Friday, September 29

Turning to microalgae for eco-solutions


A worker carries out the filtering process in microalgae production, at the outdoor algae cultivation facility in SBC.

SARAWAK is once again shining on the world map with the establishment of the world’s largest mass microalgae biomass production facility known as CHITOSE Carbon Capture Central (C4).

Blessed with pristine land and water, with almost constant light cycles and temperature conditions, and without the extremes seasons of winter and summer, Sarawak provides an ideal setting for developing microalgae-based biotechnological applications.

C4 uses flat-panel photo-bioreactor technology to produce microalgae. This seems like a promising alternative to producing biofuels, foods and pigments, in view of the higher yield per unit area. A further favoured situation is that the algae have an ability to grow on wastewater using non-arable land along with high carbon dioxide (CO2) sequestration potential.

In terms of geographical position, Sarawak is strategically located so as to facilitate access to major international markets such as Japan, Taiwan, China and Singapore. In addition, there is also the availability of qualified and skilled local workforce.

‘A huge momentum’

According to Chitose Laboratory Corp executive officer and chief bioengineer Dr Takanori Hoshino, the project is funded by Japan’s New Energy and Industrial Technology Development Organization (NEDO) but it would not have been successful without the collaboration of other players like Sarawak Biodiversity Centre (SBC), Sarawak Energy Bhd (SEB) and ENEOS Corporation.

The C4, he adds, is ideally located to make use of the SEB’s waste stream released by the Sejingkat coal power station by absorbing the CO2 to grow microalgae in a carbon circular economy.

Photo shows the C4, the world’s largest mass microalgae biomass production facility.

SBC, on the other hand, provides the qualified researchers and skilled manpower.

Dr Hoshino says the worldwide concern over the negative effects of climate change towards human and environment has synergised the development of CO2 utilisation technologies.

The culturing of microalgae for CO2 bio-fixation has gained a huge momentum due to its high photosynthetic rate that allows bio-fixation of CO2 to be more efficient than terrestrial plants.
In addition, lipids from microalgae biomass can be converted to biodiesel – a renewable fuel that causes less CO2 emission than that of fossil-diesel when combusted.

“Microalgae are the most efficient feedstock to produce diverse and complicated chemical compounds including, but not limited to, fuels, plastics, food and feed,” says the bioengineer, adding that cultivation of microalgae is so far the best practice to fix solar energy into biomass.

SBC researchers Hafizah Booty (left) and Lee Jong Jen.

The highlight – biodiesel

Microalgae’s use is biofuel production makes this an attractive solution. The technology works in a way that during the photosynthesis of microalgae, CO2 is captured and turned into carbohydrate, which is then used to form lipids, nucleic acids and proteins.

“Their fast growth rate and simple cell structure make it possible for microalgae to have 10 to 50 times higher CO2 bio-fixation efficiency than that of conventional agricultural crops,” says Dr Hoshino.

“Microalgae have recently attracted considerable interest worldwide, due to their extensive application potential in the renewable energy, biopharmaceutical, and nutraceutical industries. Microalgae are renewable, sustainable, and economical sources of biofuels, bioactive medicinal products, and food ingredients.

“In order to improve the sustainability of our society, the dependence on fossil resources needs to be minimised, and that on recyclable biomass needs to be increased.”

Dr Hoshino says microalgae contain tons of nutritional components that can be utilised as food products.

According to him, starting from 2027, it is going to be mandatory for all airline companies globally to have certain percentage of their jet fuels to be mixed with biofuel.

He points out that once bio-jet fuel – otherwise known as ‘sustainable aviation fuel’ – could be mass-produced from microalgae biomass, they would eye exporting the product not only to Southeast Asian countries, but also to the United States and Europe.

A search in the International Civil Aviation Organisation (ICAO) website has revealed that ICAO has adopted the Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA) to reduce greenhouse gas (GHG) emission for the aviation sector.

One of the carbon offsetting measures is to use sustainable bio-jet fuel accredited under CORSIA. With the commitment of CORSIA, the minimum blending of bio-jet fuel is two per cent starting 2027, and the approved blending could be up to 50 per cent.

Under CORSIA, all airline operators with annual emissions greater than 10,000 tonnes of CO2 are required to report their emissions on an annual basis, with monitoring having already started in January 2019.

The CO2 offsetting requirements in CORSIA are being implemented in phases, with mandatory implementation to begin in 2027.

What is microalgae?

To this question, Dr Hoshino describes microalgae as ‘unicellular photosynthetic microorganisms, living in saline or freshwater environments, which convert sunlight, water and CO2 to microalgal biomass’.

These microorganisms perform photosynthesis, which is an important natural mechanism to reduce the atmospheric CO2 concentration. Microalgae are also characterised by a short generation time, multiplying exponentially under favourable environmental conditions.

In relation to C4, flat-panel photo-bioreactor technology is used to produce microalgae. The photo-bioreactor is especially advantageous for microalgae, which are difficult to be cultivated stably due to contamination problems.

The flat-panel photo-bioreactor comprises a disposable non-structural element for holding liquid medium for microalgae cultivation – a hollow, cage-like, structure component, stable and essentially non-deformable, and penetrable for light, capable of supporting non-structural element. Such component can withstand the pressure of the liquid medium and allow sufficient light to enter to the medium for the photo-cultivation of microalgae.

“The flat-panel photo-bioreactor is simple to operate, and can provide a semi-open environment and also, it can minimise contamination risks. Another advantage is its up-scaling capability, as well as its low-cost simple construction and operation,” says Dr Hoshino.

What impact does microalgae production has on environment? To this question, Dr Hoshino simply responds: ‘Positive’.

“It uses up CO2, thus reducing carbon emissions,” he adds.

“Through microalgae, CO2 can be captured and recycled into biomass which, in turn, could be utilised as a carbon source to produce organic compounds for the production of bioenergy and other value-added products.

“Utilisation of CO2 is critical to resolving climate change crisis. Microalgae have exhibited a potential to directly capture emitted CO2 from the atmosphere.”

Issues and challenges

Is there any problem in microalgae cultivation? What is the most challenging one?

To these questions, the bioengineer says one main issue is the possible presence of biological contaminants.

Fungi, among the main contaminants in microalgal cultures, are able to influence the production and quality of biomass significantly.

“However, we have currently managed to effectively reduce as much as possible by using the flat-panel photo-bioreactor technology.

“Contaminants are inevitable, and we are constantly trying to find strategies to minimise or to control contamination,” he adds.

In the contamination controlling culture system for the biofuel production from microalgae and cyanobacteria, effective controlling of the contamination level, facilitating the substrate consumption or product production, as well as industrial application potential, are the crucial goals to be pursued.

Meanwhile, Dr Hoshino says the microalgae cultivation farm at C4 spans about five hectares and there is a plan to expand it to 100 hectares in three years, and 2,000 hectares towards 2030.

Dr Hoshino says the microalgae cultivation farm at C4 covers about five hectares and there is a plan to expand it to 100 hectares in three years, and 2,000 hectares towards 2030.

‘Microalgae library’

According to SBC chief executive officer Dr Yeo Tiong Chia, the research on algae began in 2012, and has since entailed the establishment of a database of micro algae collection in Sarawak.

Run in collaboration with Mitsubishi Corporation, with technical support from Chitose Laboratory, the research works meant to identify useful microalgae indigenous to Sarawak for biomass, feedstock, biofuel, food, and health supplement production.

Currently, the SBC’s ‘microalgae library’ has grown to having over 650 unique and curated strains, with over half of them having biotechnological potential.

The SBC microalgae library has grown to having over 650 unique and curated strains, with over half of them having biotechnological potential.

Moreover, the outdoor cultivation facilities now include a small scale photo-bioreactor system covering an area of 81m², and a pilot scale proof-of-concept algae cultivation facility covering 1,000m².

The flat-panel photo-bioreactor technology is used to mitigate the presence of biological contaminants in microalgal cultures.

Declared open in 2019 by Premier of Sarawak Datuk Patinggi Tan Sri Abang Johari Tun Openg, the pilot facility could produce up to six tonnes of algae biomass per year.

“It is a great pleasure for SBC to be able to provide the researchers and manpower to Chitose Group in their current collaboration project.

“The project’s in line with the Sarawak government’s effort towards developing renewable energy to ensure that the state would be at the forefront in mitigating climate change.

“Research in producing algae-based renewable biofuel is part of Sarawak’s efforts to develop its Sustainable Green Agenda, particularly green energy.”

A worker runs the harvesting of algae at the SBC’s outdoor algae cultivation facility.

Adding on, Dr Yeo says with the new algae initiatives, it would open up more job opportunities to local science graduates.

“This surely would give Sarawak a lot of benefits, both economically and environmentally,” he adds.