MOBILIZING FOREST RESIDUES

Transcription

1 MOBILIZING FOREST RESIDUES WATER/BIOENERGY NEXUS IN LARGE-SCALE UTILIZATION OF FOREST RESIDUES AS FEEDSTOCKS FOR HYDROTHERMAL PRODUCTION OF ENERGY COMMODITIES Northern River Basins Study (1996) Geoff Whitfield Bio-GHG Management Program, Expert Advisory Committee 06/11/2014 1

2 ENERGY COMMODITIES Power and Combined Heat and Power (CHP) Thermal energy Liquid, solid, gaseous fuels THERMOCHEMICAL PATHWAYS FOR PRODUCTION OF ENERGY COMMODITIES FROM BIOMASS Gasification: with and without co-gasification of coals and/or petcoke Catalyzed gasification: (for example) substitute natural gas (SNG) Liquefaction: Bio-crude oil fungible with fossil carbon-based synthetic crudes Drop-in fuels Carbonization (torrefaction): Bio-coals 11/6/2014 2

3 CASE STUDY: HYDROTHERMAL LIQUEFACTION (HTL) Upgrading of Bio-crude from Hydrothermal Liquefaction, Aalborg University (2013) Biomass dissolved and liquefied to produce bio-oil, gas and water with dissolved organics [O] 85% of oxygen in biomass removed as CO 2 and H 2 O Hydrotreatment to produce bio-oil fungible with fossil carbon-based synthetic crudes 06/11/2014 3

4 WATER AS REAGENT Critical point Gasification, Liquefaction and Deoxy-Liquefaction of Switchgrass using Sub- and Supercritical Water 06/11/2014 4

5 COMPARISON OF HTL AND FAST PYROLYSIS PATHWAYS TO BIO-OILS #6 RFO H/C (dry basis) Woody biomass #6 RFO Fas pyrolysis Hydrothermal liquefaction Biomass 1.40 Van Krevelen diagram Fast pyrolysis HTL crude O/C (dry basis) Comparison of bio-oils derived from fast pyrolysis and hydrothermal liquefaction by [2] NMR, PNNL (Sept. 04,2014) 06/11/2014 5

6 HYDROTHERMAL LIQUEFACTION SCHEMATIC Water conserved Water produced: Techno-economic analysis of liquid fuel production from woody biomass via hydrothermal liquefaction (HTL) and upgrading, Pacific Northwest National Laboratory (2014) Characteristics of this stream is the focus of this discussion 11/6/2014 6

7 PROCESS WATER BALANCE ASSOCIATED WITH HYDROTHERMAL LIQUEFACTION Conservation of 100 kg water/100 kg dry biomass processed by not drying wet biomass at 50% moisture content Produced water: Net production (kg/100 kg dry wood fed) 10.0 Nominally 5kg water produced/ 100 kg dry biomass processed Process water consumption (L/L product) Techno-economic analysis of liquid fuel production from woody biomass via hydrothermal liquefaction (HTL) and upgrading, Pacific Northwest National Laboratory (2014) 06/11/2014 7

8 CHARACTERISTICS OF PRODUCED WATER Pacific Northwest National Laboratory (PNNL) data: COD of the aqueous phase in the range of 50,000 to 70,000 mg/l, up to as high as 100,000 mg/l Feed buffered with sodium carbonate to maintain a ph > 4 Confirmed by academic data: TOC (mg/l) ph Cellulose 14, Xylan 13, (averages of 4 experimental states) (COD = K x TOC; K 4) Lignin 4, Primary components: Sodium salts of glycolic acid acetic acid and propanoic acid. Acetone, methanol and ethanol Low concentrations of lignin products such as guical and catecol detected by GC-MS 06/11/2014 8

9 INSTALLATION OF BIO-OIL PRODUCTION INTO AN EXISTING PULP MILL Characteristics of influent at two hardwood-based bleached Kraft pulp mills Thermophillic Aerobic Biological Treatment of Bleached Kraft Pulp Mill Effluent and its Effect on Floc Formation and Settleability, University of Toronto (1999) A guard process block may be required between a bio-oil production facility located at an existing pulp mill and the parent facility 06/11/2014 9

10 SUMMARY: WATER MATTERS Water is conserved and produced in the production of fuels from biomass through hydrothermal liquefaction Produced water presents significant treatment requirements in order to meet standards: Recovery of valuable chemicals from the wastewater stream may offset compliance costs References consulted in order to understand context: 1. Northern River Basins Study (1996) 2. Synthesis of Ecological Information Related to the Peace-Athabasca Delta, AECOM (March 2010) 3. Alberta s Forest Sector Water CEP Plan, Alberta Forest Products Association (2011) 06/11/