Provide a process alternatives evaluation and detailed process design package for a flexible scrubber system to remove a variety of biomass derived pyrolysis oils.
PROCESS DESIGN FOR PILOT-SCALE PYROLYSIS SCRUBBER PROCESS
Process Engineering Associates, LLC (PROCESS) was contracted by the client, Alliance for Sustainable Energy, LLC (part of the National Renewable Energy Laboratory – NREL) to provide a Front-End Loading Level 3 (FEL-3) process design package for a proposed scrubber process in the Thermochemical Process Development Unit (TCPDU). The TCPDU is a pilot scale process for the thermochemical conversion of biomass to fuels. Due to the TCPDU’s evolving objectives and capabilities, the TCPDU requires a scrubber process that can collect pyrolysis oil product from both fast pyrolysis and catalytically upgraded pyrolysis processes.
PROCESS performed the following project tasks:
- An alternatives evaluation was performed and submitted for the client’s consideration. PROCESS pursued a design selected by the client that is similar to the TCPDU’s existing scrubber and incorporates two identical trains that have the flexibility to operate either in series or in parallel, to accommodate the R&D nature of the TCPDU.
- Heat and material balance (HMB) calculations and a process flow diagram (PFD) were prepared for the new scrubber process. This involved detailed review of existing R&D data as well as actual process data from the existing scrubber process in an effort to define a potential envelope of operation for processing a highly variable feed pyrolysis vapor stream to the new scrubber process. PROCESS generated a design case based on the data provided by the client. PROCESS used its licensed commercial computer process simulation software (Chemstations’ CHEMCAD) to perform sensitivity analyses and generate HMB calculations for several production cases.
- Preliminary top-view and side-view equipment layout drawings were generated. PROCESS visited the TCPDU and collected data from the existing scrubber process as well as reviewed the proposed indoor location for the new scrubber. The ascertained preliminary equipment sizing and space envelope dimensions were represented to scale in the preliminary equipment layout drawings.
- A preliminary capital cost estimate was prepared using equipment sizing data.
- A full set of piping and instrumentation diagrams (P&IDs) for the process was produced. From the P&IDs, instrument and valve lists were generated for all instruments and valves associated with the PLC control system. The lists also provided pertinent information for data sheet specifications.
- Process duty data sheets were produced for all major equipment including vessels, heat exchangers, chillers, filters, pumps, and relief valves. Heat demands from the HMB were used to calculate utility requirements for cooling water supply to the heat exchangers and chillers. The energy balance portion of the HMB was used to calculate utility usage quantities for heating requirements. System pressures and flow rates from the HMB were used to generate pump and relief valve requirements.
A complete FEL-3 package that included the above-mentioned documentation was issued to the client. The FEL-3 package provides information that can be carried forward to a more detailed mechanical design phase, particularly for the purpose of issuing for bids to construct. The detailed design phase will be contracted to an EPC firm, and indication from the client is that they intend to continue contracting PROCESS to provide support services under the EPC firm.
- Biomass Alternative Fuels Research & Development
- Process alternatives evaluation
- Scrubber design
- Detail process design package development