FIELD OF THE INVENTION
[0001] The invention relates to a process for treating lignocellulosic material, and in
particular involves the acid catalyzed hydrolysis of impregnated wood chips to partially
de-polymerize the lignin matrix with subsequent distillation, condensation and recovery
of the acid catalyst.
BACKGROUND OF THE INVENTION
[0002] Prior art processes for treating lignocellulosic material often require high temperatures
and pressures to ensure the chemical reactions proceed at a sufficient rate. As a
result, special pressure vessels and specialized equipment is necessary to withstand
the harsh conditions. This makes processing facilities very expensive to outfit and
maintain, as well as being expensive to operate, with high energy demands.
[0003] In addition, strong chemicals are generally required to produce the desired oxidation
or reduction reaction. The chemicals attack the equipment as well as the lignocellulosic
material, again increasing maintenance costs for the facility. Once used, the chemicals
must be disposed of, creating potential environmental hazards and pollution. Even
water used during the treatment process can become contaminated and require careful
handling to prevent pollution and environmental damage. Fresh chemicals must then
be purchased to replace those lost during the treatment process.
[0004] Most processing facilities, despite the expensive, sophisticated equipment in place,
can only be used to process a limited selection of plant material. Different plant
materials require different processing conditions and chemicals, and occasionally
different processing methods, meaning other plant materials cannot be processed without
a complete re-tooling of the process line, if at all. It is preferable to be able
to process many types of vegetation without the need to re-tool or change the facility
equipment.
[0005] WO 2004/106624 A1 discloses methods for producing pulp and lignin from lignocellulosic material. The
methods involve acid catalyzed hydrolysis. The lignocellulosic material is impregnated
with an acid and heated. During the heating lignin is depolymerized at relatively
low temperatures, and the acid catalyst is distilled off. The acid catalyst is collected
and recycled after impregnation and heating. The lignocellulosic material is then
digested in an alkaline solution under heat, dissolving the lignin and allowing the
pulp to be removed. Acid is added to the black liquor to precipitate the lignin which
is then removed. The resultant amber liquor can be further processed into other ancillary
products such as alcohols and/or unicellular proteins.
[0006] It is therefore an object of the invention to provide a process for treating lignocellulosic
material which overcomes the above limitations and provides other desirable features.
[0007] This and other objects of the invention will be appreciated by reference to the summary
of the invention and to the detailed description of the preferred embodiment that
follow.
SUMMARY OF THE INVENTION
[0008] The invention provides a continuous and batch system to produce cellulose, native
lignin and unicellular protein from any form of vegetation in a closed process.
[0009] The hydrolytic Catalytic Reactor Process (CRP) produces commercial grade pulp and
separates sweet liquor (sugars and hemi cellulose) from native form lignin - a natural
lignin not altered by high temperatures or adverse process conditions. The sweet liquor
is further converted to a unicellular protein which can be converted to many different
products. The process's waters and the catalytic chemicals are recycled.
[0010] The crux of the CRP process is the acid catalyzed hydrolysis of impregnated wood
chips. The acid catalyst effects the partial de-polymerization of the lignin matrix
in the chemical reactor with subsequent distillation, condensation and recovery of
the acid catalyst and recovery of native-form lignin. Much of the prior art in the
field uses reduction/oxidation chemical reaction mechanisms. This basic difference
in reaction mechanism allows for significant advantages of the CRP process.
[0011] For example, the vegetation is impregnated in a solution of nitric acid and/or ammonium
hydroxide and water. After a period of time at room temperature and atmospheric pressure
the chemical solution is recycled. The biomass is then moved to a catalytic reactor
and heated. Evaporated impregnate is recovered via an absorption tower and is recycled
back to chemical solution. The biomass is moved to an alkaline solution before being
cooled to separate pulp from black liquor. The pulp may be processed as desired to
produce saleable products. Black liquor is pumped to separation tank and is treated
to precipitate lignin. The solution is filtered to separate sweet liquor and lignin.
The lignin is dried and the sweet liquor is fermented to produce unicellular protein.
[0012] The process can utilize any species of plant including hardwoods, softwoods, shrubs,
grain species, grasses etc. The process can utilize sawdust as the sole starting material
(something that cannot be done commercially or specifically stated in patents examined
to date).
[0013] The quality and quantity of lignin produced dictates the reaction conditions throughout
the process. A distinct advantage is the elimination of "dry" raw materials. Indeed,
green starting material can be utilized and is even preferred for the acid catalyzed
hydrolysis of the native lignin polymer depending on the quantity of pulp, lignin
and sweet liquor required.
[0014] The CRP pulping process does not require added pressure at any stage nor temperature
ranges anywhere near those of traditional Kraft pulping processes. Basically, all
temperatures at various stages of the process are below 90°C and no external pressure
is added to the reaction system.
[0015] The CRP pulping process is a closed system where virtually all chemicals used are
recovered for reuse. Water used in the pulping process is recovered in saleable byproducts,
filtered for reuse or vented as steam. The vented steam could be used in providing
energy for the pulping process thereby eliminating even this small loss of water and
a potential energy source. The recovery of catalytic chemicals eliminates the need
for high chemical cost during each cycle of the pulping process.
[0016] A small amount of chemicals are needed to bring back to strength each recovered chemical
before being re-introduced into the process. The recovery of chemicals does not require
external energy expense to achieve this (unlike current recovery stages in Kraft mills).
[0017] By using this novel process the following benefits are achieved:
- 1. Wet starting materials can be used - it is not necessary to dry the chips as the
water is essential to the hydrolysis.
- 2. Hydrolysis uses low temps, low pressures and little energy input.
- 3. Weak acids and bases are used, minimizing raw material costs and degradation of
final products.
- 4. The acid catalysts are distilled and recycled allowing closed cycles.
- 5. The chemical reactor pulping process is essentially pollution free.
- 6. The chemical reactor pulping process gives a high yield of native Klason lignin.
- 7. The chemical reactor pulp yield of alpha cellulose is high.
- 8. The sweet liquor after precipitation is suitable for fermentation of unicellular
protein.
- 9. The chemical reactor process is scalable with suitable mixer designs and when combined
with the projected operating cost gives a return on construction investment of less
than 2 years.
- 10. The chemical reactor process is highly efficient with costs half that of typical
Kraft mills.
[0018] This results in the use of radically lower concentrations of acids and base during
the impregnation and digestion stages as well as significantly lower temperatures.
[0019] Since the CRP pulping process is a closed system with virtually zero discharge of
chemicals or water into the environment, a mill utilizing this process will easily
meet and exceed current environmental standards. Bearing this in mind, a pollutant-free-pulp
mill could also garner tremendous profit potential under an EPA carbon dioxide pollution
credit system.
[0020] The ability to process a wide variety of vegetation without any re-tooling gives
flexibility in pulp production. Currently, mills are designed to produce specific
pulp types and utilize specific wood species as raw materials. Furthermore, most mills
require chips meeting stringent quality specifications. These limitations are avoided
by the invention.
[0021] The economic viability of the CRP pulp process may be realized in the sale of pulp
alone. Other benefits are potential EPA credits and the production of native lignin
products and of unicellular protein for sale to others. It is noted that unicellular
protein from a vegetative source would be free of any BSE pathogens and would be the
preferred feed for cattle and other livestock animals presently raised for human consumption.
[0022] In one aspect, the object of the invention is achieved by a method for processing
lignocellulosic material, comprising an impregnation step wherein the lignocellulosic
material is soaked in an impregnate solution; a first recycling step wherein the impregnate
solution is drained, filtered, strengthened and recycled to the impregnation step;
a catalytic reaction step wherein the soaked lignocellulosic material is agitated
in a catalytic reaction chamber and heated to a temperature above the vaporization
point of the impregnate solution, thereby producing vaporized impregnate solution
and lignin; a second recycling step wherein the vaporized impregnate solution is condensed
and recycled to the saturation step; a digestion step wherein the lignin is agitated
in a digester in the presence of black iron and an alkaline solution to produce pulp
and a full strength black liquor; a processing step wherein the pulp is drained, washed
and dried thereby producing dried pulp and dilute black liquor; a third recycling
step wherein the dilute black liquor is recycled to the digestion step; a separation
step wherein the full strength black liquor is cooled and agitated in the presence
of an acid solution, thereby producing sweet liquor and precipitating natural form
lignin; a filtration step wherein the sweet liquor is filtered to remove the natural
form lignin; and a fermentation step wherein the sweet liquor is added to bacteria
in a fermentation tank, thereby producing a unicellular protein as a fermentation
product. The impregnate may be a nitric acid solution, or an ammonium hydroxide solution.
[0023] In another aspect, the object of the invention is achieved by an apparatus for processing
lignocellulosic material, the apparatus comprising an impregnation infeed to feed
lignocellulosic material and impregnate solution into an impregnation tank, the impregnation
tank comprising an impregnation outfeed; a catalytic reaction chamber connected to
the impregnation tank through the impregnation outfeed, the catalytic reaction chamber
comprising a first agitator and a catalytic outfeed; a digester unit connected to
the catalytic reaction chamber through the catalytic outfeed, the digester unit comprising
a second agitator mechanism and a digester outfeed; a lignin separator connected to
the digester unit through the digester outfeed, the lignin separator comprising a
third agitator mechanism and a separator outfeed; and a fermentation tank connected
to the lignin separator through the separator outfeed.
[0024] In a further aspect, the impregnation tank may comprise a recycling outfeed for recycling
the impregnate solution and returning it to the impregnation tank. In yet a further
aspect, the catalytic reactor may comprise an impregnate condensation unit for recycling
said impregnate solution and returning it to said impregnation tank
[0025] The foregoing was intended as a broad summary only and of only some of the aspects
of the invention. It was not intended to define the limits or requirements of the
invention. Other aspects of the invention will be appreciated by reference to the
detailed description of the preferred embodiment and to the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] The preferred embodiment of the invention will be described by reference to the drawings
in which:
Figure 1 is a schematic view of the parts used according to a preferred embodiment
of the process;
Figure 2 is the acid catalyzed hydrolysis mechanism;
Figure 3 is a flow chart and mass balance for pulp, lignin and protein during the
Catalytic Reactor Process (Nitric Acid);
Figure 4 is a flow chart and mass balance for pulp, lignin and protein during the
Catalytic Reactor Process (Ammonium Hydroxide);
Figure 5 is a hot plate calibration curve for CRP experiments; and
Figure 6 is a series of photos of the fibers obtained through CRP from various fiber
sources.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE INVENTION
[0027] Figure 1 shows a schematic of the preferred embodiment of the process. Chips from
infeed 2 are placed in impregnating chamber 4 along with an impregnate solution. After
the chips have soaked for an appropriate amount of time, excess impregnate is removed
and cleaned, such as by filter mechanism 6 and collected in recovery tank 10. It is
then strengthened and returned, such as by pump 12, to impregnating chamber 4.
[0028] Meanwhile, the impregnated chips are moved by appropriate means, such as auger mechanism
8, to catalytic reactor 20. To control the feed of chips from impregnating chamber
4 to the catalytic reactor 20, various mechanisms may be used. In the preferred embodiment,
holding tank 14 holds the impregnated chips until they may be fed through hopper 16
into measurement device 18. Measurement device 18 then controls the feed rate of chips
into catalytic reactor 20.
[0029] In catalytic reactor 20, the chips are heated by heater 22 to a temperature above
the evaporation temperature of the impregnate, but sufficiently low that the properties
of the lignin compounds formed are not compromised. The chips are also agitated to
ensure thorough heating of the biomass.
[0030] Evaporated impregnate is removed from catalytic reactor 20 by a mechanism such as
pump 24 and collected in a condensing chamber or absorption tower 26. The impregnate
is condensed and returned to recovery tank 10 for reuse in impregnating chamber 4.
[0031] Outfeed 28 passes the catalyzed biomass into the digester 30, where the biomass is
mixed with an alkaline solution. The mixture is heated and agitated in the presence
of black iron to produce black liquor and pulp.
[0032] Excess black liquor is removed from the digested pulp by means such as press 32.
Removed black liquor is collected in tank 34 and returned to digester 30, such as
by pump 36. The pressed pulp is processed, such as by washer 38, as required.
[0033] Black liquor passes from digester 30 to lignin tank 40, where it is cooled, agitated
and acidified to precipitate lignin, thereby forming sweet liquor and lignin.
[0034] The sweet liquor and lignin pass through a separation device, such as filter 42,
where the lignin is collected for further processing. The sweet liquor passes through
the filter 42 into fermentation tank 44.
[0035] In fermentation tank 44, bacteria is added to the sweet liquor to produce unicellular
protein, which may then be processed as necessary.
[0036] The following describes the process according to the preferred embodiment of the
invention. The process is shown schematically in the flowcharts of Figures 3 and 4,
for nitric acid impregnate and ammonium hydroxide impregnate, respectively.
1. Raw material is prepared by chopping plant species into convenient lengths of hard
and soft woods into chips approximately the size of existing commercially available
chips in use today. However, smaller chips can be used due to the longer fiber lengths
produced from the weaker chemicals and lower temperatures used in the CRP process.
2. The raw material is loaded into an impregnation chamber 4 and saturated with an
impregnate. The impregnate may be nitric acid, ammonium hydroxide and or both. For
example, if the raw material is hardwood and nitric acid is used, the chips may be
soaked in 15% HNO
3 for 18 hours. If the raw material is softwood or other vegetation, they are soaked
in 12% HNO
3 for 16 hours. If the impregnate is ammonium hydroxide, the chips are soaked in 10%
NH
4OH regardless of the raw materials.
3. Excess impregnate is drained off, filtered and brought back to strength for reuse
in recovery tank 10.
4. The impregnated material is transferred to the catalytic reactor 20 at a pH of
2 to 5. At this stage, temperature is maintained between 60°C and 85°C for a maximum
of 80 minutes. It is important that the catalytic reactor 20 be kept within this optimal
temperature and time range to produce high yields and quality of the finished products,
especially unaltered lignin compounds. If the material is kept beyond the optimum
time, then excessive material oxidization occurs rather than the preferred catalytic
hydrolyzation of the lignin polymer, thus inhibiting the subsequent stages. Heating
impregnated materials beyond the optimum temperature also leads to reduced yields
and alters the desired state of lignin (rendering an inferior gummy product). The
times held at optimum temperature range from 10 to 80 minutes depending on the raw
materials used. The chemical reaction taking place during the catalytic reaction step
is shown in Figure 2.
During the heating of the impregnated material, impregnate is released in a vapor
form, withdrawn and sent to a condensing chamber or absorption tower 26 where it is
collected for reuse. After a sufficient time, the lignin is catalytically hydrolyzed
to the desired molecular state and the raw material is now ready to be passed to the
alkaline bath stage.
In this catalytic stage, agitation is important as in a large reactor there would
not be sufficient time to thoroughly heat the entire mass of impregnated material
before passing onto the alkaline digesting stage, thus affecting both yield and quality
of final products.
5. Caustic soda is added to the material passed from the catalytic reactor 20 in the
digester 30. The caustic soda strength is as follows:
4L of 20% NaOH to 200L of water if the starting raw material is hardwood;
4L of 15% NaOH to 200L of water if starting raw material is softwood or other plant
species.
The alkaline bath is heated to an optimum temperature range of 60 - 85°C for a time
period of 60 minutes. During this alkaline stage, at a pH of 9 to 12, the mixture
is agitated in the presence of black iron and there is a separation of the pulp from
the black liquor. The pulp passes through screeners and a press that extract any black
liquor. The black liquor is recycled back into the alkaline digester. Once all the
pulp has been removed from the alkaline bath, it is washed and dried and the remaining
black liquor is returned to the digester 30, then is passed into the lignin tank 40.
Photos of fibers obtained through the process, using various starting materials are
shown in Figure 6. Properties of the CRP pulp at this stage are shown in Table 1.
Table 1 - Analysis results of the CRP pulp *
Component |
Sample 1 |
Sample 2 |
Alpha cellulose % |
86.5 |
85.7 |
Beta cellulose % |
1.3 |
4.1 |
Gamma cellulose % |
12.2 |
10.2 |
Kappa number |
51.6 |
44.5 |
Lignin content % (by calculation |
7.74 |
6.68 |
* Sample was chlorited prior to testing with results calculated on chlorited sample
weights. All results were calculated relative to sample weight on oven dry basis.
Alpha, beta, and gamma cellulose: per ESM 035B (ref: TAPPI n03). Kappa number: per
ESM 091B (ref: TAPPI T236). |
6. The black liquor is passed into the lignin tank 40 and rapidly cooled to a temperature
range of 43-50°C (this is important to maintain the native state of the lignin). At
this point, 10% sulfuric acid is added to the black liquor if the impregnate was nitric
acid; 12% hydrochloric acid is added if the impregnate was ammonium hydroxide. The
ratio of sulfuric acid to black liquor is 2L acid to 200L black liquor at a pH of
2 to 5. The agitators are started to precipitate the lignin from the black liquor
before the mixture cools below 43°C. The separation process takes about 1 hour.
7. From the lignin tank 40, the sweet liquor and precipitated lignin mixture is released
into a fermentation tank. The sweet liquor passes through a filter 42 while the lignin
powder remains on top of the filter. The native lignin is carried to a dryer where
it is dried at a temperature range of 43-50°C. Deviation from this range destroys
the native lignin state. Properties of the native lignin are shown in Table 2.
Table 2 - Analysis results of the CRP lignin
Component |
Sample 1 |
Sample 2 |
Klason Lignin % |
83.0 |
76.7 |
To the fermentation tank 44, a bacteria (torula) is added to the sweet liquor to activate
the fermentation process. Once the fermentation is complete, the unicellular protein
is filtered, dried and packaged, or washed to reduce ph and used for other products.
The residual water from the fermentation process is treated and recycled back into
the process.
[0037] Agitators are used in the catalytic reactor 20 and digester 30 and are important
to achieving the optimum results, as far as desired yields and quantity of finished
product.
[0038] In the catalytic reactor 20, the agitators are used to achieve and maintain the optimum
temperature range for the de-polymerization of lignin to occur. The optimum temperature
must be reached as quickly as possible to avoid undesired oxidization of the lignin.
This oxidization will provide for lignin compounds to begin to form from the ketone,
aldehyde, and etc, chemical classes, all of which are undesirable. Also, oxidization
of the lignin will provide cleaved sites to allow crosslinking between lignin polymers,
another undesirable result. Oxidization will result in low yields of native lignin
and sweet liquors depending on the extent of the oxidization reaction within the catalytic
chamber. The design of the agitators is contingent upon whether a batch process plant,
or a continuous feed plant is utilized. The agitators are used to both quickly bring
up to temperature the impregnated biomass and begin breaking up the biomass itself.
[0039] In a continuous feed plant, agitators in the catalytic reactor 20 will also transfer
continuously the impregnated biomass to the alkaline bath or digester 30.
[0040] In the digester 30, the agitators are used to achieve an optimal product yield. If
reacted, the biomass is simply dropped into an alkaline solution and allowed to sit,
and the surface of the chips will begin to undergo digestion. This will bring lignin
out of the chips and into the alkaline solution. If lignin is left too long in the
presence of NaOH, it will begin to oxidize, an unwanted result. Very aggressive agitation
is utilized to tear the chips into ever-smaller pieces allowing the NaOH to quickly
be utilized before the oxidization of the lignin begins in significant amounts. The
result is sodium molecules attached to cleavage points on the lignin polymers rendering
the lignin water-soluble.
[0041] The agitators also result in homogenous optimum temperature ranges.
[0042] The operating conditions of the process are as follows.
[0043] To treat 60 kg of pine chips, the chips are impregnated with 315L of ammoniacal acid
solution containing 27.5L of nitric acid and 4L of hydroxide of ammonia.
[0044] After 12 hours of impregnation, the acid solution is withdrawn for later re-circulation
and the chips are placed in the reactor to effect the reaction of catalytic hydrolysis
at temperature of 75°C, maximum 80°C during the time of 90 minutes; taking into account,
when it reaches the temperature of 75°C during the reaction, the gases have recuperated
the NOx in water or in recycled acid solutions.
[0045] At the end of the reaction, the chips are discharged in the alkaline bath for de-lignifying
the chips, where they are preheated at 75°C in a mixture of 315L of NaOH at 4%. The
reaction of de-lignifying is done at about 80°C and to a maximum of 90°C for 90 minutes.
The heating is then stopped to let it cool to 75°C, before the mixture is processed
through a filter to separate the cellulose from the black liquor.
[0046] The black liquor is sent to a lignin tank where it is agitated and the concentrated
sulphuric acid is carefully added until the pH is lowered to 3.0. It is left to rest
and then passed through a filter to separate the lignin from the sweet liquor.
[0047] The filtered sweet liquor is sent to a fermentation tank where bacteria may be added
to produce a unicellular protein.
[0048] At the end of the process, the lignin and cellulose is washed to retrieve the excess
of acid and caustic soda respectively. The water that was used for the process is
standard faucet or running water.
[0049] The following are details of experiments run using the process of the invention.
The pH values of the acids and bases used are listed in Table 3 and the calibration
curve for the hot plate used is tabulated in Table 4 and graphically shown in Figure
5.
Table 3: pH Values of Acids and Bases - May 17
Acids: |
Temp °C |
pH |
12% nitric |
18.2 |
1.86 |
10% sulfuric |
18.3 |
1.85 |
12% hydrochloric |
18.3 |
1.90 |
Bases: |
Temp °C |
pH |
10% ammonium hydroxide |
18.2 |
12.42 |
15% sodium hydroxide |
18.2 |
13.23 |
Table 4: Hot Plate Calibration - May 17
Setting |
Temp °C |
1.0 |
35 |
1.5 |
42 |
2.0 |
52 |
2.5 |
60 |
3.0 |
64 |
3.5 |
69 |
4.0 |
73 |
4.5 |
78 |
5.0 |
83 |
5.5 |
90 |
6.0 |
97 |
Nitric acid test:
May 19
[0050] To 500ml Northern White Pine bedding (Sun Seed - Son thing Special) - weight 64.49g
- was added 500ml of H
2O and let soak for 15 minutes. Excess water drained. Wet mass now weighed at 503.75g
(Buchner funnel vacuumed for 15 min) with beaker. Beaker weight 390.21 g minus the
weight of absorbed water is 113.54 - 64.49 = 49.05g.
[0051] Poured in 700ml of nitric acid at 11:10 a.m. May 19. Temperature of chips and acid
was 15.6°C (60°F).
[0052] There was 440ml of H
2O (from soaking chips) left.
% H
2O =49.05/113.54 = 43.2%
[0053] Hot plate setting for 83°C (182F) or 1.8 - 1.6 (turned switch off).
[0054] At 9:05 - HNO
3 impregnate - added to Buchner funnel. Gravity drain for 30 minutes and soak time
21 hrs - 55 minutes until May 20.
May 20
[0055] After impregnation, chips (wet) weighed 215.96g
215.96 - 113.54 = 102.4/215.96x 100% = 47.42% nitric acid
[0056] 102.42g nitric acid
102.42g nitric acid volume wise is approximately 800ml.
[0057] At 10:00 a.m., started distillation (setting at 5) there was 605ml of nitric acid
drained off - pH was less than zero on the drained off acid.
[0058] After 10 minutes turned down to 1.6. Pure nitric acid was coming across. Vapor temp.
90°C - nitric dropping into collection beaker with 100ml H
2O.
Minutes - Temp
[0059]
10 - 94 - 95°C
20 - 91°C
25 - 74°C
at 25 minutes measure chip temp = 88.9°C (194°F)
[0060] Sample #1 - 50 ml of drained HNO
3 impregnate - pH less than zero
We recovered 110ml HNO
3H
2O distilled volume -10ml pure HNO
3 came across 10 x 100% = 9.09%
Minutes - Temp
[0061]
30 - 68°C |
83°C chips |
60 - 70°C |
|
70 - 70°C |
86°C chips |
80 - 70°C |
92°C |
[0062] Sample #2 - first recovery at 25 minutes distillate - 100ml H
2O and 10ml HNO
3 Volume of 1st recovery 110ml
[0063] Put 10ml 15% NaOH into 1L of H
2O (mixture for alkaline bath)
[0064] 11:40 a.m. - 75°C alkaline digester, chips put in stirring at 10 setting - added
2 black iron bolts.
[0065] Sample # 3 - 2nd recovery at 80 minutes distillate - 100ml H
2O and 1.5ml HNO
3
Volume of 2nd recovery - 101.5
[0066] 12:10 - added 12 black iron bolts.
12:25 - added 90ml of 15% NaOH temp. 87°C - dropped hot plate setting to 4. Temperature
at 1:15pm was 96°C (too hot).
[0067] Strained out the pulp from black liquor. The black liquor volume was 920ml. A 40ml
sample (sample #4 was collected).
[0068] Black liquor cooled in cold-water bath - Temp. was 44°C
[0069] To the black liquor was added 10ml of 10% H
2SO
4 to precipitated lignin and filtered - time was 1:45pm.
[0070] 0.86g weight of filter paper
[0071] Another 10ml of 10% H
2SO
4 was added and filtered.
[0072] Third acid addition was 80ml of 10% H
2SO
4 at 3:15pm - cover and set overnight
[0073] Pulp wash water used - 1600ml
Black liquor produced - 1000ml.
May 21
[0074] Dry pulp 22.08gm - light brown, coarse, short fiber
Filter paper #1 - 1.22g - Wt.. Lignin - 0.36g
(Tare 0.86g) #2 - 0.99g - Wt. lignin - 0.13g
[0075] Vacuum filter 1000ml of sweet liquor/lignin mixture after setting overnight (9:20
a.m.) Sweet liquor volume 910ml
[0076] Weight of liquor and filter paper 3.95g
Weight of lignin = 3.95 - 0.86 = 3.09g (hard and black chunks)
Total lignin's = 3.09 + 0.36 + 0.13 = 3.58g
[0077] Black liquor Specific gravity - 0.999
Sweet liquor Specific gravity - 1.003
Nitric Acid - May 20
[0078] To 100.04 fresh chips was added - 700 ml of 12% HNO
3 - used approx. 300ml too much.
[0079] 4:00 p.m. - start of impregnation of Riverside pine chips - chips and slivers from
bottom of conveyor to loading dock 18.9°C (66°F) impregnation temp.
[0080] 10:15 a.m. - draining of HNO
3 yielded a volume of 660ml - drained for 15 minutes. (sample # 6) - Bolts weight 183.79g
[0081] Put chips into distillation setup at 10:40 a.m.. Chip temp was 22.2°C (72°F) - Hot
plate settings manual adjusted 1.0 - 1.6.
10:55 a.m. - chip temp. 60°C (140°F )- vapor temp 37°C
11:05 a.m. - chip temp. 84.4° C (184°F) - vapor temp 70°C
started the 80min countdown at 11:05 a.m.
11:10a.m. - chip temp 87.8° C (190°F) - vapor temp 76°C
11:25 a.m. - chip temp 84.4°C (184°F) - vapor temp 64°C
11:45 a.m. - chip temp 83.9°C (183°F) - vapor temp 64°C
12:00 p.m. - chip temp 84.4°C (184°F) - vapor temp 64°C
12:05p.m. - hot plate set at 2.0 to distill off nitric acid
12:10p.m. - chip temp 91.1°C (196°F) - vapor temp 75°C
12:20 p.m. - chip temp 92.2°C (198°F) - vapor temp 85°C
12:30 p.m. - chip temp - vapor temp 87°C
[0082] Nitric volume was (collected from distillation) 105.5 (sample #7) pH = .70 =5.5 ml
of HNO
3.
At 1:00 p.m., added impregnated chips to 80°C alkaline bath.
1:05 added another 10ml of 15% NaOH
1:10 added another 10ml of 15%NaOH
1:15 added another 10ml of 15%NaOH
At 1:00 80°C
1:10 74°C
1:20 76°C
1:30 85°C - setting 4
1:40 85°C
1:50 86°C
2:00 85°C
2:10 85°C - shut off agitator/heat
[0083] 830ml of black liquor recovered, collected sample #8.
Added 30ml H
2SO
4. Temp. at 2:30 p.m. was 36°C.
Filtered off pulp (100/0-15% sticks in long fiber pulp - yellow color. - 1200ml) Water
wash
May 22
[0084] Sweet liquor after filtering - 740ml - light straw yellow 40ml Sample #9N Pulp dried
at 100°C - wt 42.67g
Lignin filter cloth 10:30 a.m. (dry overnight) - wt 1.60g
Lignin filter paper #1 11:00 a.m. (air dry overnight) - wt 2.89 -0.86 = 2.83g
Lignin filter paper #2 11:15 a.m. (air dry overnight) - wt 2.82 - 0.86 = 1.96g
Lignin filter paper #3 11:30 a.m. (air dry overnight) - wt 1.51 - 0.86 = 0.65g
- light brown lignin - total wt 7.04g
- Whatman® filter paper #4 - filter cloth nylon fine weave from pilot plant
Black liquor Specific gravity - 0.985
Sweet liquor Specific gravity - 0.989
Tap water Specific gravity - 0.982 at 20°C
1:05 added another 10m1 of 15% NaOH
1:10 added another 10ml of 15%NaOH
1:15 added another 10ml of 15%NaOH
At 1:00 80°C
1:10 74°C
1:20 76°C
1:30 85°C - setting 4
1:40 85°C
1:50 86°C
2:00 85°C
2:10 85°C - shut off agitator/heat
[0085] 830ml of black liquor recovered, collected sample #8.
Added 30ml H
2SO
4. Temp. at 2:30 p.m. was 36°C.
Filtered off pulp (100/0-15% sticks in long fiber pulp - yellow color. - 1200ml) Water
wash
May 22
[0086] Sweet liquor after filtering - 740ml - light straw yellow 40ml Sample #9N Pulp dried
at 100°C - wt 42.67g
Lignin filter cloth 10:30 a.m. (dry overnight) - wt 1.60g
Lignin filter paper #1 11:00 a.m. (air dry overnight) - wt 2.89 -0.86 = 2.83g
Lignin filter paper #2 11:15 a.m. (air dry overnight) - wt 2.82 - 0.86 = 1.96g
Lignin filter paper #3 11:30 a.m. (air dry overnight) - wt 1.51 - 0.86 = 0.65g
- light brown lignin - total wt 7.04g
- Whatman® filter paper #4 - filter cloth nylon fine weave from pilot plant
Black liquor Specific gravity - 0.985
Sweet liquor Specific gravity - 0.989
Tap water Specific gravity - 0.982 at 20°C
1. Verfahren zum Verarbeiten lignocellulosehaltigen Materials, aufweisend:
einen Imprägnierschritt, in dem das lignocellulosehaltige Material in einer Imprägnierlösung
eingeweicht wird;
einen ersten Rückführungsschritt, in dem die Imprägnierlösung ausgelassen, gefiltert,
aufkonzentriert und an den Imprägnierschritt zurückgeführt wird;
einen Katalyse-Reaktionsschritt, in dem das imprägnierte lignocellulosehaltige Material
in einer Katalyse-Reaktionskammer (20) gerührt und auf eine Temperatur über dem Verdampfungspunkt
der Imprägnierlösung erwärmt wird, wodurch verdampfte Imprägnierlösung und Lignin
erzeugt wird;
einen zweiten Rückführungsschritt, in dem die verdampfte Imprägnierlösung kondensiert
und an den Imprägnierschritt zurückgeführt wird;
einen Aufschlussschritt, in dem das Lignin in einem Kocher (30) in der Anwesenheit
von Roheisen und einer alkalischen Lösung gerührt wird, um Pulpe und eine konzentrierte
Schwarzlauge zu erzeugen;
einen Bearbeitungsschritt, in dem die Pulpe entwässert, gewaschen und getrocknet wird,
wodurch ein getrockneter Halbstoff und eine verdünnte Schwarzlauge erzeugt wird;
einen Abscheidungsschritt, in dem die vollkonzentrierte Schwarzlauge gekühlt und in
der Gegenwart einer sauren Lösung gerührt wird, wodurch Süßlauge erzeugt wird, und
wobei Lignin in natürlicher Form ausgefällt wird;
einen Filtrationsschritt, in dem die Süßlauge filtriert wird, um das Lignin in natürlicher
Form zu entfernen; und
einen Fermentierschritt, in dem die Süßlauge zu Bakterien in einem Fermentiertank
(44) zugegeben wird, wodurch als ein Fermentationsprodukt ein einzelliges Protein
erzeugt wird,
dadurch gekennzeichnet, dass das Verfahren ferner
einen dritten Rückführungsschritt aufweist, in dem die verdünnte Schwarzlauge an den
Aufschlussschritt zurückgeführt wird.
2. Verfahren gemäß Anspruch 1, wobei das Imprägniermittel eine Salpetersäurelösung ist.
3. Verfahren gemäß Anspruch 2, wobei die Salpetersäurelösung 10 bis 30 Gewichtsprozent
Säure enthält.
4. Verfahren gemäß Anspruch 1, wobei das Imprägniermittel eine Ammoniumhydroxidlösung
ist.
5. Verfahren gemäß Anspruch 4, wobei die Ammoniumhydroxidlösung 10 bis 30 Gewichtsprozent
Ammonium enthält.
6. Vorrichtung zum Verarbeiten von lignocellulosehaltigem Material, aufweisend:
eine Imprägnierzufuhr (2) zum Einfüllen lignocellulosehaltigen Materials und Imprägnierlösung
in einen lmprägniertank (4), wobei der Imprägniertank (4) einen Imprägnierauslass
aufweist;
eine Katalyse-Reaktionskammer (20), die über den Imprägnierauslass mit dem Imprägniertank
verbunden ist, wobei die Katalyse-Reaktionskammer (20) ein erstes Rührwerk und einen
Katalysatauslass (28) aufweist;
eine Aufschlusseinheit (30), die über den Katalysatauslass (28) mit der Katalyse-Reaktionskammer
(20) verbunden ist, wobei die Aufschlusseinheit (30) einen zweiten Rührwerkmechanismus
und einen Aufschlussauslass aufweist;
einen Ligninabscheider (42), der über den Aufschlussauslass mit der Aufschlusseinheit
verbunden ist, wobei der Ligninabscheider einen dritten Rührwerkmechanismus und einen
Abscheiderauslass aufweist; und
einen Fermentiertank (44), der über den Abscheiderauslass mit dem Ligninabscheider
(42) verbunden ist;
dadurch gekennzeichnet, dass die Vorrichtung ferner Mittel zum Rückführen verdünnter Schwarzlauge in die Aufschlusseinheit
(30) aufweist.
7. Vorrichtung gemäß Anspruch 6, wobei der Imprägniertank (4) ferner einen Rückführauslass
zum Rückführen der Imprägnierlösung und zu deren Rückführung in den Imprägniertank
(4) aufweist.
8. Vorrichtung gemäß Anspruch 6 oder 7, wobei die Katalyse-Reaktionskammer (4) ferner
mit einer Imprägniermittel-Kondensiereinheit (26) zum Rückführen der Imprägnierlösung
und zu deren Rückführung in den Imprägniertank (4) verbunden ist.
1. Procédé de traitement d'une matière lignocellulosique, comprenant :
- une étape d'imprégnation, dans laquelle ladite matière lignocellulosique est trempée
dans une solution d'imprégnation ;
- une première étape de recyclage, dans laquelle ladite solution d'imprégnation est
drainée, filtrée, renforcée et recyclée à ladite étape d'imprégnation ;
- une étape de réaction catalytique, dans laquelle ladite matière lignocellulosique
trempée est agitée dans une chambre de réaction catalytique (20) et chauffée à une
température située au-dessus du point de vaporisation de ladite solution d'imprégnation,
produisant par là une solution d'imprégnation vaporisée et de la lignine ;
- une seconde étape de recyclage, dans laquelle ladite solution d'imprégnation vaporisée
est condensée et recyclée à ladite étape de saturation ;
- une étape de digestion, dans laquelle ladite lignine est agitée dans un digesteur
(30) en présence de fer noir et d'une solution alcaline pour produire de la pâte et
une liqueur noire de force maximale ;
- une étape de traitement, dans laquelle ladite pâte est drainée, lavée et séchée,
produisant par là une pâte séchée et une liqueur noire diluée ;
- une étape de séparation, dans laquelle ladite liqueur noire de force maximale est
refroidie et agitée en présence d'une solution acide, produisant par là une liqueur
sucrée et précipitant la lignine de forme naturelle ;
- une étape de filtration, dans laquelle ladite liqueur sucrée est filtrée pour retirer
ladite lignine de forme naturelle ; et
- une étape de fermentation, dans laquelle ladite liqueur sucrée est ajoutée à des
bactéries dans un réservoir de fermentation (44), produisant par là une protéine unicellulaire
en tant que produit de fermentation ;
caractérisé par le fait que ledit procédé comprend en outre :
- une troisième étape de recyclage, dans laquelle ladite liqueur noire diluée est
recyclée à ladite étape de digestion.
2. Procédé selon la revendication 1, dans lequel ladite solution d'imprégnation est une
solution d'acide nitrique.
3. Procédé selon la revendication 2, dans lequel ladite solution d'acide nitrique comprend
10 à 30 % d'acide en poids.
4. Procédé selon la revendication 1, dans lequel ladite solution d'imprégnation est une
solution d'hydroxyde d'ammonium.
5. Procédé selon la revendication 4, dans lequel ladite solution d'hydroxyde d'ammonium
comprend 10 à 30 % d'ammonium en poids.
6. Appareil de traitement de matière lignocellulosique, comprenant :
- une alimentation d'imprégnation (2) pour introduire de la matière lignocellulosique
et une solution d'imprégnation dans un réservoir d'imprégnation (4), ledit réservoir
d'imprégnation (4) comprenant une sortie d'imprégnation ;
- une chambre de réaction catalytique (20) reliée audit réservoir d'imprégnation à
travers ladite sortie d'imprégnation, ladite chambre de réaction catalytique (20)
comprenant un premier agitateur et une sortie catalytique (28) ;
- une unité digesteur (30) reliée à ladite chambre de réaction catalytique (20) à
travers ladite sortie catalytique (28), ladite unité digesteur (30) comprenant un
second mécanisme agitateur et une sortie de digesteur ;
- un séparateur de lignine (42) relié à ladite unité digesteur à travers ladite sortie
de digesteur, ledit séparateur de lignine comprenant un troisième mécanisme agitateur
et une sortie du séparateur ; et
- un réservoir de fermentation (44) relié audit séparateur de lignine (42) à travers
ladite sortie de séparateur ;
caractérisé par le fait que ledit appareil comprend en outre des moyens de recyclage de la liqueur noire diluée
à ladite unité digesteur (30).
7. Appareil selon la revendication 6, dans lequel ledit réservoir d'imprégnation (4)
comprend en outre une sortie de recyclage pour le recyclage de ladite solution d'imprégnation
et le retour de celle-ci audit réservoir d'imprégnation (4).
8. Appareil selon l'une des revendications 6 ou 7, dans lequel ladite chambre de réaction
catalytique (4) est reliée en outre à une unité de condensation d'imprégnation (26)
pour le recyclage de ladite solution d'imprégnation et le retour de celle-ci audit
réservoir d'imprégnation (4).