- Anaerobic Digestion is an exothermal four-step breakdown of a wide range of biomass(carbs, protein, fat) into C1/C2molecules, reversing photosynthesis (=a mechanical cow)
- Methanogenesis, the last of the four steps, requiresmcractivity only found inArchae, and releasesmethane as value product into the gas phase, lowering the thermodynamic cost of separation
- AD is rate limited byArchaeagrowth rates (doubling times) to 20d HRT
- Seaweed is largely an inconvenient, high-ash, high-salt substrate with challenging logistics andmoderate conversion performance as feed, and hence as AD substrate, while competing withabundant terrestrial biomass that is now left unused to decompose, with easier to accessibility
- Various LCA models have shown irrecoverable CI scores (+120-+150 g CO2eq/ MJ)
- Key value drivers for CNG are ecosystem services, i.e. methane and pollution avoidance or carbonsequestration, resulting in renewable fuel production (i.e. LCFS, REDD2), and not merely thecommodity revenue
- Price is a function of amount, form, location, use, time and environmental attributes
- Conversion rates of 60-80% leave biomass digestate as burden and boon
Digital library
-
-
A PDF on "Seaweed to biofuels - future perspectives by industry actor".
-
Increased seaweed consumption may be linked to the lower incidence of metabolic syndrome in eastern Asia. This study investigated the responses to two tropical green seaweeds, Ulva ohnoi (UO) and Derbesia tenuissima (DT), in a rat model of human metabolic syndrome. Male Wistar rats (330–340 g) were fed either a corn starch-rich diet or a high-carbohydrate, high-fat diet with 25% fructose in drinking water, for 16 weeks. High-carbohydrate, high-fat diet-fed rats showed the signs of metabolic syndrome leading to abdominal obesity, cardiovascular remodelling and non-alcoholic fatty liver disease. Food was supplemented with 5% dried UO or DT for the final 8 weeks only. UO lowered total final body fat mass by 24%, systolic blood pressure by 29 mmHg, and improved glucose utilisation and insulin sensitivity. In contrast, DT did not change total body fat mass but decreased plasma triglycerides by 38% and total cholesterol by 17%. UO contained 18.1% soluble fibre as part of 40.9% total fibre, and increased magnesium, while DT contained 23.4% total fibre, essentially as insoluble fibre. UO was more effective in reducing metabolic syndrome than DT, possibly due to the increased intake of soluble fibre and magnesium.
-
Biogenic habitat structure, such as that created by foundation macrophytes, shapes the interactions of higher trophic level organisms by creating three-dimensional refuge spaces. In recent decades, many kelp habitats have transformed into turf-dominated communities. This represents a fundamental change in the overall habitat structure in these communities, with an unknown impact on upper trophic level organisms. We investigated how macroalgae morphology affects a common residential mid-trophic level wrasse, Tautogolabrus adspersus (cunner), which utilizes macroalgae for both refuge and foraging. Three studies were conducted: in situ behavioral video observations, a refuge choice experiment, and a foraging efficiency experiment. Video observations revealed that in kelp-dominated and mixed habitat types cunner use macroalgae more often for refuge than for foraging, but in turf-dominated habitats refuge and foraging events were equal. In these habitats, refuge-seeking was more often associated with a tall, morphologically simple kelp. The refuge choice experiment supported our video ob- servations with cunner preferentially seeking refuge beneath taller but less morphologically complex algae in- stead of shorter filamentous forms. In predation trials, macroalgae complexity did not significantly affect the number of prey the fish captured. Our results provide evidence that the refuge-seeking behavior of this re- sidential mid-trophic level fish may be impacted by the ongoing shifts in macroalgae dominance in the Gulf of Maine. Loss of its preferred refuge (tall, canopy-forming kelps) may force it to use the less-preferred introduced turf algae instead. However, whether turf provides sufficient protection for this species remains unclear. With the ongoing loss of kelp in temperate coastal ecosystems worldwide, it is important to understand the potential indirect effects that changes in habitat structure will have on the trophic interactions of upper level organisms.
-
We compared post-harvest processing of two species of Ulva (chlorophyta) using 36 washing time-by-temperature combinations. We quantified the yield of crystallized salt after evaporation of the washing water as a target product and characterized the composition of salts and processed biomass, with the additional aim of improving the composition of the processed biomass for production of fertilizer, feed or fuel. Washing of biomass of Ulva ohnoi and Ulva tepida effectively reduced its mineral content with concomitant production of crystalline salts with Na:K ratios of 1.1-2.2 and a maximum of 19% soluble fiber (ulvan). The maximum yield of salt was 29% of the biomass for U. ohnoi and 36% for U. tepida. Salts from both species have potential for human health applications and functional foods. Washing increased the energy content of the biomass from both species by 20-50% to a maximum of 18 MJ kg-1 and protein contents by 11-24% to a maximum of 27.4%. The production of seaweed salt is therefore a novel first step in a cascading biorefinery model for the utilization of macroalgal biomass which simultaneously improves the quality of the processed biomass for production of fertilizer, feed or fuel.
-
India has extensive seaweed resources and these have been surveyed by several workers. In India, more attention is being bestowed on increasing the production of economically important seaweeds by different culture techniques. The growth rate and production of Gelidiella acerosa, Gracilaria edulis, Hypnea musciformis, Acanthophora spicfera and Sargassum spp. in different culture methods have been studied. Considerable data are also available on the commercial exploitation of Indian seaweeds. The important commercial products from seaweeds are agar-agar, algin, mannitol and proteins. The algae are also found to bear bioactive substances such as toxins and antibiotics. Attempts have been made to develop antiviral, antifungal and antimicrobial substance from seaweeds.
-
Survey of seaweed resources in deep water was carried out in the area between Valinokkam and Kilakkarai during January 1989 and March,l990 respectively. In the survey from Valinokkam to Kilakkarai 33 species of marine algae were recorded of which 8 species belong to Chlorophyta, 8 to Phaeophyta and 17 to Rhodophyta. Only one species of seagrass Halophila ovalis was recorded. Among the 200 sq Icm area surveyed, vegetation occurred only in 27.5 sq.km with a total standing crop of 2962.5 tonnes (wet wt).
-
The seaweeds are used for the production of polysaccharides such as agar, algin, carragennan and they are harvested from intertidal regions along the southeast shores of India. The resource potential from intertidal regions was estimated (Anon 1978)
-
Survey of the deep water area from Kilakkarai (Appa Tivu to Rameswaram Island (Dhanushkodi) was undertaken from December 1990 to January 1991 in the IV Sector survey of Deep water Seaweed Resources off Tamil Nadu coast, which formed the last phase of the survey from Rameswaram to Kanyakumari carried out during 1986-91. An area of 417.5 sq.km. was surveyed yielding a total biomass of 18,162.5 tons (wet) seaweeds. Out of 167 stations surveyed in 13 transects, vegetation occurred only in 12 stations. Of the 29 species of marine algae recorded 8 belonged to Chlorophyta, 8 to Phaeophyta, 12 to Rhodophyta, and I to Cyanophyta, One species of seagrass Cymodocea serrulata was also recorded. Twenty species were found in estimable quantities, of which the following 8 species were abundant: Halimeda macroloba, Spatoglossum asperum, Zonaria crenata, Sargassum ilicijolium, Amphiroa fragilissima, Hypnea musciformis, Botryocladia leptopoda and Lyngbya majuscula with a biomass of 1325, 9775, 650, 1550, 1925,300,862.5 and 1012.5 tons (wet) respectively. The species of Hypnea and Sargassum could be exploited for the manufacture of phytochemicals.
-
The southern coast of Tamil Nadu from Mandapam to Kanyakumari supports luxuriant growth of economically important seaweeds and the total standing crop was estimated at 22,000 tonnes (wet). All the seaweed based industries in India mostly depend on the raw material available from this area. The seaweeds exploited from this region, particularly the agarophytes Gelidiella acerosa and Gracilaria edulis are insuiBcient to meet the raw material requirement of the industries.
Pages
Marine Agronomy Group, CAFNRM, UH-Hilo
200 W. Kawili st., HI 96720, USA
Contact: Marine.Agronomy.Group@gmail.com
Funding for this web portal is provided by the World Wildlife Fund and the University of Hawaii-Hilo.