The energy-waste nexus

Transcription

1 The energy-waste nexus Joshua Rhodes, PhD The Webber Energy Group The University of Texas at Austin Turning Waste Streams Into Energy Is An Untapped Opportunity Waste Water: Biogas or algal biofuels or soil amendments (Dillo Dirt) Waste Restaurant Grease: Biodiesel Agricultural Waste: Biogas or solid fuel pellets Municipal Solid Waste: Biogas or solid fuel pellets Unrecycled Plastics: Solid fuel pellets Food Waste: Biogas Waste Heat: Thermoelectric generation CO2 Waste: 6 Gt/yr in USA alone could be used for EOR & crop growth, Nuclear Waste: Reprocess into new fuels 2 1

2 Of the 250 million tons of MSW, about half is landfilled; the rest is recycled, composted or incinerated 2011 U.S. Annual Solid Waste Flow [Million Tons] Source: U.S. EPA Graphic: Michael E. Webber, The University of Texas at Austin Total Materials Recovery 86.9 Recovery For Recycling 66.2 Recovery For Composting 20.7 Total Materials Recycled 58.2 Returned to Landfill 8 Total MSW Generation Discards After Recovery Discards To Landfill Total MSW To Landfill Combustion to Energy Recovery Getting in the gas game natural gas from MSW US MSW Materials Generation, 254 Million Tons 9 % 6.2 % 12.8 % 13.5 % 27 % 14.6 % Category Food Glass Metals Other Paper Plastics Rubber, Leather & Textiles Wood Yard Trimmings 4.5 % 9.1 % 3.3 % Houston is ~2% of US population MSW (that can be digested) would yield 28 Bcf gas/yr 0.1% US usage *,** Prices of biogas from MSW range: $5.75-9/MMBTU *** * ** CommercialFoodWasteCollectionStudy2015.pdf *** 4 files/publications/ni_r_14-02_full_pdf.pdf 2

3 6/7/16 Henry Hub Spot Price ($/MMBTU) A carbon price can help biogas methane 12 AEO 2016 projection AEO 2016 projection + $80/ton CO2 Projected data* 10 Est. cost to produce biogas from MSW** * ** 02_full_pdf.pdf Year 5 Some MSW/forestry residue can also be directly burned for fuel Nacogdoches Biomass Plant 114 MW capacity ~45k homes peak Is expensive to run ~$50/MWh ERCOT average: $35/MWh 2014 capacity factor: 16%* With carbon tax, would increase * 6 3

4 6/7/16 Solid Recovered Fuel (SRF) Pellets Can Be Used To Displace Fossil Fuels John Fyffe John Fyffe EXPERIMENTAL RESULTS Recovered plastics can be an energy dense fuel 3.3. MANUFACTURING VARIABLES AND CHALLENGES Can produce more energy per lb than some types of coal Figure 5.1: The photo of the final SRF material that was analyzed that shows the heterogeneous nature of SRF (Photo credit: Total Petrochemicals & Refining USA, Inc.). Figure 3.3: The fuel extruder compresses the raw material before forcing it out radially through adjustable dies. Heat caused by compression and friction can fuse the material, and additional process heat can be added if needed. Shown here are various lengths of SRF being extruded through 1.25 by 1.25 dies with no heat added. Figure 5.2: This photo is a close up of the final SRF material sent from TXI to be tested (Photo credit: Total Petrochemicals & Refining USA, Inc.). Lower sulfur content, lowhigh chlorine Lower CO2 & SO2, higher NOx 5% energy reduction at cement kilns 8 43 Figure 3.4: This figure is a close up shot of SRF being extruded out the bottom of the fuel extrusion equipment and onto a conveyor belt. The SRF either breaks apart in sections from the weight of the fuel itself or from being pulled along by the conveyor belt. 31 4

5 Joshua Rhodes, PhD The energy-waste The breakeven costs of shale gas plays will make biogas from MSW difficult Henry Hub Price (5/17/2016) Mancos Marcellus WV T2 Henry Hub Price + $80 CO 2 San Juan CBM Eagle Ford Dry Gas Barnett Core Dry Cost to produce CH 4 from biogas ** Barnett Core Wet Haynesville Tier 1 Haynesville Core Horn River SW Marcellus Wet Breakeven cost to produce gas $/MMBTU* *Industry Watch, Oil and Gas, Winter 2015 CRITICAL UPDATE ** 02_full_pdf.pdf 10 5