scholarly journals Impact of Water Content on Energy Potential and Combustion Characteristics of Methanol and Ethanol Fuels

Energies ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 3491 ◽  
Author(s):  
Jozef Martinka ◽  
Peter Rantuch ◽  
Igor Wachter
Keyword(s):  
Water Content ◽  
Fire Risk ◽  
Combustion Characteristics ◽  
Flash Point ◽  
Heat Of Combustion ◽  
Combustion Characteristic ◽  
Energy Potential ◽  
Effective Heat ◽  
Effective Heat Of Combustion ◽  
The Impact

Methanol and ethanol are among the most important biofuels and raw materials used to produce biorenewable fuels. These fuels are used with varying water contents. Nevertheless, the exact impact of the water content of these fuels on the energy potential and combustion characteristics is still unknown. Besides that, there are two noticeable risks (environmental impact of combustion and fire risk) associated with their production, processing, and utilization. Likewise, impact of the water content of these fuels on fire risk and the impact of their combustion on the environment is also unknown. The best indicator of energy potential is the effective heat of combustion, and the best combustion characteristic and indicator of the impact of the combustion of alcohols on the environment is the carbon monoxide (CO) yield, whereas the fire risk of liquid fuels is quantified by the flash point and maximum heat release rate (mHRR). The dependency of flash point on the water content was determined via the Pensky-Martens apparatus and the dependencies of the effective heat of combustion, CO yield, and mHRR on the water content were determined via the cone calorimeter. With increased water content, the flash points of both methanol and ethanol exponentially increased and the both effective heat of combustion and mHRR almost linearly decreased. In the range of water content from 0 to 60%, the CO yield of both methanol and ethanol was practically independent of the water content.

scholarly journals Fire Risk of Halogen-Free Electrical Cable

2018 ◽  
Vol 26 (42) ◽  
pp. 21-27
Author(s):  
Jozef Martinka ◽  
Peter Rantuch ◽  
Igor Wachter ◽  
Karol Balog
Keyword(s):  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Fire Risk ◽  
Heat Of Combustion ◽  
Total Heat Release ◽  
Electrical Cable ◽  
Effective Heat ◽  
Effective Heat Of Combustion ◽  
Halogen Free

Abstract This paper deals with the fire risk of a selected halogen-free electrical cable. The research was objected to a three-core power electric cable for a fixed installation CHKE J3x1.5 (cross section of each copper core was 1.5 mm2) with a declared class of reaction to fire B2ca, s1, d1, a1. The electrical cable was manufactured and supplied by VUKI, a. s., Slovakia. The fire risk of the electric cable was evaluated based on the heat release rate, total heat release, smoke release rate, total smoke release and effective heat of combustion. These parameters were measured using a cone calorimeter at 50 kW m−2 (specimens and cone emitter were placed horizontally during the test). The measured electrical cable showed a maximum heat release rate of nearly 150 kW m−2, a maximum average heat emission rate of almost 100 kW m−2, a total heat release of almost 130 MJ m−2, a maximum smoke release rate of almost 2.5 s−1, a total smoke release of more than 800 m2 m−2, an effective heat of combustion (cable as a whole) of nearly 9 MJ kg−1 and an effective heat of emission (polymeric parts of the cable) of 26.5 MJ kg−1.

A review of thermal properties of timber and char at elevated temperatures

2021 ◽  
pp. 1420326X2110355
Author(s):  
Long Shi ◽  
Michael Y. L. Chew
Keyword(s):  
Thermal Conductivity ◽  
Heat Capacity ◽  
Thermal Properties ◽  
Specific Heat ◽  
Specific Heat Capacity ◽  
Fire Risk ◽  
Empirical Models ◽  
Heat Of Combustion ◽  
Effective Heat ◽  
Effective Heat Of Combustion

Timber is one of the most frequently adopted combustible materials in the built environment. The thermal properties are the determining factors for assessing the fire risk in a building. The main thermal properties of timber and their char are reviewed, especially those temperature-dependent and moisture-dependent properties, including kinetic properties, ignition properties, thermal conductivity, specific heat capacity, effective heat of combustion and thermal diffusivity. The study has collected and summarized various thermal properties data and empirical models of hardwood and softwood with different mass percentages in cellulose, hemicellulose and lignin, as temperature increases. The average ignition temperature and effective heat of combustion of softwood are about 12.9% and 9.5% higher than those of hardwood, respectively. From most of the previous models, the thermal conductivity of timber char increases as temperature rises. Cellulose with a high density shows a higher thermal conductivity, but its impacts on the specific heat capacity are limited. Models to predict the main thermal properties of the hardwood, softwood and char are recommended. The collected data, together with those empirical models, can provide useful data resources and tools for the related fire risk assessments.

Effective Heat of Combustion for Flaming Combustion of Mediterranean Forest Fuels

2010 ◽  
Vol 47 (2) ◽  
pp. 461-474 ◽  
Author(s):  
J. Madrigal ◽  
M. Guijarro ◽  
C. Hernando ◽  
C. Díez ◽  
E. Marino
Keyword(s):  
Heat Of Combustion ◽  
Mediterranean Forest ◽  
Forest Fuels ◽  
Effective Heat ◽  
Flaming Combustion ◽  
Effective Heat Of Combustion

scholarly journals QUANTITATIVE ASSESSMENT OF HYDROPOWER POTENTIAL BY THE IMPACTS OF CLIMATE TRANSFORMATION ON THE EXAMPLE OF THE RIVERS OF GEORGIA

World Science ◽  
2019 ◽  
Vol 1 (10(50)) ◽  
pp. 4-9
Author(s):  
Grigol Khelidze ◽  
Lena Shatakishvili ◽  
Bachana Pipia
Keyword(s):  
Climate Change ◽  
Water Content ◽  
Quantitative Assessment ◽  
River Basins ◽  
Transformation Process ◽  
Energy Potential ◽  
Impact Of Climate Change ◽  
Hydropower Potential ◽  
The Impact

The purpose of the work is the quantitative assessment of the impact of climate change on the runoff of the rivers of Georgia and, consequently, on their hydropower potential. To this end, the sections of 19 river basins located in six regions of Georgia, where natural runoff is maintained, have been reviewed – it is not regulated. The results of the study confirm the change of the water content of the selected rivers and hence their hydro- energy potential, which is related to the climate transformation process.

scholarly journals Fire Behavior of Thermally Thin Materials in Cone Calorimeter

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1297
Author(s):  
Marouane El El Gazi ◽  
Rodolphe Sonnier ◽  
Stéphane Giraud ◽  
Marcos Batistella ◽  
Shantanu Basak ◽  
...  
Keyword(s):  
Heat Flux ◽  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Cone Calorimeter ◽  
Fire Hazard ◽  
Heat Of Combustion ◽  
Sample Weight ◽  
Effective Heat ◽  
Effective Heat Of Combustion

In this study, a representative set of thermally thin materials including various lignocellulosic and synthetic fabrics, dense wood, and polypropylene sheets were tested using a cone calorimeter at different heat fluxes. Time-to-ignition, critical heat flux, and peak of heat release rate (pHRR) were the main parameters considered. It appears that the flammability is firstly monitored by the sample weight. Especially, while the burning rate of thermally-thin materials does never reach a steady state in cone calorimeter, their pHRR appears to be mainly driven by the fire load (i.e., the product of sample weight and effective heat of combustion) with no or negligible influence of textile structure. A simple phenomenological model was proposed to calculate the pHRR taking into account only three parameters, namely heat flux, sample weight, and effective heat of combustion. The model allows predicting easily the peak of heat release rate, which is often considered as the main single property informing about the fire hazard. It also allows drawing some conclusions about the flame retardant strategies to reduce the pHRR.

scholarly journals Heat of Combustion as the Key Fire Characteristics of Electrical Cables

2019 ◽  
Vol 27 (44) ◽  
pp. 29-39
Author(s):  
Jozef Martinka ◽  
Peter Rantuch ◽  
Martina Hladová ◽  
Janka Sulová ◽  
Aleš Nečas ◽  
...  
Keyword(s):  
Aluminium Hydroxide ◽  
Heat Of Combustion ◽  
Inorganic Filler ◽  
Outer Sheath ◽  
Effective Heat ◽  
Cross Section Area ◽  
Significant Difference ◽  
Effective Heat Of Combustion ◽  
Fire Characteristics ◽  
Electrical Cables

Abstract This scientific study deals with investigation of the heat of combustion and effective heat of combustion of selected electrical cables. Two different electrical cables for rated voltage of 0.6/1 kV were investigated. Both cables were power three-core with cross-section area of each core of 1.5 mm2. The cores of both cables were made of a bar cooper wire. Insulations of conductors of both cables were made of silane cross-linked polyethylene without any inorganic filler, while the bedding and outer sheath were made of polyethylene-based copolymer (the beddings were filled with two fillers - aluminium hydroxide and calcium carbonate, while the outer sheath were filled only with aluminium hydroxide). Reaction to fire class of both cables was B2ca, s1, d0, a1. The main difference in the investigated cables was that the core of one of them was wrapped in a glass mica tape (this cable showed circuit integrity maintenance under fire conditions during 180 minutes). The heat of combustion and effective heat of combustion were determined by the oxygen bomb calorimeter according to the ISO 1716:2018 standard. The highest effective heat of combustion showed the insulation of wires (for both cables 42.47 ± 0.03 MJ/kg), lower value showed outer sheath (interval form13.61 to 15.26 MJ/kg) and the lowest value was determined for bedding (interval from 4.69 to 6.39 MJ/kg). The effective heath of combustion per unit of length of both investigated cables lies in the interval from 1.37 to 1.38 MJ/m. Therefore, there is no significant difference in effective heats of combustion of the electrical cables investigated.

Heat Release Rate and Effective Heat of Combustion Measurements: A Comparative Study of Thermal and Oxygen Consumption Techniques

1995 ◽  
Vol 13 (6) ◽  
pp. 482-499 ◽  
Author(s):  
Fatima Moussan ◽  
Jean-Louis Delfau ◽  
Christian Vovelle ◽  
Christian Pham Van Cang ◽  
Gérard Bosseboeuf
Keyword(s):  
Oxygen Consumption ◽  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Radiant Heat ◽  
Heat Of Combustion ◽  
Second Step ◽  
Thermal Method ◽  
Effective Heat ◽  
Effective Heat Of Combustion

A new calorimeter especially built for the measurement of the heat release rate and effective heat of combustion of composite materials is pre sented. Two procedures can be used to obtain these data: the first one is based on the direct measurement of the convective and radiant heat liberated by the flame, the second involves oxygen consumption measurement. Preliminary ex periments were carried out with a gas burner to calibrate and check the inertia of the thermal method. In a second step, measurements were performed on PMMA and PVC samples. The results obtained with both methods are very similar and in agreement with literature values.

Effective heat of combustion for flaming combustion of conifers

2006 ◽  
Vol 36 (3) ◽  
pp. 659-663 ◽  
Author(s):  
Vytenis Babrauskas
Keyword(s):  
Moisture Content ◽  
Forest Fire ◽  
Fire Hazard ◽  
Douglas Fir ◽  
Wood Products ◽  
Experimental Results ◽  
Heat Of Combustion ◽  
Benchmark Testing ◽  
Effective Heat ◽  
Effective Heat Of Combustion

The heat of combustion of burning trees is often used in forest-fire hazard modeling to relate mass-loss results to the heat produced; therefore reliable values are needed. Experimental results for the effective heat of combustion of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) trees are presented as a function of moisture content. It is also shown that during a forest fire, the effective heat of combustion does not correspond to the oxygen-bomb-test value. Instead, the value will always be lower, since the heat of combustion of char is higher than that of the pyrolysate vapors, and char mostly remains unburned during a forest fire. These are the first and only experimental results obtained from testing of actual trees. But results from benchmark testing and studies on wood products by other investigators are broadly consistent with our findings. It is further shown that moisture content has a major effect on the effective heat of combustion. A quantitative expression for the effective heat of combustion, as a function of moisture content, is obtained. Benchmark testing by earlier researchers established that generally there is only a slight species effect on the heat of combustion; therefore the present Douglas-fir results can be applied in more general forest-fire modeling.

scholarly journals Assessing the Economic and Environmental Impacts of Alternative Renewable Portfolio Standards: Winners and Losers

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3319
Author(s):  
Jamal Mamkhezri ◽  
Leonard A. Malczynski ◽  
Janie M. Chermak
Keyword(s):  
New Mexico ◽  
Environmental Impacts ◽  
The State ◽  
Policy Implications ◽  
Renewable Portfolio Standard ◽  
County Level ◽  
Renewable Portfolio Standards ◽  
Energy Potential ◽  
Output Analysis ◽  
The Impact

State-mandated renewable portfolio standards affect substantial portions of the total U.S. electricity supply. Renewable portfolio standards are environmentally motivated policies, yet they have the potential to greatly impact economy. There is not an agreement in the literature on the impact of renewable portfolio standards policies on regional economies, especially on job creation. By integrating various methodologies including econometrics, geographic information system, and input–output analysis into a unique system dynamics model, this paper estimates the economic and environmental impacts of various renewable portfolio standards scenarios in the state of New Mexico, located in Southwestern U.S. The state is endowed with traditional fossil fuel resources and substantial renewable energy potential. In this work we estimated and compared the economic and environmental tradeoffs at the county level under three renewable portfolio standards: New Mexico’s original standard of 20% renewables, the recently adopted 100% renewables standard, and a reduced renewable standard of 10%. The final one would be a return to a more traditional generation profile. We found that while the 20% standard has the highest market-based economic impact on the state as a whole, it is not significantly different from other scenarios. However, when environmental impacts are included, the 100% standard yields the highest value. In addition, while the state level economic impacts across the three scenarios are not significantly different, the county-level impacts are substantial. This is especially important for a state like New Mexico, which has a high reliance on energy for economic development. A higher renewable portfolio standard appears to be an economic tool to stimulate targeted areas’ economic growth. These results have policy implications.

scholarly journals Smallholder perceptions of land restoration activities: rewetting tropical peatland oil palm areas in Sumatra, Indonesia

2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Caroline Ward ◽  
Lindsay C. Stringer ◽  
Eleanor Warren-Thomas ◽  
Fahmuddin Agus ◽  
Merry Crowson ◽  
...  
Keyword(s):  
Smallholder Farmers ◽  
Fire Risk ◽  
Land Restoration ◽  
Peatland Restoration ◽  
Drainage Canals ◽  
Perceived Impacts ◽  
The Government ◽  
Restoration Target ◽  
Peat Fires ◽  
The Impact

AbstractThe Indonesian government committed to restoring over 2 million ha of degraded peatland by the end of 2020, mainly to reduce peat fires and greenhouse gas emissions. Although it is unlikely the government will meet this target, restoration projects are still underway. One restoration strategy involves blocking peatland drainage canals, but the consequences of this for smallholder farmers whose livelihoods are dependent on agriculture are unclear. This paper investigates perceived impacts of canal blocks on smallholder farmers and identifies factors that affect their willingness to accept canal blocks on their land. We use data from 181 household questionnaires collected in 2018 across three villages in Jambi province, Sumatra. We found that the majority of respondents would accept canal blocks on their farms, perceiving that the blocks would have no impact on yields or farm access, and would decrease fire risk. Respondents who would not accept blocks on their farms were more likely to use canals to access their farms and perceive that canal blocks would decrease yields. The majority of farmers unwilling to accept canal blocks did not change their mind when provided with an option of a block that would allow boat travel. Our results improve understanding of why some smallholders may be unwilling to engage with peatland restoration. Further research is needed to understand the impact of canal blocks on smallholders’ yields. Engaging with stakeholders from the outset to understand farmers’ concerns, and perceptions is key if the government is to succeed in meeting its peatland restoration target and to ensure that the costs and benefits of restoration are evenly shared between local stakeholders and other actors.

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