BIO FUELS. Sustainable Energy Options. UAU212F Spring Throstur Thorsteinsson 1. Biomass share in TPES

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1 Sustainable Energy Options UAU212F BIO FUELS Throstur Thorsteinsson Biomass share in TPES Provided about 10.2% (50.3 EJ) of global (TPES) in Traditional use of wood, straws, charcoal, dung and other manures for cooking, space heating and lighting by generally poorer populations in developing countries accounts for about 30.7 EJ, 20 to 40% occurs in unaccounted informal sectors including charcoal production and distribution. TPES from biomass for electricity, heat, combined heat and power (CHP), and transport fuels was 11.3 EJ in 2008 and the share of modern bioenergy was 22% Biomass sources for energy Feedstock Conversion Heat / Power Roundwood products are saw logs and veneer logs for the forest products industry and wood chips that are used for making pulpwood used in paper, newsprint and Kraft paper. In 2009, reflecting the downturn in the economy, there was a decline to 3.25 (total) and 1.25 (industrial) billion m 3 Commercial (solid lines) and developing (dashed lines). Lignocellulosic biomass Biomass energy conversion Throstur Thorsteinsson (ThrosturTh@hi.is) 1

2 Gasifier The biomass in the gasifier undergoes four processes; drying, pyrolysis, Pyrolysis is the thermal decomposition of the dry biomass in the absence of oxygen. oxidation reduction. The products are bio-char (charcoal), liquids (oils) and gaseous products. The products of pyrolysis are then subjected to oxidation the end result of which is a combination of carbon, water and carbon dioxide. Gasifier outcome The final products are a gas the combustible part of which is hydrogen (10-20% by volume), carbon monoxide (15-30%) and methane (2-4%); the remainder is nitrogen and non-reacted carbon dioxide Biofuel production and trade 2009 Biofuel production Global biofuel production Uncertain size of source Important factors include Population and economic/technology development how these translate into fibre, fodder and food demand (especially share and type of animal food products in diets) and development in agriculture and forestry. climate change impacts on future land use including its adaptation capability; considerations set by biodiversity and nature conservation requirements; and consequences of land degradation and water scarcity. Throstur Thorsteinsson (ThrosturTh@hi.is) 2

3 Technical potential Must know: The amount of land available for biomass plantations. Regional distribution of the land and distances to consumption centers. Productivity of the land. Water Availability. Environmental implications. Technical and economic performance of conversion technologies. Biomass technical potential Global technical potential Biofuel vs. fossil fuel GHG CO 2 mitigation potential Source: OECD, 2007; Biofuels: Is the cure worse than the disease? Throstur Thorsteinsson (ThrosturTh@hi.is) 3

4 Lifecycle GHG emissions Sustainability 2050 projections 2050 deployment scenarios Env & soc/eco impacts of bioenergy Social aspect Land conflicts Indecent work The Social Costs and Benefits of Biofuels: The Intersection of Environmental, Energy and Agricultural Policy Local social and environmental impact of biofuels Throstur Thorsteinsson 4

5 Efficiency Corn ethanol production requires 1.29 gallons of fossil fuels per gallon of ethanol produced, and soy biodiesel production requires 1.27 gallons of fossil energy per gallon of diesel produced. In addition, approximately three gallons of ethanol are needed to displace two gallons of gasoline. Environmental issues Land, Water, and Nutrient Consumption Pollution from Growing & Harvesting Effluents from Thermal Conversion Processes Combustion Emissions Centralized Steam, Electricity Generation Refuse Based Fuels: Trace Hydrocarbons (PAH), Dioxins, Furans Metals HCl Wood Stoves & Fireplaces PAH Other Complex Organics Particulates CO 2 Management If Fossil and Biomass Consumption Offset by New Biomass Growth Environment and biomass power Environment Soil erosion and deforestation Impact on water resources Loss of biodiversity Pollution Fossil fuel Fossil fuels in transport Fossil fuel is material which has been formed by natural processes such as the anaerobic decomposition of organic remains (plants or animals), usually over a long period of time Fossil fuels include petroleum, coal, peat and natural gas Fossil fuels are rich in carbon Petroleum based fuels dominate transport fuels and have for almost a century High energy content Infrastructure in place Familiar Cheap Throstur Thorsteinsson (ThrosturTh@hi.is) 5

6 Biomass attributes Renewable Connected to farming - economics Multiuse food, shelter, energy, materials Environmental concerns include land and water use, fertilizer and other nutrient requirements Vegetation Photosynthesis: Energy energy (sunlight) 6+ 6CO2 + 2 H2O H2O => C HC6H12O6 O 6O + 6O Respiration: C6H12O6 C (organic matter) + 6H12O6 6O2 6O2 => 6CO2 + 6 H2O + 6energy CO2 6 H2O Energy 6 2 Starch from corn Bioethanol from grain corn feedstock Opportunities for Biotechnology Fermentation Yeasts that can: Use a broader substrate spectrum Have higher yields Are resistant to ethanol or pretreated substrates Production of more valuable co-products Improved catalysts - enzyme production Genetic engineering of plant feedstocks Biofuels Biofuels - production Ethanol (alcohols) Biodiesel Methane Biogasoline Hydrogen Ethanol Fermentation (sugars, starch and cellulose) Hydration Anaerobic bacteria Biodiesel Transesterification Vegetable oil refining F-T (any carbon source) Tropsch_process Methane Gasification Fermentation Pyrolysis Biogasoline Aqueous Phase Reforming (sugars) Hydrogen Gasification, pyrolysis Bacteria Throstur Thorsteinsson (ThrosturTh@hi.is) 6

7 Biofuels - history Biofuels today First generation Biodiesel from energy crops and animal fat Ethanol from sugars and starch Second generation Ethanol from cellulose (cheaply!) Third generation Anaerobic bacteria Algae Ethanol Biodiesel PROS Carbon neutral (?) Can utilize existing infrastructure - mix in gasoline Less pollution Can use waste Well known tech (!) Energy source, not energy carrier CONS Food vs. fuel Pollutes (CO 2 ) Land use Upper limit on production Production can depend on weather Energy balance not great sometimes PROS Carbon neutral Can utilize existing infrastructure - mix in regular diesel Less pollution and good for engine Can use waste Well known tech Energy source, not energy carrier CONS Food vs. fuel Pollutes Land use Upper limit on production Production can depend on weather Energy balance not great sometimes methyl linoleate Methane Biogasoline PROS Carbon neutral Less pollution Can use waste Produced in landfills Well known tech Energy source, not energy carrier CONS Pollutes (a little) Needs new infrastructure Upper limit on production PROS Carbon neutral (?) Can utilize existing infrastructure - is gasoline Less pollution Can use waste Energy source, not energy carrier CONS Food vs. fuel Pollutes Land use Upper limit on production Production can depend on weather New tech Throstur Thorsteinsson (ThrosturTh@hi.is) 7

8 Biomass Biomass classification 11% of total world energy consumption. In developing countries on average 35% comes from biomass (19% in China) but in very poor countries such as e.g. Bangladesh biomass account for up to 90% of energy supply. A)Plant Biomass a) Woody biomass: Trees and shrubs, bamboo, palms b) Non-woody biomass: sugarcane, cotton, stems and roots, grass etc c) Processed waste: Corn husks, nut shells, sawmill waste, industrial wood waste, black liquor from pulp mills, municipal waste. d) Processed fuels: charcoal, wood alcohol (ethanol), plant oil, biogas B)Animal Biomass: Manure Issues Biofuel by feedstock used Biomass is often perceived as a fuel of the past because of: Low efficiency Energy density low, EROI low - implications for: land use Water use -water already is scarce Water quality Soil fertility thus management practices MUST be sustainable Biodiversity impacts Pollution and unpredictable quality Particulate pollution, water quantity in biomass Association with poverty Poor mans fuel Drop in global grain stocks Factors Short term Extreme weather conditions (cereals, milk) Some production decline in important exporting countries (Argentina: milk; EU: milk) Low stocks Long term Growing food demand in emerging economies Higher production costs: oil price Demand for biofuels Throstur Thorsteinsson (ThrosturTh@hi.is) 8

9 Consumption gains Feedstock requirements for bio fuels become a major new source of demand Whole Milk Powder Food security and biofuels Poor countries import Hunger, malnutrition have economic causes: income, food prices Bioefuels affect food security in developing countries through income generated in domestic biofuel production world price impact of biofuel production in OECD countries Rising world price of food benefits producers, harms consumer Poor urban consumers are negatively affected by rising food prices Many poor farmers in developing countries are net food consumers Overall, developing countries are net importers of food, in particular cereals (in 2016: 143 mill tonnes, excl. rice) Africa in particular is a net importer (SSA in 2016: 18 mill tonnes, excl. rice Country size cereal net exports Policies Biofuel demand in OECD countries is largely driven by policies (subsidies, tax breaks, blending requirements, ) These policies raise demand for agricultural products and world prices of food and harm food consumers Country size in proportion to cereal net exports OECD tariffs harm biofuels producers in developing countries Throstur Thorsteinsson (ThrosturTh@hi.is) 9

10 OECD Policies benefits OECD summary Energy security? Fighting climate change? Improving the environment? Supporting rural development? Creating economic benefits? Superior to improving energy efficiency? Current hike of world food prices is in part result of production shortfalls, transitory but also reflects growth of biofuel use which is expected to accelerate largely as result of rich country policies with questionable benefits and negative impacts on food security Barrier to biomass use Uncompetitive costs unless the input the biomass is free not yet competitive with oil, gas or coal as of yet. This can be fixed via technological development. Relatively inefficient (low EROI) Has socioeconomic implications Low public acceptability Potentially large environmental impacts Competition for land use w/ agriculture e.g. Water use Biomass to electricity (USA) Type of Biomass # Installations Capacity (MW) Wood Pulping liquor Bagasse and other agricultural residue Digester Gas Landfill Gas Tires 3 69 Total (+ other) Source: Adapted From Table 5-2 T.C. Schweizer, et al., EPRI Report No. TR (1998). Challenges Low heat to power efficiency of combustion steam turbines 18-24% (14,000-19,000 Btu/kWh) Supply stability and economics Alkali and other trace metal deposits and emissions Particulate Deposits and Emissions NO x Emissions Cost of Electricity $ /kWh Lower Energy Density Oxygen = wt % dry basis Use of Land, Water, Nutrients Displacement of Higher Value Crops Biogas ~ ½ CH 4, ½ CO 2 From Anaerobic Digestion of wet Biomass Animal, Human Wastes Sewage Sludge Crop Residues NOT Lignin By-Products: Nitrogen-rich Sludge (Fertilizer) and Fewer Pathogens Extensive Use in India and China (Millions of Digesters); Industrialized Countries (Stockyards, Municipal Sewage, ~5000 Digestors) Major Goals Environmental Neutralization of Waste Fertilizer From Waste Throstur Thorsteinsson (ThrosturTh@hi.is) 10

11 Opportunities for biomass Reducing Greenhouse Gas CO 2 Restoring Forest Resources Renewable Carbon Source for Energy Future Dominated by Non-Carbon Based Electricity, e.g. Nuclear, Geothermal, and Solar. Biomass Becomes Significant Raw Material for: Liquid Hydrocarbon Fuels Chemicals Other High Value Products Summary Biomass to electricity and fuels: R&D Opportunities and challenges Increasing Conversion Efficiency Better catalysts Lower land and water use impacts Harvesting and processing Municipal and food processing residuals provide opportunities Scarcity of landfills Concerns about disease vectors and toxins Environmental effects of biomass utilization warrant careful scrutiny needs LCA approaches Advantages Countermeasure to Global Climate Forcing by Fossil CO 2 Renewable Carbon Source for Premium Products Ecosystem Management: Forests, Water Facilitate Transition to Lower Fossil Contribution Genetically Tailored Crops: Sunshine-to-Gasoline Economics still is a Major Challenge Iceland Þorvaldseyri - repjurækt Thermochemical, chemical, PROCESSES Thermochemical processes Thermochemical processes.. Biomass combustion Process where carbon and hydrogen in the fuel react with excess oxygen to form CO 2 and water and release heat. Direct burning of biomass is popular in rural areas for cooking. Wood and charcoal are also used as a fuel in the industry. Combustion processes are well understood and a wide range of existing commercial technologies are tailored to the characteristics of the biomass and the scale of their applications. Biomass can also be co-combusted with coal in coal-fi red plants (van Loo and Koppejan, 2002; Faaij, 2006; Egsgaard et al., 2009). Pyrolysis The thermal decomposition of biomass occurring in the absence of oxygen that produces a solid (charcoal), a liquid (pyrolysis oil or bio-oil) and a gas product. The relative amounts of the three co-products depend on the operating temperature and the residence time used in the process. High heating rates of the biomass feedstocks at moderate temperatures (450 C to 550 C) result in oxygenated oils as the major products (70 to 80%), with the remainder split between a biochar and gases. Slow pyrolysis (also known as carbonization) is practiced throughout the world, for example, in traditional stoves in developing countries, in barbecues in Western countries, and in the Brazilian steel industry (Bridgwater et al., 2003; Laird et al., 2009). Throstur Thorsteinsson (ThrosturTh@hi.is) 11

12 Thermochemical processes Chemical processes Biomass Gasification Occurs when a partial oxidation of biomass happens upon heating. This produces a combustible gas mixture rich in CO and hydrogen (H 2 ) that has an energy content of 5 to 20 MJ/Nm 3 This energy content is roughly 10 to 45% of the heating value of natural gas. Fuel gas can then be upgraded to a higher-quality gas mixture called biomass synthesis gas or syngas (Faaij, 2006). Transesterification The process through which alcohols (often methanol) react in the presence of a catalyst (acid or base) with triglycerides contained in vegetable oils or animal fats to form an alkyl ester of fatty acids and a glycerine by-product. The hydrogenation of vegetable oil, animal fats or recycled oils in the presence of a catalyst yields a renewable diesel fuel-hydrocarbons that can be blended in any proportion with petroleum-based diesel and propane as products. This process involves reacting vegetable oil or animal fats with H2 (typically sourced from an oil refinery) in the presence of a catalyst (Bauen et al., 2009a). Throstur Thorsteinsson (ThrosturTh@hi.is) 12