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Bioresource Technology xxx (2014) xxx–xxx

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Bioresource Technology

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Retrofitting hetrotrophically cultivated algae biomass as pyrolyticfeedstock for biogas, bio-char and bio-oil production encompassingbiorefinery

http://dx.doi.org/10.1016/j.biortech.2014.09.0700960-8524/� 2014 Elsevier Ltd. All rights reserved.

⇑ Corresponding author. Tel./fax: +91 40 27191664.E-mail address: [email protected] (S. Venkata Mohan).

Please cite this article in press as: Sarkar, O., et al. Retrofitting hetrotrophically cultivated algae biomass as pyrolytic feedstock for biogas, bio-char aoil production encompassing biorefinery. Bioresour. Technol. (2014), http://dx.doi.org/10.1016/j.biortech.2014.09.070

Omprakash Sarkar, Manu Agarwal, A. Naresh Kumar, S. Venkata Mohan ⇑Bioengineering and Environmental Sciences (BEES), CSIR-Indian Institute of Chemical Technology (CSIR-IICT), Hyderabad 500 007, India

h i g h l i g h t s

� Fresh microalgae and oil extractedmicroalgae showed potential aspyrolytic feedstock.� Pyrolysis of algae produced biogas,

bio-oil and bio-char.� Bio-oil showed fuel properties.� Sand additive pyrolysis improved

biogas from oil extracted microalgae.

g r a p h i c a l a b s t r a c t

a r t i c l e i n f o

Article history:Received 30 July 2014Received in revised form 14 September 2014Accepted 15 September 2014Available online xxxx

Keywords:LipidsOil extracted microalgaeSand additiveBiohydrogenAdsorbent

a b s t r a c t

Algal biomass grown hetrotrophically in domestic wastewater was evaluated as pyrolytic feedstock forharnessing biogas, bio-oil and bio-char. Freshly harvested microalgae (MA) and lipid extractedmicroalgae (LEMA) were pyrolysed in packed bed reactor in the presence and absence of sand as additive.MA (without sand additive) depicted higher biogas (420 ml/g; 800 �C; 3 h) and bio-oil (0.70 ml/g; 500 �C;3 h). Sand addition enhanced biogas production (210 ml/g; 600 �C; 2 h) in LEMA operation. Thecomposition of bio-gas and bio-oil was found to depend on the nature of feedstock as well as the processconditions viz., pyrolytic-temperature, retention time and presence of additive. Sand additive improvedthe H2 composition while pyrolytic temperature increment caused a decline in CO2 fraction. Bio-char pro-ductivity increased with increasing temperature specifically with LEMA. Integration of thermo-chemicalprocess with microalgae cultivation showed to yield multiple resources and accounts for environmentalsustainability in the bio-refinery framework.

� 2014 Elsevier Ltd. All rights reserved.

1. Introduction

Renewable and sustainable energy production from photosyn-thetic microalgae has attracted a considerable interest in thedomain of energy and environment (Alcantara et al., 2013;Christenson and Sims, 2011; Watanabe et al., 2014). Due to high

photosynthetic efficiency and rapid growth rates associated withmicroalgae cultivation, microalgae are being considered as anattractive biomass for the production of chemicals and fuels. Culti-vation of microalgae biomass for biodiesel production has gainedwide interest from researchers across the world (Devi et al.,2013, 2012; Venkata Mohan and Devi, 2014). After extracting thelipid, attention is being given to reuse residual algal biomass toother value-added co-products (Lam et al., 2014; VenkataSubhash and Venkata Mohan, 2014; Maddi et al., 2011). To makemicroalgal based biofuel production process sustainable it is

nd bio-

http://dx.doi.org/10.1016/j.biortech.2014.09.070

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2 O. Sarkar et al. / Bioresource Technology xxx (2014) xxx–xxx

imperative to mimic integrated biorefinery concept facilitatingproduction of diverse value added by-products from microalgaebiomass.

Usually pyrolysis is employed to covert a variety of biomass res-idues including municipal solid waste, plastic waste, agriculturalresidues, sludge, etc. into various forms of energy and materials.Pyrolysis facilitates the thermal decomposition of a material inthe absence of oxygen or any other oxygen-containing reagent(air, water, carbon dioxide) and as a result, a solid material (char),gas and condensable liquids fractions (oils) are obtained (Lorenzoet al., 2014). As a fuel, bio-oil has several environmental advanta-ges over fossil fuels since it is renewable, locally produced andhas lower environmental impact (close to CO2/GHG neutral, noSOx emissions, 50% lower NOx emissions). There are severalreviews focused on biomass pyrolysis for liquid fuel production(Oasma and Czernik, 1999; Czernick and Bridgwater, 2004;Mohan et al., 2006). The solid bio-char is similar to fossil coal,and this is useful as it can be used as bio-fuel (high calorific value),as chemical adsorbent (as a substitute for activated carbon) or forsoil amendment (Brennan et al., 2014; Agarwal et al., 2015). Thepyrolysis product quality and distribution depends mainly onpyrolytic temperature, heating rate, residence time, type of reactor,type of feedstock, etc. (Zanzi et al., 1996; Bridgwater, 2003). Afterextracting lipids from microalgae, the leftover biomass residue(deoiled) needs to be effectively utilized. In this regard, an attemptwas made in this communication to explore the potential of har-vested microalgae (MA) as well as lipid extracted microalgal bio-mass (LEMA) as pyrolytic feedstock. The influence of sandadditive on biogas, bio-char and bio-oil composition was studiedin comparison to and feedstock composition variation.

2. Methods

2.1. Feedstock

Heterotrophically cultivated microalgae (mixed consortia) wereused as pyrolytic feedstock in two diverse forms. After dual modecultivation viz., growth and stress phases in domestic wastewater,the harvested algae biomass (MA) was solar dried. Half of the solardried microalgal biomass was used as feedstock for pyrolysisdirectly. Remaining half was subjected for lipid extraction andthe resulting residual biomass (LEMA) was also used as feedstockalong with MA separately.

2.2. Experimental setup and operation

The pyrolysis set-up broadly consists of three parts: pyrolysisreactor, furnace and condenser (Agarwal et al., 2013). The lengthof the reactor was 45.72 cm (25.4 mm diameter; 3 mm thick;SS316) with one end welded to a 6 mm pipe (SS316) and the otherto a 3 mm thick flange of 50.8 mm diameter (SS304). The formerserves as the inlet and the latter as outlet. The flange joints areclosed by four 25 mm bolts with an asbestos packing. The reactorwas placed inside a furnace (40.64 cm � 10.16 cm) with 35.56 cmheating zone insulated with glass-wool through ceramic tube.Heating coil (3 kW) was wound around the ceramic tube. The inletand outlet were connected to nitrogen cylinder and ice-bath con-denser, respectively. The ice-bath condenser was used to cool thegas produced and to separate the condensable gases.

The pyrolysis experiments were carried out in nitrogen richatmosphere in a packed bed reactor on batch mode basis afterloading MA and LEAM separately. A fixed amount of dry algae sam-ple (3 g) was packed in the reactor and purged with pure nitrogen(99.99%) to remove the trapped air inside the reactor. The nitrogengas was not purged during the course of pyrolysis operation.

Please cite this article in press as: Sarkar, O., et al. Retrofitting hetrotrophically coil production encompassing biorefinery. Bioresour. Technol. (2014), http://dx

Coarse sand (0.63–1 mm) was used as an additive for equal distri-bution of heat during the reaction in some specified experiments. Itwas mixed with algae in the ratio of 1:9, prior to being packed inthe reactor. The most common constituent of sand is silica in formof quartz with sodium, calcium and iron silicates being the minorconstituents. The reactor was heated at a constant rate of 12 �Cper min. The decomposition of the sample was evaluated atselected temperatures and retention times with sand additive(SA; 600 �C; 1 and 2 h) and without sand additive (SL; 500, 600and 800 �C; 3 h). The volatile substances evolved during pyrolysiswere passed through ice-bath condenser to separate the condens-able gases from the non-condensable ones (bio-oil).

Transesterification of bio-oil was performed by refluxing inchloroform/methanol and hexane with methanol in the presenceof H2SO4 as a catalyst. Refluxing was performed at 65–70 �C for2 h in a round bottom flask and later washed in a retort funnel withdistilled water to maintain neutral pH. After washing, diethyl etherwas added to the reaction mixture and the Fatty Acid Methyl Esters(FAME) were collected from the organic phase which was sepa-rated from aqueous phase using a separating funnel. Pinch of anhy-drous sodium sulphate was added to the organic layer to removetraces of water and finally the organic phase was subjected toevaporation for solvent recovery leaving FAME content in the tube.The concentrated samples were analysed for the presence of fattyacid methyl esters (FAME) by gas chromatography.

2.3. Analysis

The volume of biogas evolved from pyrolysis was measuredthrough water displacement technique. The compositional analysisof bio-gas was evaluated by gas chromatograph (NUCON 5765)using thermal conductivity detector (TCD) with 1/800 � 2 m Haye-sep Q column employing nitrogen as carrier gas. The injector anddetector were maintained at 60 �C each and the oven was operatedat 40 �C isothermally. The biogas was quantified with the calibra-tion gas supplied by Span Gas & Equipments Ltd., Navi Mumbai,India. FAME composition were analysed by using GC with FID(flame ionization detector) (Nucon-5765) through capillary col-umn (Valcobond (VB) 30 mm (0.25 mm � 0.25 lm)) using nitrogenas carrier gas (1 ml/min). The temperature of the oven was initiallymaintained at 140 �C (for 5 min), later increased at a rate of 4 �C/min to reach 240 �C and maintained for 10 min. The injector anddetector temperatures were maintained at 280 and 300 �C, respec-tively with a split ratio of 1:10. FAME (fatty acid methyl ester)composition was compared with the standard FAME mix (C8–C22;LB66766, SUPELCO). Thermo-gravimetric analysis (TGA) was stud-ied with Mettler Toledo (TGA/SDTA 851e) system.

3. Results and discussion

3.1. Cultivation of microalgae biomass and lipid extraction

Microalgae cultivation was performed by sequentially integrat-ing growth and stress phase each with seven days of retentiontime. The growth phase was operated in heterotrophic mode usingdomestic wastewater. Stress phase was induced by transferring the7th day biomass from growth phase into tap water which providesnutrient limiting conditions. After stress phase the microalgae washarvested, dried and subjected to lipid extraction (Chandra et al.,2014). The total lipid productivity of 21.2% was obtained. The freshmicroalgal biomass (after 14 days; MA) were sun dried and thenlipid were extracted (LEAM) and sealed in container prior to usein pyrolysis studies.

Both algae based feedstocks were subjected to thermogravimet-ric analysis (TGA) in nitrogen atmosphere (Fig. 1). For the fresh

ultivated algae biomass as pyrolytic feedstock for biogas, bio-char and bio-.doi.org/10.1016/j.biortech.2014.09.070


O. Sarkar et al. / Bioresource Technology xxx (2014) xxx–xxx 3

microalgae (MA), biomass has undergone three phases of weightloss, one between 50 and 100 �C, the second at 300 �C–400 �C(24%) and a third loss around 750 �C–800 �C (57.13%). The first shiftrepresents weight loss caused by dehydration of the microalgaesample. Nearly 60% weight was reduced in the first shift of physicalchange representing evaporation of water content in the sample.The second and third weight shifts are attributed to losses oforganic compounds and decomposition of the algae biomass,respectively. For deoiled algae (LEMA) also the first peak was seenat 50–100 �C (1.84%) followed by 300 �C–400 �C (21.19%), and at750 �C–800 �C (54%). In MA and LEMA the TGA curve illustrated areduction in the peak between 750 �C and 800 �C, proved reductionin the volatile matter content. This supports that with increase intemperature and retention time the reaction rate increased andtherefore, the volatile matter might evolve in the form of bio-gas(Peng et al., 2001).

3.2. Biogas

The biogas yield and composition were found to depend on thepyrolysis temperature, retention time and presence of additive(Fig. 1). During all the conditions the gas volume increased pro-gressively as a function of temperature. Operation with sand asan additive and retention time variations documented markedimprovement in the biogas yield as well as composition. Maximumbiogas yield was documented at 800 �C with SL operation for bothMA (420 ml/g) and LEMA (320 ml/g). Increase in thermal decom-position time for MA and sand addition influenced the total gasvolume. With SL operation at 500, 600 and 800 �C the gas volumeincreased to 200 ml/g, 240 ml/g and 420 ml/g, respectively. Oper-ating with SA increased the gas production at 600 �C varying withdecomposition time [1 h – 230 ml/g (MA) and 200 ml/g (LEMA);2 h – 240 ml/g (MA) and 210 ml/g (2 h)]. For LEMA, biogas yieldwith SA operation (200 ml/g) at 600 �C is comparable with thegas obtained (180 ml/g (500 �C; 3 h); 220 ml/g (600 �C; 3 h)) withSL operation because of uniform distribution of heat inside thereactor. The results depicted that the oil extracted algae biomasscan be reutilized for pyrolytic biogas production in a sustainableand biorefinery route. Pyrolytic time, temperature and sand

Fig. 1. TGA curves of microalgae/oiled (MA) and deoiled/lipi


addition also influenced the biogas composition significantly apartfrom the volume.

3.2.1. Bio-hydrogenH2 yield was observed to vary with the biomass nature, pyro-

lytic temperature and retention time (Fig. 2). MA pyrolysis underSL condition (800 �C) documented highest H2 yield (110.5 ml/g;3 h), followed by LEMA (100 ml/g; 3 h). SL operation showed lowerH2 yield at lower decomposition temperature for both the algalfeedstocks used [MA – 7.56 ml/l (500 �C); 18.50 ml/g (600 �C);LEMA – 3.40 ml/g (500 �C); 41.58 ml/g (600 �C)] attributing itseffect on product formation. Moreover, operation with LEMA andSL also documented higher biogas yields at high temperature(800 �C: 36.8 ml/g) compared to lower temperature operations(500 �C: 1.1 ml/g and 600 �C: 13.86 ml/g) (Table 1). This signifiesthe functional role of temperature on biohydrogen yields as a func-tion of feedstock composition. Effect of retention time with SAoperation was also evaluated in both the pyrolytic operations(MA and LEMA). Initially with low RT, MA operation (SA: 600 �C,1 h) showed higher H2 production (93.3 mg/g) followed by 2 h RT(SA: 55.4 ml/g (600 �C)). Whereas, with LEMA SA condition with1 h RT at 600 �C documented lower biogas yield (10.3 mg/g) than2 h operation (18.4 ml/g). The presence of sand as additive reducedthe activation energy and maximized H2 yield without need toreach high decomposition temperature for extended time. How-ever, variations in the H2 production varied with the compositionof feedstock. This ascribes the influence of biomass compositionand decomposition time on the biogas composition/yields withthe function of temperature. The H2 content is probably causedby the poly-condensation of free radicals generated during thepyrolysis process and by dehydrogenation reactions with the oiland char. It is evident from results that LEMA pyrolysis showed rel-atively lower yield of H2 compared to oil bound microalgae.

3.2.2. Bio-methaneThe maximum bio-methane (CH4) production was observed at

800 �C with LEMA-SL operation (100 ml/g) followed by MA-SL(47.8 ml/g). Lower decomposition temperature documentedcomparatively less CH4 yields with MA-SL [1.2 ml/g (500 �C);

d extracted microalgae (LEMA) at different heating rate.



Fig. 1 (continued)


10.6 ml/g (600 �C)] than LEMA [31 ml/g (500 �C); 50 ml/g (600 �C)].Overall, LEMA pyrolytic operation showed maximum bio-methaneyields compared to MA. RT has a significant influence on thebio-methane yields. Initially MA with 1 h decomposition time(SA: 600 �C) showed 10.3 ml/g of CH4 yield, which increased to50.1 ml/g with RT of 2 h. whereas, in case of LEMA, 1 h operation(SA: 600 �C) yielded 31 ml/g followed by 50 ml/g at 2 h. Theformation of CH4 can be attributed to the release of methyl radi-cals. Similar to the H2 yield, with increasing temperature, theCH4 production from both the types of algae feedstock improvedwith an exception that the CH4 yield from LEMA at 800 �C was lessthan that from MA.

3.2.3. Carbon dioxideAmong the biogas composition, CO2 was observed as major

component in all the experimental variations studied (Fig. 1). How-ever, specifically CO2 fraction was lower with deoiled algal (LEMA)pyrolysis compared to lipid bound microalgae (MA). Based on thepyrolytic feedstock used, MA operation showed a increasing trendwith CO2 production with an increase in decomposition tempera-ture or time. On the contrary, LEMA operation showed marginaldrop with increment in decomposition temperature or time. Com-paratively SL operation yielded higher CO2 with MA operation.Decomposition temperature showed direct correlation with CO2

yield with MA pyrolytic operation. At 500 �C (3 h) operation withSL mode, 191.2 ml/g yield of CO2 was recorded followed by600 �C (SL; 210.8 ml/g; 3 h) and 800 �C (SL; 261.6 ml/g; 3 h)(Fig. 3). LEMA operation with SL (3 h) mode operation documentedmarginal variation in CO2 production (175.4 ml/g (500 �C);164.5 ml/g (600 �C); 172.5 ml/g (800 �C). However, in both thepyrolytic operations, the influence of RT on CO2 production wasevident. With lower RT (1 h, 600 �C), MA process showed126.2 ml/g followed by 155 ml/g (4 h). Similarly with LEMA at600 �C operation for 1 h RT resulted in 178.5 ml/g yield followedby a drop in the production (146 ml/g). The influence of SA wasmarginal with CO2 production. In general, the pyrolysis of biomassproduces a gas rich in oxides of carbon due to the high oxygen con-tent of the feed material. The formation of the gaseous compounds


is a consequence of cracking reactions and the reactions betweenthe species formed during pyrolysis. The origin of CO2 can beattributed primarily to the existence of carboxyl groups in the pro-tein and saccharides in the algae as well as lipids particularly withMA feedstock.

3.3. Bio-oil profile

Oil produced during pyrolysis is one of the important valueadded product (Mata et al., 2009; Sharif Hossain and Salleh,2008; Yanik et al., 2013; Demirbas�, 2007). MA (lipid bound micro-algae) only showed bio-oil production. Due to lipid extraction,LEMA did not yield pyrolytic oil. Both increments in decompositiontime as well as temperature have had a negative effect on thepyrolytic oil production. Higher oil production was specificallyobserved at lower temperatures. With SL operation, higher oilyields were observed (0.70 ml/g) at 500 �C (3 h) operation followedby 600 �C (3 h; 0.30 ml/g) and 800 �C (3 h; 0.27 ml/g). Sand addi-tion did not show any impact on bio-oil yields, whereas retentiontime affected the productivity (0.20/0.17 ml/g (1/2 h); 600 �C).

Lipid bound microalgae (MA) with SL operation at 500 �C (3 h)and 600 �C (3 h) yielded higher bio-oil and were selected for oilprofile analysis after transesterification. The composition of transe-sterified pyrolytic algal-oil showed good properties that enable itsuse as fuel (Table 2). Heptadecanoic acid (C17:0) was the majorcomponent observed with 500 �C operation which is a good fuelproperty desirable for use in diesel engines. At higher pyrolytictemperature (600 �C), the oil showed comparatively broadercontour depicting the presence of butyric acid (C4:0), lauric acid(C12:0), stearic acid (C18:0), cis-11-eicosanoic acid (C20:1) andcis-11,14,17-eicosatrienoic acid (C20:3). Among these, butyric acidcan be used for the preparation of butyrate methyl esters or stearicacid which has fuel based applications. Algal based oil has lowoxygen content, higher carbon and hydrogen content and a lowerdensity than bio-oil produced from lignocelluloses materials (Duet al., 2011). Bio-oil from fast pyrolysis of microalgae has low oxy-gen content with a higher heating value of 29 MJ/kg, a density of1.16 kg/1 and a viscosity of 0.10 Pas which makes it suitable for



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Fig. 2. Effect of decomposition time and temperature on biogas production from microalgae (MA) and lipid extracted microalgae (LEMA) with sand additive (SA) and sandless (SL) pyrolytic conditions.


fuel oil (Miao et al., 2004). Fatty acid composition showed thepresence of higher saturated fatty acids (SFA) over unsaturatedfatty acids (USFA) depicting the lower risk on the combustioncharacteristics and ignition delay (Benjumea et al., 2011). Thedistribution of straight-chain alkanes of the saturated fractionsfrom microalgae bio-oils were similar to diesel fuel (Miao et al.,2004).

Table 1Comparative evaluation of products obtained from pyrolysis of microalgae (MA) and lipid

Pyrolysis conditions Retention time (h) Biogas (ml/g) H2 (ml/g) CH4 (ml/g)

MASL 500 �C 3 200 7.56 1.20SL 600 �C 3 240 18.50 10.66SL 800 �C 3 420 110.46 47.88SA 600 �C 1 230 93.36 10.35SA 600 �C 2 240 28.80 56.16

LEMASL 500 �C 3 180 3.40 1.13SL 600 �C 3 220 41.58 13.86SL 800 �C 3 320 110.59 36.86SA 600 �C 1 220 31.09 10.36SA 600 �C 2 220 55.44 18.48


3.4. Bio-char

Bio-char is as potential value addition to improve soil fertilityand thus allow increased crop production. Bio-char act as a sinkfor atmospheric carbon dioxide in terrestrial ecosystems(Lehmann and Joseph, 2006; Grierson et al., 2011; Wang et al.,2013). Fig. 4 depicts the yield of bio-char from MA and LEMA in SA

extracted microalgae (LEMA) pyrolysis at different operation conditions.

CO2 (ml/g) H2 (%) CH4 (%) CO2 (%) Bio-char (mg/g) Bio-oil (ml/g)

191.24 1.26 0.20 95.62 0.43 0.70210.84 2.57 1.48 87.85 0.33 0.30261.66 8.77 3.80 62.30 0.56 0.27126.29 13.53 1.50 54.91 0.63 0.20155.04 4.00 7.80 64.60 0.53 0.17

175.46 0.63 0.21 97.48 0.45 –164.56 6.30 2.10 74.80 0.51 –172.54 11.52 3.84 53.92 0.50 –178.55 4.71 1.57 81.16 0.58 –146.08 8.40 2.80 66.40 0.55 –



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and SL operation. More or less similar trend of bio-char formationwas seen from both MA and LEMA. SL operation showed relativelyhigher productivity than SA. Pyrolytic time, temperature andsand addition did not have much effect on bio-char production(MA – 0.426 mg/g to 0.555 mg/g; LEMA – 0.447 mg/g to 0.507 mg/g).Generally during pyrolysis, dehydration stage occurs up to200 �C which leads to weight loss due to moisture removal fromthe algal biomass. The next stage (200–600 �C) is the devolatilisa-tion; where about 60% weight loss occurs due to the loss of volatilecomponents. The last stage (600–800 �C) is called solid decomposi-tion; where the weight loss is much slower. In the devolatilisatonstage between 200 and 600 �C, the biogas production was highestwith MA compared with LEMA, which indicates that highest volatilematter was released resulting in highest yield of bio-oil. The thermaldecomposition breaks the compound and volatile gases werereleased as temperature increases to a specific point (Griersonet al., 2009). There exists a relationship between the chemicalstructure of solid bio-char and the composition of released gasesat different temperatures (Singh et al., 2014). Algal bio-char has alower carbon content, surface area and cation exchange capacitycompared with the lignocellulose bio-char but has a higher pHand gives a higher content of nitrogen, ash and inorganic elements(Chaiwong et al., 2012). The addition of bio-char to soils enhancesmicrobial activity. Bio-char produced from algal feedstocks havehigher nutrients including minerals (Peacocke, 2001). Goodamounts of nitrogenous compounds are present in algae which arederived from the pyrolysis of peptides or the decomposition andcondensation of amino acids (Lorenzo et al., 2014). Bio-char hasdemonstrated its potential as a soil ameliorant capable of improvingwater holding capacity and nutrient status of many soils (Lehmannand Joseph, 2009). Biochar also helps to uptake polycyclic aromatichydrocarbons (PAHs) and toxic elements from soil which results in

Table 2Composition of pyrolysis bio-oil from microalgal (MA) pyrolysis at 500 �C; 3 h (3 h) and 6

Parameter Sample

Temperature 500 �C 600 �CFatty acids Common name Lipid

numberProperty Common

Heptadecanoicacid

C17:0 Combustion of dieselengines

Butyric astearic aceicosenoicis-11,14acid


improving crop productivity (Brennan et al., 2014). Bio-char afterapplying appropriate pretreatment can be used as an adsorbentfor removing pollutants from wastewater (Agarwal et al., 2015;Brennan et al., 2014). Based on the multiple utilities, bio-char canbe considered as one of the potential value addition to algal cultiva-tion in the context of biorefinery.

4. Conclusions

Pyrolysis of hetrotrophically cultivated algae resulted in pro-duction of bio-char, bio-oil and bio-gas. The profile of pyrolyticproducts was found to depend on the nature of feedstock, decom-position time/temperature and presence of sand as additive.Higher temperature and long decomposition time favoured bio-gas yield with lipid bound algae. Sand additive pyrolysis of lipidextracted algae showed good bio-gas production with increasedH2 yield and decreased CO2 production even at lower decomposi-tion temperature/time. Pyrolytic algae-oil showed good fuel prop-erties. Study depicted the potential of algal biomass as a renewablefeedstock for multi-product recovery that contributes for thedevelopment of sustainable biorefinery platform.

Acknowledgements

Authors acknowledge the Director, CSIR-IICT for kind supportand encouragement in carrying out this work. Research was sup-ported by Council of Scientific and Industrial Research (CSIR),New Delhi, India, in the form of XII five year network project (BioEn(CSC-0116); SETCA (CSC-0113) and by Department of Biotechnol-ogy (DBT) in the form of SAHYOG-EU-FP7-KBBE project (BT/IN/EU/07/PMS/2011).

00 �C (3 h).

name Lipidnumber

Property

cid, lauric acid,id, cis-11-c acid,,17-eicosatrienoic

C4:0C12:0C18:0C20:1C20:3

Preparation of butyrate esterslike methyl butyrate, medicinalproperties. As biofuel in engines lubricant,drying of oils




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