Modifying a Davison Circulating Riser to accommodate biomass-derived feedstocks

Transcription

1 Modifying a Davison Circulating Riser to accommodate biomass-derived feedstocks Jessica Olstad, Mark Jarvis, Yves Parent, Kim Magrini, Brady Peterson, Mike Sprague, & Glenn Powell tcbiomass 2017, Chicago, IL September 21, 2017

2 Background Decreasing petroleum resources, increasing energy demand, and environmental concerns need for biomass-derived resources Using existing petroleum refining infrastructure is an attractive option o Lower capital investment o Co-process petroleum/bio-products reduction in Green House Gases (GHG) 2

3 What is FCC? FCC = Fluid Catalytic Cracking unit o VGO + E-Cat Gasoline Used widely in petroleum industry DCR is small scale FCC o Operated adiabatically o Temperatures, catalyst/oil ratios, final products are comparable Work done at the DCR scale is directly relatable to commercial scale 3

4 Differences Between VGO and Pyrolysis Vapor Feeds VGO Vapor Feed* Carbon in feed (g/hr) Molecular weight of feed (g/mol) Cat:Feed (VGO or biomass) 7 to 8 35 *Biomass:N 2 ratio = 1 VGO Oxygen present in vapor feed Pyrolysis Vapor 4

5 Biomass Vapor Upgrading Operational differences between feeding liquid feedstock (VGO) and vapors to DCR: Feed carbon density Feed molecular weight Different catalyst fluidization & more gas in feed stream o Reduced contact time o Increased mass transfer o Diluent effects Reduce compound densities 1-Ring Naphthenic & Olefins VGO + VGO Ecat + Ecat 3-Ring Aromatics 2-Ring Aromatics 2-Ring Aromatics 1-Ring Naphthenic & Olefins 1-Ring Aromatics 2-Ring Naphthalene Paraffin & Isoparaffins VGO + E-Cat + N 2 3-Ring Aromatics 1-Ring Aromatics 2-Ring Naphthalene Paraffin & Isoparaffins 5

6 DCR Modifications to Operate with Pyrolysis Vapors VENT HOT PYROLYSIS VAPORS STRIPPER CONDENSER BIOMASS FEED SYSTEM REGENERATOR FLUIDIZEDBED REACTOR GAS PRODUCT motor FILTER LOCK HOPPER CHAR HANDLING AIR motor SCRUBBER/ SEPARATOR TOP PHASE MIDDLE PHASE LIQUID PRODUCT BOTTOM PHASE AIR motor QUENCHFLUID PUMP N2 STEAM LIQUID PRODUCT Operational issues to be discussed: Catalyst loss Fractional condensation REACTOR OIL FEED SYSTEM 6

7 Original DCR Condensation System Stripper (1) Vapor Outlet Stabilizer is reflux-style condenser: Heat Exchanger (HX) Bypass Stabilizer (2) (1) Head chilled with internal refrigeration coil (-12 C) (2) Packed bed (ceramic saddle packing, ¼ ) Column gives fairly good C 4 -C 5 product split Liquid Collection 7

8 Issue: Catalyst Capture & Return Stripper Vapor Outlet Problem: Catalyst escaped stripper, mixed with condensed product in heat exchanger, caused blockage Bypass HX Stabilizer Liquid Collection Solution: Installed cyclone on stripper exit to catch and return catalyst *Still lose catalyst fines, but can operate for extended periods without blockages 8

9 Issue: Inadequate Product Condensation HX ESP Cold Finger Coalescing Filter Vapor Outlet Stripper (Vapor) Problem: Minimal product collection; material accumulates in stabilizer, doesn t drain to collection vessel Solution: Installed fractional condenser (Liquid) Bypass Liquid Collection Stabilizer 9

10 Fractional Condenser (FC) Results Carbon Efficiency* Without FC 5.9 With FC 31.9 *Biomass to recoverable liquid hydrocarbon VGO (wt%) Vapor (wt%) Heat Exchanger ESP Cold Finger 3.2 * Coalescing Filter Stabilizer 13.2 ** *Coalescing filter value added to HX value **Amount collected was negligible Collected fractions from VGO + E-Cat experiment 10

11 Summary Liquid (VGO) and pyrolysis vapor feeds are very different o Result in different operating parameters Multiple modification iterations required o Solids cyclone Operate for extended periods without catalyst blockages o Fractional condensation Effectively condense and collect liquid product Fractional condenser (FC) significantly improves product collection o Biomass to hydrocarbon C efficiency without FC = 5.9 o Biomass to hydrocarbon C efficiency with FC = 31.9 Products are potentially refinery compatible 11

12 Acknowledgements Funding Bioenergy Technologies Office (BETO) Office of Energy Efficiency & Renewable Energy (EERE) VPU Crew Mark Jarvis Yves Parent Brady Peterson Mike Sprague Glenn Powell Managers Kim Magrini Mark Nimlos Adam Bratis EHS Dennis Smith Doug Herrick 12