An Investigation on the Economic Feasibility of Macroalgae as a Potential Feedstock for Biorefineries

Abstract

Macroalgal biomass has been considered as a prospective feedstock for biofuel production as, among other benefits, it is an abundant source of renewable sugars and its growth does not require arable land, fresh water, or intense care. Successful commercial deployment of macroalgae-based biorefineries, however, depends on their economic viability at industrial scales. A key objective of this study was to carry out a detailed technoeoconomic analysis (TEA) of a macroalgae biorefinery to understand the economic potential and cost drivers of macroalgae as a feedstock for the production of biofuels and biochemicals. Ethanol was used as a representative macroalgae-derived product, given the wealth of public information available to model this option, and the analysis was extended to biomass-derived sugars in order to explore the production of other fermentation-derived chemicals. Sensitivity analysis was performed on various cost drivers, such as macroalgae price, yield, solids loading, and enzyme loading during hydrolysis. With a feedstock price of $100/MT, depending on the maturity of the other key process parameters (i.e., yield, solids loading, and enzyme loading), the minimum ethanol selling price (MESP) was observed to be in the range of $3.6-8.5/gal and reduced to $2.9-7.5/gal with macroalgae priced at $50/MT. For production of chemicals, sugar prices were in the range of ¢21-47/lb or ¢16-40/lb with macroalgae priced at $100/MT and $50/MT, respectively. Given the challenging economics of the macroalgae biorefinery, coproduction of alginate was used to show the importance of multiple revenue sources, though issues regarding market saturation continue to arise when dealing with products of disparate market sizes.

Moving towards the second generation of lignocellulosic biorefineries in the EU: Drivers, challenges, and opportunities

“…Seaweeds are currently used in production of food, feed and nutritional supplements. They demonstrate a rapid growth rate, high photosynthetic efficiency and do not require either arable land or fresh water resources to grow [31]. Seaweeds (particularly green algae) have seen noticeable investigation for production of biofuels [32]; the ash content in red and brown algae can reach up to 60%, while the cellulose content is generally low in all seaweeds [33].…”

Carbon Sources for Biomass, Food, Fossils, Biofuels and Biotechnology - Review Article

“…Gao and McKinley, (1994) reported about the great potential of macroalgae for environmentally friendly biomass production for biofuels and CO2 bioremediation, without to compete with terrestrial crops for farm land in contrast with land plants, driving next generation of economic opportunities and pollution abatement. Increased attention have recently received the very promising 3 rd generation biofuels, such as biodiesel, bioethanol, biomethane, biohydrogen and biomass-to-liquid biofuel, derived from sustainable micro-and macroalgal biomass (Schenk et al, 2008;Dragone et al, 2010;Méndez-Vilas, 2010;Kröger and Müller-Langer, 2012;Konda et al, 2015) called as 3 rd generation biomass (Xu et al, 2014). Marine based macroalgal biomass (marine seaweeds) is an abundant source of renewable sugars, not requiring arable land, fresh water or intense care for its production, among other benefits (Konda et al, 2015).…”

“…Increased attention have recently received the very promising 3 rd generation biofuels, such as biodiesel, bioethanol, biomethane, biohydrogen and biomass-to-liquid biofuel, derived from sustainable micro-and macroalgal biomass (Schenk et al, 2008;Dragone et al, 2010;Méndez-Vilas, 2010;Kröger and Müller-Langer, 2012;Konda et al, 2015) called as 3 rd generation biomass (Xu et al, 2014). Marine based macroalgal biomass (marine seaweeds) is an abundant source of renewable sugars, not requiring arable land, fresh water or intense care for its production, among other benefits (Konda et al, 2015). Microalgae reemerged recently as one of most promising alternative and abundant feedstock sources for next generation of food, feed, cosmetics, renewable energy, biofuels, valuable chemicals, natural and other products (Stephens et al, 2010;Rumin et al, 2015).…”

“…They have a shorter growth cycle as compared to plants and are a promising alternative source for lipids and carbohydrates of various forms for third generation biodiesel and ethanol production (Adams et al, 2009;Chaudhary et al, 2014), they don't occupy agricultural lands and they needn't any fertilizer for cultivation (Özçimen and İnan, 2015). Marine 3 rd generation macroalgae biomass has many advantages over terrestrial plant biomass as a prospective feedstock for producing biofuels and chemicals by natural or engineered microbial cells (Wei et al, 2013;Konda et al, 2015). Irradiance, temperature, nutrients, grazing and stand density are most important parameters affecting sea biomass production (Gao and McKinley, 1994).…”

The DOE Bioenergy Research Centers: History, Operations, and Scientific Output

“…Lupoi et al [101] and Sykes et al [102] developed new spectrographic methods to characterize lignin and carbohydrate content of biomass, respectively, thereby permitting rapid screening of samples for potential yield of fuel. Konda et al [103] model the economics of fuel using microalgae feedstock, while Sinistore et al [18] model ethanol synthesis from switchgrass. The integrative nature of the BRCs focuses and supports this interdisciplinary work, which generates fundamental knowledge while always keeping an eye toward practical implications.…”