Biochar/Brick Co-production System - Revision history

Rasmus: inserted categorization

2016-08-21T17:03:35Z

inserted categorization

← Older revision		Revision as of 17:03, 21 August 2016
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	[[Category:Housing and construction]]		[[Category:Housing and construction]]
	[[Category:Materials]]		[[Category:Materials]]
			[[Category:Biochar]]

Rasmus: clarifications

2016-04-28T03:20:35Z

clarifications

← Older revision		Revision as of 03:20, 28 April 2016
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	== Alternative Design Considerations==		== Alternative Design Considerations==
	An entirely different approach would be to have an open, complete burn as in the [[Kon-Tiki Kiln]] but only use it to add heat to the system, not ~~use it for~~ fuel. There would still have to be some fuel added to the brick shaft but perhaps at a somewhat (greatly?) reduced level. The air entering the VSBK from below would be pre-heated (heat exchanger?) before entering the burn zone.		An entirely different approach would be to have an open, complete burn as in the [[Kon-Tiki Kiln]] but only use it to add heat to the system, not fuel. There would still have to be some fuel added to the brick shaft but perhaps at a somewhat (greatly?) reduced level. The air entering the VSBK from below would be pre-heated (heat exchanger?) before entering the burn zone.

	Yet another approach would be to make the char ~~but~~ capture the pyrolysis gas (wood gas), condense it down to [[pyrolysis oil]] and then use that to co-fire a standard, unmodified VSBK.		Yet another approach would be to make the char in a separate facility and capture the pyrolysis gas (wood gas), condense it down to [[pyrolysis oil]] and then use that to co-fire a standard, unmodified VSBK.

	[[Category:Housing and construction]]		[[Category:Housing and construction]]
	[[Category:Materials]]		[[Category:Materials]]

Rasmus at 14:11, 27 April 2016

2016-04-27T14:11:37Z

← Older revision		Revision as of 14:11, 27 April 2016
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	*further extension of the concept for even better air quality: rather than emit the exhaust gas into the open environment, pump it into a [[biofilter]].		*further extension of the concept for even better air quality: rather than emit the exhaust gas into the open environment, pump it into a [[biofilter]].

	[[File:Drawing - VSBK Biochar co-production system.jpg\|600px\|thumb\|right\|Biochar/Brick Co-Production System: suitable biomass is added at the top of the biochar production unit, moves down the shaft and is pyrolyzed into biochar, which is removed at the bottom. The [[pyrolysis]] gases exit through the back of this unit (connection not shown) and enter the VSBK shaft where they are burned~~, firing~~ the bricks.]]		[[File:Drawing - VSBK Biochar co-production system.jpg\|600px\|thumb\|right\|Biochar/Brick Co-Production System: suitable dry biomass is added at the top of the biochar production unit, moves down the shaft and is pyrolyzed into biochar, which is removed at the bottom. The [[pyrolysis]] gases exit through the back of this unit (connection not shown) and enter the VSBK shaft where they are burned to fire the bricks.]]

	[[File:Other drawings - VSBK biochar.jpg\|800px\|thumb\|right\|Additional early sketches. Air entering the biochar-making unit should be very limited, in order to prevent full combustion. It is only needed to maintain a sufficiently high temperature of about 450-550°C. Most air enters through the VSBK unit. Exhaust heat from the VSBK may be used to pre-~~warm~~ biomass. Image on the right side is view from the top.]]		[[File:Other drawings - VSBK biochar.jpg\|800px\|thumb\|right\|Additional early sketches. Air entering the biochar-making unit should be very limited, in order to prevent full combustion. It is only needed to maintain a sufficiently high temperature of about 450-550°C. Most air enters through the VSBK unit. Exhaust heat from the VSBK may be used to pre-heat the biomass. Alternatively, it could be used to pre-heat the air entering the VSBK. Image on the right side is view from the top.]]

	==Technical Challenges==		==Technical Challenges==

Rasmus at 13:06, 27 April 2016

2016-04-27T13:06:56Z

← Older revision		Revision as of 13:06, 27 April 2016
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	[[File:Drawing - VSBK Biochar co-production system.jpg\|600px\|thumb\|right\|Biochar/Brick Co-Production System: suitable biomass is added at the top of the biochar production unit, moves down the shaft and is pyrolyzed into biochar, which is removed at the bottom. The [[pyrolysis]] gases exit through the back of this unit (connection not shown) and enter the VSBK shaft where they are burned, firing the bricks.]]		[[File:Drawing - VSBK Biochar co-production system.jpg\|600px\|thumb\|right\|Biochar/Brick Co-Production System: suitable biomass is added at the top of the biochar production unit, moves down the shaft and is pyrolyzed into biochar, which is removed at the bottom. The [[pyrolysis]] gases exit through the back of this unit (connection not shown) and enter the VSBK shaft where they are burned, firing the bricks.]]

	[[File:Other drawings - VSBK biochar.jpg\|800px\|thumb\|right\|Additional early sketches. Image on the right side is view from the top.]]		[[File:Other drawings - VSBK biochar.jpg\|800px\|thumb\|right\|Additional early sketches. Air entering the biochar-making unit should be very limited, in order to prevent full combustion. It is only needed to maintain a sufficiently high temperature of about 450-550°C. Most air enters through the VSBK unit. Exhaust heat from the VSBK may be used to pre-warm biomass. Image on the right side is view from the top.]]

	==Technical Challenges==		==Technical Challenges==
	Some reports suggest that high-quality [[biochar]] requires low reaction pressures, to allow all volatiles to evaporate and leave only the char behind. The simplest way to achieve this is the "open burn" approach as demonstrated by the [[Kon-Tiki Kiln]]. Now if the pyrolysis gas is captured, this may result in higher pressures inside the pyrolysis zone, potentially reducing the evaporation of volatiles. Possible solutions are: 1.) build higher smokestack to increase draft, 2.) forced draft system using electrical fans that pull out the exhaust, or 3.) blow CO2-rich exhaust gases into the pyrolysis zone to limit oxygen but still drive out the volatiles.		Some reports suggest that high-quality [[biochar]] requires low reaction pressures, to allow all volatiles to evaporate and leave only the char behind. The simplest way to achieve this is the "open burn" approach as demonstrated by the [[Kon-Tiki Kiln]]. Now if the pyrolysis gas is captured, this may result in higher pressures inside the pyrolysis zone, potentially reducing the evaporation of volatiles. Possible solutions are: 1.) build higher smokestack to increase draft, 2.) forced draft system using electrical fans that pull out the exhaust, or 3.) blow CO2-rich exhaust gases into the pyrolysis zone to limit oxygen but still drive out the volatiles.

	There is a potential design conflict here in that the draft on the system has to accommodate both the brick firing and the pyrolysis. This may make this whole concept not feasible. If the draft on the char is very high, then a larger percentage of the biomass will burn to ash (and the temperature may be above the optimal 450-~~550C~~ range). If the draft is too low, then the temperature may be too low for good-quality biochar and also the amount of residual volatiles may be elevated. For the bricks, if the draft on them is too high or too low, quality will be affected. This can potentially be resolved in different ways. A throttle mechanism could be inserted between char and bricks. Also, an extra chimney could be added that is only for the char, to make sure that there is always enough draft. This would waste some fuel and heat but it could perhaps be captured for other purposes (e.g. steam production). Also, as mentioned in the previous paragraph, CO2-rich exhaust could be blown into the char which would have the advantage that it would pre-heat the newly added biomass. So this may be fixable but at the cost of having a more convoluted system.		There is a potential design conflict here in that the draft on the system has to accommodate both the brick firing and the pyrolysis. This may make this whole concept not feasible. If the draft on the char is very high, then a larger percentage of the biomass will burn to ash (and the temperature may be above the optimal 450-550°C range). If the draft is too low, then the temperature may be too low for good-quality biochar and also the amount of residual volatiles may be elevated. For the bricks, if the draft on them is too high or too low, quality will be affected. This can potentially be resolved in different ways. A throttle mechanism could be inserted between char and bricks. Also, an extra chimney could be added that is only for the char, to make sure that there is always enough draft. This would waste some fuel and heat but it could perhaps be captured for other purposes (e.g. steam production). Also, as mentioned in the previous paragraph, CO2-rich exhaust could be blown into the char which would have the advantage that it would pre-heat the newly added biomass. So this may be fixable but at the cost of having a more convoluted system.

	== Alternative Design Considerations==		== Alternative Design Considerations==

Rasmus at 23:14, 25 April 2016

2016-04-25T23:14:18Z

← Older revision		Revision as of 23:14, 25 April 2016
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	==Development Proposal==		==Development Proposal==
	*Proposal: carbon-negative VSBK fired with pyrolysis gas, with [[biochar]] as a co-product		*Proposal: carbon-negative VSBK fired with pyrolysis gas, with [[biochar]] as a co-product
			*Co-products in addition to bricks: [[biochar]], heat for space heating, greenhouses, steam, even electricity, etc.
	*This would need relatively close monitoring but there is potential for automation.		*This would need relatively close monitoring but there is potential for automation.
	*The typical VSBK is coal-fired, mostly using low-quality coal fines: pieces of coal are scattered onto the bricks from the top. The brick kiln could be re-designed as part of a [[pyrolysis]] system to run on [[pyrolysis]] gas.		*The typical VSBK is coal-fired, mostly using low-quality coal fines: pieces of coal are scattered onto the bricks from the top. The brick kiln could be re-designed as part of a [[pyrolysis]] system to run on [[pyrolysis]] gas.
			*There is a need for a backup system in case the pyrolysis shaft is temporarily non-operational (e.g. methane supply)
	*This type of gas-fired kiln would have cleaner emissions than the coal-fired one (less soot/particulates, CO, NOx, heavy metals, organic pollutants, etc.). Emissions would also be cleaner than from a biomass-fired kiln, because pyrolysis is generally cleaner than combustion. The concept is therefore suitable to conditions in the developing world, where a lot of the demand for bricks is in rapidly growing urban areas with dense populations.		*This type of gas-fired kiln would have cleaner emissions than the coal-fired one (less soot/particulates, CO, NOx, heavy metals, organic pollutants, etc.). Emissions would also be cleaner than from a biomass-fired kiln, because pyrolysis is generally cleaner than combustion. The concept is therefore suitable to conditions in the developing world, where a lot of the demand for bricks is in rapidly growing urban areas with dense populations.
	*Co-products in addition to bricks: [[biochar]], heat for space heating, greenhouses, steam, even electricity, etc.
	*further extension of the concept for even better air quality: rather than emit the exhaust gas into the open environment, pump it into a [[biofilter]].		*further extension of the concept for even better air quality: rather than emit the exhaust gas into the open environment, pump it into a [[biofilter]].

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	==Technical Challenges==		==Technical Challenges==
	Some reports suggest that high-quality [[biochar]] requires low reaction pressures, to allow all volatiles to evaporate and leave only the char behind. The simplest way to achieve this is the "open burn" approach as demonstrated by the [[Kon-Tiki Kiln]]. ~~In contrast,~~ if the pyrolysis gas is captured, ~~then~~ this may result in higher pressures inside the pyrolysis zone, reducing the evaporation of volatiles. ~~Potential~~ solutions are: 1.) build higher smokestack to increase draft, 2.) forced draft system using electrical fans that pull out the exhaust, or 3.) blow CO2-rich exhaust gases into the pyrolysis zone to limit oxygen but still drive out the volatiles.		Some reports suggest that high-quality [[biochar]] requires low reaction pressures, to allow all volatiles to evaporate and leave only the char behind. The simplest way to achieve this is the "open burn" approach as demonstrated by the [[Kon-Tiki Kiln]]. Now if the pyrolysis gas is captured, this may result in higher pressures inside the pyrolysis zone, potentially reducing the evaporation of volatiles. Possible solutions are: 1.) build higher smokestack to increase draft, 2.) forced draft system using electrical fans that pull out the exhaust, or 3.) blow CO2-rich exhaust gases into the pyrolysis zone to limit oxygen but still drive out the volatiles.

	There is a potential conflict here in that the draft has to accommodate both the brick firing and the pyrolysis. This may make this whole concept not feasible. If the draft on the char is very high, then a larger percentage of the biomass will burn to ash (and the temperature may be above the optimal 450-550C range). If the draft is too low, then the temperature may be too low for good-quality biochar and also the amount of residual volatiles may be elevated. For the bricks, if the draft on them is too high or too low, quality will be affected. This can potentially be resolved in different ways. A throttle mechanism could be inserted between char and bricks. Also, an extra chimney could be added that is only for the char, to make sure that there is always enough draft. This would waste some heat but it could perhaps be captured for other purposes (e.g. steam production). Also, as mentioned in the previous paragraph, CO2-rich exhaust could be blown into the char which would have the advantage that it would pre-heat the newly added biomass. So this may be fixable but at the cost of having a more convoluted system.		There is a potential design conflict here in that the draft on the system has to accommodate both the brick firing and the pyrolysis. This may make this whole concept not feasible. If the draft on the char is very high, then a larger percentage of the biomass will burn to ash (and the temperature may be above the optimal 450-550C range). If the draft is too low, then the temperature may be too low for good-quality biochar and also the amount of residual volatiles may be elevated. For the bricks, if the draft on them is too high or too low, quality will be affected. This can potentially be resolved in different ways. A throttle mechanism could be inserted between char and bricks. Also, an extra chimney could be added that is only for the char, to make sure that there is always enough draft. This would waste some fuel and heat but it could perhaps be captured for other purposes (e.g. steam production). Also, as mentioned in the previous paragraph, CO2-rich exhaust could be blown into the char which would have the advantage that it would pre-heat the newly added biomass. So this may be fixable but at the cost of having a more convoluted system.

	== Alternative Design Considerations==		== Alternative Design Considerations==
	An entirely different approach would be to an open, complete burn as in the [[Kon-Tiki Kiln]] but only use it ~~for~~ heat, not for fuel. There would still have to be some fuel added to the brick shaft but perhaps at a somewhat (greatly?) reduced level. The air entering the VSBK from below would be pre-heated (heat exchanger?) before entering the burn zone.		An entirely different approach would be to have an open, complete burn as in the [[Kon-Tiki Kiln]] but only use it to add heat to the system, not use it for fuel. There would still have to be some fuel added to the brick shaft but perhaps at a somewhat (greatly?) reduced level. The air entering the VSBK from below would be pre-heated (heat exchanger?) before entering the burn zone.

	Yet another approach would be to make the char but capture the pyrolysis gas (wood gas), condense it down to [[pyrolysis oil]] and then use that to co-fire a standard, unmodified VSBK.		Yet another approach would be to make the char but capture the pyrolysis gas (wood gas), condense it down to [[pyrolysis oil]] and then use that to co-fire a standard, unmodified VSBK.

Rasmus: /* Technical Challenges */ typo fixed

2016-04-25T21:11:25Z

Technical Challenges: typo fixed

← Older revision		Revision as of 21:11, 25 April 2016
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	==Technical Challenges==		==Technical Challenges==
	Some reports suggest that high-quality [[biochar]] requires low reaction pressures, to allow all volatiles to evaporate and leave only the char behind. The simplest way to achieve this is the "open burn" approach as demonstrated by the [[Kon-Tiki Kiln]]. In contrast, if ~~the~~ the pyrolysis gas is captured, then this may result in higher pressures inside the pyrolysis zone, reducing the evaporation of volatiles. Potential solutions are: 1.) build higher smokestack to increase draft, 2.) forced draft system using electrical fans that pull out the exhaust, or 3.) blow CO2-rich exhaust gases into the pyrolysis zone to limit oxygen but still drive out the volatiles.		Some reports suggest that high-quality [[biochar]] requires low reaction pressures, to allow all volatiles to evaporate and leave only the char behind. The simplest way to achieve this is the "open burn" approach as demonstrated by the [[Kon-Tiki Kiln]]. In contrast, if the pyrolysis gas is captured, then this may result in higher pressures inside the pyrolysis zone, reducing the evaporation of volatiles. Potential solutions are: 1.) build higher smokestack to increase draft, 2.) forced draft system using electrical fans that pull out the exhaust, or 3.) blow CO2-rich exhaust gases into the pyrolysis zone to limit oxygen but still drive out the volatiles.

	There is a potential conflict here in that the draft has to accommodate both the brick firing and the pyrolysis. This may make this whole concept not feasible. If the draft on the char is very high, then a larger percentage of the biomass will burn to ash (and the temperature may be above the optimal 450-550C range). If the draft is too low, then the temperature may be too low for good-quality biochar and also the amount of residual volatiles may be elevated. For the bricks, if the draft on them is too high or too low, quality will be affected. This can potentially be resolved in different ways. A throttle mechanism could be inserted between char and bricks. Also, an extra chimney could be added that is only for the char, to make sure that there is always enough draft. This would waste some heat but it could perhaps be captured for other purposes (e.g. steam production). Also, as mentioned in the previous paragraph, CO2-rich exhaust could be blown into the char which would have the advantage that it would pre-heat the newly added biomass. So this may be fixable but at the cost of having a more convoluted system.		There is a potential conflict here in that the draft has to accommodate both the brick firing and the pyrolysis. This may make this whole concept not feasible. If the draft on the char is very high, then a larger percentage of the biomass will burn to ash (and the temperature may be above the optimal 450-550C range). If the draft is too low, then the temperature may be too low for good-quality biochar and also the amount of residual volatiles may be elevated. For the bricks, if the draft on them is too high or too low, quality will be affected. This can potentially be resolved in different ways. A throttle mechanism could be inserted between char and bricks. Also, an extra chimney could be added that is only for the char, to make sure that there is always enough draft. This would waste some heat but it could perhaps be captured for other purposes (e.g. steam production). Also, as mentioned in the previous paragraph, CO2-rich exhaust could be blown into the char which would have the advantage that it would pre-heat the newly added biomass. So this may be fixable but at the cost of having a more convoluted system.

	== Alternative Design Considerations==		== Alternative Design Considerations==

Rasmus at 20:47, 25 April 2016

2016-04-25T20:47:03Z

← Older revision		Revision as of 20:47, 25 April 2016
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	[[File:Drawing - VSBK Biochar co-production system.jpg\|600px\|thumb\|right\|Biochar/Brick Co-Production System: suitable biomass is added at the top of the biochar production unit, moves down the shaft and is pyrolyzed into biochar, which is removed at the bottom. The [[pyrolysis]] gases exit through the back of this unit (connection not shown) and enter the VSBK shaft where they are burned, firing the bricks.]]		[[File:Drawing - VSBK Biochar co-production system.jpg\|600px\|thumb\|right\|Biochar/Brick Co-Production System: suitable biomass is added at the top of the biochar production unit, moves down the shaft and is pyrolyzed into biochar, which is removed at the bottom. The [[pyrolysis]] gases exit through the back of this unit (connection not shown) and enter the VSBK shaft where they are burned, firing the bricks.]]

	[[File:Other drawings - VSBK biochar.jpg\|~~600px~~\|thumb\|right\|Additional early sketches. Image on the right side is view from the top.]]		[[File:Other drawings - VSBK biochar.jpg\|800px\|thumb\|right\|Additional early sketches. Image on the right side is view from the top.]]

	==Technical Challenges==		==Technical Challenges==

Rasmus at 18:10, 25 April 2016

2016-04-25T18:10:53Z

← Older revision		Revision as of 18:10, 25 April 2016
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	[[File:Other drawings - VSBK biochar.jpg\|600px\|thumb\|right\|Additional early sketches. Image on the right side is view from the top.]]		[[File:Other drawings - VSBK biochar.jpg\|600px\|thumb\|right\|Additional early sketches. Image on the right side is view from the top.]]

	==Technical ~~challenges and alternative design considerations~~==		==Technical Challenges==
	Some reports suggest that high-quality [[biochar]] requires low reaction pressures, to allow all volatiles to evaporate and leave only the char behind. The simplest way to achieve this is the "open burn" approach as demonstrated by the [[Kon-Tiki Kiln]]. In contrast, if the the pyrolysis gas is captured, then this may result in higher pressures inside the pyrolysis zone, reducing the evaporation of volatiles. Potential solutions are: 1.) build higher smokestack to increase draft, 2.) forced draft system using electrical fans that pull out the exhaust, or 3.) blow CO2-rich exhaust gases into the pyrolysis zone to limit oxygen but still drive out the volatiles.		Some reports suggest that high-quality [[biochar]] requires low reaction pressures, to allow all volatiles to evaporate and leave only the char behind. The simplest way to achieve this is the "open burn" approach as demonstrated by the [[Kon-Tiki Kiln]]. In contrast, if the the pyrolysis gas is captured, then this may result in higher pressures inside the pyrolysis zone, reducing the evaporation of volatiles. Potential solutions are: 1.) build higher smokestack to increase draft, 2.) forced draft system using electrical fans that pull out the exhaust, or 3.) blow CO2-rich exhaust gases into the pyrolysis zone to limit oxygen but still drive out the volatiles.

	There is a potential conflict here in that the draft has to accommodate both the brick firing and the pyrolysis. This may make this whole concept not feasible. If the draft on the char is very high, then a larger percentage of the biomass will burn to ash (and the temperature may be above the optimal 450-550C range). If the draft is too low, then the temperature may be too low for good-quality biochar and also the amount of residual volatiles may be elevated. For the bricks, if the draft on them is too high or too low, quality will be affected. This can potentially be resolved in different ways. A throttle mechanism could be inserted between char and bricks. Also, an extra chimney could be added that is only for the char, to make sure that there is always enough draft. This would waste some heat but it could perhaps be captured for other purposes (e.g. steam production). Also, as mentioned in the previous paragraph, CO2-rich exhaust could be blown into the char which would have the advantage that it would pre-heat the newly added biomass. So this may be fixable but at the cost of having a more convoluted system.		There is a potential conflict here in that the draft has to accommodate both the brick firing and the pyrolysis. This may make this whole concept not feasible. If the draft on the char is very high, then a larger percentage of the biomass will burn to ash (and the temperature may be above the optimal 450-550C range). If the draft is too low, then the temperature may be too low for good-quality biochar and also the amount of residual volatiles may be elevated. For the bricks, if the draft on them is too high or too low, quality will be affected. This can potentially be resolved in different ways. A throttle mechanism could be inserted between char and bricks. Also, an extra chimney could be added that is only for the char, to make sure that there is always enough draft. This would waste some heat but it could perhaps be captured for other purposes (e.g. steam production). Also, as mentioned in the previous paragraph, CO2-rich exhaust could be blown into the char which would have the advantage that it would pre-heat the newly added biomass. So this may be fixable but at the cost of having a more convoluted system.

			== Alternative Design Considerations==
	An entirely different approach would be to an open, complete burn as in the [[Kon-Tiki Kiln]] but only use it for heat, not for fuel. There would still have to be some fuel added to the brick shaft but perhaps at a somewhat (greatly?) reduced level. The air entering the VSBK from below would be pre-heated (heat exchanger?) before entering the burn zone.		An entirely different approach would be to an open, complete burn as in the [[Kon-Tiki Kiln]] but only use it for heat, not for fuel. There would still have to be some fuel added to the brick shaft but perhaps at a somewhat (greatly?) reduced level. The air entering the VSBK from below would be pre-heated (heat exchanger?) before entering the burn zone.

Rasmus: inserted final image

2016-04-25T18:01:39Z

inserted final image

← Older revision		Revision as of 18:01, 25 April 2016
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	[[File:Drawing - VSBK Biochar co-production system.jpg\|600px\|thumb\|right\|Biochar/Brick Co-Production System: suitable biomass is added at the top of the biochar production unit, moves down the shaft and is pyrolyzed into biochar, which is removed at the bottom. The [[pyrolysis]] gases exit through the back of this unit (connection not shown) and enter the VSBK shaft where they are burned, firing the bricks.]]		[[File:Drawing - VSBK Biochar co-production system.jpg\|600px\|thumb\|right\|Biochar/Brick Co-Production System: suitable biomass is added at the top of the biochar production unit, moves down the shaft and is pyrolyzed into biochar, which is removed at the bottom. The [[pyrolysis]] gases exit through the back of this unit (connection not shown) and enter the VSBK shaft where they are burned, firing the bricks.]]

			[[File:Other drawings - VSBK biochar.jpg\|600px\|thumb\|right\|Additional early sketches. Image on the right side is view from the top.]]

	==Technical challenges and alternative design considerations==		==Technical challenges and alternative design considerations==

Rasmus: inserted illustration

2016-04-25T17:40:16Z

inserted illustration

← Older revision		Revision as of 17:40, 25 April 2016
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	[[File:~~Drawing -~~ VSBK ~~Biochar co-production system~~.jpg\|600px\|thumb\|right\|~~Biochar/Brick Co-Production System~~: ~~suitable biomass is added at the top~~ of ~~the~~ biochar production ~~unit, moves down the shaft and is pyrolyzed into biochar, which is removed at the bottom~~. ~~The [[pyrolysis]]~~ gases ~~exit through the back of this unit (connection not shown)~~ and ~~enter the~~ VSBK ~~shaft where they are burned, firing the bricks~~.]]		[[File:VSBK mod biochar.jpg\|600px\|thumb\|right\|Concept: combination of VSBK and biochar production. Pyrolysis gases from biochar production are captured and used to fire bricks in a VSBK.]]

	The concept is to couple the production of [[biochar]] with the production of fired bricks, analogous to the [[Biochar-Lime Co-production System]]. The [[pyrolysis]] gas generated during [[biochar]] production is not flared off but used to fire bricks in a [[Vertical Shaft Brick Kiln]] (VSBK). The process is carbon-negative, because part of the carbon (25-30%) is retained as recalcitrant [[biochar]].		The concept is to couple the production of [[biochar]] with the production of fired bricks, analogous to the [[Biochar-Lime Co-production System]]. The [[pyrolysis]] gas generated during [[biochar]] production is not flared off but used to fire bricks in a [[Vertical Shaft Brick Kiln]] (VSBK). The process is carbon-negative, because part of the carbon (25-30%) is retained as recalcitrant [[biochar]].
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	*Co-products in addition to bricks: [[biochar]], heat for space heating, greenhouses, steam, even electricity, etc.		*Co-products in addition to bricks: [[biochar]], heat for space heating, greenhouses, steam, even electricity, etc.
	*further extension of the concept for even better air quality: rather than emit the exhaust gas into the open environment, pump it into a [[biofilter]].		*further extension of the concept for even better air quality: rather than emit the exhaust gas into the open environment, pump it into a [[biofilter]].

			[[File:Drawing - VSBK Biochar co-production system.jpg\|600px\|thumb\|right\|Biochar/Brick Co-Production System: suitable biomass is added at the top of the biochar production unit, moves down the shaft and is pyrolyzed into biochar, which is removed at the bottom. The [[pyrolysis]] gases exit through the back of this unit (connection not shown) and enter the VSBK shaft where they are burned, firing the bricks.]]

	==Technical challenges and alternative design considerations==		==Technical challenges and alternative design considerations==