session 2 14h50 silkina_su

Sustainable Pathways for Algal Bioenergy

Sustainable Pathways for Algal Bioenergy Sustainable Pathways for Algal Bioenergy

THE BIOREMEDIATION AND PHOTOPHYSIOLOGY EXPERIMENTS IN

PILOT PBRs WITH AIMS OF MECHNISITIC MODELS DEVELOPMENT

A Silkina, N Ginnever

Centre for Sustainable Aquatic Research,

Swansea University


The EnAlgae Project

WP1

Cultivation & processing

WP2

Routes to market

WP3

Guiding industry and policy

Data collection from 9 pilot facilities Best practice sharing Outreach

Economic Modelling Life Cycle Analysis Regulation and Policy

Smart information and data tools


Objectives of EnAlgae project

- Reduce risk and accelerate implementation of pilots;

- Implement algal biotechnologies within process chains;

- Generate reliable data to inform the development of an ICT (modelling) decision support tool

- Provide product and process descriptions

- Develop and share best practice among algal biomass and bioenergy producers across NWE


EnAlgae Lead Partner – Centre for Sustainable Aquatic Research (CSAR)

Swansea University

• PBR capacity ~ 5000L • monitoring and (bio)chemical analysis …. • research for harvesting and processing • modelling tool developement


EnAlgae Targets for remediation

Test suitability of waste stream use : agricultural, fish farm and AD municipal waste as nutrients source

Compare the Nitrogen and Phosphorus uptake by different species in different cultivation PBR

Compare the productivity of species

Provide the data set for modelling tool


Bioremediation – Why use waste?

A number of cost/efficiency advantages

Environmental advantages

Phosphate sources are scarcer and will be economically unviable to mine by 2030

Waste nutrients source can help to reduce the mining of phosphorous and recycle this valuable mineral

Difficulties of preparation (e.g. filtration) associated with using liquid and solid waste sources

Liquid wastes- high in Ammonia -toxic to algae

Not have an optimal nutrient profile

Algae need adaptation to the waste source during initial cultivation


Species used

Chlorella minutissima

Scenedesmus sp.

Isolate from steel industrial site


Experimental conditions

15-25 days of cultivation in tubular PBR

Batch and Semi continuous mode

Close monitoring of biological parameters –

cells, biovolume, cellular C:N:P:Chl

Water chemistry and biochemistry analysis –

DIN, DIP, pH, T, PFD; lipid, carbohydrates

Log-in data-

pH, T; light


• Cultures were able to grow using waste nutrients • Cultures again entered a growth phase after partial harvest

growth rate

Results of growth

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Nutrient uptake by algae

• Waste nutrients are gradually taken up by the algae during cultivation

• P and N uptake

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PSII photoefficiency

Fv/Fm is the efficiency of photosystem 2 (PSII), the main light harvesting and processing complex in microalgae Can be used as a measure of cell stress

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Biochemical composition summary

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% Carb composition

% Lipid composition

% Protein

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Growth using fish waste

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CONTROL

Trout waste

• The specific growth rate is similar to control sample

• Waste nutrients are gradually taken up by the algae during cultivation

• P is accumulated in cell

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Summary & Conclusion Species N uptake

rate

P uptake

rate

Max

Productivity

Producti

on rate

mg(N)L-1d-1 mg(P)L-1d-1 (g L-1) (g L-1 d-1)

C. minutissima

Control

5.27 ±0.8 0.41±0.1 1.73 ±0.08 0.12

C. minutissima

experimental

7.17 ±0.4 0.43±0.1 1.56 ±0.07 0.11

Scenedesmus sp.

Control

6.82 ±0.5 0.39±0.1 2.03 ±0.1 0.11

Scenedesmus sp.

Experimental

7.17 ±0.4 0.37±0.1 1.13 ±0.05 0.09

• Cultures were successfully grow using waste nutrients • Nutrient uptake related regulatory standards of waste release • Potential exploitation of algal biomass


Design of PBR comparison

Vertical and horizontal

Tubular reactors were compared

In control and waste remediation

condition, productivity is higher in vertical system with Ø 110 mm(Causerma et al, 2011)

The specific biomass (e.g. reach on lipids) quickly achieved on horizontal tubular PBRØ 43 mm


Lighting and Harvesting: The

effect on the growth and

photophysiology of

Nannochloropsis oculata

Dr Naomi Ginnever, Dr Alla Silkina, Professor Kevin Flynn


Experiment and Rationale

In order to develop the photosynthetic and lighting portion of the Enalgae model experiments were undertaken to establish the effect of photoperiod (at a consistent photodose) and harvesting on the growth, photophysiology, physiology and biochemistry.

Experiments were undertaken in a 400L tubular bioreactor, which was artificially lit using metal halide lights. The photodose (15.471 mol photons m-2) was maintained over 4 experimental runs. 2 had a photoperiod of 11 hours and 2 had a photoperiod of 7 hours and 20 minutes. Supplied nutrient levels were calculated based on the known average cellular N content and the desired cell density


Methodology

Samples were taken daily for cell counts and PAM fluorescence analysis PAM fluorescence measurements were made using a Walz PhytoPAM and these data were analysed using an iterative curve fitting solution (Eilers and Peeters (1988) This provided several photosynthetic parameters which are useful indicators of cell health, stress and light acclimation The quantum efficiency of photosystem II (Fv/Fm) is a very valuable measure of the overall cell health/stress Light saturation coefficient (Ek) indicates the light acclimation state of the cells


Initial Results

The cultures were not harvested until 40 million cells were reached A 25% harvest was performed 3 times reducing the cell numbers to 30 million cells

N=2, Experimental replicates

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Max div.day-1 =0.733, 0.711


Initial Results

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The Fv/Fm dropped dramatically after inoculation and after the initial partial harvest There then appeared to be an acclimation as the dramatic drop was not observed post partial harvest again

The carotenoid content in the cultures of both experimental photoperiods increased significantly during the run From 0.5 ng (106 cells) to 1.75 ng (106 cells) and 0.65 ng (106 cells) to 2.1 ng (106 cells) (both P= <0.05)


Initial Results

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The Ek increase increased post innoculation The Ek curve then saturated, and did not increase further This is likely due to the reduction in light per cell as the culture density increased meaning the cells do not need to become acclimated to a higher light level

The ratio of Chl a to carotenoids decreased during the growth curve in both cultures


Discussion and Conclusions

The analysis of the biomass of is at an early stage and will be analysed in detail to fully understand the effect of different photoperiods and light levels on the photosystems and cellular composition Work is also being completed to investigate the effect of photoperiod using different LED colour mixes Data from outdoor experimental runs at different times of year are also being incorporated into the model to complete this component of the model



The data suggests that despite the photodose being the same, the increased light level results in a longer lag phase After the 3rd harvest there is also a slower recovery Therefore it is recommended that a lower light level be used for longer photoperiod The higher light level did result in a non-significantly higher carotenoid content



The initial partial harvesting had a negative effect on the photophysiology and resulted in a slight reduction in div.day However this effect was not observed after the second harvest At the 3rd harvest only the higher light level was negatively effected Therefore it is clear harvesting may have a negative effect if a large harvest is performed and at high light levels.


THANK YOU FOR YOUR ATTENTION

[email protected] [email protected]


The Enalgae model and decision support tool will be available for use by industry in NW Europe after the project is complete

mailto:[email protected]

mailto:[email protected]

session 2 14h50 silkina_su

Technology

sustainable pathways

algal bioenergygrowth

algal biotechnologies

algal bioenergycultures

algal bioenergybioremediation

algal bioenergynutrient

waste nutrientsnutrient

algal bioenergyenalgae