Biomass modelling

Yoshida, T., Oshima, Y., Matsumura, Y., Gasification of biomass model compounds and real biomass in supercritical water, Biomass Bioenenergy, 2004, 26,... 

Previous studies in conventional reactor setups at Philip Morris USA have demonstrated the significant effectiveness of nanoparticle iron oxide on the oxidation of carbon monoxide when compared to the conventional, micron-sized iron oxide, " as well as its effect on the combustion and pyrolysis of biomass and biomass model compounds.These effects are derived from a higher reactivity of nanoparticles that are attributed to a higher BET surface area as well as the coordination of unsaturated sites on the surfaces. The chemical and electronic properties of nanoparticle iron oxide could also contribute to its higher reactivity. In this work, we present the possibility of using nanoparticle iron oxide as a catalyst for the decomposition of phenolic compounds. 

P Li, E. J. Shin, D. Miser, M. R. Hajaligol, and F. Rasouli, The catalytic/oxidative effects of iron oxide nanoparticles on carbon monoxide and the pyrolytic products of biomass model compounds, In Nanotechnology in Catalysis, edited by B. Zhou, S. Hermans, and G. A. Somorjai (Kluwer Academic/Plenum Publishers, New York 2004) pp. 515-542. 

Kruse, A. Abeln, J. Dinjus, E. Kluth, M. Petrich, G. Schacht, M. Sadri, E. Schmieder, H. (1999). Gasification of Biomass and Biomass Model Compounds in Hot Compressed Water. AIRAPT-I7 International Conference on High Pressure Science and Technology, 25-30 Juli, 1999, Honolulu, Hawaii, USA (in press). 

In the experiments pinewood was chosen as biomass model component. Pinewood contains practically no sulphur, has a very low nitrogen content and also contains practically no alkali nor heavy metals and is scientifically interesting for so called zero-reference experiments. The research work described in this paper was primarily directed toward emission studies and the main goals were ... 

Madlener and Myles [34] in their work have systemized socioeconomic impacts according to four different dimensions social aspects, macro level, the supply side, and the demand side, using the Austrian Biomass Model based on a computable general equilibrium (CGE) model. 

Figure 5.67. Concentration/time plot of structured biomass model according to Williams (1967) Biomass G and K compartment (xq,Xk) and total biomass (x) and substrate (s) simulated on the basis of Equs. 5.228d-f with =0.0125...

Temperature, pH, and feed rate are often measured and controlled. Dissolved oxygen (DO) can be controlled using aeration, agitation, pressure, and/or feed rate. Oxygen consumption and carbon dioxide formation can be measured in the outgoing air to provide insight into the metaboHc status of the microorganism. No rehable on-line measurement exists for biomass, substrate, or products. Most optimization is based on empirical methods simulation of quantitative models may provide more efficient optimization of fermentation. 

In this way, the near-linear chlorophyll-phosphorus relationship in lakes depends upon the outcome of a large number of interactive processes occurring in each one of the component systems in the model. One of the most intriguing aspects of those components is that the chlorophyll models do not need to take account of the species composition of the phytoplankton in which chlorophyll is a constituent. The development of blooms of potentially toxic cyanobacteria is associated with eutrophication and phosphorus concentration, yet it is not apparent that the yield of cyanobacterial biomass requires any more mass-specific contribution from phosphorus. The explanation for this paradox is not well understood, but it is extremely important to understand that it is a matter of dynamics. The bloom-forming cyanobacteria are among the slowest-growing and most light-sensitive members of the phytoplankton. ... 

A Monod rate model is used to demonstrate the rate of biomass generation. We neglect the cell death rate. Let us denote the ratio of biomass rate of generation to biomass concentration, rJX, that is the specific growth rate /a also denotes the dilution rate D is defined as number of tank volumes passed through per unit time, FIV. After substitution of D and /a into (6.8.1), the following equation is obtained ... 

The Monod rate model is valid for a CSTR bioreactor with maximum specific growth rate of 0.5 li 1 and K, 2 g-1. What would be a suitable dilution rate at steady-state condition, where there is no cell death if initial substrate concentration is 50g-l-1 and yield of biomass on substrate is 100%. 

The cells activities have been described based on a multi-species biofilm model, and the microbial kinetics by a mathematical model. Using this model predicts that the biomass on the external surface of the biofilm has higher activity than the biomass near the solid support surface, and that condition may occur, after the biofilm has reached a critical dept or formed... 

The performance of a biochemical reactor is designed and evaluated based the reaction rate equation. The rate of biomass generation is based on the Monod rate model ... 

We wish to compare the performance of two reactor types plug flow versus CSTR with a substrate concentration of Csf = 60g-m 3 and a biomass yield of Y = 0.1. In a plug flow bioreactor with volume of 1 m3 and volumetric flow rate of 2.5 m -li what would be the recycle ratio for maximum qx compared with corresponding results and rate models proposed for the chemostat ... 

Several studies, based on models, examined the effects of land-use change on the global carbon cycle and conclude that there is a net release of carbon due to land clearing. However, the results and conclusions of these studies are based on assumed sizes of vegetation carbon pools which are inputs to the models. For example, Melillo et al. 24) concluded that boreal and temperate deciduous forests of the northern hemisphere are net sources of atmospheric carbon. Their analysis used values for carbon density derived by Whittaker and Likens 19) from work by Rodin and Bazilevich (27). Rodin and Bazilevich extrapolated results of small, unrelated studies in Europe and the USSR to estimate total biomass of Eurasian boreal and temperate deciduous forests. Their estimates have since been extrapolated to forests worldwide and are used often today. 

Most estimates of global vegetation biomass densities are extrapolations from studies never intended to represent large areas (e.g. 79, 36) or they were derived from questionnaires sent to botanists (57). These estimates are still used commonly in the examination and modeling of the global carbon cycle. Some of the earliest estimates were made when almost no quantitative data were available and the data or the estimates were largely speculative. Other estimates are... 

Essentially all organic matter in the ocean is ultimately derived from inorganic starting materials (nutrients) converted by photosynthetic algae into biomass. A generalized model for the production of plankton biomass from nutrients in seawater was presented by Redfield, Ketchum and Richards (1963). The schematic "RKR" equation is given below ... 

Inasmuch as the RKR model is a generalization, specific exceptions should be expected. The most important exceptions relate to growth conditions that can affect the stoichiometry of nutrient incorporation into plankton biomass. During respiration, the... 

This section gives models for the rates of birth, growth, and death of cell populations. We seek models for (1) the rate at which biomass is created, (2) the rates at which substrates are consumed, (3) the rates at which products are generated, (4) the maintenance requirements for a static population, and (5) the death rate of cells. The emphasis is on unstructured models. 

Biomass Production. Biomass is usually measured by dry weight of viable cells per unit volume X. We bypass the sometimes tricky problems associated with this measurement except to say that it is the province of the microbiologist and usually involves plate cultures and filtration followed by drying. Suppose there is one limiting nutrient S, and that all other nutrients are available in excess. Then the Monod model for growth is... 

The typical bioreactor is a two-phase stirred tank. It is a three-phase stirred tank if the cells are counted as a separate phase, but they are usually lumped with the aqueous phase that contains the microbes, dissolved nutrients, and soluble products. The gas phase supplies oxygen and removes by-product CO2. The most common operating mode is batch with respect to biomass, batch or fed-batch with respect to nutrients, and fed-batch with respect to oxygen. Reactor aeration is discussed in Chapter 11. This present section concentrates on reaction models for the liquid phase. 

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