Influence of temperature and residence time in the pyrolysis of woody biomass waste in a continuous screw reactor

2016 ◽  
Vol 95 ◽  
pp. 416-423 ◽  
Author(s):  
J. Solar ◽  
I. de Marco ◽  
B.M. Caballero ◽  
A. Lopez-Urionabarrenechea ◽  
N. Rodriguez ◽  
...  
Keyword(s):  
Residence Time ◽  
Woody Biomass ◽  
Biomass Waste ◽  
Influence Of Temperature ◽  
Screw Reactor

scholarly journals Optimization of Charcoal Production Process from Woody Biomass Waste: Effect of Ni-Containing Catalysts on Pyrolysis Vapors

Catalysts ◽  
2018 ◽  
Vol 8 (5) ◽  
pp. 191 ◽  
Author(s):  
Jon Solar ◽  
Blanca Caballero ◽  
Isabel De Marco ◽  
Alexander López-Urionabarrenechea ◽  
Naia Gastelu
Keyword(s):  
Energy Production ◽  
Treatment Phase ◽  
Woody Biomass ◽  
Producer Gas ◽  
Charcoal Production ◽  
Biomass Waste ◽  
Screw Reactor ◽  
Low Temperature Pyrolysis ◽  
Vapor Treatment ◽  
Very High

Woody biomass waste (Pinus radiata) coming from forestry activities has been pyrolyzed with the aim of obtaining charcoal and, at the same time, a hydrogen-rich gas fraction. The pyrolysis has been carried out in a laboratory scale continuous screw reactor, where carbonization takes place, connected to a vapor treatment reactor, at which the carbonization vapors are thermo-catalytically treated. Different peak temperatures have been studied in the carbonization process (500–900 °C), while the presence of different Ni-containing catalysts in the vapor treatment has been analyzed. Low temperature pyrolysis produces high liquid and solid yields, however, increasing the temperature progressively up to 900 °C drastically increases gas yield. The amount of nickel affects the vapors treatment phase, enhancing even further the production of interesting products such as hydrogen and reducing the generated liquids to very low yields. The gases obtained at very high temperatures (700–900 °C) in the presence of Ni-containing catalysts are rich in H2 and CO, which makes them valuable for energy production, as hydrogen source, producer gas or reducing agent.

scholarly journals Emission Reductions from Woody Biomass Waste for Energy as an Alternative to Open Burning

2011 ◽  
Vol 61 (1) ◽  
pp. 63-68 ◽  
Author(s):  
Bruce Springsteen ◽  
Tom Christofk ◽  
Steve Eubanks ◽  
Tad Mason ◽  
Chris Clavin ◽  
...  
Keyword(s):  
Woody Biomass ◽  
Biomass Waste ◽  
Emission Reductions ◽  
Open Burning

scholarly journals Northward migration of the boreal forest confirmed by satellite record

2021 ◽  
Author(s):  
Min Feng ◽  
Joseph Sexton ◽  
Panshi Wang ◽  
Paul Montesano ◽  
Leonardo Calle ◽  
...  
Keyword(s):  
Climate Change ◽  
Boreal Forest ◽  
Residence Time ◽  
Woody Biomass ◽  
Atmospheric Co2 ◽  
Climate Feedback ◽  
Tree Cover ◽  
Greenhouse Warming ◽  
Terrestrial Biosphere ◽  
Northern Latitudes

Abstract The boreal forest is one of Earth’s most climatologically sensitive regions, and changes in the cover and structure of its vegetation pose a positive carbon-climate feedback on atmospheric greenhouse warming. The region has also experienced more than three times climatological warming of any forested biome in recent decades. While ecological models predict a northward shift of boreal tree cover in response to climate change, comprehensive data have not been available to test the hypothesis. Here we report a test of the magnitude, direction, and significance of changes in the boreal canopy based on the longest and highest-resolution record of calibrated satellite maps to date. The boreal canopy increased in density and shifted northward from 1984 to 2020, with the largest and most significant gains in its northern latitudes. Net forest gains occurred despite stable rates of disturbance across all but the region’s southernmost latitudes, implicating widespread release of climatological limitation on growth over changing distribution of fire, harvest, insect, and other disturbances. These new forests will sequester carbon as they mature, increasing its residence time in woody biomass, and will play a key role in how the terrestrial biosphere attenuates atmospheric CO2 increases.

scholarly journals A generic pixel-to-point comparison for simulated large-scale ecosystem properties and ground-based observations: an example from the Amazon region

2018 ◽  
Vol 11 (12) ◽  
pp. 5203-5215 ◽  
Author(s):  
Anja Rammig ◽  
Jens Heinke ◽  
Florian Hofhansl ◽  
Hans Verbeeck ◽  
Timothy R. Baker ◽  
...  
Keyword(s):  
Residence Time ◽  
Aboveground Biomass ◽  
Measurement Errors ◽  
Large Scale ◽  
Woody Biomass ◽  
Data Availability ◽  
Permanent Plots ◽  
Small Scale ◽  
Statistical Measures ◽  
Local Point

Abstract. Comparing model output and observed data is an important step for assessing model performance and quality of simulation results. However, such comparisons are often hampered by differences in spatial scales between local point observations and large-scale simulations of grid cells or pixels. In this study, we propose a generic approach for a pixel-to-point comparison and provide statistical measures accounting for the uncertainty resulting from landscape variability and measurement errors in ecosystem variables. The basic concept of our approach is to determine the statistical properties of small-scale (within-pixel) variability and observational errors, and to use this information to correct for their effect when large-scale area averages (pixel) are compared to small-scale point estimates. We demonstrate our approach by comparing simulated values of aboveground biomass, woody productivity (woody net primary productivity, NPP) and residence time of woody biomass from four dynamic global vegetation models (DGVMs) with measured inventory data from permanent plots in the Amazon rainforest, a region with the typical problem of low data availability, potential scale mismatch and thus high model uncertainty. We find that the DGVMs under- and overestimate aboveground biomass by 25 % and up to 60 %, respectively. Our comparison metrics provide a quantitative measure for model–data agreement and show moderate to good agreement with the region-wide spatial biomass pattern detected by plot observations. However, all four DGVMs overestimate woody productivity and underestimate residence time of woody biomass even when accounting for the large uncertainty range of the observational data. This is because DGVMs do not represent the relation between productivity and residence time of woody biomass correctly. Thus, the DGVMs may simulate the correct large-scale patterns of biomass but for the wrong reasons. We conclude that more information about the underlying processes driving biomass distribution are necessary to improve DGVMs. Our approach provides robust statistical measures for any pixel-to-point comparison, which is applicable for evaluation of models and remote-sensing products.

Influence of Temperature, Water Content and C/N Ratio on the Aerobic Fermentation Rate of Woody Biomass

2017 ◽  
Vol 43 (4) ◽  
pp. 231-237
Author(s):  
Nobuhide Takahashi ◽  
Shun Mochizuki ◽  
Kento Masuda ◽  
Iori Shimada ◽  
Mitsumasa Osada ◽  
...  
Keyword(s):  
Water Content ◽  
Woody Biomass ◽  
Aerobic Fermentation ◽  
Influence Of Temperature ◽  
Fermentation Rate ◽  
Temperature Water

scholarly journals Divergent predictions of carbon storage between two global land models: attribution of the causes through traceability analysis

2016 ◽  
Vol 7 (3) ◽  
pp. 649-658 ◽  
Author(s):  
Rashid Rafique ◽  
Jianyang Xia ◽  
Oleksandra Hararuk ◽  
Ghassem R. Asrar ◽  
Guoyong Leng ◽  
...  
Keyword(s):  
Carbon Cycle ◽  
Carbon Storage ◽  
Residence Time ◽  
Net Primary Productivity ◽  
Storage Capacity ◽  
Woody Biomass ◽  
Residence Times ◽  
Ecosystem Carbon ◽  
Global Land ◽  
Traceability Analysis

Abstract. Representations of the terrestrial carbon cycle in land models are becoming increasingly complex. It is crucial to develop approaches for critical assessment of the complex model properties in order to understand key factors contributing to models' performance. In this study, we applied a traceability analysis which decomposes carbon cycle models into traceable components, for two global land models (CABLE and CLM-CASA′) to diagnose the causes of their differences in simulating ecosystem carbon storage capacity. Driven with similar forcing data, CLM-CASA′ predicted  ∼ 31 % larger carbon storage capacity than CABLE. Since ecosystem carbon storage capacity is a product of net primary productivity (NPP) and ecosystem residence time (τE), the predicted difference in the storage capacity between the two models results from differences in either NPP or τE or both. Our analysis showed that CLM-CASA′ simulated 37 % higher NPP than CABLE. On the other hand, τE, which was a function of the baseline carbon residence time (τ′E) and environmental effect on carbon residence time, was on average 11 years longer in CABLE than CLM-CASA′. This difference in τE was mainly caused by longer τ′E of woody biomass (23 vs. 14 years in CLM-CASA′), and higher proportion of NPP allocated to woody biomass (23 vs. 16 %). Differences in environmental effects on carbon residence times had smaller influences on differences in ecosystem carbon storage capacities compared to differences in NPP and τ′E. Overall, the traceability analysis showed that the major causes of different carbon storage estimations were found to be parameters setting related to carbon input and baseline carbon residence times between two models.

Influence of Temperature and Pressure on the Non-Catalytic Partial Oxidation of Natural Gas

2010 ◽  
Vol 5 (1) ◽  
Author(s):  
Philipp Brüggemann ◽  
Peter Seifert ◽  
Bernd Meyer ◽  
Matthias Müller-Hagedorn
Keyword(s):  
Natural Gas ◽  
Residence Time ◽  
Partial Oxidation ◽  
Flow Reactor ◽  
Catalytic Partial Oxidation ◽  
Outlet Temperature ◽  
Influence Of Temperature ◽  
Comparison Results ◽  
Temperature And Pressure ◽  
Non Equilibrium

The influence of temperature and pressure on the non-catalytic partial oxidation and reforming of natural gas in an entrained-flow reactor under non-equilibrium conditions has been investigated experimentally in pilot scale.As thermochemical equilibrium suggests, the methane conversion increases drastically with temperature, but does not reach equilibrium in the investigated range of parameters (Tmax = 1450 °C; 30 bar (3 MPa) < p(g) < 100 bar (10 MPa), 5 s < ? < 20 s). A practical method to describe the non-equilibrium state of a partial oxidation product gas at high temperatures due to kinetic limitations and/or mixing conditions within a reactor is by calculating apparent equilibrium temperatures Teq,ap for the main global kinetic reactions from the measured concentrations of the gas. The temperature difference between Teq,ap and the measured reactor outlet temperature Tex results in the temperature differental approach (?TApp = Teq,ap - Tex).In this paper, typical parameters influencing ?TApp for the methane reforming reaction (temperature T, pressure p, residence time ?) were examined. ?TApp was found in the range between -300 K and -50 K in non-catalytic partial oxidation. Its absolute value decreases with increasing pressure and decreasing ratio of steam to fuel carbon H2O : Cf , but is just weakly dependent on the reactor temperature Tex in a range from 1100-1450 °C. The results were used for the evaluation and further development of a model combining kinetics and residence time behaviour of the non-catalytic partial oxidation and reforming of natural gas.For comparison, results from catalytic autothermal reforming of natural gas and non-catalytic partial oxidation of liquid hydrocarbons are also presented.

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