Potential use of saline resources for biofuel production using halophytes and marine algae: prospects and pitfalls

Abstract

There exists a global challenge of feeding the growing human population of the world and supplying its energy needs without exhausting global resources. This challenge includes the competition for biomass between food and fuel production. The aim of this paper is to review to what extent the biomass of plants growing under hostile conditions and on marginal lands could ease that competition. Biomass from salt-tolerant algae and halophytes has shown potential for bioenergy production on salt-affected soils. Halophytes and algae could provide a bio-based source for lignoceelusic biomass and fatty acids or an alternative for edible biomass currently produced using fresh water and agricultural lands. The present paper provides an overview of the opportunities and challenges in the development of alternative fuels from halophytes and algae. Halophytes grown on marginal and degraded lands using saline water offer an additional material for commercial-scale biofuel production, especially bioethanol. At the same time, suitable strains of microalgae cultured under saline conditions can be a particularly good source of biodiesel, although the efficiency of their mass-scale biomass production is still a concern in relation to environmental protection. This review summaries the pitfalls and precautions for producing biomass in a way that limits environmental hazards and harms for coastal ecosystems. Some new algal and halophytic species with great potential as sources of bioenergy are highlighted.

Exploring the Potentials of Halophytes in Addressing Climate Change-Related Issues: A Synthesis of Their Biological, Environmental, and Socioeconomic Aspects

“…Biofuel and renewable energy production: Halophytes may also be used as a renewable source of bioenergy, such as biofuel, thus helping to reduce reliance on fossil fuels and fight climate change [173][174][175]. They can be grown on marginal lands, which are not suitable for conventional crops, thereby would reduce the food versus fuel dilemma [176].…”

“…They can be grown on marginal lands, which are not suitable for conventional crops, thereby would reduce the food versus fuel dilemma [176]. Interestingly, many halophytes have a similar or even better lignocellulose composition compared to conventional biofuel feedstock, which makes the halophytic biomass highly suitable for the production of bio-ethanol, a common type of biofuel [175]. Similarly, the seeds of a number of halophytes are rich in oil, which can be converted into bio-diesel, another form of biofuel [176].…”

Economic Uses of Salt-Tolerant Plants

“…Consequently, interest has grown in the use of third-generation feedstocks—plants that can grow on saline land and/or be irrigated with salt water. Salt-tolerant plants offer a new opportunity for biofuel production where competition for land use for food is minimized, see [ 103 ]. The data in eHALOPH suggest that just 10 families offer more than 80% of the 97 species with economic uses as fuel, fuelwood, charcoal, or bioenergy ( Table 11 ).…”

Biodiesel Production from the Marine Alga Nannochloropsis oceanica Grown on Yeast Wastewater and the Effect on Its Biochemical Composition and Gene Expression

“…Vital factors behind the encouragement to generate biodiesel from nonfood resources are commercial interest and the growing awareness of environmental and energy challenges. Since algae and halophytes can grow in saltwater and use carbon dioxide (CO 2 ) from the air for photosynthesis, they may be viable solutions since they do not require the agricultural land and freshwater needed for the cultivation of agricultural crops [ 1 ]. Microalgae may survive in a wide variety of environments.…”