Heavy consequences of moisture content on biomass for energy Sylvain Volpé, FE, M.Sc. and Denis Cormier, FE, M.Sc Harnessing biomass II, North Bay, Nov. 2011
New paradigms Moving Energy
Energy content Same weight Same energy content Heat value (GJ/odt) Hard Maple Jack Pine Aspen 19.5 20.8 20.0
Moisture content effect on heat value Moisture content is a major consideration for CHP and most thermochemical processes. 100 Firing Efficiency - Gas @ 300 F 90 80 Summer Winter Efficiency (%) 70 60 50 40 30 0 10 20 30 40 50 60 70 80 Moisture Content (%)
MC impact on biomass supply? Supply costs Moisture content 5
Impact of Moisture Reduction Wood load White birch 55% 35% 56% 52% 17% 11% 27% 37% Load 16.3 tonnes 22.6 tonnes Max. payload = 36 tonnes
Impact of Moisture Reduction Energy Content 55% 35% Calorific content 12.6 GJ/tonne 15.1 GJ/tonne 20% Total energy 57 MWh 95 MWh
Impact of Moisture Reduction Transport Cost 55% 35% * 15 $/green tonne Transport cost 9.50 $/MWh 5.50 $/MWh 4 $/MWh More for water Emphasis and payment should be on energy content not GMt
Wood moisture Fibre saturation point Moisture in wood: (1) water in the fibres (bound water) and (2) free water circulating between fibres Water becomes free water when wood fibres are saturated Fibre saturation point at 20 C and relative humidity of 99 % is 30 % Free water tends to evaporate from wood when piled Bound water requires more energy to be eliminated 9
Moisture content impact on boiler efficiency 10
Biomass storage strategies Season and duration of storage In summer, stored biomass can lose 10 to 25 % of moisture Fall and winter precipitations can reduce summer moisture loss and raise moisture content level by 10 to 15 % if no covering is done 11 Nurmi, 2002
Moisture content? Biomass energy value? Energy cost? Economic advantages of using biomass? 12
Forest biomass energy cost conversion tool Increase awareness among biomass users that moisture content has a considerable impact on the financial feasibility of an energy project Show that forest biomass is a financial viable option to fossil fuels. FPJoule can answer the two following questions: 1. What is the impact of moisture content on the energy cost of biomass; 2. What are the potential annual savings using forest biomass instead of fossil fuels? FPJoule is available for free on the web at: www.fpinnovations.ca/fpjoule 13
Energy cost calculation Biomass energy content based on species, tree part, and moisture content Conversion tool to calculate monetary equivalents Economic advantages calculations Annual biomass requirement and the procurement cost based on boiler size Comparing supply cost of traditional energy sources to forest biomass 14
Fuel parameters Adjustable default values (Higher heating value, boiler efficiency, unit cost) The Reference section lists the information sources used (articles and internet links) Report generation Printable results including: Fuel parameters used Comparison with other fuels 15
Practical application 1: Delivery price based on energy content? Traditional method of payment Species group: Hardwood Tree section: Stem Moisture content: 45% Biomass price: 40 $/GMt Energy based payment Equivalent energy price established according to historical biomass deliveries : 18.41 $/MWh Calorific content 7.82 GJ/tonne Total energy 69.5 MWh Load value 1280 $ 16
Practical application 1: Delivery price based on energy content? Moisture content: 45% Load value 1280 $ Moisture content: 40% Calorific content 8.78 GJ/tonne Total energy 78.0 MWh Load value 1436 $ + value of 12% 17 Incentive to bring dryer fuel to the plant
Practical application 2: Annual savings with biomass? 18 Boiler using heavy oil Annual cons. : 500 000 L Purchase price : 0.80 $/L HHV : 43.5 MJ/kg Burning efficiency : 82 % Annual cost : 400 000 $ Energy supply cost : o 25.3 $/MJ Boiler using biomass Biomass price : 35 $/GMt HHV : 20 MJ/kg Moisture content : 50 % Burning efficiency : 69 % Biomass required :2 291 GMt Annual cost : 80 185 $ Energy supply cost : 5.1 $/MJ Annual savings = 320 000$!
Practical application 3 Which supplier to choose? Biomass at 35 $/GMt Species group: Softwood Tree section: Bark Moisture content: 50% Net calorific value: 7.11 GJ/t Equivalent energy value: 17.71 $/MWh Biomass at 40 $/GMt Species group: Softwood Tree section: Bark Moisture content: 40% Net calorific value: 9.08 GJ/t Equivalent energy value: 13.87 $/MWh Cheaper by 22%! 19
Thank you! Contact FPInnovations Sylvain Volpé Researcher 570 blvd. Saint- Jean Pointe- Claire, QC, H9R 3J9 Canada Phone: 514-782- 4521 Email: sylvain.volpe@fpinnovations.ca www.fpinnovations.ca 20