Anaerobic Digestion and Seaweed Cultivation, Biorefinery and Biofuel. Queen s University Marine Laboratory Portaferry, Northern Ireland 16th Jan 2015

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1 Anaerobic Digestion and Seaweed Cultivation, Biorefinery and Biofuel Queen s University Marine Laboratory Portaferry, Northern Ireland 16th Jan 2015

2 Seasonal gas production changes from anaerobically digested macroalgae Hilary Redden: Durham University

3 Contents Rational Methods Results Conclusions Ascophyllum nodosum, Boulmer, Northumberland, UK.

4 Rational: global warming and energy reserves About 80%, 50% and 30% of coal, gas and oil reserves, respectively, would need to remain below Earth's surface if the world is to limit an increase in global mean temperature to 2 C. The uneven distribution of unburnable carbon has farreaching consequences for fossil-fuel owners. Tanzania's energy minister, Sospeter Muhongo, said: We in Africa, we should not be in the discussion of whether we should use coal or not., we are going to use our natural resources because we have reserves which go beyond 5 billion tons. Climate science: Unburnable fossil-fuel reserves, M. Jakob & J. Hilaire, Nature 517, (08 January 2015) doi: /517150a

5 Rational Oil and gas will run out Photo credit: Dunbar platform, Alan Keller 2009

6 Rational We will be seeing more of these in our lifetime

7 Supplies under pressure from growing need for energy Particularly, easily portable energy A number of alternative strategies being developed anon ww.npr.org 7

8 Solar Power Alternative strategies High Tech Solutions Wave Wind Photo credit: anon Photo credit: Alan Crawford, Istockphoto Fuel Cells Photo credit: anon

9 Tidal

10 Plant oils Photo credit: Alan Crawford, Istockphoto Miscanthus Grass Alternative strategies Land Based Biomass Many not suitable for the UK or Northern Latitudes Uses cropland which could be used for food crops Photo credit: anon Short Rotation Coppicing Ethanol Photo credit: Alan Crawford, Istockphoto Photo credit: anon Photo credit: anon

11 Photo credit: anon Some biomass cultivation uses marginal land e.g. Microalgae Economic harvesting of microalgae still a major hurdle

12 Use the Sea for Biomass Cultivation: Use Macroalgae Laminaria digitata Palmaria palmata Ascophyllum nodosum Fucus serratus

13 How to Use Macroalgae Use it as biomass in anaerobic digesters to produce methane gas Methane can then be used for combined heat and power production

14 Macroalgae Better known as seaweed or sea vegetable It s already an established industry The growth and harvesting of macroalgae for food, food additives, pharmaceuticals and nutriceuticles, is a multi-million dollar industry Often produced as a waste material from other aquaculture ventures e.g. salmon and mussel farming Rapid growth rates

15 Considerations: The Use of Macroalgae However, like land plants and microalgae, macroalgae are known to be variable in chemical composition

16 Considerations: The Use of Macroalgae However, like land plants and microalgae, macroalgae are known to be variable in chemical composition Major sources of variability are; Species Season Physical location

17 Considerations: The Use of Macroalgae However, like land plants and microalgae, macroalgae are known to be variable in chemical composition Major sources of variability are; Species Season Physical location Their chemical composition is only beginning to be studied in any detail, particularly in Northern European species, as regards Variation Between Species and Variation Within Species With respect to Annual or Multiple Annual Cycles

18 Question: Has much work been done using seasonal or monthly sampling when anaerobically digesting macroalgae? Type of waste Algae Sample Date N/I Month Methane (%) per unit dry solids Ulva sp. No Cultivated Gracilaria tikvahiae No Cultivated 6-78 Macrocystis pyrifera N/I Alginate sludges N/I Ulva sp. Juices N/I 81 Macrocystis sp. & Durvillea No March sp. Alginate sludges N/I Gracilaria tikvahiae No Cultivated 57.3 L. hyperborea No September L. hyperborea No March Questions to be answered Does gas production vary with species Does gas production vary with month / season of collection Does methane production vary with species Does methane production vary with month / season of collection When is the best month or season to use macroalgae as a biomass source for anaerobic digestion? Key word hits from Web of Science w/b 05/01/15 keyword No. hits keyword No. hits A. nodosum yes October& April N/I (not indicated) methane 105,689 anaerobic 226,222 Seaweed 59 macroalgae 94 Papers 45 Seasonal 2 Seasonal 2

19 Overview of Anaerobic Digestion: The breakdown sequence from complex to simple molecules and reformation into anaerobic bacteria. Liquefaction Acid formation Methane formation Fat and Oil Carbohydrate Protein H 2 & CO 2 Long chain fatty acids Simple sugars Volatile fatty acids Acetate CO 2 & CH 4 Amino acids Ammonia Anaerobic bacteria/archaea multiplication Cell synthesis

20 Seasonal gas production changes from anaerobically digested macroalgae : Method 1 trial per month 12 month set collected 1 bottle per species (9 species + 1 Control) Fed the equivalent of 1 g dry mass per day for 10 days Short term test Will demonstrate the effect of easily digestible material Saline environment (35 ppt), Temperature 35 ⁰C Gas sampled for methane content every 2 nd day Rate of gas production recorded each day At the beginning and end of each run Total suspended solids Total volatile solids

21 Study Species Ascophyllum nodosum Fucus serratus F. vesiculosis Laminaria digitata L. hyperborea Mastocarpus stellatus Palmaria palmata Porphyra umbilicalis Ulva lactuca 5 brown 3 red 1 green

22 Study Species: Today s Focus On Fucus serratus (FS) an abundant mid-shore (littoral) species Laminaria digitata (LD) an abundant lower tidal (sub littoral) species Porphyra umbilicalis (PU) an upper shore (high littoral) species Ulva lactuca (UL) a problem species can be attached or free floating All could be cultivated

23 Fucus serratus

24 Laminaria digitata

25 Porphyra umbilicalis

26 Ulva lactuca 30 cm

27 Shore Height Distribution Ulva lactuca Porphyra umbilicalis Fucus serratus Laminaria digitata High water Low water

28 Laminaria digitata Porphyra umbilicalis Fucus serratus Anaerobic digestate starter mix of all 9 species plus paper sludge, sugar processing sludge, sewage sludge, beach waste Ulva lactuca Solids content was not determined but is typically 5 20% dry solids content Uses ppt saline 35 o C Using wet material the equivalent of 1 g dry mass of each species per litre added (control is a mix of the 9 species)

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31 Gas flows in from digester Gas pressure forces silica oil down Bubble formed at angle of joint Bubble counter light path Counter detects broken path and registers this at counter

32 Results Percentage dry weight over time Total Suspended Solids Total Volatile Solids Methane production

33 Percentage lyophilised mass Spring Summer Autumn Winter Spring Summer Autumn Winter Spring Summer Autumn Winter Spring Summer Autumn Winter Percentage lyophilised mass Percentage Dry Mass Over Time %Mass FS LD PU UL Species by season Percentage lyophilised mass by species and season FS (Fucus serratus) LD (Laminaria digitata), PU (Porphyra umbilicalis) UL (Ulva lactuca) Seasons equinox to solstice Spring (April, May, June) Summer (July, August, September) Autumn (October, November, December) Winter(January, February, March) %Mass FS LD PU UL Species by year Percentage lyophilised mass by species and year

34 Percentage lyophilised mass Spring Summer Autumn Winter Spring Summer Autumn Winter Spring Summer Autumn Winter Spring Summer Autumn Winter Percentage lyophilised mass Percentage Dry Mass Over Time %Mass FS LD PU UL Species by season Percentage lyophilised mass by species and season Mass varies by Species Season Year of collection FS (Fucus serratus) LD (Laminaria digitata), PU (Porphyra umbilicalis) UL (Ulva lactuca) Seasons equinox to solstice Spring (April, May, June) Summer (July, August, September) Autumn (October, November, December) Winter(January, February, March) %Mass FS LD PU UL Species by year Percentage lyophilised mass by species and year

35 Weight of wet material (g) Weight of wet material required to feed the equivalent of 1 g dry mass per litre into my anaerobic digesters 12.0 Weight of wet material fed Max Min Weight of wet material required can increase/decrease by 250% throughout the year Which has implications on the cost of harvesting AN FS FV LD LH MS PP UL PU Control Species Difference in mass required to feed 1 g dry weight per litre over the year Species Max (g) Min (g) Mass change FS x 1.58 LD x 2.16 UL x 2.10 PU x 2.33

36 Sep-09 Aug-09 Sep-09 Aug-09 Sep-09 Aug-09 Sep-09 grams per litre Sep-09 Aug-09 Sep-09 Aug-09 Sep-09 Aug-09 Sep-09 Grams per litre Digested mass changes: Total Suspended Solids Start_TSS/litre 30.0 Finish_TSS/litre PU UL FS LD Species by Month Digested mass changes: Total Volatile Solids Start_VSS/litre Finish_VSS/litre PU UL FS LD Species by Month

37 Sep-09 Aug-09 Sep-09 Aug-09 Sep-09 Aug-09 Sep-09 grams per litre Sep-09 Aug-09 Sep-09 Aug-09 Sep-09 Aug-09 Sep-09 Grams per litre Total Suspended Solids Start_TSS/litre Finish_TSS/litre PU UL FS LD Total Volatile Solids Species by Month Start_VSS/litre Finish_VSS/litre PU UL FS LD Species by Month Laminaria digitata and Porphyra umbilicalis both digest well

38 Sep-09 Aug-09 Sep-09 Aug-09 Sep-09 Aug-09 Sep-09 grams per litre Sep-09 Aug-09 Sep-09 Aug-09 Sep-09 Aug-09 Sep-09 Grams per litre Total Suspended Solids Start_TSS/litre Finish_TSS/litre PU UL FS LD Total Volatile Solids Species by Month Start_VSS/litre Finish_VSS/litre PU UL FS LD Species by Month Ulva lactuca and Fucus serratus both accumulate at 1g added per litre

39 Percentage Methane Methane Production: Overall Mean Percentage Methane AN FS FV LD LH MS PP PU UL C Species

40 Percentage Methane Methane L / g lypholized weight Methane production (litres per lyophilised gram) by species: mean of all months AN FS FV LD LH MS PP PU UL Species C Overall Mean AN FS FV LD LH MS PP PU UL C Species Fucus serratus and Ulva lactuca produce a lot less methane per g of material Porphyra umbilicalis falls within the same group as Laminaria digitata

41 methane production L per g lyophilised mass spring summer autumn winter spring summer autumn winter spring summer autumn winter spring summer autumn winter Methane production (litres per lyophilised gram) by species, by Season L per g FS LD Species by Season PU UL Species/Season Ascophyllum nodosum April, May, June July, Aug, Sept Oct, Nov, Dec Autumn Jan, Feb, Mar Fucus serratus Spring Summer Autumn Winter F. vesiculosis Autumn Winter Laminaria digitata Autumn Winter L. hyperborea Autumn Winter Mastocarpus stellatus Autumn Palmaria palmata Summer Autumn Winter Porphyra umbilicalis Spring Autumn Ulva lactuca Spring Winter Autumn (October, November, December) is the best Season for most species

42 Jul-09 Aug-09 Sep-09 Apr-10 May-10 Jun-10 Jul-09 Aug-09 Sep-09 Apr-10 May-10 Jun-10 Jul-09 Aug-09 Sep-09 Apr-10 May-10 Jun-10 Jul-09 Aug-09 Sep-09 Apr-10 May-10 Jun-10 Litres of methane gas per g lyophilised material Methane production (litres per lyophilised gram) by species, by month L/g methane FS LD PU UL Species by Month Large changes can occur between months e.g. Between December and January for LD Between January and February for UL

43 Methane production (litres per lyophilised gram) by species, by day of trial

44 Methane production (litres per lyophilised gram) by species by day of trial Over the 10 days of each trial the % methane production from Fucus serratus and Ulva lactuca often declines but conversely increases with Laminaria digitata and Porphyra umbilicalis Laminaria digitata and Porphyra umbilicalis can exceed a loading rate of 1 g dry mass per litre to increase total gas and % methane production

45 The Drivers of Methane Production Principal Component Analysis : Percentage Methane production % lypholized wt % Fatty acid methyl ester (FAME Dry) %Fatty acid methyl ester (FAME Wet) %Protein Dry %Protein Wet %soluble saccharides Dry %soluble saccharides Wet

46 Principal component analysis : Percentage methane production PRINCIPAL COMPONENT 1 All Species % lypholized wt %FAME Dry %FAME Wet %Protein Dry %Protein Wet %soluble saccharides Dry %soluble saccharides Wet PRINCIPAL COMPONENT 2 % lypholized wt %FAME Dry %FAME Wet %Protein Dry %Protein Wet %soluble saccharides Dry %soluble saccharides Wet

47 Principal component analysis : Percentage methane production PRINCIPAL COMPONENT 1 ALL FS LD PU UL % lypholized wt %FAME Dry %FAME Wet %Protein Dry %Protein Wet %soluble saccharides Dry %soluble saccharides Wet PRINCIPAL COMPONENT 2 % lypholized wt %FAME Dry %FAME Wet %Protein Dry %Protein Wet %soluble saccharides Dry %soluble saccharides Wet

48 Question: Has much work been done using seasonal or monthly sampling? Questions to be answered Does methane production vary with species: YES Does methane production vary with season and month of collection: YES When is the best month or season to use macroalgae as a biomass source for anaerobic digestion? Methane production levels adequate and comparable to other studies Species differences are apparent With percentage dry weight (P>0.001) With methane production (P>0.001) Seasonal differences are apparent With percentage dry weight (P>0.001) With methane production (P>0.001) Generally, October, November, December best months for collection

49 Conclusions Anaerobic digestion worked efficiently in seawater Methane production levels adequate and comparable to other studies Species differences are apparent Seasonal differences are apparent (Generally, October, November, December best months for collection) Loading rate should be adjusted throughout the year to maximise methane production Optimal methane production levels may involve blending species throughout the year Weight of wet material required can increase/decrease 2.5 times throughout the year. This will affect the cost of biomass collection Principal component analysis indicates that although the lyophilised weight is important for influencing methane production so also is the fatty acid content, protein content and soluble saccharides in the wet material. However, this varies with species.

50 Considerations Looking at the data over a two year period and the variability between species and season coupled to the differences that can be seen between one month and the next. For some species the highest FAME, protein and soluble saccharides measured in one month could be the lowest measured in the same month the next year The macroalgae has been responding to local weather and water conditions So the results you get one year may not reflect what is measured the next year and longer term measurements will help remove some of this uncertainty. It could be that the stage in the macroalgae lifecycle is important in conjunction with the season of the year Ulva has a short life cycle and can be diploid or haploid, so where it is in it s growth and reproductive strategy may have an effect on digestibility This may also be true of the annuals, biennials and perennials

51 Conclusions Production of biogas from the anaerobic digestion of macroalgae is feasible Saccharina latissima growing on nets in Strangford Lough 2014 Porphyra growing on nets in Asian waters

52 References Black, W. A. P. (1948). "Seasonal variation in chemical constitution of some of the sub-littoral seaweeds common to Scotland. Part II. Laminaria digitata." Journal of the Society of Chemical Industries 67: Black, W. A. P. (1948). "The seasonal variation in chemical constitution of some of the littoral seaweeds common to Scotland. Part I. Ascophyllum nodosum." Black, W. A. P. (1948). "The seasonal variation in chemical constitution of some of the sub-littoral seaweeds common to Scotland. Part III Laminaria saccharina and Saccorhiza bulbosa." Journal of the Society of Chemical Industries 67: Black, W. A. P. (1948). "The seasonal variation in chemical constitution of some of the sub-littoral seaweeds common to Scotland: Part I. Laminaria cloustoni." Journal of the Society of Chemical Industries 67: Black, W. A. P. (1950). "The seasonal variation in weight and chemical composition of the common British Laminariaceae." Journal of the Marine Biological Association of the United Kingdom XXIX: Carpentier, B., C. Festino, et al. (1988). "Anaerobic digestion of flotation sludges from the alginic acid extraction process." Biological Wastes 23(4). Ghosh, S., D. J. Klass, et al. (1981). "Bioconversion of Macrocystis Pyrifera to Methane." Journal of Chemical Technology and Biotechnology 31: Habig, C., D. A. Andrews, et al. (1984). "Nitrogen recycling and methane production using Gracilaria tikvahiae: A closed system approach." Resources and Conservation 10(4): Habig, C., T. A. DeBusk, et al. (1984). "The effect of nitrogen content on methane production by the marine algae Gracilaria tikvahiae and Ulva sp." Biomass 4(4): Habig, C. and J. H. Ryther (1983). "Methane production from the anaerobic digestion of some marine macrophytes." Resources and Conservation 8(3): Kerner, K. N., J. F. Hanssen, et al. (1991). "Anaerobic digestion of waste sludges from the alginate extraction process." Bioresource Technology 37(1): Morand, P. and X. Briand (1999). "Anaerobic digestion of Ulva sp. 2. Study of Ulva degradation and methanisation of liquefaction juices." Journal of Applied Phycology 11(2): Morand, P., X. Briand, et al. (2006). "Anaerobic digestion of Ulva sp. 3. liquefaction juices extraction by pressing and a technico-economic budget." Journal of Applied Phycology 18(6): Vergara-Fernandez, A., G. Vargas, et al. (2008). "Evaluation of marine algae as a source of biogas in a two-stage anaerobic reactor system." Biomass and Bioenergy 32(4):