PRODUCTION OF LIQUID HYDROCARBONS FROM AUTOTROPHIC MICROBIAL BIOMASS BY LOW TEMPERATURE AUTOCATALYTIC CONVERSION. PART 3: HARVESTING PROCEDURES OF MICROALGAE IN SEAWATER.

Información del proyecto

Identificador del acuerdo de subvención: EN3B0019

Proyecto cerrado

Fecha de inicio 1 Febrero 1986

Fecha de finalización 31 Octubre 1987

Financiado con arreglo a

• Research and development programme (EEC) in the field of Non-Nuclear Energy, 1985-1988

Coste total

Sin datos

Aportación de la UE

Sin datos

Coordinado por

AACHEN UNIVERSITY OF TECHNOLOGY
Germany

Objetivo

Large quantities of biomass suitable for conversion into oil can be achieved by large scale production of fast growing microalgae. In production of this kind, the harvesting procedure is a crucial step. The most promising procedure is flocculaion followed by either settling or floating at the surface (due to gas bubbles). The chemical procedure has been tested under pilot plant conditions involving sedimentation tanks of 1000 to 1300 l. A local rise of the pH in the surface region of these tanks was sufficient to flocculate the algae in the whole volume. This technique is simple, reliable and economically acceptable. The expenditure corresponds to 5-10 United States cents per kg oil produced by the subsequent conversion process.
THE HARVESTING PROCEDURE IS CRUCIAL IN ANY LARGE SCALE PRODUCTION OF MICROALGAE. THE WELL KNOWN LABORATORY TECHNIQUES (MENBRANE FILTRATION OR CENTRIFUGATION) ARE NOT APPLICABLE AT LARGE SCALE. A PROMISING PROCEDURE IS INDUCED FLOCCULATION FOLLOWED BY EITHER SPONTANEOUS SETTLING OR FLOATING AT THE SURFACE (DUE TO GAS BUBBLES). THE ECONOMIC CONCEPT OF PRODUCING OIL FROM MICROALGAE BY LOW TEMPERATURE CATALYTIC CONVERSION INCLUDES RECYCLING THE RESIDUES OF THE PYROLYSIS WHICH MEANS ABOUT 60% OF THE NITROGEN, ALMOST ALL OF THE PHOSPHORUS AND ABOUT 30-40% OF THE NON-CONVERTED CARBON. BECAUSE OF THIS RECYCLING IT IS NOT POSSIBLE TO USE COMMONLY APPLIED FLOCCULATING AGENTS WHICH CONTAIN ALUMINIUM OR IRON. THESE METALS WOULD ACCUMULATE IN THE ALGAE PONDS. FOR THIS REASON, A PROCEDURE IS BEING APPLIED WHERE FLOCCULATION STARTS FROM SEAWATER-OWN COMPONENTS, A TECHNIQUE WHICH USES FINELY DISPERSED PRECIPITATES OF MAGNESIUM HYDROXIDE FORMED AT ABOUT PH 10 AS COAGULATION CENTRE FOR ALGAE CELLS. AFTER THE CULTURE HAS REACHED PH 9.7 DURING THE DAY, THE PH IS LOCALLY RAISED TO ABOUT 10 WHICH INDUCES THE WANTED FLOCCULATION. WE TESTED AN ELECTROCHEMICAL AND CHEMICAL WAY TO PERFORM THE LOCAL RAISE OF THE PH. IN BOTH METHODS, THE SEDIMENTATION EFFICIENCY AFTER FLOCCULATION TURNED OUT TO BE ABOUT 90%. THE CHEMICAL WAY COSTS APPROXIMATELY 2 US CENTS PER KG OF DRY ALGAE HARVESTED, I.E. ABOUT 8-10 US CENTS PER KG OF OIL PRODUCED. THE COMING EXPERIMENTS ARE AIMED AT FURTHER REDUCING THIS NUMBER.

Ámbito científico (EuroSciVoc)

• ciencias naturales › ciencias de la tierra y ciencias ambientales conexas › geología › sedimentología
• ciencias naturales › ciencias biológicas › microbiología › ficología
• ciencias naturales › ciencias químicas › química inorgánica › metales alcalinotérreos
• ciencias naturales › ciencias químicas › química orgánica › hidrocarburo
• ciencias naturales › ciencias químicas › química inorgánica › metales de postransición

Programa(s)

• FP1-ENNONUC 3C - Research and development programme (EEC) in the field of Non-Nuclear Energy, 1985-1988

Tema(s)

Datos no disponibles

Convocatoria de propuestas

Datos no disponibles

Régimen de financiación

CSC - Cost-sharing contracts

Coordinador

AACHEN UNIVERSITY OF TECHNOLOGY

• Aportación de la UE: Sin datos
• Dirección: Templergraben 55 ; 52056 AACHEN ; Alemania
• Coste total: Sin datos

Participantes (2)

Consiglio Nazionale delle Ricerche (CNR)

Italia

• Aportación de la UE: Sin datos
• Dirección: 501 Firenze
• Coste total: Sin datos

THE UNIVERSITY OF TUEBINGEN

Alemania

• Aportación de la UE: Sin datos
• Dirección: Auf der Morgenstelle 18 ; 72076 TUEBINGEN
• Coste total: Sin datos