February 12, 2016
New Demonstration Plant for
B-DASH Project is completed:
Carbon Dioxide Capture from Biogas
and its Reuse for Microalgae
Cultivation
“Demonstration of carbon dioxide capture from biogas and its reuse for
microalgae cultivation“ adopted as a B-DASH Project 2015 is a joint research of
Japan Sewage Works Agency (JS), Toshiba Corporation, Euglena Corporation,
Nikkan Tokushu Co.Ltd, Nihon Suido Consultants Co.Ltd and Saga City. The
demonstration plant for the research has been recently completed in Saga City,
Saga Prefecture.
B-DASH Project, which stands for Breakthrough by Dynamic Approach in Sewage
High Technology Project, has been promoted by Ministry of Land, Infrastructure,
transport and Tourism (MLIT) of Japan since 2011. This demonstration is carried
out as a contract research of National Institute for Land and Infrastructure
Management (NILIM.)
Microalgae are one of the promising, usable biomass capturing people’s attention
because of its fast growth. In the demonstration, unused carbon dioxide is
captured from sewage biogas as a new resource, and together with filtrate, reused
for microalgae cultivation. The research demonstrates that the system has a
removability of nitrogen/phosphorus in return water and the productivity of
microalgae cultivation.
Demonstration facilities recently completed are as follows:
 CCU (CO2 capture and utilization) System using PSA unit:
Efficiently captures CH4 and CO2 from sewage sludge biogas using PSA
(Pressure Swing Adsorption).
 Microalgae cultivation system:
Efficiently cultures microalgae using captured CO2 and mineral-rich filtrate
including nitrogen, phosphorus, etc.
Carbon Dioxide Capture from Biogas and its Reuse for Microalgae Cultivation
Researchers: Toshiba Corporation, Euglena Corporation, Nikkan Tokushu Co. Ltd, Nihon Suido Consultants Co. Ltd, Japan Sewage Works Agency(JS), and Saga City
Site of demonstration: Saga City WWTP
Period of demonstration: 2015 ‐
Demonstration Overview
Solubilize thickened sludge and capture CO2 from biogas generating through solubilization. Cultivate microalgae with captured CO2 and filtrate to demonstrate the following capabilities.
① Capability of capturing CO2
② Productivity of microalgae (euglena)
③ Removability of nitrogen/phosphorus in filtrate
④ Capability of sludge solubilization
Microalgae or Euglena (the Japanese name: Midori‐Mushi) is usable for animal food or fertilizer as a value added resource
Demonstration Flowchart
Sludge solubilization stabilizes the amount of biogas and increases its revenue
Scope of demonstration
Microalgae cultivation
Capture highly concentrated CO2
from biogas
Recycle facilities of captured CO2
CO2(Over 99%)
Filtrate
(N/P)
CO2 capture and utilization
(CCU)
Utilize CO2
Reduce load of return water
Biogas
Community
Dewatering facilities
Sewage sludge
Waste
water
Digester
WWTP
Sludge solubilization facilities
Cultivate microalgae with captured CO2 and filtrate
Produce fertilizer from sewage sludge Major Demonstration Facilities
Sludge solubilization facility
Sludge before solubilization
Sludge after solubilization
The facility mechanically solubilizes thickened sludge using shear force and cavitation generated by high‐speed rotation of built‐in discs. The acceleration of digestion by solubilization can lead to stabilize the generation of digestion gas and to increase its production.
PSA Unit
The PSA unit adopted in the demonstration consists of three absorbent towers. The three towers capture high purity gases which are more than 99% of CO2 and 90% of CH4 with automatic, repetitive control.
Absorbent media
Greenhouse Cultivation
Cultivation Tank
A greenhouse enables easy temperature control and supplemental lighting. The greenhouse cultivation can produce microalgae of stable quality not affected by weather.
This facility cultivate microalgae (euglena) using filtrate and CO2. It can not only capture microalgae as valuables, but reduce nitrogen and phosphorus in filtrate.