Technological options and social cost considerations of woody biomass conversion Hsien H. KHOO Reginald B.H. TAN Institute of Chemical and Engineering Sciences (ICES) SINGAPORE 3rd International Conference on Life Cycle Management University of Zurich August 27 to 29, 2007
ICES – Who We Are Research areas: Chemicals, engineering & science, Research areas: Chemicals, engineering & science, energy & environment, energy & environment, biomass utilization, LCA biomass utilization, LCA
LCA / LCM research Examples LCA projects: • CO 2 sequestration • National electricity systems (ocean and generation underground storage) • Packaging materials • LCA of Mineral (paper/cardboard) carbonation (CO 2 sequestration with • Aluminium metal supply industrial residues) chain • GHG intensity of plastic production • Zinc metal recycling • • Biomass conversion and Biomass conversion and • National waste utilization, etc utilization, etc management • Waste-to-energy systems
LCA Network (East Asia) Forming collaborations: Exchanging Forming collaborations: Exchanging - Biomass utilization and information/data, sharing - Biomass utilization and information/data, sharing conversion experience, developing conversion experience, developing LCA/LCIA - Technology development LCA/LCIA - Technology development methodologies, etc .. - Etc methodologies, etc .. - Etc [ Indra Gandhi Institute of Development Research; Thailand Environmental Institute; University of Philippines Los Banos; Joint Graduate School of Energy & Environment (King Mongkut Uni.); Konkuk University, Korea; National Institute of Advanced Industrial Science and Technology, Beijing University of Technology ... ]
Types of Biomass in Singapore • Small island with land area: 682.7 square km • Population of 4.553 million, and rapid industrialization • The types of identified biomass in Singapore are: � wastepaper and cardboard (531,500 tons / year) � food residue (1,098,600 tons / year) � timber and scrap wood (from industry, construction & demolition and tree felling/pruning) (239,300 tons / year) � horticultural (also from tree felling and pruning) (199,500 tons / year) � sewage sludge (93,900 tons/year) � animal wastes
Other sources (from the Garden City Garden City) Trees along walkways and roads Felling and pruning activities
Woody Biomass in Singapore Industrial and demolition/construction waste wood Convert into ENERGY
LCM for biomass utilization • Growing concerns over energy security have led to the promotion of renewable energy resources : Biomass • Life cycle management can be used to compare the technological options for biomass-to-energy conversion • Taking into account: air emissions and external costs Bio - -technology technology Bio Charcoal Bio -Oil Wood Horticultural Bio -Oil Bio -Oil Garbage Sewage Food residue sludge Bio - Bio - -Gas -Gas Gas Gas Bio Bio
Connecting LCM with Costs Integration of LCM with Costs Integration of LCM with Costs Standard LCA/LCM Standard LCA/LCM - ISO framework applied - ISO framework applied - Same ISO framework applied - Same ISO framework applied - Input-output flow - Input-output flow - Input-output flow also - Input-output flow also (inventory) according to (inventory) according to according to Functional Unit according to Functional Unit Functional Unit Functional Unit - From inventory results - From inventory results - From Inventory → → impact - From Inventory → impact → connect with cost → assessment calculations → connect with cost assessment calculations functions functions - Final results: Total Total - Final results: Total - Final Results: Total costs Total costs - Final Results: Total costs Environmental impacts Environmental impacts Environmental impacts
Compare two different technologies Waste-to-energy: wood waste Electricity Electricity Carbonization: wood waste Charcoal Charcoal Translating all LCI into costs: • Energy inputs -> costs • Operations -> costs • Air emissions -> social costs of pollution • Worth of final product -> ( - ve ) costs $$$ (price) $$$ (social costs) $$$ (price) $$$ (social costs) $$$ $$$ Energy Air Pollution Energy Air Pollution (operations) (operations) - $$$ (value) - $$$ (value) Materials Materials Product Product Process Process Process Process Process Process Process Process Process … … … 1 1 1 2 2 2 X X X Generic LCM-cost model
Social Costs of Air Pollution Social Costs of Air Pollution NO NO 2 NOx NO 3 HNO 3 NH 3 NH 3 NH 4 NO 3 SO 2 (NH 4 ) 2 SO 4 SOx SO 4 And how to include it in LCA/LCM
Social Costs of Pollution Studies have been carried out to quantify costs ($$) of damages to human health due to air pollution. These involve: � specification of emissions emitted: kg pollutant of SO2, NO2, CO, PM, dioxins, etc.. � transportation and dispersion of the pollutants in the air � impact pathways (inhalation, incidental digestion) � monetary valuation of the damage caused (also known as externalities ) Spadaro & Rabl (2002), Air pollution damage estimates: the cost per kilogram of pollutant . Int. J. Risk Assessment and Management , 3, pp. 75-98. adfas Quah Boon (2003), The economic cost of particulate air pollution on health in Singapore . J. Asian Economics , 14, pp. 73-90.
Costs factors for each technology Waste Treatment Technology Costs and operating conditions Incinerator Carbonizer Type of material processed Waste wood Waste Wood Electricity Charcoal Main product (940 kWh/ton) (135 kg/ton) Value of product S$0.12/kWh S$1.29/kg Operating costs in SGD/ton 70 100 Electricity requirements 70 78.37 (kWh/ton wood) Natural gas Kerosene Other energy requirements (0.23 m 3 /ton) (5.8 liter/ton) S$0.7 per m 3 natural S$0.53 per liter Other Costs gas kerosene Thermal value of wood taken as 4.7 MWh/ton; efficiency of incinerator 20%
Air emissions and Social costs Main Air emissions Incinerator 1 Japan Carbonizer 2 (kg/ton waste wood) SO X 0.12 0.65 NO X 1.01 0.43 CO 0.18 0.033 CO 2 1280 43.89 Dioxins/furan 6.89 E-08 0 PM 0.021 0.015 Estimated social and economic cost of emissions 3 Dioxins CO CO 2 SO x NO x PM /furans $/kg 0.004 0.057 0.58 2.92 30.0 3.6E+07 1 Tan, Khoo (2006) Impact Assessment of Waste Management Options in Singapore, J. of Air & Waste Manage. Assoc . 56: 244-254. 2 Actree Corp. (2005) Report for Exhaust Gas Analysis (in Japanese) 3 Spadaro & Rabl (2002) Air pollution damage estimates: the costs per kilogram of pollutant, Int J. Risk Assess. Manage. 3: 75-98.
LCA model Social Cost ($) Energy Cost Process Cost ($) ($) Emissions to Air SOx, NOx, CO, CO 2 , dioxins/furans and PM Enetgy input Natural Gas 3 70 kWh 0.23 m 940 kWh Value Waste wood Incinerator electricity (- $Cost) 1 ton Functional Functional unit unit Waste wood 135 kg Value Carbonizer (- $Cost) 1 ton charcoal Energy input Kerosene 5.8 Liter 78.37 kWh Process Cost Energy Cost ($) ($) Material and energy flow, and associated pollution and costs
Simple math representation for estimating total value (P Total ) P Total = P E / C – C EN – C OP – SC PE Where P Total = Total value (estimate) Total pollutant (kg) P E / C = Worth of product product Worth of multiplied by cost of pollutant C OP = Operating Costs ($/kg) = Total costs ($) And SC PE = Sum of social costs of pollution = ∑ CO 2 (total in kg)* C CO2 ($/kg) + SO 2 (total in kg)* C SO2 ($/kg) + … Where C CO2 / SO2 ... is the unit cost per pollutant
Results for breakdown of costs Social costs of pollution Projected costs for 1 ton of wood treated 120 80 40 0 SGD -40 -80 -120 -160 -200 Energy Usage Process Pollution Products (Social Costs) Incineration Carbonization Worth of product (Shown as negative costs)
Results for estimating total value of system Nearly similar w/o Nearly similar w/o considering social considering social costs (pollution) costs (pollution) Total value per ton of wood waste treated 70 60 50 40 30 20 SGD 10 0 -10 -20 -30 -40 -50 with Social with Social w/o social w/o social costs costs costs costs Incineration Carbonization Incineration Carbonization
Integration of Social Costs & Economic Integration of Social Costs & Economic factors with LCM factors with LCM Based on the selection of a common Functional Unit (ton • woody biomass waste), all costing factors were identified and compared • Social impacts of pollution translated into costs ($$) • Final results are presented in Monetary values -> provides an estimation of biomass-to-energy system in terms of product worth vs. other external cost factors • Limitation of gate-to-gate model: any other emissions relating to Use Stage not included in the system boundary • Future work should cover Capital, Commissioning and Construction
Recommend
More recommend
