R&D for Biofuel Technology
The DBT has established a very strong R&D Programme aimed at achieving the targets set forth on the Vision 2020.
There are more than 70 R&D projects towards development of technology for Bioethanol, biodiesel, biobutanol, biohydrogen and enzyme development.
Department has been supporting a number of projects on Cellulosic Bioethanol which includes developing technology for pre-treatment of substrates, enzyme development for breakdown of different substrates, fermentation of sugars to ethanol, ligocellulosic conversion from lab to pilot scale.
Pre-treatment and pelletisation
Studies on pelletisation and delignification of cellulosic biomass (rice straw, cotton stalk, sweet sorghum, switchgrass, Prosopisjuliflora and Lantana camara) was tried via two stage pre-treatments involving an alkali.
Acid was tried for cotton stalks, Lantana camara and Prosopisjuliflora which resulted in 85 per cent or higher delignification for all the three residues.
Of the various methods tried for pre-treatment of rice straw the best results has been found using 0.5 per cent NaOH at room temperature.
Enzymatic delignification for banana stem/ wheat straw using laccase from Pleurotusostreatus showed good results. Efforts are continued for optimisation of enzymatic delignification and scale up from DBT projects at TNAU & IITK.
Enzymatic hydrolysis and fermentation of lignocellulose
Two novel bifunctional cellulolytic enzymes with good activities were developed for application in lignocellulosic ethanol at DBT-ICGEB Centre.
- Endoglucanase/-glucosidase chimera (EG5)
- Endoglucanase/xylanase (Endo5A-GS-Xyl11D)
Also an engineered E. coli strain (SSY10) has been developed to ferment C5/C6 into ethanol via native pathway engineering with encouraging ethanol yields from both C5/C6 sugars.
SSY10 also efficiently fermented lignocellulosichydrolysates generated via acid treatment and via ammonia treatment to ethanol at neat theoretical maximum yield.
The isolated Paenibacillusat ICGEB Centre at this centre strain that produces cellulolytic enzymes as well as glucose, xylose, cellobiose and glycerol and produce ethanol.
Integrated process technology for conversion of crop residues into ethanol and methane
Two mutants, Aspergillusterreus NIH2624, of cellulytic enzyme have been generated with greater specific activities of cellulose at SPRERI, Gujarat. In order to improve the process economics re-cycling of the enzyme has been attempted with more than 90 per cent enzyme recovery.
Attempts for efficient conversion of rice straw to methane rich biogas has also been attempted.
Butanol is being looked as a sustainable and next generation biofuel studies are in progress for production, process optimisation, scale up at UDSC New Delhi and ARI Pune.
After initial screening, characterisation and optimisation of different butanol producing strains batch studies has been conducted with few high yielding strains. An increased yield of butanol has been achieved after fed batch studies.
The production of butanol has been successfully scaled up to 30L fermenter under the optimised conditions.
30 L Fermentor for Biobutanol
Department has recently initiated supporting research projects on production of biohydrogen realising the potential of biohydrogen as a fuel for future.
With the studies conducted enhanced biohydrogen production has been observed using Iron and Nickel nanoparticles.
Clostridium butyricum strain isolated at TERI, New Delhi has been studied for biohydrogen production using different cost effective substrates and maximum hydrogen production was obtained at 2.5% molasses concentration.
Experimental set up for volumetric hydrogen quantification (by water displacement method) generated during molasses fermentation by Clostridium butyricum TM9A strain in 150 litre pilot scale bioreactor (100 litre working volume)
The process has also been scaled up at lab scale and results demonstrated that C. butyricum strain could produce 14 litre of pure hydrogen from 10 litre of basal nutrient solution and further successful scale up of hydrogen production has been carried out from proto scale to pilot scale in 100 litre working volume by using 150 litre scale bioreactor with good H2 production efficiency.
Further optimisations of parameters are in progress to scale up this process in 1000 litre scale. For this 1500 litre scale bioreactor will be used.
Scientist `G’/ Adviser In-charge
Scientist ‘D’ / Principal Scientific Officer