Air and Steam Gasification of Almond Biomass

Experiments were performed on a laboratory scale fluidized bed gasifier to characterize the gasification products of almond shell and hull removed in nut processing operations and to determine the effect of gasifying media on bed agglomeration. The higher heating value of syngas during air gasification of almond biomass ranged from 4 to 6 MJ m(-3) while gas concentrations ranged from 14 to 18% H-2, 3-4% CH4, 43-50% N-2, 16-19% CO, and 16-17% CO2. For steam gasification, higher heating value was 10-12 MJ m(-3) and gas concentrations were 35-40% H-2, 5-7% CH4, 17-21% N-2, 18-21% CO, and 16-18% CO2. The high level of potassium in the almond shells led to strong corrosion and bed agglomeration due to flue gas transport of potassium compounds. These resulting pervasive kalsilite reactions were significantly worse under air gasification than under steam gasification. As a result of prolonged duration and elevated temperature approaching 1,000 degrees C, the corrosinal reaction changes to formation of an adhesive potassium distillate melt locally forming strong bonds. This latter is interpreted as a result of aerosol transported of melt particles.California Energy Commission [PIR-07-002, PIR-11-008]; Almond Board of California; USDA-NIFA/UC Agricultural Experiment Station; California Almond Hullers and Processors AssociationThis work was supported by the California Energy Commission [PIR-07-002 and PIR-11-008]. We also acknowledge the generous support of the Almond Board of California, the California Almond Hullers and Processors Association, and USDA-NIFA/UC Agricultural Experiment Station

Inorganic soil and groundwater chemistry near Paducah Gaseous Diffusion Plant, Paducah, Kentucky

Near-surface soils, boreholes, and sediments near the Paducah Gaseous Diffusion Plant (PGDP) were sampled in 1989-91 as were monitoring wells, TVA wells, and privately-owned wells. Most wells were sampled two or three times. The resulting chemical analyses have been published in previous reports and have been previously described (CH2M HILL 1991, 1992; Clausen et al. 1992). The two reports by CH2M HILL are controversial, however, because, the concentrations of some constituents were reported to exceed background levels or drinking water standards and because both on-site (within the perimeter fence at PGDP) and off-site pollution was reported to have occurred. The groundwater samples upon which these interpretations were based may not be representative, however. The CH2M HILL findings are discussed in the report. The purpose of this report is to characterize the inorganic chemistry of groundwater and soils near PGDP, using data from the CH2M HILL reports (1991, 1992), and to determine whether or not any contamination has occurred. The scope is limited to analysis and interpretation of data in the CH2M HILL reports because previous interpretations of these data may not be valid, because samples were collected in a relatively short period of time at several hundred locations, and because the chemical analyses are nearly complete. Recent water samples from the same wells were not considered because the characterization of inorganic chemistry for groundwater and soil requirements only one representative sample and an accurate analysis from each location

Hydrogen Bus Technology Validation Program

Heavy duty engines are substantial contributors to NOX and PM emissions inventories in urban areas, and stringent emissions standards have been adopted as a consequence. CARB has passed very strict emissions standards for heavy duty engines beginning in 2007. Meeting these standards, especially for NOX emissions, may be difficult for conventional transit bus technologies. The purpose of the Hydrogen Bus Technology Evaluation Program was to develop and evaluate hydrogen enriched natural gas (HCNG) engine technology in transit buses and to demonstrate NOX emissions reductions below the CARB 2007 standards. Collier Technologies, Inc. modified a John Deere 8.1 liter natural gas engine to operate on a mixture of 30% hydrogen and 70% natural gas. The engine was tested on a dynamometer to determine emissions and fuel economy, and these values were compared with data from conventional CNG engines. UC Davis developed both an HCNG combustion model to understand the processes inside the engine and a dynamic vehicle model to understand the benefits of HCNG buses. The results indicate that HCNG bus NOX emissions can meet the CARB 2007 standards. Based on information from this program, Collier Technologies has developed a prototype HCNG engine which can be used to retrofit CNG buses

Hydrogen Bus Technology Validation Program

Heavy duty engines are substantial contributors to NOX and PM emissions inventories in urban areas, and stringent emissions standards have been adopted as a consequence. CARB has passed very strict emissions standards for heavy duty engines beginning in 2007. Meeting these standards, especially for NOX emissions, may be difficult for conventional transit bus technologies. The purpose of the Hydrogen Bus Technology Evaluation Program was to develop and evaluate hydrogen enriched natural gas (HCNG) engine technology in transit buses and to demonstrate NOX emissions reductions below the CARB 2007 standards. Collier Technologies, Inc. modified a John Deere 8.1 liter natural gas engine to operate on a mixture of 30% hydrogen and 70% natural gas. The engine was tested on a dynamometer to determine emissions and fuel economy, and these values were compared with data from conventional CNG engines. UC Davis developed both an HCNG combustion model to understand the processes inside the engine and a dynamic vehicle model to understand the benefits of HCNG buses. The results indicate that HCNG bus NOX emissions can meet the CARB 2007 standards. Based on information from this program, Collier Technologies has developed a prototype HCNG engine which can be used to retrofit CNG buses.UCD-ITS-RR-05-29, Civil Engineering

Hydrogen Bus Technology Validation Program

Heavy duty engines are substantial contributors to NOX and PM emissions inventories in urban areas, and stringent emissions standards have been adopted as a consequence. CARB has passed very strict emissions standards for heavy duty engines beginning in 2007. Meeting these standards, especially for NOX emissions, may be difficult for conventional transit bus technologies. The purpose of the Hydrogen Bus Technology Evaluation Program was to develop and evaluate hydrogen enriched natural gas (HCNG) engine technology in transit buses and to demonstrate NOX emissions reductions below the CARB 2007 standards. Collier Technologies, Inc. modified a John Deere 8.1 liter natural gas engine to operate on a mixture of 30% hydrogen and 70% natural gas. The engine was tested on a dynamometer to determine emissions and fuel economy, and these values were compared with data from conventional CNG engines. UC Davis developed both an HCNG combustion model to understand the processes inside the engine and a dynamic vehicle model to understand the benefits of HCNG buses. The results indicate that HCNG bus NOX emissions can meet the CARB 2007 standards. Based on information from this program, Collier Technologies has developed a prototype HCNG engine which can be used to retrofit CNG buses.

Characterization of almond processing residues from the Central Valley of California for thermal conversion

Characterization of biomass relevant to thermochemical conversion processes and other applications is critical to the design and proper operation of energy conversion, biorefining, and other facilities, especially in regard to estimating critical problems related to fouling and slagging from ash constituents. Residue feedstock from almond production was obtained from seven huller and sheller facilities located throughout the Central Valley of California. Results of proximate (moisture, ash, volatile and fixed carbon content), ultimate (C, H, N, S, O composition), heating value, major and trace elements, and melting behavior analyses (all reported on a wt.% dry basis) reveal many similarities and also differences that potentially affect their utilization. The moisture content of air-dried feedstock is an average of 9.7% with only the separated hull material having a higher value (12.2%) and the fine component (1100 degrees C) suggested by pellet fusibility test. (C) 2015 Elsevier B.V. All rights reserved.California Energy Commission; California Institute for Energy and the EnvironmentWe thank Kelly Covello of the Almond Hullers & Processors Association for arranging visits to member facilities throughout the state for interviews and sample collection. This work was funded in part by the California Energy Commission and the California Institute for Energy and the Environment. The XRF analyses were done by Activation Laboratories Ltd, Ontario, Canada, the INAA analyses at the UC Davis McClellan Nuclear Research Center, and the ICPMS analyses at the UC Davis Interdisciplinary Center for Inductively-Coupled Plasma Mass Spectroscopy

Polyhydroxybutyrate Rice Hull and Torrefied Rice Hull Biocomposites

Raw and torrefied rice hulls (RRH and TRH) were incorporated into polyhydroxybutyrate (PHB) as fillers using extrusion and injection molding to produce biomass-polymer composites. Filler and composite materials were characterized by particle size analysis, thermomechanical analysis, thermogravimetric analysis, differential scanning calorimetry, FTIR analysis, CHNSO analysis, and mechanical testing. Heat distortion temperature of the RRH composites were 16–22 °C higher than TRH composites. The RRH composite samples showed a 50–60% increase in flexural modulus and 5% increase in stress at yield compared to PHB, while TRH composite samples showed nearly equal flexural modulus and a 24% decrease in stress at yield. The improved mechanical properties of the RRH composites in comparison to TRH composites were due to better particle-matrix adhesion. FTIR analysis showed RRH particles contained more surface functional groups containing oxygen than TRH particles, indicating that RRHs should be more compatible with the polar PHB plastic. SEM images showed space between filler and plastic in TRH composites and better wetted filler particles in the RRH composites