scholarly journals Preliminary project design for insect production: part 1 – overall mass and energy/heat balances

2021 ◽  
pp. 1-12
Author(s):  
R. Kok
Keyword(s):  
Scientific Data ◽  
Project Design ◽  
Trial And Error ◽  
Project Development ◽  
Feed Composition ◽  
System Productivity ◽  
Energy Balances ◽  
Parameter Values ◽  
Cooling Air ◽  
Mass And Energy Balances

Preliminary project design (PPD) is an initial stage in project development that makes it possible for an entopreneur to gain insight into the feasibility and potential profitability of setting up an insect production facility. In this paper a simple, spreadsheet-based model is presented to facilitate the first step of PPD by estimating the overall mass and energy balances for a proposed project. The model calculates outputs on the basis of scientific data and estimated values for operating parameters for the system that is proposed. With the model it is easy to use a trial-and-error approach to investigate the effect of different parameter values on system operation. Thus, the entopreneur can enter values for parameters such as feed composition, temperature of the cooling air, etc. and see the effect on system productivity, conversion efficiency, energy requirements, etc. immediately. This facilitates the overall procedure of reaching final decisions about the organism, the feed, the processing approach, the scale of operation, etc. Normally, this is an iterative procedure that is based on ‘trial-and-error’, the two aspects being referred to here as the ‘twin components of an iterative knowledge engine’. Thus, the outputs from the model will depend very much on the scientific data supplied and the values of the input parameters while, at the same time, use of the model will highlight what additional scientific data is needed and what alternate parameter values might prove profitable. Overall, the model allows the user to explore a large possibility space for both process constitution and operation much more quickly and easily than by experimental means alone. As such, it is a tool that can aid the entopreneur in thinking about a project and considering various alternatives, as well as in making decisions before a major commitment is made to any particular option. It is stressed here that PPD is only a preliminary stage in project development and that the investigation of overall process mass and energy balances is only the first step thereof. It is also stressed that results from modelling are invariably subject to empirical verification as well as ‘common-sense filtering’. The model presented is general and thus not oriented to the production of any species in particular.

Innovative energy and mass balance of a continuous evaporating crystallizer

2019 ◽  
pp. 646-654
Author(s):  
Jan Iciek ◽  
Kornel Hulak ◽  
Radosław Gruska
Keyword(s):  
Energy Balance ◽  
Mass Balance ◽  
Working Conditions ◽  
Crystallization Process ◽  
Heat Losses ◽  
Inert Gas ◽  
Gas Removal ◽  
Energy Balances ◽  
Heat Released ◽  
Mass And Energy Balances

The article presents the mass and energy balances of the sucrose crystallization process in a continuous evaporating crystallizer. The developed algorithm allows to assess the working conditions of the continuous evaporating crystallizers and the technological and energy parameters. The energy balance algorithm takes into account the heat released during the crystallization of sucrose, which was analyzed in this study, heat losses to the environment and heat losses due the vapor used for inert gas removal.

Mass and energy balances of an autothermal pilot carbonization unit

2019 ◽  
Vol 120 ◽  
pp. 144-155 ◽  
Author(s):  
Andrea Maria Rizzo ◽  
Marco Pettorali ◽  
Renato Nistri ◽  
David Chiaramonti
Keyword(s):  
Energy Balances ◽  
Mass And Energy Balances

scholarly journals A continuum model for meltwater flow through compacting snow

2017 ◽  
Vol 11 (6) ◽  
pp. 2799-2813 ◽  
Author(s):  
Colin R. Meyer ◽  
Ian J. Hewitt
Keyword(s):  
Continuum Model ◽  
Pore Space ◽  
Water Storage ◽  
Greenland Ice Sheet ◽  
Percolation Process ◽  
Surface Mass ◽  
Run Off ◽  
Flow Through ◽  
Energy Balances ◽  
Mass And Energy Balances

Abstract. Meltwater is produced on the surface of glaciers and ice sheets when the seasonal energy forcing warms the snow to its melting temperature. This meltwater percolates into the snow and subsequently runs off laterally in streams, is stored as liquid water, or refreezes, thus warming the subsurface through the release of latent heat. We present a continuum model for the percolation process that includes heat conduction, meltwater percolation and refreezing, as well as mechanical compaction. The model is forced by surface mass and energy balances, and the percolation process is described using Darcy's law, allowing for both partially and fully saturated pore space. Water is allowed to run off from the surface if the snow is fully saturated. The model outputs include the temperature, density, and water-content profiles and the surface runoff and water storage. We compare the propagation of freezing fronts that occur in the model to observations from the Greenland Ice Sheet. We show that the model applies to both accumulation and ablation areas and allows for a transition between the two as the surface energy forcing varies. The largest average firn temperatures occur at intermediate values of the surface forcing when perennial water storage is predicted.

scholarly journals Exergy analysis of a co-generation plant

2008 ◽  
Vol 12 (4) ◽  
pp. 75-88 ◽  
Author(s):  
Nenad Ferdelji ◽  
Antun Galovic ◽  
Zvonimir Guzovic
Keyword(s):  
Exergy Analysis ◽  
Plant Performance ◽  
Total System ◽  
Process Unit ◽  
Generation Plant ◽  
Thermodynamic Performance ◽  
Valuable Method ◽  
Energy Balances ◽  
Mass And Energy Balances ◽  
Research Resources

Limitations of traditional first-law analysis, based upon thermodynamic performance of process unit coupled with mass and energy balances, are not a serious limitation when dealing with familiar systems. However, when dealing with more uncongenial, complex ones, it provides incomplete insight for such evaluation. These limitations came from the fact that first-law analysis does not indicate the sources or magnitudes of entropy production, which is, by the second law, essential criterion for scaling losses. An evaluation of plant performance will usually require a comparison of the thermodynamic performance of process units with available data from existing plants. Therefore, exergy analysis is more than useful, providing information about magnitudes of losses and their distribution throughout the system as well. Such analysis is very thankful at the level of process units but applied on higher system levels e.g. the comparison of overall plant performance (total system) or the performance of subsystems, represents the valuable method for indicating where research resources can be directed to best advantage.

From Component to Macro Energy Systems: A Common Design and Off-Design Modeling Approach

2011 ◽  
Author(s):  
S. Rech ◽  
A. Lazzaretto
Keyword(s):  
Energy Systems ◽  
Level Of Detail ◽  
Design Specification ◽  
Mathematical Functions ◽  
Independent Variables ◽  
Performance Curves ◽  
Systems Models ◽  
Energy And Momentum ◽  
Energy Balances ◽  
Mass And Energy Balances

A common approach for simulation of energy systems at design and off-design conditions is presented, which uses the same concepts and terminology independently of system dimension, complexity and detail. The paper shows that the higher the dimension of the system, the simpler is the model of each part of the system, but concepts and approach to built the model remain the same, being those commonly used in the literature. The approach consists in organizing energy systems models according to some criteria, which help enhance system models comprehension, and build them more easily. For any dimension and level of detail of the system these criteria consist in identifying the design specification from the environment surrounding the system, choosing the independent variables depending on the nature of the model, organizing them into categories, defining performance curves (characteristic maps) of each part of the system and organizing mass and energy balances into categories. Particular emphasis is given on modeling of system units behavior, which is generally described by the mathematical functions (characteristic maps) linking outflow to inflow variables. Examples of characteristic maps of the system units at each level of detail are shown, and models are then completed by mass, energy and momentum balances linking the behavior of all system units.

scholarly journals Mass and Energy Balances of Dry Thermophilic Anaerobic Digestion Treating Swine Manure Mixed with Rice Straw

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Sheng Zhou ◽  
Jining Zhang ◽  
Guoyan Zou ◽  
Shohei Riya ◽  
Masaaki Hosomi
Keyword(s):  
Anaerobic Digestion ◽  
Rice Straw ◽  
Swine Manure ◽  
Rice Production ◽  
Methane Yield ◽  
Manure Treatment ◽  
Thermophilic Anaerobic Digestion ◽  
Forage Rice ◽  
Energy Balances ◽  
Mass And Energy Balances

To evaluate the feasibility of swine manure treatment by a proposed Dry Thermophilic Anaerobic Digestion (DT-AD) system, we evaluated the methane yield of swine manure treated using a DT-AD method with rice straw under different C/N ratios and solid retention time (SRT) and calculated the mass and energy balances when the DT-AD system is used for swine manure treatment from a model farm with 1000 pigs and the digested residue is used for forage rice production. A traditional swine manure treatment Oxidation Ditch system was used as the study control. The results suggest that methane yield using the proposed DT-AD system increased with a higher C/N ratio and shorter SRT. Correspondently, for the DT-AD system running with SRT of 80 days, the net energy yields for all treatments were negative, due to low biogas production and high heat loss of digestion tank. However, the biogas yield increased when the SRT was shortened to 40 days, and the generated energy was greater than consumed energy when C/N ratio was 20:1 and 30:1. The results suggest that with the correct optimization of C/N ratio and SRT, the proposed DT-AD system, followed by using digestate for forage rice production, can attain energy self-sufficiency.

scholarly journals The ups and downs of working with industry to collect fishery-dependent data: the Irish experience

2011 ◽  
Vol 68 (8) ◽  
pp. 1670-1678 ◽  
Author(s):  
Colm Lordan ◽  
Macdara Ó Cuaig ◽  
Norman Graham ◽  
Dominic Rihan
Keyword(s):  
Scientific Data ◽  
Dependent Data ◽  
Management Systems ◽  
Project Design ◽  
Critical Aspect ◽  
Successful Management ◽  
Joint Research ◽  
Time Horizons ◽  
Fisheries Policy ◽  
The Many

Abstract Lordan, C., Ó Cuaig, M., Graham, N., and Rihan, D. 2011. The ups and downs of working with industry to collect fishery-dependent data: the Irish experience. – ICES Journal of Marine Science, 68: 1670–1678. Working with the fishing industry to collect fishery-dependent data for scientific and advisory purposes is essential in most countries, but despite the many advantages of working with fishers, it is not without challenges. The objectives and the ups and downs of 16 recent projects in Ireland are described, and four case studies are discussed in detail. Some common themes that characterize both successful and unsuccessful experiences are identified. One critical aspect is industry's sometimes unrealistic time-horizons and expectations when engaging in scientific data collection. Detailed communication of objectives, procedures, results, and relevance not only to industry representatives, but also to vessel owners and crew, is required throughout the life cycle of a project. For some projects, there is a clear need to include incentives in the design, but for others this is less critical. The critical needs for ongoing quality control and assurance, validation of data, and appropriate project design are discussed, along with the link between successful management systems and participatory research. Finally, comment is provided on how the expected reforms of the EU's Common Fisheries Policy will place new demands on joint research.

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