6.6 Environmental Implications
133
6.6.1 Cultivation and Harvest of Red Algae
An estimated 1180 kg of seaweed biomass is required to produce 1 kL of the carrageenan containing say which can then be further processed to produce carrageenan.
In addition to the benefits of growing algae as discussed in Chap. 5 and this chapter
on alginate and fucoidan, red algae compared to the brown algae are easier to cultivate on a large scale since they have a vegetative reproductive cycle which is less
complex than that of brown algae. A particular type of the Rhodophyta known as
coralline algae has played a significant role in the formation of coral reefs for billions of years and still continues to do so (Moreira-Gonzalez et al. 2019). Harvesting
of red algae from the wilds or cultivating in aquaculture or open seas ensures that
the conditions in the water are equally conducive for the growth and functioning of
these coral-forming red algae. Hence, red algae cultivation for alginate production
encourages the maintenance of marine biodiversity.
6.6.2 Energy Consumption
The drying stage consumes much of the energy in the production process. The filtrate
from the extraction only contains about 2–3% carrageenan, and the final product
needs to be dried to at least 4% moisture content for storage and packaging. In this
dry state, the growth of microbes is minimized hence allowing a longer shelf life of
the carrageenan. Where there is intense sunlight and the weather is sufficiently hot
in the day, drying can be done outdoors to save cost from using electrical dryers.
Energy is also consumed in transportation of the cultivated biomass to the factory
for further processing. In the life cycle assessment carried out by Gosh et al. (2015),
transportation of the cultivated biomass accounted for 13% of the environmental
impact in the cultivation stage. In the processing of biomass into carrageenan and
sap, the high-density polyethylene production for packaging shed and electricity
made up 97.3% of the carbon footprint, with electricity consumption accounting for
25.2% and plastic packaging accounting for 54.2% of this.
When transportation by sea, road and rail was compared, transportation by sea for
conveying biomass to factory for processing proved to be the least energy-consuming
method while road consumed the most energy. Climate impact by road, rail and sea
was 138.5%, 51.8% and 141%, respectively (Ghosh et al. 2015). In some cases where
transportation by road is the only option, the most efficient means of transportation
needs to be sought. For instance where the place of cultivation (usually shore) is at a
relatively close distance to the processing factory, tricycle carts could be considered
as an option; however where quantities are on a large scale, this is not practical.
Energy consumption can be minimized by using more fuel efficient machinery
and transportation systems. Even where manual labor is used, it is important to have
the most efficient process in place, to make optimal use of manpower. Transportation
by sea to distances of up to 7200 km to other countries is even less energy-consuming
133
6.6.1 Cultivation and Harvest of Red Algae
An estimated 1180 kg of seaweed biomass is required to produce 1 kL of the carrageenan containing say which can then be further processed to produce carrageenan.
In addition to the benefits of growing algae as discussed in Chap. 5 and this chapter
on alginate and fucoidan, red algae compared to the brown algae are easier to cultivate on a large scale since they have a vegetative reproductive cycle which is less
complex than that of brown algae. A particular type of the Rhodophyta known as
coralline algae has played a significant role in the formation of coral reefs for billions of years and still continues to do so (Moreira-Gonzalez et al. 2019). Harvesting
of red algae from the wilds or cultivating in aquaculture or open seas ensures that
the conditions in the water are equally conducive for the growth and functioning of
these coral-forming red algae. Hence, red algae cultivation for alginate production
encourages the maintenance of marine biodiversity.
6.6.2 Energy Consumption
The drying stage consumes much of the energy in the production process. The filtrate
from the extraction only contains about 2–3% carrageenan, and the final product
needs to be dried to at least 4% moisture content for storage and packaging. In this
dry state, the growth of microbes is minimized hence allowing a longer shelf life of
the carrageenan. Where there is intense sunlight and the weather is sufficiently hot
in the day, drying can be done outdoors to save cost from using electrical dryers.
Energy is also consumed in transportation of the cultivated biomass to the factory
for further processing. In the life cycle assessment carried out by Gosh et al. (2015),
transportation of the cultivated biomass accounted for 13% of the environmental
impact in the cultivation stage. In the processing of biomass into carrageenan and
sap, the high-density polyethylene production for packaging shed and electricity
made up 97.3% of the carbon footprint, with electricity consumption accounting for
25.2% and plastic packaging accounting for 54.2% of this.
When transportation by sea, road and rail was compared, transportation by sea for
conveying biomass to factory for processing proved to be the least energy-consuming
method while road consumed the most energy. Climate impact by road, rail and sea
was 138.5%, 51.8% and 141%, respectively (Ghosh et al. 2015). In some cases where
transportation by road is the only option, the most efficient means of transportation
needs to be sought. For instance where the place of cultivation (usually shore) is at a
relatively close distance to the processing factory, tricycle carts could be considered
as an option; however where quantities are on a large scale, this is not practical.
Energy consumption can be minimized by using more fuel efficient machinery
and transportation systems. Even where manual labor is used, it is important to have
the most efficient process in place, to make optimal use of manpower. Transportation
by sea to distances of up to 7200 km to other countries is even less energy-consuming