Repositorio
Institucional

Torres-Aravena, Alvaro

Meier, Leslie

Vilchez, Carlos

Cuaresma, Maria

Jeison, David

Effect of pH Change on the Microalgae-Based Biogas Upgrading Process

MDPI

APPLIED SCIENCES-BASEL

en

An alternative way to remove CO2 from biogas is the use of photosynthetic microorganisms, such as microalgae. This can be achieved by the operation of an open photobioreactor, connected with a mass transfer column, such as a counterflow column. This technology provides up-graded biogas with high quality. The microalgal uptake of CO2 from the biogas in counterflow columns generates pH changes in microalgae culture. To clarify the potential effect of these dynamic pH conditions in the culture, the effect of pH change on the photosynthetic activity and PSII quantum yield was studied for microalgae Chlorella sorokiniana. Thus, assays were carried out, where the pH drop reported in the counterflow columns was replicated in batch microalgae culture through HCl addition and CO2 injection, moving the culture pH from 7.0 to 5.0 and from 7.0 to 5.8, respectively. Moreover, the effect of light/darkness on photosynthetic activity was tested when the pH decreased. The results obtained in this research showed that the photosynthetic activity decreased for the light conditions when the pH was shifted by HCl addition and CO2 injection. Despite this, the value of the PSII quantum yield remained at 0.6-0.7, which means that the microalgae culture did not suffer a negative effect on the photosynthetic system of cells because a high value of PSII efficiency remained. In the same way, the results indicated that when the pH change was corrected, the photosynthetic activity recovered. Moreover, the apparent affinity constant for dissolved inorganic carbon (KDIC) was 0.9 mu M at pH 5 and 112.0 mu M at pH 7, which suggests that the preferred carbon source for C.sorokniana is CO2. Finally, all the results obtained indicated that the pH drop in the counter-flow column for biogas upgrading did not cause permanent damage to the photosynthetic system, and the decrease in the photosynthetic activity as a result of the pH drop can be recovered when the pH is corrected.

artículo original

This research was funded by FONDECYT-ANID CHILE, grant number 1120488, CRHIAM Centre (CONICYT/FONDAP) grant number 15130015, and VRIEA-PUCV grant number 039.315/2022.

Esta investigación fue financiada por FONDECYT-ANID CHILE, beca número 1120488, beca Centro CRHIAM (CONICYT/FONDAP) número 15130015 y beca VRIEA-PUCV número 039.315/2022.

10.3390/app122312194

PDF

biogas upgrading

microalgae

carbon sequestration

pH

INORGANIC CARBON

BIOMASS

GROWTH

PHOTOSYNTHESIS

PERFORMANCE

ANHYDRASE

RATIO

Química Multidisciplinaria

Ingeniería Multidisciplinaria

Ciencia de Materiales

Multidisciplinaria

Física Aplicada

mejora de biogás

microalgas

secuestro de carbono

pH

CARBONO INORGÁNICO

BIOMASA

CRECIMIENTO

FOTOSÍNTESIS

RENDIMIENTO

ANHIDRASA

RATIO

Biotecnología Ambiental

Microbiología

Bioproductos (Productos que se manufacturan usando biotecnología como materia prima), Biomateriales, Bioplásticos, Biocombustibles, Químicos Brutos y Finos, Bioderivados, Materiales nuevos Bioderivados

Effect of pH Change on the Microalgae-Based Biogas Upgrading Process

artículo original

version publicada

CC BY 4.0

CC BY 4.0

acceso abierto

acceso abierto

ANID-FONDECYT 15130015

PUCV 039.315/2022

CONICYT-FONDAP 15130015

ANID FONDECYT 15130015

WOS:000895522600001