l c o n t a i n e d a n average of 1 8 % water of p y r o l y s i s for a recovered y i e l d of 5 5 % d r y p y r o l y s i s o i l .

T a b l e I. P r i m a r y O i l C o l l e c t i o n T r a i n ( R u n 83)

Exit Temperature °C 15-Inch-diameter c y c l o n i c condenser 1-Inch-diameter transfer l i n e H X R 3-Inch-diameter v o r t e x condenser Dry-ice trap C o a l e s c i n g filter Total

50 40 30 -17 -17

Weight Percent of Dry Oil

H 0 Weight Percent in Wet Oil

50 21

20 10 8 30 31 18

23 11 5 100

2

T h e c o l l e c t i o n of the p y r o l y s i s oils is difficult due t o t h e i r tendency t o f o r m aerosols a n d also due t o the v o l a t i l e n a t u r e of m a n y of the o i l c o n s t i t u e n t s . A s the aerosols agglomerate i n t o larger droplets, they c a n be removed b y c y c l o n i c separators. However, the s u b m i c r o n aerosols cannot be efficiently collected b y c y c l o n i c or i n e r t i a l techniques, a n d c o l l e c t i o n b y i m p a c t of the aerosols due to t h e i r B r o w n i a n or r a n d o m m o t i o n m u s t be u t i l i z e d . A coalescing filter is r e l a t i v e l y p o r o u s , b u t i t contains a large surface area for the aerosol p a r t i c l e s to i m p a c t b y B r o w n i a n m o t i o n as t h e y are swept t h r o u g h b y the p y r o l y s i s gases. O n c e the aerosol droplets i m p a c t the filter fibers, t h e y are c a p t u r e d a n d coalesce i n t o large drops t h a t c a n flow d o w n the fibers a n d be collected. P y r o l y s i s Y i e l d s . Before the present c o l l e c t i o n s y s t e m h a d been developed, mass a n d e l e m e n t a l balances showed t h a t the y i e l d s of o x y g e n a t e d p y r o l y s i s oils generated i n the v o r t e x reactor m u s t be very h i g h a n d t h a t the observed large lack of mass balance closure c o u l d not be due t o large water y i e l d s . B a s e d o n e l e m e n t a l a n a l y s i s of the char, o i l , a n d gases, a char y i e l d of 1 2 . 7 % corresponds to c a l c u l a t e d y i e l d s of 6 9 % o i l v a p o r s , 1 4 % water, a n d 4 . 3 % gases. W i t h o u t the recycle l o o p , gas y i e l d s have been observed to be i n the 3 t o 4 % range of the p y r o l y z e d feedstock. However, w i t h the recycle l o o p i n s t a l l e d , the gas y i e l d s


11.

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143


were seen t o increase t o a b o u t 1 4 % due t o a n increase i n the c r a c k i n g of the o i l v a p o r s t o a c h a r a c t e r i s t i c a l l y different slate of p e r m a n e n t gases (15).

Minor

changes i n the o p e r a t i o n of t h e v o r t e x reactor are e x p e c t e d t o reduce the gas y i e l d s i n the f u t u r e a n d t o result i n e n h a n c e d p y r o l y s i s o i l y i e l d s . P h e n o l i c s / N e u t r a l s f o r A d h e s i v e s . T h e f r a c t i o n a t i o n scheme d e s c r i b e d i n F i g u r e 3 allowed the i s o l a t i o n o f 2 1 % t o 3 1 % of the s t a r t i n g o i l as a P / N f r a c t i o n ,


as s h o w n i n T a b l e I I . T h i s f r a c t i o n consists o f 7 3 % p h e n o l i c s , e x t r a c t able b y aqueous s o d i u m h y d r o x i d e s o l u t i o n f r o m a n e t h y l acetate s o l u t i o n , a n d 2 7 % neutrals.

T h e t o t a l y i e l d of the P / N f r a c t i o n was r e p r o d u c i b l e (cf.

r u n s 79

a n d 83 i n T a b l e I I ) . I s o l a t i o n of the P / N f r a c t i o n f r o m o i l s condensed f r o m the c y c l o n e a n d t r a n s f e r - l i n e heat exchanger i n d i c a t e s t h a t the P / N f r a c t i o n p r e d o m i n a t e s i n the t r a n s f e r - l i n e heat exchanger condensate.

E x p e r i m e n t 78

was collected f r o m the c y c l o n i c condenser, a n d t h u s , the results c o m p a r e w e l l w i t h those f r o m e x p e r i m e n t 81 A .

T a b l e I I . F r a c t i o n a t i o n of S a w d u s t P y r o l y s i s O i l s Y i e l d s (% o n d r y o i l basis) Ethyl Acids

Phenols/

Experiment

Acetate

Water

No.

Insoluble

Soluble

78

43

25

6

21

79

29

37

7

26

81

23

39

7

31

8 1 A - cyclone

45

26

5

23

8 1 B - heat exchanger

20

28

9

47

Neutrals

T h e typical whole o i l contained about 6.2% and 0.4% phenolic hydroxy and c a r b o x y l i c a c i d contents, respectively. T h e P / N f r a c t i o n c o n t a i n e d 6 . 6 % p h e n o l i c h y d r o x y a n d n o c a r b o x y l i c a c i d content, whereas, the acids f r a c t i o n c o n t a i n e d 9 . 2 % a n d 0 . 9 % o f p h e n o l i c h y d r o x y a n d c a r b o x y l i c a c i d contents, respectively. T h e a p p a r e n t m o l e c u l a r weight d i s t r i b u t i o n s of selected f r a c t i o n s of i s o l a t e d o i l c o m p o n e n t s are s h o w n i n F i g u r e 5.

T h e phenols f r a c t i o n c o n t a i n e d the

highest a p p a r e n t m o l e c u l a r weight c o m p o n e n t s , a n d t h e i r a b s o r p t i o n s p e c t r a i n the U V region resembled t h a t of l o w - m o l e c u l a r - w e i g h t l i g n i n s . F r o m the m o l e c u l a r b e a m M S o f the p y r o l y s i s p r o d u c t s o f the P / N f r a c t i o n s , a n u m b e r of p h e n o l i c c o m p o u n d s were detected:

guaiacol

(2-methoxyphenol)

( m / z 124), catechols ( m / z 110), isomers o f s u b s t i t u t e d 2 - m e t h o x y p h e n o l s a l k y l groups such as m e t h y l ( m / z 138), v i n y l ( m / z 150),

with

3-hydroxy-propen(l)-

y l ( m / z 180), a l l y l ( m / z 164), h y d r o x y e t h y l ( m / z 168), a n d e t h y l (152), m o s t l i k e l y i n the para p o s i t i o n .

I n a d d i t i o n , a few c a r b o h y d r a t e - d e r i v e d

compo-

nents are also present i n t h i s f r a c t i o n such as f u r f u r y l a l c o h o l a n d o t h e r f u r f u r a l derivatives.



144


W h o l e Oil

Acids

F i g u r e 5. H i g h - p e r f o r m a n c e size e x c l u s i o n c h r o m a t o g r a m s o f pine sawdust p y r o l y s i s oils a n d fractions o f acids, phenols, a n d n e u t r a l s c o n t a i n e d i n the e t h y l acetate soluble o i l .


11.

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145


F r o m the p r o t o n N M R o f the P / N f r a c t i o n , of the t o t a l p r o t o n i n t e n s i t y , the a r o m a t i c p r o t o n s (6.5 t o 10 p p m ) c o n s t i t u t e 5 2 % , the a l i p h a t i c (1.5 t o 3.5 p p m ) a b o u t 2 0 % , a n d the m e t h o x y region (3.0 t o 4.2 p p m ) 3 0 % , w h i c h is i n agreement w i t h the p r o p o s e d c o m p o u n d s o b t a i n e d f r o m the m o l e c u l a r b e a m M S pyrolysis experiment. T h e

1 3

C - N M R s p e c t r a o f the P / N f r a c t i o n also i n d i c a t e d

m i x t u r e s o f c o m p o u n d s w i t h a r o m a t i c c a r b o n s i n the 110 t o 148 p p m r e g i o n , a


very p r o n o u n c e d m e t h o x y peak at 55.6 p p m , a n d a l i p h a t i c c a r b o n s . P r e l i m i n a r y A d h e s i v e T e s t i n g R e s u l t s . P h e n o l at a p H o f 11 w i t h t w i c e the m o l a r a m o u n t o f f o r m a l d e h y d e was c o m p a r e d w i t h C a s c o p h e n 313 ( c o m m e r c i a l s o f t w o o d p l y w o o d r e s i n b y B o r d e n C h e m i c a l s ) . A t 124 ° C , C a s c o p h e n 313 t o o k 12.2 m i n u t e s t o g e l , whereas, the p h e n o l w i t h a d d e d p a r a f o r m a l d e h y d e d i d not gel even after 30 m i n u t e s . T a b l e I I I .

T a b l e I I I . G e l T i m e s for C a s c o p h e n a n d P h e n o l i c s / N e u t r a l s from Pyrolysis Oils

pH

Temperature

Gel Time,

Equivalent

Percent

^C

Minutes

Cascophen T i m e

Equivalent T i m e

118

15.3

125

12.2

130

9.7

Cascophen

1

Phenols/Neutrals

2

9.0

3

127

12.0

11.1

9.5

4

127

5.2

11.1

9.5

124

3.7

12.6

9.5

112

6.2

18.2

29 34

9.5

101

10.8

23.4

46

9.5

89

24J)

29J)

-

h g C a s c o p h e n + 0.2 m L o f 5 0 % N a O H , p H 11.5.

x

2

4g

Phenol/neutrals from

sawdust

p y r o l y s i s oils reacted

with

1

g

p a r a f o r m a l d e h y d e a n d 0.5 m L of 5 0 % N a O H . 3

0 . 2 m L of 5 0 % N a O H .

4

0 . 4 m L of 5 0 % N a O H .

O f the v a r i o u s f r a c t i o n s of p y r o l y s i s o i l , o n l y the P / N f r a c t i o n gave a p o s i t i v e gel test u n d e r these c o n d i t i o n s . I n p r e l i m i n a r y gel t e s t i n g o f the P / N e x t r a c t , a r b i t r a r i l y 1 g o f p a r a f o r m a l d e h y d e was a d d e d to 4 g o f the e x t r a c t . T h e p H of



146


the e x t r a c t was a d j u s t e d b y a d d i n g 0.2 t o 0.8 m L of 5 0 % ( w / w ) N a O H . T h e r e a p p e a r e d t o be a s t r o n g buffering o f the p H b y the e x t r a c t at a p H o f 9.5. C a s c o p h e n 313 was used for c o m p a r i s o n . T h e i n f o r m a t i o n o b t a i n e d is presented i n T a b l e I I I . A t 0.5 m L of a d d e d N a O H , the gel t i m e of the P / N f r a c t i o n was m u c h shorter t h a n t h a t of the C a s c o p h e n , w i t h a gel t i m e of o n l y 2 9 % t h a t o f C a s c o p h e n at 124 ° C , at 112 ° C , i t was 3 4 % ; a n d at 101 ° C i t was 4 6 % t h a t o f C a s c o p h e n . A t the o r i g i n a l p H of 3 o f the P / N f r a c t i o n , there was no g e l l i n g o f the m i x t u r e even at 132 ° C w i t h the same a m o u n t o f a d d e d p a r a f o r m a l d e h y d e . T h e n o v o l a k s p r e p a r e d were characterized b y s o l i d - s t a t e C - N M R spec t r a . T h e peaks i n the C - N M R s p e c t r a o b t a i n e d i n t h i s s t u d y were assigned o n the basis of c o m p a r i s o n s w i t h s o l u t i o n - a n d s o l i d - s t a t e C - N M R of n o v o l a k s (12) a n d s o l u t i o n - s t a t e l i g n i n N M R s p e c t r a (17, 18). T h e s p e c t r a o f a p h e n o l - f o r m a l d e h y d e n o v o l a k a n d s i m i l a r n o v o l a k i n w h i c h 5 0 % b y v o l u m e of the p h e n o l was replaced b y the P / N f r a c t i o n f r o m the fast p y r o l y s i s o f p i n e sawdust are c o m p a r e d i n F i g u r e 6. T h e a u t h e n t i c n o v o l a k ( F i g u r e 6a) p r o d u c e d m a i n peaks ( f r o m d e c o n v o l u t i o n ) at 150, 130, a n d 120 p p m c o r r e s p o n d i n g t o hydroxy-substituted aromatic carbons, unsubstituted meia-aromatic carbons, a n d u n s u b s t i t u t e d p a r a - a r o m a t i c carbons, respectively; a n d i n the a l i p h a t i c re g i o n , the m a i n peaks are at 35 a n d 40 p p m , assigned t o ortho-para m e t h y l e n e bridges a n d para-para m e t h y l e n e bridges, respectively. T h e presence a n d i n t e n sity o f s u c h peaks c o r r e s p o n d t o the f o r m a t i o n o f r a n d o m n o v o l a k s as discussed by B r y s o n et a l . (12). O n s u b s t i t u t i o n o f p h e n o l w i t h the P / N f r a c t i o n ( F i g ure 6 b ) , the key peaks o f the r a n d o m n o v o l a k r e m a i n , b u t peaks c h a r a c t e r i s t i c of the types o f p h e n o l i c c o m p o u n d s present also appear such as at 155 p p m (metaa r o m a t i c carbons a t t a c h e d t o m e t h o x y g r o u p s ) , 55 p p m ( m e t h o x y g r o u p s ) , a n d 20 p p m ( a l i p h a t i c groups). K e y differences between the a u t h e n t i c n o v o l a k a n d the P / N - s u b s t i t u t e d n o v o l a k are i n r e l a t i v e p e a k intensities. W h i l e the r a t i o of u n s u b s t i t u t e d m et a- a r o m a t i c carbons t o ortho-para m e t h y l e n e bridges (130 t o 35 p p m ) i n the a u t h e n t i c s a m p l e is r o u g h l y 7:1, the r a t i o i n the P / N n o v o l a k is a p p r o x i m a t e l y 4:1 ( 6 0 % o f the o r i g i n a l value). S u c h a difference is e x p e c t e d , since the P / N n o v o l a k contains a n u m b e r of met α-substituted m e t h o x y c o m p o u n d s . T h e p h e n o l - f o r m a l d e h y d e novolak has a higher r a t i o o f h y d r o x y - s u b s t i t u t e d a r o m a t i c c a r b o n s (150 p p m ) to u n s u b s t i t u t e d m e t a - a r o m a t i c carbons (130 p p m ) t h a n the P / N n o v o l a k ( 4 0 % versus 3 0 % ) . 1 3

1 3

1 3

A few p r e l i m i n a r y resols have also been m a d e w i t h a 5 0 % replacement of p h e n o l b y the P / N f r a c t i o n o f the w o o d o i l . Tests have s h o w n these adhesives t o have shear strengths a n d w o o d f a i l u r e c o m p a r a b l e t o t h a t o b t a i n e d w i t h B o r d e n ' s C a s c o p h e n 313. T h i s work is i n progress. T e c h n o e c o n o m i c A s s e s s m e n t . A l t h o u g h the use of f r a c t i o n a t e d p y r o l y s i s oils as adhesives is s t i l l i n the e a r l y phases of development, a t e c h n o l o g i c a l as sessment o f the process was m a d e u s i n g the best p r o j e c t i o n s a v a i l a b l e for the y i e l d s a n d o p e r a t i n g c o n d i t i o n s . A d e t a i l e d process flowsheet was m a d e w i t h mass a n d energy balances a r o u n d each m a j o r piece o f e q u i p m e n t . T h e e q u i p ment was sized a n d t h e n v a l u a t e d u s i n g d a t a f r o m the l i t e r a t u r e . T h e costs


C H U M ET AL.


147


11.

F i g u r e 6. C P / M A S

1 3

C - N M R of novolaks:

a) p h e n o l - f o r m a l d e h y d e ;

b) phe-

n o l : p h e n o l s / n e u t r a l s (1:1) p i n e sawdust p y r o l y s i s o i l f r a c t i o n a n d f o r m a l d e h y d e .

American Chemical Society Library 1155 16th St. N.W. Washington. U.C. 20036 In Adhesives from Renewable Resources; Hemingway, R., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 1989.


148


for i n s t a l l e d e q u i p m e n t were c a l c u l a t e d u s i n g s t a n d a r d cost factors (19). All costs were u p d a t e d t o f o u r t h q u a r t e r 1986 d o l l a r s u s i n g the C E cost i n d e x . T h e process flowsheet i n c l u d e d a feedstock d r y i n g step u s i n g waste process heat. T h e d r y i n g step has a significant cost, b u t any m o i s t u r e i n the feedstock w o u l d be e v a p o r a t e d first i n the p y r o l y s i s step a n d t h e n a c c u m u l a t e d i n the process where i t w o u l d have t o be e v a p o r a t e d a g a i n w i t h p r e m i u m heat i n the i n c i n e r a t i o n section o f the furnace. S t e a m was used as the carrier gas at a weight r a t i o o f 1.33 t i m e s t h a t o f the feedstock. T h e energy for the d r y i n g step w o u l d be o b t a i n e d f r o m the c o o l i n g a n d c o n d e n s a t i o n o f the p y r o l y s i s process s t r e a m . T h e e x t r a c t i o n of the P / N f r a c t i o n was assumed to be b y the use o f Ε A as the solvent. T h e E A soluble acids were removed by a n aqueous s o d i u m c a r b o n a t e w a s h . T h e aqueous phase was first heated t o b o i l off the E A , w h i c h has a s i g nificant s o l u b i l i t y i n w a t e r . T h e water-soluble organics were t h e n c o n c e n t r a t e d i n triple-effect evaporators p r i o r t o t h e i r i n c i n e r a t i o n i n the convection section of the p y r o l y s i s furnace. T h e economics o f the p r o d u c t i o n of the P / N f r a c t i o n were e v a l u a t e d for a 1 5 % interest rate over a 20-year a m o r t i z a t i o n p e r i o d . T h e p r o d u c t i o n costs were s h o w n t o be a s t r o n g f u n c t i o n o f p l a n t size a n d feedstock costs as s h o w n i n F i g u r e 7. T h e cost t o p r o d u c e the P / N f r a c t i o n was p r o j e c t e d t o be a b o u t $0.10 per p o u n d i n a p l a n t c o n s u m i n g 1,000 T P D feedstock cost i n g $10 per d r y t o n . P r o d u c t i o n i n a s m a l l 250 T P D p l a n t w o u l d a d d a b o u t $0.06 per p o u n d . Increasing the feedstock cost t o $40 per d r y t o n w o u l d a d d $0.07 per p o u n d o f P / N . I f the p l a n t were t o be i n t e g r a t e d w i t h a n e x i s t i n g forest p r o d u c t s m i l l , some o f the costs r e l a t e d t o feedstock p r e p a r a t i o n w o u l d be c o n s i d e r a b l y reduced. It was c o n c l u d e d t h a t t h i s process has considerable economic p o t e n t i a l i f i t is developed p r o p e r l y a n d the a s s u m p t i o n s m a d e are verified t h r o u g h a d d i t i o n a l research a n d development. Conclusions Fast p y r o l y s i s o f b i o m a s s provides a m e t h o d for the p r o d u c t i o n of phenolics t h a t has the p o t e n t i a l t o replace at least 5 0 % or m o r e o f the p h e n o l i n p h e n o l f o r m a l d e h y d e t h e r m o s e t t i n g resins. T h e gel tests i n d i c a t e t h a t the P / N f r a c t i o n s f r o m p i n e sawdust p y r o l y s i s w i t h p a r a f o r m a l d e h y d e have shorter gel t i m e s t h a n c o m m e r c i a l p l y w o o d resins s u c h as C a s c o p h e n 313, even w i t h o u t p r e p o l y m e r f o r m a t i o n . A n o v o l a k f o r m u l a t i o n has been p r e p a r e d u s i n g 1:1 b y v o l u m e of p h e n o l a n d P / N f r a c t i o n a n d a b o u t h a l f o f the a m o u n t o f f o r m a l d e h y d e t h a t w o u l d be used t h a n i f p h e n o l alone were e m p l o y e d . V e r y p r o m i s i n g resols have also been m a d e w i t h a s i m i l a r s u b s t i t u t i o n o f the P / N f r a c t i o n for p h e n o l . W o o d t e s t i n g a n d resin f o r m u l a t i o n development are o n g o i n g a c t i v i t i e s . T h e p r o j e c t e d economics suggest t h a t a d d i t i o n a l research a n d development o f t h i s process are fully warranted.



11.

C H U M ET AL.

149


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Cases I 1 0 0 0 TPD, $ 4 0 / τ

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1000 TPD, $10/T 250 TPD, $ 4 0 / T 250 TPD, $ 2 0 / T I

0

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0.05

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$/lb of Phenols and Neutrals F i g u r e 7. A m o r t i z e d costs o f phenolics a n d n e u t r a l s f r a c t i o n f r o m p i n e sawdust p y r o l y s i s c a l c u l a t e d as a f u n c t i o n o f feedstock cost a n d p l a n t size.

Note that

the c a l c u l a t i o n s i n c l u d e costs associated w i t h a l l feedstock p r e p a r a t i o n as i f t h i s were a n i n d e p e n d e n t p l a n t .


150


A cknowledgment s T h i s w o r k was s u p p o r t e d b y the Office of I n d u s t r i a l P r o g r a m s of the U . S . p a r t m e n t of E n e r g y , W a s t e P r o d u c t s U t i l i z a t i o n B r a n c h , F T P 587.

The

De

encour

agement o f the D O E p r o g r a m m a n a g e r s , M r . A . S c h r o e d e r a n d D r . J . C o l l i n s , is g r a t e f u l l y a c k n o w l e d g e d . T h e C o l o r a d o S t a t e U n i v e r s i t y R e g i o n a l N M R ter, f u n d e d b y

the

N a t i o n a l Science F o u n d a t i o n G r a n t N o .


g r a t e f u l l y a c k n o w l e d g e d for the C P / M A S

N M R spectra.

Cen

C H E - 8 2 0 8 8 2 1 , is

Dr.

R. Evans kindly

p r o v i d e d the m o l e c u l a r - b e a m m a s s - s p e c t r o m e t r i c d a t a . H i s h e l p a n d t h a t of D r . T . M i l n e are g r a t e f u l l y a c k n o w l e d g e d . W e determinations and M r .

also t h a n k M s .

F . P o s e y for

M . R a t c l i f f for the s o l u t i o n - s t a t e N M R d a t a .

water

Mr.

A.

P o w e r ( A . J . P o w e r a n d A s s o c i a t e s , B o u l d e r , C o l o r a d o ) p e r f o r m e d the e c o n o m i c assessment, w h i c h w i l l be p u b l i s h e d i n d e t a i l elsewhere. Literature Cited

1. Soltes, E. J.; Elder, T . J . In Organic Chemicals from Biomass, Goldstein, I. S., E d . ; C R C : Boca Raton, FL, 1981, p. 63. 2. Overend, R. P.; Milne, T . Α.; Mudge, L . K . , Eds.; Fundamentals Biomass Conversion, Elsevier: London, 1985.

of Thermοchemical

3. Soltes, E. J.; L i n , S . - C . In Progress Biomass Conversion; Tillman, D . Α.; John, E. C., Eds.; Academic Press: New York, Vol. 4, 1983, p. 79, and references therein. 4. Preprints of papers presented at the Denver American Chemical Society Meeting, Production, Analysis and Upgrading Oils from Biomass, Division of Fuel Chemistry Preprints, A C S : Washington, D C , Vol. 32, No. 2, 1987. 5. Elder, T . J . ; Soltes, E. J . Wood and Fiber, 1979, 12,

217.

6. Elder, T . J . The Characterization and Potential Utilization of Phenolic Compounds Found in Pyrolysis Oil. P h . D . Dissertation, Texas A & M University, 1979. 7. Russel, J . ; Reinmath, W . F . ; "Method for Making Adhesives from Biomass," Patent 4 508 886, 1985.

U.S.

8. Davis, H. G.; Eames, Μ. Α.; Figueroa, C.; Gansby, R. R.; Schlaeger, L. L.; Watt, D . W . In Fundamentals of Thermochemical Conversion of Biomass; Overend, R. P.; Milne, Τ. Α.; Mudge, L . K., Eds.; Elsevier: London, 1027, 1985. 9. Nelson, D . Α.; Molten, P. M . ; Russell, J . Α.; Hallen, R. T . Ind. Res. Dev., 23. 471-475, 1984.

Eng.

Chem. Prod.

10. Diebold, J . P.; Scahill, J . W . Division Fuel Chemistry preprints, A C S : Washington, D C ; Vol. 32, No. 2, p. 21, 1987. 11. Sarkanen, Κ. V . ; Schuerch, C. Anal. Chem., 1955, 27,

1245.

12. Bryson, R. L . ; Hatfield, G . R.; Early, Τ. Α.; Palmer, A . R.; Maciel, G . E. Macro molecules, 1983, 16, 1669. 13. Chum, H . L.; Johnson, D . K.; Tucker, M . P.; Himmel, M . E. Holzforschung, 1987, 97. 14. Evans, R. J . ; Milne, T . A . Energy and Fuels, 1987, 1 (2),

41,

123.

15. Diebold, J . P., The Cracking Kinetics of Depolymerized Biomass Vapors in a Contin uous, Tubular Reactor, Thesis T-3007, Colorado School of Mines, Golden, C O , 1985.


11.

C H U M E T AL.

Biomass Pyrolysis OU Feedstocks

151

16. Diebold, J . P. In Proceedings of Specialist's Workshop on Fast Pyrolysis of Biomass, Copper Mountain, C O , October 19-22,1987. Solar Energy Research Institute, Golden, C O , SERI/CP-622-1096 (NTIS). 17. Nimz, H. H.; Tschirner, U.; Stahle, M.; Lehmann, R.; Schlosser, M. J. Wood Chem. Technol., 1984, 4 , 265. 18. Kringstadt, K . P.; Morck, R. Holzforschung, 1983, 37, 237.


19. Guthrie, Κ. M. Process Plant Estimating, Co. of America, C A , 1974.

Evaluation and Control, Craftsman Book

R E C E I V E D September 6, 1988


Biomass Pyrolysis Oil Feedstocks for Phenolic ... - ACS Publications

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