Review and Assessment of Commercial Vendors/Options for Feeding and Pumping Biomass Slurries for Hydrothermal Liquefaction

The National Advanced Biofuels Consortium is working to develop improved methods for producing high-value hydrocarbon fuels. The development of one such method, the hydrothermal liquefaction (HTL) process, is being led by the Pacific Northwest National Laboratory (PNNL). The HTL process uses a wet biomass slurry at elevated temperatures (i.e., 300 to 360°C [570 to 680°F]) and pressures above the vapor pressure of water (i.e., 15 to 20 MPa [2200 to 3000 psi] at these temperatures) to facilitate a condensed-phase reaction medium. The process has been successfully tested at bench-scale and development and testing at a larger scale is required to prove the viability of the process at production levels. Near-term development plans include a pilot-scale system on the order of 0.5 to 40 gpm, followed by a larger production-scale system on the order of 2000 dry metric tons per day (DMTPD). A significant challenge to the scale-up of the HTL process is feeding a highly viscous fibrous biomass wood/corn stover feedstock into a pump system that provides the required 3000 psi of pressure for downstream processing. In October 2011, PNNL began investigating commercial feed and pumping options that would meet these HTL process requirements. Initial efforts focused on generating a HTL feed and pump specification and then providing the specification to prospective vendors to determine the suitability of their pumps for the pilot-scale and production-scale plants. Six vendors were identified that could provide viable equipment to meet HTL feed and/or pump needs. Those six vendors provided options consisting three types of positive displacement pumps (i.e., diaphragm, piston, and lobe pumps). Vendors provided capabilities and equipment related to HTL application. This information was collected, assessed, and summarized and is provided as appendices to this report

Material Balance Assessment for Double-Shell Tank Waste Pipeline Transfer

PNNL developed a material balance assessment methodology based on conservation of mass for detecting leaks and mis-routings in pipeline transfer of double-shell tank waste at Hanford. The main factors causing uncertainty in these transfers are variable property and tank conditions of density, existence of crust, and surface disturbance due to mixer pump operation during the waste transfer. The methodology was applied to three waste transfers from Tanks AN-105 and AZ-102

Shear Strength Measurement Benchmarking Tests for K Basin Sludge Simulants

Equipment development and demonstration testing for sludge retrieval is being conducted by the K Basin Sludge Treatment Project (STP) at the MASF (Maintenance and Storage Facility) using sludge simulants. In testing performed at the Pacific Northwest National Laboratory (under contract with the CH2M Hill Plateau Remediation Company), the performance of the Geovane instrument was successfully benchmarked against the M5 Haake rheometer using a series of simulants with shear strengths (τ) ranging from about 700 to 22,000 Pa (shaft corrected). Operating steps for obtaining consistent shear strength measurements with the Geovane instrument during the benchmark testing were refined and documented

Final Report One-Twelfth-Scale Mixing Experiments to Characterize Double-Shell Tank Slurry Uniformity

The objectives of these 1/12-scale scoping experiments were to Determine which of the dimensionless parameters discussed in Bamberger and Liljegren (1994) affect the maximum concentration that can be suspended during jet mixer pump operation in the full-scale double-shell tanks Develop empirical correlations to predict the nozzle velocity required for jet mixer pumps to suspend the contents of full-scale double-shell tanks Apply the models to predict the nozzle velocity required to suspend the contents of Tank 241 AZ-101 Obtain experimental concentration data to compare with the TEMPEST( )(Trent and Eyler 1989) computational modeling predictions to guide further code development Analyze the effects of changing nozzle diameter on exit velocity (U0) and U0D0 (the product of the exit velocity and nozzle diameter) required to suspend the contents of a tank. The scoping study experimentally evaluated uniformity in a 1/12-scale experiment varying the Reynolds number, Froude number, and gravitational settling parameter space. The initial matrix specified only tests at 100% U0D0 and 25% U0D0. After initial tests were conducted with small diameter, low viscosity simulant this matrix was revised to allow evaluation of a broader range of U0D0s. The revised matrix included full factorial test between 100% and 50% U0D0 and two half-factorial tests at 75% and 25% U0D0. Adding points at 75% U0D0 and 50% U0D0 allowed evaluation curvature. Eliminating points at 25% U0D0 decreased the testing time by several weeks. Test conditions were achieved by varying the simulant viscosity, the mean particle size, and the jet nozzle exit velocity. Concentration measurements at sampling locations throughout the tank were used to assess the degree of uniformity achieved during each test. Concentration data was obtained using a real time ultrasonic attenuation probe and discrete batch samples. The undissolved solids concentration at these locations was analyzed to determine whether the tank contents were uniform ( ±10% variation about mean) in concentration. Concentration inhomogeneity was modeled as a function of dimensionless groups. The two parameters that best describe the maximum solids volume fraction that can be suspended in a double-shell tank were found to be 1) the Froude number (Fr) based on nozzle velocity (U0) and tank contents level (H) and 2) the dimensionless particle size (dp/D0). The dependence on the Reynolds number (Re) does not appear to be statistically significant

Pulse Jet Mixing Tests With Noncohesive Solids

This report summarizes results from pulse jet mixing (PJM) tests with noncohesive solids in Newtonian liquid conducted during FY 2007 and 2008 to support the design of mixing systems for the Hanford Waste Treatment and Immobilization Plant (WTP). Tests were conducted at three geometric scales using noncohesive simulants. The test data were used to independently develop mixing models that can be used to predict full-scale WTP vessel performance and to rate current WTP mixing system designs against two specific performance requirements. One requirement is to ensure that all solids have been disturbed during the mixing action, which is important to release gas from the solids. The second requirement is to maintain a suspended solids concentration below 20 weight percent at the pump inlet. The models predict the height to which solids will be lifted by the PJM action, and the minimum velocity needed to ensure all solids have been lifted from the floor. From the cloud height estimate we can calculate the concentration of solids at the pump inlet. The velocity needed to lift the solids is slightly more demanding than "disturbing" the solids, and is used as a surrogate for this metric. We applied the models to assess WTP mixing vessel performance with respect to the two perform¬ance requirements. Each mixing vessel was evaluated against these two criteria for two defined waste conditions. One of the wastes was defined by design limits and one was derived from Hanford waste characterization reports. The assessment predicts that three vessel types will satisfy the design criteria for all conditions evaluated. Seven vessel types will not satisfy the performance criteria used for any of the conditions evaluated. The remaining three vessel types provide varying assessments when the different particle characteristics are evaluated. The assessment predicts that three vessel types will satisfy the design criteria for all conditions evaluated. Seven vessel types will not satisfy the performance criteria used for any of the conditions evaluated. The remaining three vessel types provide varying assessments when the different particle characteristics are evaluated. The HLP-022 vessel was also evaluated using 12 m/s pulse jet velocity with 6-in. nozzles, and this design also did not satisfy the criteria for all of the conditions evaluated

Review and Assessment of Commercial Vendors/Options for Feeding and Pumping Biomass Slurries for Hydrothermal Liquefaction

The National Advanced Biofuels Consortium is working to develop improved methods for producing high-value hydrocarbon fuels. The development of one such method, the hydrothermal liquefaction (HTL) process, is being led by the Pacific Northwest National Laboratory (PNNL). The HTL process uses a wet biomass slurry at elevated temperatures (i.e., 300 to 360°C [570 to 680°F]) and pressures above the vapor pressure of water (i.e., 15 to 20 MPa [2200 to 3000 psi] at these temperatures) to facilitate a condensed-phase reaction medium. The process has been successfully tested at bench-scale and development and testing at a larger scale is required to prove the viability of the process at production levels. Near-term development plans include a pilot-scale system on the order of 0.5 to 40 gpm, followed by a larger production-scale system on the order of 2000 dry metric tons per day (DMTPD). A significant challenge to the scale-up of the HTL process is feeding a highly viscous fibrous biomass wood/corn stover feedstock into a pump system that provides the required 3000 psi of pressure for downstream processing. In October 2011, PNNL began investigating commercial feed and pumping options that would meet these HTL process requirements. Initial efforts focused on generating a HTL feed and pump specification and then providing the specification to prospective vendors to determine the suitability of their pumps for the pilot-scale and production-scale plants. Six vendors were identified that could provide viable equipment to meet HTL feed and/or pump needs. Those six vendors provided options consisting three types of positive displacement pumps (i.e., diaphragm, piston, and lobe pumps). Vendors provided capabilities and equipment related to HTL application. This information was collected, assessed, and summarized and is provided as appendices to this report

Material Balance Assessment for Double-Shell Tank Waste Pipeline Transfer

PNNL developed a material balance assessment methodology based on conservation of mass for detecting leaks and mis-routings in pipeline transfer of double-shell tank waste at Hanford. The main factors causing uncertainty in these transfers are variable property and tank conditions of density, existence of crust, and surface disturbance due to mixer pump operation during the waste transfer. The methodology was applied to three waste transfers from Tanks AN-105 and AZ-102

Assessment of Jet Erosion for Potential Post-Retrieval K-Basin Settled Sludge

Packaged K-Basin sludge will be transported to the T Plant on the Hanford Site where it will be interim stored. The sludge will be retrieved from the storage containers and processed for disposal. A sample of high uranium content canister sludge, designated 96-13, "self-cemented" during laboratory storage. This sample was uncharacteristically strong compared to expected K-Basin material. The purpose for this work is to evaluate the potential retrieval of such sludge after storage at the T Plant via jet erosion. The specific objectives of this report are to determine the modes of erosion and the methods used to measure/assess the erodibility parameters of sludge and identify those parameters applicable to jet erosion. The erodibility parameters of sample 96-13 are characterized to the extent possible. These objectives have been met based on literature review, past experience at Pacific Northwest National Laboratory, and observation of sample 96-13 video during hot-cell activities

NON-NEWTONIAN FLUID CAVERN AND NEWTONIAN CLOUD HEIGHT TESTS TO CHARACTERIZE PULSE JET MIXER OPERATION AJK2011-0

ABSTRACT Pulse jet mixing systems are being developed for use in the Waste Treatment Plant in Washington State. To assist with system development, scaled tests were conducted to obtain experimental measurements of the cloud height for Newtonian slurries and cavern heights for a Non-Newtonian yield stress material. The measurements were required to assess the effective mixing and material mobilization produced during pulse jet mixer operation. The cloud height measurements were obtained for a single steady-state jet directed downward in a spherical-bottom tank. The cloud tests used glass beads in water to evaluate the height of the suspended slurry as a function of jet velocity. Cloud testing revealed that the glass bead material was suspended in the tank quickly and developed a distinctive height for each combination of flow rate and particulate size tested. The solids loading had minimal impact on the cloud height for a given particle size. During all cloud tests, the surface of the tank remained relatively calm, indicating that the slurry was dissipating the mixing energy of the relatively high velocity jet. Cavern tests were conducted to obtain experimental data of non-Newtonian fluid mixing for fluid properties similar to those of certain tank wastes. A transparent material that exhibited a yield stress and shear thinning behavior was used to obtain measurements of steady-state cavern heights as a function of jet velocity. For the non-Newtonian fluid cavern tests, distinct cavern volumes were readily developed for the four velocities tested. A linear relationship was observed to exist between cavern height and nozzle velocity. Since the experimental work detailed in this paper was completed, additional scaled tests have been conducted with pneumatic drive systems and direct drive systems similar to that described for this effort. Data from both types of measurements are shown to be linear; however, effects from the reciprocating drive systems that are not yet incorporated into models may be affecting the ability to collapse this data independent of scale. It is recommended that future efforts to assess performance of PJM operations using scaled tests consider employing direct drive systems to aid in evaluating scaling trends. A test system can be configured to allow testing at both reciprocating and direct drive conditions; thereby allowing direct comparison between them

Shear Strength Measurement Benchmarking Tests for K Basin Sludge Simulants

Equipment development and demonstration testing for sludge retrieval is being conducted by the K Basin Sludge Treatment Project (STP) at the MASF (Maintenance and Storage Facility) using sludge simulants. In testing performed at the Pacific Northwest National Laboratory (under contract with the CH2M Hill Plateau Remediation Company), the performance of the Geovane instrument was successfully benchmarked against the M5 Haake rheometer using a series of simulants with shear strengths (τ) ranging from about 700 to 22,000 Pa (shaft corrected). Operating steps for obtaining consistent shear strength measurements with the Geovane instrument during the benchmark testing were refined and documented