US20150252267A1

US20150252267A1 - Production, Conditioning, Testing and Applications of Cardboard and Chipboard Biochar

Info

Publication number: US20150252267A1
Application number: US14/603,456
Authority: US
Inventors: Jeff Licht; Hugh S. McLaughlin
Original assignee: Individual
Current assignee: LICHT JEFF
Priority date: 2014-01-23
Filing date: 2015-01-23
Publication date: 2015-09-10

Abstract

Processing vessel systems; methods for biochar production; methods for biochar conditioning; methods for cardboard and chipboard biochar blending; and methods for co-generated heat from cardboard and chipboard pyrolysis. Cardboard and chipboard are paper-based products consisting of virgin or post-consumer waste abandoned fibers, repurposed as feedstocks used for thermochemical conversion (pyrolysis) and carbonization of ligno cellulosic biomass. The conditioned cardboard and chipboard biochars improve soil nutrition, improve soil moisture retention, slow soil mineralization, bind or limit heavy metal uptake in soils and plants, improve plant physiological response such as water use efficiency. Co-generation of bioenergy output during pyrolysis is also involved.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional Application No. 61/930,569, filed Jan. 23, 2014, which application is incorporated herein by reference in its entirety.

FIELD

The present invention relates to processing vessels, production (pyrolysis), post-pyrolysis conditioning, testing and application of cardboard and chipboard biochars to resolve agricultural and environmental needs and provide bioenergy.

BACKGROUND

Cardboard (CB) and chipboard (ChB) solid wastes represent between 1-2% of all solid waste in landfills in the United States; 2% of the residential waste stream and 30% of all commercial/industrial solid waste is comprised of these ligno cellulosic-derived materials. Sadly the vast majority of this waste finds its way not to recycling but to abandonment. Removal from waste sites would improve soil and air quality through a reduction in aerobic and anaerobic metabolic microbial processes, reduced atmospheric emissions (CO₂, CH₄and N₂O) and increased carbon (C) sequestration. Even when removed from the post-consumer waste stream, recycling is generally restricted to repurposing through re-pulping and re-fabrication to its original life of cardboard and chipboard. However, conversion to biochar represents a different and significantly beneficial strategy. Biochar production for use as a soil amendment includes products derived from hardwood and paper softwood (W02011014392A4; US20110023566 A1), grass, corn stover (U.S. Pat. No. 8,398,738 B2), sugar cane and animal bone (WO20111097183 A2), hull, shell and food waste (US20110023566 A1), paper waste and sludge (WO2010129988 A1), manure (JP2001252558; U.S. Pat. No. 6,189,463; U.S. Pat. Pub. 2009/0031616), and poultry litter (US20120237994A1). A recent forecast on trends in biochar feedstock sourcing suggests an opportunity to capitalize on recycling of urban waste such as CB and ChB.

SUMMARY

The invention comprises at least the following: processing vessels used to produce CB and ChB biochars; methods for producing, conditioning and testing pyrolyzed CB and ChB biochars before and after addition to soils; benefits of CB and ChB biochars to enhance soil nutrient and moisture holding capacity, enhance plant physiological outcomes such as increased water use efficiency, sorb heavy metals (e.g., Pb, Sb, Cu and As) in soils and plants; and produce co-generated bioenergy as a by-product of CB and ChB pyrolysis in a processing vessel.
Embodiments of the invention comprise thermochemical conversion of CB and ChB into biocarbon, paperchar or enhanced biochar (individually or collectively sometimes referred to herein as “biochar”). The biochar can be used in situations that include but are not limited to the following: to provide restorative nutrient and moisture to impoverished agricultural land, mitigate depreciating groundwater assets, generate an alternative fuel to deforestation, and comprise an antidote to harmful anthropogenic and environmental factors. Not only are there broad opportunities to collect, produce and distribute CB and ChB biochars but this process can be manifest without the aid of enormous, scaled up production facilities and equipment, though one cascading benefit is comprised of production of CB and ChB biochars in large processing vessels distributed through well-developed networks. The universality of CB and ChB methods described herein, including stacking and dehydrating feedstock and conditioning of post-pyrolysis biochars, is matched by the universality of the feedstocks themselves, namely two well-defined species of universally sourced ligno cellulosic waste which may be processed in a similar manner to that described herein, without regard to geographic location. The same universal characteristic cannot be applied to other cellulosic or ligno cellulosic feedstocks, such as wood, for example, where even a specie may not be considered a unique feedstock depending on its geographical location, or where subspecies exist, for example, or more than one specie is mixed with others to provide multi-feedstock sources. Three micro gasifiers (U.S. Pat. No. 6,830,597) and a retort (e.g., U.S. Pat. No. 6,902,711) (both such patents incorporated herein by reference in their entirety) can be employed herein. Feedstocks are typically batch (not continuous or semi-continuous) fed into the three micro gasifier processing vessels, and hatch or semi-continuous fed into larger retorts or reactors.

INCORPORATION BY REFERENCE

All patents, patent applications, publications and data described in this specification are herein incorporated by reference to the same extent as if each individual publication, patent, patent application or datum was specifically incorporated into this document.

BRIEF DESCRIPTION OF FIGURES

The novel features of the invention are set forth with particularity in the appended claims. A better understanding of the claimed invention (including but not limited to the functionality of the pyrogenic products and their implementation as soil conditioners, benefit to plant performance, or heat output), may be obtained by reference to the following figures which illustrate embodiments of the principles of the invention.

FIG. 1 is an exploded view of a processing vessel.

FIG. 2 is an exploded view of another processing vessel.

FIG. 3 is an exploded view of another processing vessel.

FIG. 4 shows a power supply-fan-duct device used to increase air for combustion.

FIG. 5 is a cross-sectional view of feedstock and wood fuel installation in the vessels of FIGS. 1-3.

FIG. 6 compares pyrolysis temperatures and processing vessel type.

FIG. 7 a compares outdoor moisture/evaporation test of CB inoculated Entisols.

FIG. 7 b compares outdoor moisture/evaporation test of ChB inoculated Entisols.

FIG. 7 c compares Atterburg roll (gm H ₂0/3 mm+/−diameter) characteristics following dehydration according to soil type.

FIG. 7 d compares shrinkage (gm shrinkage/4.77 cm diameter) characteristics following dehydration according to soil type.

FIG. 8 illustrates data which compares biochar adsorption rates following GACS testing.

FIG. 9 compares pyrolysis temperatures according to processing vessel type.

BRIEF DESCRIPTION OF TABLES

The novel features of the invention are set forth with particularity in the appended claims. To gain a better understanding of production, conditioning and functionality of the pyrogenic products and their implementation for soil enhancement, improved plant performance and co-generated energy, these will be obtained by reference to the following tables which illustrate embodiments based on pre- and post-treatment soil and plant physiological outcomes of which:
TAB. 1 shows Tukey pairs of plasticity results as example of kitchen moisture test.
TAB. 2 shows five week nutrient milestones for Entisols treated with CB and ChB biochars.
TAB. 3 shows one year follow up nutrient milestones for Entisols treated with CB and ChB biochars.
TAB. 4 compares nutrient analysis of CB and ChB biochars.
TAB. 5 compares elemental analyses of CB and ChB biochars.
TAB. 6 shows heavy metal uptake management via CB biochar soil added to contaminated soils.
TAB. 7 shows effect of CB biochar additive on intrinsic WUE determined by δ¹³C 0/00.
TAB. 8 shows effect of CB biochar additive on instantaneous WUE determined by seasonal x A/g,

DETAILED DESCRIPTION

Included herein are: (1) design and fabrication of three processing vessels used to produce CB and ChB biochars; (2) methods for producing, conditioning and testing pyrolyzed CB and ChB biochars before and after addition to soils; (3) benefits of CB and ChB biochars to enhance (a) soil nutrient and moisture holding capacity, (b) enhance plant physiological outcomes such as increased water use efficiency and (c) block or reduce uptake of heavy metals (e.g., Pb, Sb, Cu and As) in soils and plants and (4) co-generation of bioenergy as a by-product of CB and ChB pyrolysis in a retort (or reactor).
Embodiments of the invention include: design, fabrication and use of processing vessels; feedstock arrangement, production and post-pyrolysis conditioning; post-conditioning blending and testing of biochars with soils and plants; and outcomes. In one aspect, three (sizes of) top lit updraft device (TLUD) or micro gasifier processing vessels to thermochemically convert CB and ChB feedstocks were designed and manufactured. The vessels are fabricated from metal parts as shown in FIGS. 1, 2 and 3. Another aspect is comprised of an air duct assembly FIG. 4 used with either a 9V battery and low voltage wire or a low voltage power adapter 51 connected to a fan (recycled from a desktop computer) 49 via a connecting section FIG. 45 for use with the vessels shown in FIGS. 2 and 3. Another aspect is a method for installing feedstock and wood fuel; this installation process is similar for embodiments in retorts or processing vessels or reactor other than those described herein. Another aspect is the conversion of cardboard (with fluting and liner board) and chipboard (without fluting) to another solid phase for conditioning soil and co-generated heat resulting from pyrogenic gases.
To enable a consistent approach to production, conditioning and testing, it was desirable to select universally available feedstocks with generally consistent physical (e.g., thickness), construction (fluted or not fluted) and chemical properties. In another aspect prior to the conditioning phase, raw biochars were pulverized. In a further aspect to characterize and measure the effect of conditioned biochar as a soil

TABLE•1

•Tukey•pair•comparisons•of•plasticity¶

Null•Hypothesis•(Soil/Biochar•pairs)••••••••••••••••••••••••••••••••••••••••P-value

Windsor•255C•CB•-••Windsor•255C•=•0	<0.01
Windsor•255B•••CB••-•Windsor•255C•=•0	<0.01
Deerfield••256B/CB•*•-••Windsor•255C•=•0	<0.01
Deerfield•256B/CB•-••Windsor•255C•==•0••••••••••••••	<0.01
Deerfield•256B•-••Windsor•255C•==•0•••	0.046
Quansett•-••Windsor•255C•==•0••••••••••••••••••••••••••••••	0.016
Quansett•••CB••-••Windsor•255C•==•0•••••	0.018•••
Windsor•255B•-••Windsor•255C•CB••==•0•••••••••	<0.01
Windsor•255B••CB••-••Windsor•255C•CB••==•0••••••••	0.010•
Deerfield•256B/••-••Windsor•255C•CB••==•0•••••••••••	<0.01
Quansett••262B-••Windsor•255C•CB••==•0•••••••••••••••••••••••	<0.01
Quansett••262B•/CB•-••Windsor•255C•CB••==•0••••••••••••••	<0.01
Windsor•255B•••CB••-••Windsor•255B•==•0•••••••••••	<0.01
Deerfield•256B/CB•Windsor•255B•==•0•••••••••••••	<0.01
Deerfield•-••Deerfield••256B/CB••==•0••••••	<0.01
Quansett••262B•-••Deerfield•256B/CB••==•0••••••••••••••••••	<0.01
Quansett•••262B•/CB••-••Deerfield•256B/CB••==•0	<0.01
		¶

additive, a set of ‘kitchen’ moisture tests were devised including, evaporation in FIG. 7 a and FIG. 7 b and plasticity in table 1 as shown on the previous page. Results in those figures and that table denote statistically significant (P=<0.01 and P=<0.05 respectively) moisture holding capacity (plant available water) as a function of statistically significant (P=<0.01) greater plasticity following CB biochar amendment in Atturburg roll tests (tests measured maximum moisture retention at the point of soil contraction contrasting 30 g samples of red oak and CB biochar amended soils). Further demonstration of CB biochar moisture holding capacity was evidenced in “slug” tests where clay shrinkage was measured after evaporation; there is significantly less clay shrinkage for specimens composed of CB biochar additive (P=<0.01) shown in FIG. 7 c. Another aspect concerns an additional test, not part of the ‘kitchen tests’, portrayed in FIG. 7 d, which revealed moisture facility of CB biochar additive following soil tension (bar) experiments comparing three biochars with a Quansett 262B control. In six repeated tests, a CB/Quansett 262B blend (10% by volume) exhibited 25% greater soil tension than its nearest cohort. The results illustrate greater capillary induction potential than its three blend test counterparts. Given results from the ‘kitchen’ and soil tension tests, CB biochar was found to exhibit greater global soil moisture

TABLE 2

Five week milestone nutrient analysis

ppm

1 year milestone

g/5 cc

CEC

pH

P

K

Ca

Mg

B

Mn

Zn

Cu

Fe

S

Pb

Windsor

255B	6.4	8.4	5.4	9.2	58	263.3	16.6	1.8	5.3	2.2	.2	12	7.7	.05
Windsor 255C	6.6	3.6	6.5	2.5	33.4	523.5	30.6	.05	30.6	.72	.2	16.2	4.5	.53
Deerfield 256B	7.1	9.4	4.9	6	36	162	14	.1	2	1.3	3.	7.3	4.8	1.1
Quansett 262B	5.4	7.2	5.4	7.1	49.7	134.8	13.4	0	1.7	.9	.1	5	3.7	.6
Windsor 255B CB	4.5	6.0	6.8	6	39	621	41	.3	1.4	1.1	.3	3.6	12	.7
Windsor 255C CB	5	10.7	5.8	16.8	49	504	37	.2	3	3.5	.2	9.4	11.2	1.4
Deerfield 256B CB	4.95	17.5	5.2	19.7	94	585	55	.2	8.2	10.2	1	17.4	16.6	12.4
Quansett 262B CB	6	9.2	5.1	8.4	73	277	36	.1	3.3	1.5	.1	7.5	8	.7

TABLE 3

One year follow up nutrient analysis

ppm

1 year milestone

g/5 cc

CEC

pH

P

K

Ca

Mg

B

Mn

Zn

Cu

Fe

S

Pb

Windsor

than its red oak biochar counterpart. These findings may be interpreted to inspire the use of CB biochar as a light weight, highly adsorptive additive for soil amendment.

Still another indicator of value is found in comparisons of CB and ChB biochar treated Entisols whose results are found in two sets of data in tables 2 and 3. Results of comparisons of organic and inorganic nutrient levels between five and one year milestones illustrate several positive mechanical aspects of CB and ChB biochar interaction with four Entisols. For example while calcium carbonate (CaCO₃) generated extremely high, initial Ca status, retesting, following mycorrhizal feeding on these carbonates, subsequent mineralization and sorption, revealed a Ca level suited to planting. P known to be an indicator and correlate of moisture adsorption held steady over the year long period testifying to the power of CB and ChB biochar crystalline structures to adhere moisture much more efficiently than the same soil untreated with the chars. While high pH values as shown below in table 4 may appear to be worrisome, they soon equilibrate, even at the five week milestone depicted in table 2. Elevated CEC in year two reflects greater nutrient sorption.
TABLE 4

CB and ChB biochar nutrient analysis

ppm

biochars g/5 cc OM pH P K Ca Mg B Mn Zn Cu Fe S Pb

Cardboard biochar 1.4 7.4 7.9 21 1095 3044 1235 70 1.2 13 0 2.1 64.3 70

Chipboard biochar 1.1 32.7 8.7 79 336 4130 1120 16.7 72 13 .8 5.7 83.5 1

Additional elemental analysis of CB and ChB found in table 5 below reveal characteristics which compliment earlier results.
TABLE 5

CB and ChB biochar elemental analysis

ID Yield Ash C H N O O/C C/N GACS

biochars % % % % % % % % % (AR)

CB 21 14.4 72.1 4.8 .2 8.2 11.3 300.4 5.2

ChB 22 19.8 63.2 6.8 .25 10 15.8 252.8 4.1

Red oak 24 1 84.7 5.3 .5 8.5 10 169.4 6.9

CB and ChB chars were shown to exhibit (a) higher feedstock to biochar yield, (b) greater ash content during slow pyrolysis, (c) nearly the same C levels as red oak, (d) advantageous O/C ratios (<40% indicates greater stability and aromaticity), (e) high C/N ratios (well above industry requirements [>100] and (f) decent adsorption compared with denser ligno celluslosic red oak in FIG. 9. In table 6 results of CB biochar added to four contaminated and one control non-firing range soils samples dug from ‘A’ horizon soil pits located in constructed berms are shown. Preliminary evidence following repeated tests indicated in sample metal sorption was higher in most CB biochar treated contaminated specimens following (10% by volume) an agitated blending procedure from analysis conducted eight weeks after the

TABLE 6

Evidence of heavy metal uptake by CB biochar

Ppm

nutrient	g/5 cc	CEC	pH	P	K	Ca	Mg	B	Mn	Zn	Cu	Fe	S	Pb

Range (D)	7.1	3.6	5.7	.9	12	73	9	.1	1.1	1.1	6.3	3	4.8	170.5
Range (D) with CB	7.2	5.3	5.7	1	21	211	23	.2	.8	2.3	5.1	11.4	6.8	108.3
Range (M)	7.5	5.4	4.9	.6	14	29	13	0	1.9	1.3	4.2	8.7	1.4	14.8
Range (M) with CB	7.2	3.9	5.8	.7	18	164	24	.2	.9	.9	1.8	6.2	4.6	26.8
Range (S)	6.5	6.5	5.9	9.3	55	289	27	.1	4.4	71.8	161	25.8	4.9	29.6
Range (S) with CB	6	8.1	6.2	10.3	70	552	61	.5	4.6	77	174	22	12	68
Background/control	5.2	17.7	4.1	.9	25	182	57	.1	5.7	1.6	.6	4.4	5.5	5.3
Background/control CB	4.2	23	4.2	1.3	51	436	110	.1	8	2.7	.7	5.8	12	27.5

heavy metal	As	Ni	Sb	Cr	Cu	Pb

Range G Shields	3.58	4.4	26.66	6.89	217	2337
Range G Shields/CB	3.52	6.3	40	8.8	188	2951
Range D Shieldt	2.03	2.4	2.6	4.88	32.2	278
Range D Shields/CB	1.83	2.9	3.4	5.4	36.1	343
Range S Shields	2.08	3.6	.53	8.20	467	47
Range S Shields/CB	1.35	3.1	.84	6.5	267	68
Range M Shields	1.11	1.6	.17	1.97	4	19
Range M Shields/CB	1.23	1.2	.34	2.3	4	24
Control Shields	1.20	1.5	.56	1.68	4	35
Control Shields/CB	.24	1.3	.31	1.08	1.1	12

procedure. Typical organic and some inorganic levels (P, K, Ca, Mg) rose in post-inoculation review. However, the most significant results were obtained for cluster analysis of six heavy metals, where

TABLE 7

intrinsic WUE status as determined by δ¹³C ‰ metrics
as an aggregate seasonal value

		June	September
Treatment	Specie	δ¹³C ‰	δ¹³C ‰	x δ C ‰

CB Rooflite	Baptisia	−27.50	−28.05	−27.77
Blend	tinctoria
CB Rooflite	Quercus	−29.13	−31.69	−30.41
Blend	ilicifolia
CB Rooflite	Lupinus	−28.75	−31.24	−29.99
Blend	perennis
CB Rooflite	Vaccinium	−30.32	−31.71	−31.01
Blend	angustifolium
Rooflite	Baptisia	−28.75	−31.35	−30.05
	tinctoria
Rooflite	Quercus	−29.00	−30.11	−29.55
	ilicifolia
Rooflite	Lupinus	−27.44	−30.96	−29.20
	perennis
Rooflite	Vaccinium	−28.62	−30.19	−29.48
	angustifolium
CB Rooflite	All species	−27.51	−31.71	−29.61
Blend
Rooflite	All species	−29.34	−31.28	−30.31

antimony (Sb) and lead (Pb) sorption increases signaled mechanical adherence in the CB biochar portion (with the other 90% contaminated soil) of the blend indicative of a tendency to block metal uptake. Other, different aspects of CB biochar influence on soils and soils inhabited by plant specimens drawn from a pitch pine scrub oak community (found near the military ranges) were studied with regards to the possible effect of CB biochar soil inoculation on plant physiological performance as measured by water use efficiency (WUE). Two tests of WUE were performed on Rooflite® soils (Skyland USA LLC, Avondale, Pa. USA) amended with CB biochar (10% by volume). The first test results appear in table 7 which comprise intrinsic C status as measured by δ¹³C 0/00 as a function of stable isotope analysis. Results indicate elevated post-photosynthate C storage resulting in higher intrinsic WUE. In table 8, results of instantaneous WUE measurements reveal increased C abundance from CB biochar addition interpreted as higher WUE following leaf-level CO₂readout, as x A/g_sthrough portable photosynthesis.

TABLE 8

Instantaneous measurement of x A/g.

	Treatment	Specie	x A/g_s

CB Rooflite Blend	Baptisia tinctoria	48.06
CB Rooflite Blend	Quercus ilicifolia	121.71
CB Rooflite Blend	Lupinus perennis	87.26
CB Rooflite Blend	Vaccinium angustifolium	33.88
Rooflite	Baptisia tinctoria	23.9
Rooflite	Quercus ilicifolia	109.92
Rooflite	Lupinus perennis	120.2
Rooflite	Vaccinium angustifolium	34.02
CB Rooflite Blend	All species	77.10
Rooflite	All species	63.76

A final aspect comprises the approximate energy balance achieved following a comparison of retort pyrolysis events. Note cardboard pyrolysis captures 20% of the total heat thrown off in the manufacture of the biochar as opposed to non-pyrolysis heat (100% burnable energy) thrown off by the combustion of cardboard in a non-anoxic vessel producing ash, a process which does not capture energy per se, and does not capture energy as a product of cardboard biochar pyrolysis.

DESCRIPTION OF THE FEEDSTOCKS

Corrugated cardboard and cardboard box feedstock (ASTM D4727) ranges from 0.25-0.38 cm (single wall)-0.50-0.76 cm thickness (double wall), combining fluting and linerboard, ranging in mass from 0.062 g/cm²-0.120 g/cm²and chipboard pad and box feedstock ranges from 0.076 cm-0.12 cm in thickness and 0.022 g/cm²-0.029 g/cm²in mass. Chipboard is typically composed of double kraft paper and coated with resin (ASTM D1037). Due to the worldwide homogeneity of both cardboard and chipboard, and the thickness dimensions (+/−0.508 cm for cardboard and +/−0.254 cm for chipboard) varying little from one geographical location to the next, the procedures described herein are invariably the same based on the non-combustion (anoxic) heating of the feedstocks in such a way as to char without diluting the chemical properties which make it so appealing, namely significant nutrient and moisture holding characteristics. Physical comparisons of CB and ChB with other biomass feedstock sources illustrate their uniqueness in form such as boxes, sheets and pads, produced for commercial consumption, defined by somewhat similar porosity and, as it turns out, similar carbonization outcomes. They are also lighter in pre- and post-pyrolysis mass, as measured by g/cc, than other feedstock types such as hardwood and paper softwood, grass, corn stover, sugar cane, animal bone hull, shell and food waste, paper sludge, manure and poultry litter.

Preparation of Feedstocks for Pyrolysis

CB and ChB feedstocks are dried for a thirty day period (<1% moisture) prior to conversion. Then they are cut, folded, shredded or rolled into 12 cm-0.45 m widths and 12 cm-2.4 m lengths for vertical introduction to a processing vessel. They may also be reduced to circular pieces 2.25-2.85 cm diameter and 0.3 to 0.4 cm thickness through the use of a hammermill press (e.g., pellet mill).

Processing Vessels

A group of 4 L, 20 L and 200 L processing vessels FIGS. 1, 2 and 3 were used to conduct pyrolysis where pyrogenic gases achieve a high temperature treatment (HTT) range between 440-512.4° C. see FIG. 9. Though the three processing vessels comprise different sizes, similar pyrolysis of the same feedstocks produces similar outcomes, i.e., pyrogenically propagated sheets still manifesting a patina comprised of either slightly ridged (fluted) in the case of the cardboard or non-ridged (non-fluted) appearance in the case of the chipboard (lacking fluting).
A 4 L aluminum TLUD 4, FIG. 1, is fabricated from a used 4 L stainless steel paint can 3 with 27 cm height and 17 cm diameter with an inner aluminum can 5 (e.g., recycled aluminum can which housed fruits or vegetables). Multiple holes are cut into the bottom of the outer can 3 which induces air flow through the bottom and into the outer combustion chamber of the outer can. A portion of a second, aluminum can is cut out to form a “crown” 7 (3 cm in depth and 17 cm in diameter) having a semi-diagonal tooth shape side and solid top. The center of the solid top of the crown 7 is removed to form a 7.5 cm wide hole or opening. When pyrolysis is initiated, a sheet metal chimney 9 (measuring 30 cm height and 7.75 cm diameter) is placed over the opening. After pyrolysis is complete, the chimney 9 is removed and a “damper” (separate flat 8 cm circular piece of aluminum) is placed over the opening; then the processing vessel is lifted from the ceramic “feet” 1 and placed on a non-flammable surface. The pyrolytic event ranges between fifty minutes and one hour. Maximum temperature (HTT) for the 4 L pyrolysis is recorded at 440° C. measured by inserting an EXTECH K-type single pole temperature thermocouple into the chimney and vertically downward into the middle of the feedstock. After cool down, between two and a half to three hours duration, the cover is removed from the micro gasifier and the biochar contents are scooped out (with scoops, pans, shovels, brooms, dustpans and similar tools) and placed temporarily in a 17 L plastic bucket.
Another embodiment of the invention is a steel 20 L TLUD 16, FIG. 2. The main portion of the unit is fabricated from a commercial steel canister 15 and 59 (38 cm in diameter and 54 cm in height) placed on ceramic block 11 and 55 with five 1.25 cm holes 18 spaced 2 cm apart around the center. Within that canister is placed a smaller 11 L aluminum (37.5 cm in diameter and 2 cm in depth) feedstock holder 17 and 61. It is covered with a circular aluminum cover 19 with five 1.25 cm holes 18 spaced 2 cm apart around the center. The canister 15 is covered with a 38 cm diameter and 1.6 cm thick stainless steel top 20 with a 7.5 cm diameter aperture. A 9 cm diameter×40 cm long chimney 21 is placed over the hole or opening during pyrolysis. As with the methods described previously, fuel is placed in the void between the outer and inner canisters 57. CB and ChB feedstock is rolled or folded and inserted vertically in the inner canister 63 FIG. 5. Unlike the method used with the smaller 4 L processing vessel, the larger 20 L vessel utilizes an air ducting feature 46, FIG. 47—to pump air from a battery operated fan 49 through a duct 47 to a 3.75 cm aperture 13 in the side of the bottom portion of the vessel 15 via a nozzle adapter 43. The fan-duct device allows the operator to add air flow as desired using a ‘D’ cell battery (not shown) or plug in power unit 51 to power the fan whose nozzle fits into the aperture 13. Air is added to the combustion chamber (to increase combustive gas rate) by engaging or disengaging battery 51. When the fan/duct is not in use, a 5 cm×3.75 cm plug fashioned from aluminum is inserted into the aperture 13. In the 20 L processing vessel, firewood is ignited, as with the previous embodiment, with an isopropyl alcohol or similar accelerant. Note, experiments with vertical as opposed to horizontal loading demonstrate greater air flow and carbonization. The pyrolytic event ranges between one hour and one hour and fifteen minutes. Maximum temperature (HTT) range during pyrolysis was recorded at 498.9-508.6° C. for CB and ChB measured by inserting an EXTECH K-type single pole temperature thermocouple into the chimney and vertically downward into the middle of the feedstock. After cool down, which is typically two and a half to three hours, the cover is removed from the micro gasifier and the biochar contents are scooped out (with scoops, pans, shovels, brooms, dustpans and similar tools) and placed temporarily in a 17 L plastic bucket.
A 200 L steel “double barrel” TLUD processing vessel 32, FIG. 3, is a further embodiment of the invention. It comprises 200 L outer 25 and 59 and 170 L inner 31 and 61 steel barrels. The outer barrel 25 (measuring 120 cm in height and 66 cm in diameter) is comprised of one open and one closed end and is situated on top of four ceramic bricks 23 and 55 (18 cm×3 cm×9 cm). The closed end, or bottom of the outer barrel, features twelve 1.25 cm holes 53 cut into the bottom, spaced 2 cm apart, in a concentric orientation to allow air entry into the bottom of the outer barrel. The top lid 37 serves as a cover for the outer barrel after pyrolysis is complete. The outer barrel is placed on top of four strategically arranged ceramic bricks 23 situated to support the undercarriage of the outer barrel. Around the bottom amongst the bricks and up the sides of the space between the inner and outer barrels are placed wood fuel (typically 2.5 cm×4 cm×15 cm pieces) 29 and 57 for combustion in a 6 cm void (chamber). Inner barrel 31 is inserted into the outer barrel 25. Barrel 31 is comprised of an enclosed bottom and a lid 33 (which has eight 1.25 cm holes 35 spaced 2 cm apart around the center of the lid). Four ceramic bricks 27 are placed below the bottom of the inner barrel. Either CB and ChB feedstocks are placed inside the inner barrel 63, FIG. 5, with space between feedstock pieces to allow gas movement. After an accelerant has been applied to the wood fuel 57 in the void between barrels 25 and 31, the inner barrel cover 33 is placed on the top of the inner barrel 31. Then the cowling 39 and chimney 41 are placed on top of the outer barrel 25. After the start of combustion, an air duct (46, FIG. 4) is again used to feed air into the bottom barrel through holes in the bottom of the outer barrel. In this instance, the duct is placed between the brick ‘feet’ 23, centered under the holes in the bottom of the outer barrel. After completion of pyrolysis the cowling 39 and chimney 41 are removed and the outer barrel steel cover is placed over the chimney hole during the post-pyrolysis, cool down process. Maximum temperature (HTT) is recorded at 522.4-550° C. for CB and ChB pyrolysis measured by inserting an EXTECH K-type single pole temperature thermocouple through a tiny peephole in the outer and inner barrels into the middle of the feedstock. After two hours to two hours and twenty-five minutes, the pyrolytic event is concluded and biochar is produced. After pyrogenic gases dissipate, the material is allowed to air cool for twenty-four hours, after which it is removed from the inner chamber as before using scoops, pans, shovels, brooms, dustpans and similar tools.
In a larger 3000 L non-TLUD processing vessel, a retort (as described by Adams (2002), Anderson (2004), McLaughlin (2006) and Wells (2006)), is an embodiment reduced to practice as a subset of pyrolysis processing, comprising biochar and heat energy production. A retort of this type is used worldwide for the purpose of small to mid-scale manufacture of biochar and production of bioenergy. This embodiment produces CB and ChB biochars in an efficient fashion. A further embodiment is comprised of still greater production output via a commercial grade reactor which follows from the same principles. Such larger production could be increased if one pelletized (approx. 3 mm thick and approx. 12 mm in length and width) the CB or ChB with a hammer mill (as noted previously) or larger device. The retort described here is constructed of steel. It features a 2.5 m³feedstock chamber with 0.18 m thick walls and a 2.76 m×1.46 m×1 m combustion chamber with two attached chimneys and a firebox, all totaling an area of around 3.7 m. The sequence for loading the retort is thus: first a cover latch attached to the feedstock chamber is opened and feedstock (cardboard or chipboard) is loaded, preferably in rolls so as to make volume more compact. This procedure also enables a quicker and more effective pyrolysis. As before, with other embodiments described earlier, starter wood is used to initiate the gasification process which precedes pyrolysis in this style retort. There are four valves mounted on the device which control a pump, fan, air and gas blowers. At the start of the combustion process, blowers and the fan are left in the “off” position until gasification sequence has started. Once combustion begins (ignition of the firewood fuel), a chamber cover is placed over the top (opening) of the device wherein a sealing gasket fixes the lid to another gasket at the top of the chamber walls; four bolts are used to fasten down the lid. After primary ignition has occurred, a gas pipe feeds gas to the gasifier. A thermocouple attached to the chamber reveals when a minimal 250-300° C. temperature is achieved wherein gasification is said to be established; at that time the combustion blower is turned off, the gasifier lid is removed and more wood fuel is added. Then the lid is replaced as before and the combustion blower is turned back on. This process is repeated wherein sufficient wood fuel is made available to maintain sufficient heat for pyrolysis. Another thermocouple (there are four in all) is used to maintain readout of temperature during pyrolysis of the feedstock. A temperature of 615° C. is maintained in order to ensure complete pyrolysis. When gas exhaust has transitioned from smoke to clear fumes, it is time to turn on the gas blower which circulates hot exhaust gas to rinse through the pyrolyzed feedstock and accelerate completion of the heating process. After a time, the retort manufactures its own flammable gas and the gas blower is used continuously from this juncture until such point where further wood fuel is required. During pyrolysis, steam is created and distillates from that steam are created using a condenser after which they are drained down. Some of the distillates form vinegar and vinegar oil which may be used to coat firewood for future retort events. The retort uses a water supply for cooling down just-made biochar. Total pyrolysis time ranges from 4.5 to 6 hours depending on temperatures achieved following initiation of gasification and amount of wood fuel added during that process. The same would apply to ranges for HTT and total pyrolysis for larger processing vessels such as reactors which are not described herein. After cool down, the char is removed from the chamber and readied for inoculation as described earlier. All of the retort processing vessels behave in a similar way; though geometry of the retorts may be different the basic results are similar with regards to venting of gasses and uniform chemical activity. Biosynthetic gas produced from cardboard and chipboard pyrolysis is characterized through estimated maximum redox potential, biochemical oxygen demand, chemical oxygen demand, volatile fatty acids and other factors which generate estimated biogas yield.

Conditioning and Charging Biochars

After removal from processing vessels, CB and ChB biochars were conditioned by the same method. This consists of three stages: conditioning, charging and inoculation. To begin conditioning, 15 L of each type of biochar particles were saturated with 13 L water and placed in a 40 L plastic tub. In this step, saturation drove off tars, sugars, ash and lime from the biochar. The same process was used to saturate the peat moss, an organic blended with the raw char to quickly activate mycorrhizal activity after wetting. After a week, as part of a charging process the two materials were mixed into a single slurry 1:1 and poured into two 40 L tubs; as the blended material was solubilized equilibration of inorganic nutrient and trace elements began to take place. In the third week, 75 mL Peters 5-10-5 fertilizer was mixed into each tub. Fertilizer inoculation added additional nutrient to increase amount of sugars for microbes to feed on. As biochar sugars were used up through microbial action, mobile matter became leachable carbon accompanied by an increase in water uptake. In the fourth week, the charging process continued; each slurry mixture was removed from the tubs and shoveled onto a wire mesh attached to a wooden frame with the screen suspended over two empty 20 L tubs. Approximately 2 L of water were drained from the slurries, after which the remaining non-liquified material was removed and air dried in a separate dry container. By week five, sufficient drying occurs for the biochars to be blended with soil.

Blending and Post-Treatment Results

After conditioning, biochars are blended with soils of various kinds including calcined clay, sandy loams and sandy clays. Prior to blending, soil and biochar are kept in moisture free containers, most often in 16 L plastic buckets, and then transferred using scoops of various sizes depending on whether blends are poured into pots or extracted as samples (ranging from 2 mg to 300 mg) for laboratory analysis. When prepared for pot use, 10% biochar volume and 90% soil volume samples are blended in plastic tubs (generally 35 L in volume). Blends are mechanically stirred to ensure even distribution of the biochar particulate. Then each blend is poured into the appropriate sized pot and labeled, or extracted for analysis and labeled. For that purpose, untreated soils and conditioned biochars are sieved through a #10 sieve before blending using a 1.5 L aluminum bowl followed by further reduction. As a field application, a conditioned biochar may be tilled into an existing field at the rate of 1:10 biochar to soil within the a to b soil horizons (to a depth no greater than 30.48 cm).

Applications and Outcomes

As discussed earlier, observations and measurements of specific outcomes follow application of embodiments of the biochar which include laboratory elemental and nutrient analyses, adsorption capacity scanning (GACS) as shown in FIG. 8, portable photosynthesis and mass spectrometry as shown in tables 7 and 8 yielding metrics of plant physiological response to CB in pitch pine scrub oak species. Standard nutrient analysis performed using typical ICP testing yielded results of eastern U.S. grassland species (Panicum, Festuca, Helichtrichon, Schizachrium and Chasmantium) Prior to and Subsequent to exposure to CB soil additive. The effect of CB as a blocking (sorption) agent with regards to uptake of heavy metals in treated contaminated (firing range) soils was described previously.
The use of CB biochar intervention as a soil conditioner may mitigate problems associated with recalcitrant urban waste, worldwide disappearance of standalone or networked biomes and depredation of isolated and sometimes networked man-made landscape features which have induced undesired anthropogenic effects. In terms of impact on crops, there is preliminary evidence by the claimants, based on earlier heavy metal sorption research, that CB biochar soil amendment may achieve sorption and improved growth of potentially hyperaccumulating crops such as Brassica oleracea (cabbage), B. oleracea (var. kale), Lactuca saliva (lettuce) and Cucumis saliva (cucumber).

Claims

What is claimed is:

1. A method for producing biochar, comprising:

providing a feedstock comprising one or both of cardboard and chipboard;

reducing the size of the feedstock;

charging the reduced size feedstock into a processing vessel; and

pyrolyzing the reduced size feedstock in the processing vessel at a maximum temperature of at least about 500° C., to create biochar.