Piloting resilient high biomass sorghum as quality feedstock for ligno-cellulosic biofuel production

A Ashok Kumar and Team a.ashokkumar@cgiar.org

2nd EU-India Conference on Advanced Biofuels Taj Mahal Hotel, New Delhi

12 March 2019

Multiple uses driving global sorghum production

• C4 diploid (2n=2x=20) Nutritious and resilient (Genome size 736 Mb –Model species)

• Global sorghum area and production is increasing marginally in well-endowed environments

• Top 10 sorghum producing nations belongs to 5 continents (2 N. America, 1 S. America; 4 in SSA; 2 in SA; 1 Australia)

• USA is the largest producer and exporter and China is largest importer (~9 m t)

• ICRISAT focuses on hybrid parents development (>950 A-/B- lines & >1000 R-lines) and sharing to exploit the ‘Heterosis’

• 270 cultivars released in 44 countries using ICRISAT-bred lines

• Stover economic value (40% of grain) is increasing (SA & WCA)

• USP for future – Nutrition, Feed/Forage, Biofuel

Sorghum is a gifted species in terms of biomass production per unit of water and time

S No Crop Dry Biomass per ha (tons)

1 Rice 2

2 Wheat 2-3

3 Maize 3-4

4 Sorghum (dual purpose)

4-5

5 Biomass sorghum >15

Sl. Crops Water

Requirement

(cm) 1 Rice 90-250

2 Wheat, Sorghum, Soybean, Tobocco 45-65

3 Maize, Groundnut 50-80

4 Sugarcane 150-250

5 Soybean 45-70

6 Cotton 70-130

7 Potato 60-80

Sweet sorghum deployed for commercial biofuel (1G)

• Worked with more than 10,000 farmers in India

• Supplied the seeds, literature • Trained farmers in crop

production for higher yields • Linked them with ethanol

distilleries and decentralized crushing units

• Farmers harvested grains and supplied stalks to distillery

• Ethanol produced in distillery

• CSH 22SS first sweet sorghum hybrid with higher stalk yield, juice yield and brix% developed and used for commercial ethanol production

Economics of sweet sorghum ethanol production (Rusni Distilleries)

Economics favors well for direct conversion of sweet sorghum juice to ethanol with variable cost of production (2008 -11)

Indicator INR Status today (INR)

Cost of raw material (fresh stalk) (Rs t-1) 600 1500?

Cost of processing (Rs t-1) 384 600?

Recovery of ethanol (l t-1) 45 55?

Cost of ethanol production (Rs l-1) 22 40?

Price of ethanol received (Rs l-1) 27 50

Benefit to cost ratio 1.22 1.25?

• Feedstock supply not continuous – limited period of operations • Ethanol price received wasn’t sufficient to make industry viable • Non compliance for ethanol blending targets - low market demand

Sweet sorghum viability to farmers and options for

effective utilization of bagasse (besides cogen)

Source: Michael Blümmel et al. 2009

aStatistically not significant

Sweet sorghum bagasse can be effectively converted in to nutrient rich compost

Treatment Intake (g/kg live weight)

Weight gain (Kg/day)

Commercial feed block 3.64 0.975a

Bagasse-leave feed block 3.76 0.871a

Sorghum stover (chopped)

1.24 -0.457

Adopted from Rajasekhar 2007

Item Sweet

sorghum

Grain

sorghum

Grain yield (t ha-1) 1.6 2.5

Stalk yield (t ha-1) 20 4 (dry)

Grain value (US$ season-1) 234 365

Stalk value (US$ season1) 293 50

Total value (US$ season-1) 527 415

Leaf stripping (US$ season-1) 15 -

Net value (US$ season-1) 512 415

Gain from sweet sorghum (US$

season-1 ha-1)

97 (23%)

Key lessons learnt from sweet sorghum ethanol initiative

• Distillery should be multi-feedstock unit and produce multiple products and by-products

• Explore sugar mills for using Sweet sorghum as complimentary feedstock –no capex

Can sweet sorghum fit in sugar mills?

JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC

Proposed Sweet sorghum based Bioenergy Calendar

Sugarcane harvesting

Sweet sorghum harvesting Sweet sorghum planting

• Ethanol price close to Rs 50 ($0.71) and large demand in India for blending • There are >600 sugar mills in India, of which >400 have distilleries attached • Sugarcane crushing: Nov-Mar

Sweet sorghum can be crushed in a sugar mill without changing a nut or bolt

Raising demand for ethanol globally giving new fillip for sweet sorghum

• The primary juice brix% (>15) is close to sugar cane

• No difficulties posed in juice fermentation or distillation

• 31 lit of ethanol obtained from ton of stalk

• New SS lines have 20-21% brix

• Great opportunity to make the chain viable and sustainable

Improved sweet sorghums for 1G Biofuel Sl. No

Genotype Days to 50%

flowering

Plant height

(m)

Brix (%)

Fresh stalk Yield

(t ha-1

)

Juice Yield

(t ha-1

)

Grain Yield

(t ha-1

)

Sugar Yield

(t ha-1

)

Ethanol Yield (t ha

-1)

Ethanol Yield

(Kg ha-1

)

Ethanol recovery (Lit/t of

biomass)

1 EVRT-2 # 6 / 18PR

87 2.7 22 49.7 25.4 4.0 4.19 2.45 2453 49.4

2 EVRT-3 # 9 / 18PR

88 2.3 22 43.9 24.3 4.5 4.00 2.34 2341 53.3

3 EVT-2 # 1 / 18PR

98 2.3 23 27.7 13.7 1.1 2.36 1.38 1384 49.9

4 EVT-2 # 19 / 18PR

91 2.5 23 35.3 18.4 2.2 3.17 1.85 1854 52.5

5 EVT-3 # 2 / 18PR

82 2.3 24 39.5 21.2 2.3 3.81 2.23 2231 56.6

6 EVT-5 # 5 / 18PR

99 2.8 23 62.1 30.7 4.0 5.30 3.10 3099 49.9

7 EVT-6 # 8 / 18PR

94 2.2 24 60.5 26.2 5.3 4.71 2.76 2758 45.6

8 CSV 24 SS 80 2.1 15 28.8 14.7 2.4 1.63 0.95 951 33.0

9 ICSV 93046 81 2.2 15 34.3 21.1 3.1 2.29 1.34 1342 39.1

High biomass sorghum is a competitive feedstock for ligno-cellulosic (2G)

biofuel production and modifying the lignin composition enhances its value

Increased Bioethanol Production

288 lit Ethanol/t of sorghum dry biomass produced by fermenting C5 + C6 sugars

Allelic studies and bmr trait introgression in sorghum

• Mutations in cinnamyl alcohol dehydrogenase (CAD2) and caffeic O- methyl transferase (COMT) genes contribute to the phenotype of bmr6 and bmr12 groups

• SNPs (and KASPRs) were developed and used for transferring bmr alleles (bmr 6 and 12) in to elite sorghum lines

Details of KASPar SNPs markers which can be used for foreground selection in marker-assisted backcrossing programs to transfer to bmr region for high biomass sorghum SNP genotyping with KASPR assays

Performance of promising advanced bmr sorghum derivatives for fresh and dry biomass yield

• Introgression of bmr 6 and 12 into elite and locally adapted high biomass cultivars was done by both ICRISAT and ICAR-IIMR, Hyderabad.

• Evaluation at IIMR showed higher fresh and dry biomass yields in bmr introgression lines Adopted from Umakanth, IIMR

Increasing drought tolerance and ratoonability

Fresh stalk yield (FSY) of main crop 60 t h -1

FSY of ratoon crop 62 t h -1 (without added water or nutrients)

Supriya Mathur et al. , 2017 Biotechnol Biofuels Vinutha et al., 2017 Trop. Grassl.-Forrajes Trop

Treatment Cellulose

% (w/w)

Xylose

% (w/w)

Arabinose

% (w/w)

Total Sugars % Lignin %

(w/w)

Ash %

(w/w)

Total of components %

(w/w)

Raw Biomass

(Triplicate)

46.29 27.26 8.22 81.77 14.56 2.42 98.75

45.19 28.01 7.99 81.19 14.77 2.88 98.84

46.01 28.11 8.09 82.21 13.90 1.75 97.86

Acid Treatment 57.39 17.99 2.21 77.59 8.01 3.17 98.77

Alkali Treatment 74.26 20.58 - 94.84 2.15 0.75 97.74

0.0

2.0

4.0

6.0

8.0

10.0

TE (

g kg

-1)

Genotype

Transpiration Efficiency (TE)

WS

Testing the high biomass sorghum hybrid in farmers fields in Numaligarh Refineries Ltd area by KVK – Golaghat, Assam, India

• On-farm trials conducted using Hybrid RVICSH 28

• Grown in 2018 Rainy season (4 months crop)

• Crop is totally rainfed • Dry Biomass Yield 16 t ha-1

• Farmers quickly adopting improved crop management

• Higher scope for scaling up • Can be an alternative to

Bamboo as 2G feedstock

USP of sorghum as biofuel feedstock

• Wider adaptability and low water requirement per unit biomass • Familiarity of crop with farmers and there are no-trade offs • Quick growth, seed propagation, hybrid technology available • Tolerance to salinity, drought with higher nutrient-use efficiency • The supply chain can be tweaked as required by industry • Year-round production possible by changing genotypes and BBP • Amenable for both 1G and 2G biofuel production (customized

genotypes available) • Augments country’s fodder supply gap besides biofuel feedstock

Thank you In partnership with CGIAR Centers, public and private organizations, governments, and farmers worldwide

Demand-driven Innovation for the Drylands

www.gldc.cgiar.org