CSP- Biomass Hybrid cogeneration system offers synergistic solution for continuous process industries. 9 th May 2013 Chennai

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1 CSP- Biomass Hybrid cogeneration system offers synergistic solution for continuous process industries RENERGY 2013 Innovation Session 9 th May 2013 Chennai T.S.Venkataraman & T.G.Sundara Raman Esvin Advanced technologies Ltd., Chennai

2 Esvin Advanced technologies ltd GROUP COMPANIES SESHASAYEE PAPER & BOARDS LTD (SPB) PONNI SUGARS (ERODE) LTD (PONNI) HIGH ENERGY BATTERIES INDIA LTD (HEB) SPB PROJECTS AND CONSULTANCY LTD (SPB-PC) SPB PAPERS Ltd.

3 Esvin Group s experience in handling Biomass The Esvin Group has been handling biomass such as Bamboo, Bagasse, and wood for pulping since 1962 and as on date is handling 4 lakh t/year of wood for pulping in their SPB paper Mill, Erode. The Group had also set up a sugar Mill in 1982 ( Ponni Sugars, at Erode) and were handing till last year about 3.0 lakh tonnes/year of Bagasse for supplying as pulping raw material to adjoining SPB paper Mill. While the above two Biomasses were used for paper making, Biomass for power generation for export was commissioned last year by Ponni Sugars A HP Boiler (112 bar and 540 deg C) and Steam turbine to generate MW, depending on availability of Bagasse and Biomass. With the recognition of Black Liquor Solids (BLS) as a biomass by MNRE, the Mill is handling 700 tpd of BLS in a HP Boiler of 65 bar and 460 deg C, producing 11MW power in a dedicated steam turbine.

4 Why CSP + Biomass hybrid? Need for Solar Energy to meet the of SPO requirement but Solar PV cannot meet the demand because of its low PLF (18%), whereas Concentrating Solar Power (CSP) gives 50% more PLF. CSP with Storage facility ideally suitable to Industrial Cogeneration Plants Conservation of Valuable Biomass is achieved where CSP + Biomass hybrid is used.

5 SOLAR PV Vs. CSP FOR COGEN APPLICATIONS PHOTO VOLTAIC PANELS PARABOLIC TROUGH Electricity production due to the photovoltaic effect- dual tracking possible. Solar PV can work average only 6- hrs on a sunny day and cannot provide steam for process SOLAR ELECTRICITY Mirrors are used that capture thermal energy by tracking the sun dawn to dusk Most economical and meaningful thermal energy generating system to integrate with conventional cogen or even IGCC SOLAR THERMAL ELECTRICITY

6 The parabolic trough

7 The 5 MW Archimede CSP plant in Italy

8 CSP -Hybridisation

9 CSP Performance Analysis Annual Capacity Factor : % Annual Solar to electricity efficiency:15-16 % Plant Peak efficiency : % Cooling Water Requirement : 3 m3/mwh Total system integrated with Grid

10 Direct steam generation Direct steam generation has the following advantages: Direct steam generation is climate and environmentally friendly and eliminates hazardous and flammable substances. Direct steam generation brings a reduction in total investment costs by eliminating components. Direct steam generation makes operating temperatures up to 500 C possible. Direct steam generation is accepted as an operating concept by financing banks.

11 CSP-Solar Thermal Operating Plants CSP technology Commercially Proven Plant Operating with steam generator : one in Thailand Design & Supply : Solar Lite, Germany Thermal Energy Conversion efficiency: > 60%

12 Solar Thermal Power Plant Thailand Electrical Power MWe Thermal Output.. 19 MWth Operating Pressure.. 30 bar Operating Temperature 330 C Efficiency : ~ 60 %

13 Merits of Direct steam generation DSG Non-toxic envirofriendly 2 Phase flow-annular Higher efficiency Commercially Proven Thermal Storage integration in place Higher steam temperature gradients Simple Overall Configuration Synthetic Oil Hazardous to environment Single Phase Flow Lower efficiency Commercially Proven Thermal storage Less expensive

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15 First commercial CSP plant in Thailand

16 Case-Study Paper Mill Seshasayee Paper -Tirunelveli Plant Plant Power Requirement MW In-house Co-generated Power 6 MW Grid Power Import 2.6 MW The boiler is designed for biomass (multi fuel) of around 85% and balance 15% using fossil fuel.

17 Typical Analysis of Biofuels( as Received at site) Biofuel Ash Moisture GCV % % Kcal/kg Rice Husk De-Oiled Bran Saw/Wood Dust Ground Nut Shell Coconut shell

18 Solar Energy Storage - worth its salt! One challenge facing the widespread use of solar energy is reduced or curtailed energy production when the sun sets or is blocked by clouds. Thermal energy storage provides a workable solution to this challenge in a concentrating solar power (CSP) system, If the receiver contains oil or molten salt as the heat-transfer medium, then the thermal energy can be stored for later use. This enables CSP with storage systems to be cost-competitive in providing uninterrupted power even on a cloudy/ slight rainy day and nonsolar period also!

19 What is Molten salt Molten salts used for indirect heat transfer are in general synthetic salt so- called Hitec salt. Available in tertiary or binary mixtures. Eutectic mixture of 53 wt.% potassium nitrate (KNO3), 40 wt.% Sodium nitrite (NaNO2) and 7wt.% Sodium nitrate ( Na No3). White solid product with a melting temperature of approx. 145 C Impurities, i.e. chlorine, sulphur, magnesium, etc. and insolubles are very low.

20 Molten salt Storage and Heat transfer system

21 Heat Transfer Media

22 Principle of operation 2- tank salt storage system The fluid is stored in two tanks one at high temperature and the other at low temperature. Fluid from the low-temperature tank flows through the solar collector or receiver, where solar energy heats it to a high temperature, and it then flows to the high-temperature tank for storage. Fluid from the high-temperature tank flows through a heat exchanger, where it generates steam for electricity production.

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24 Salient Gains of the Proposed Scheme Significant Reduction in Biomass requirement through Solar CHP Switch CHP with Back-up Storage energy ensures Solar Power during Peak hours of operation of Plant evening 6pm to midnight Higher steam temperature (400 to 420ºC) to steam turbine ensures marginal increase in Power generation : say by 0.2 to 0.3 MW

25 COGENERATION PLANT Steam generation in Boiler : 900 to 1000 tpd Fuel consumption in Boiler: Biomass consumption : tpd Balance fuel Coal : tpd Steam flow to turbine ( operating) Inlet flow : 42 tph Extraction to process : 24tph Exhaust to condenser : 18tph Specific Steam consumption for Power Generation Extraction : 8.0 tph/mw Condensing..: 6.0 tph/mw

26 Typical operating condition of the Mill (referable to only Biomass) Parameters Value Units HP steam 36.0 tph generation Specific fuel consomption 4.5 t of steam/ BD t Biomass 36/2.5=8.0 tph consumption Daily Biomass 8X24=192.0 tpd consumption. Biomass price(bd) 6000 Rs/ tonne Biomass cost 6000X192= Rs Lakhs/day

27 Total revenue realisble in this CSP+ Biomass hybrid scheme Parameters Values Units Sunny days 300 days Biomass saved 92X300=28800 t/year Cost of Biomass saved 6000X28800= 1728 Rs. Lakhs /yr Power generation 24/8+12/6=5.0 MW /day from STG SOLAR CERTIFICATE. Revenue from Solar certificates (13-3)=10 Rs. / unit 10X5000X3600 =1800 Rs. Lakhs / yr Total Revenue 3528 Rs. Lakhs /year

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