With increasing environmental and ecological concerns due to the use of petroleum-based chemicals and products, the synthesis of fine chemicals and functional materials from natural resources is of great public value. Nanocellulose may prove to be one of the most promising green materials of modern times due to its intrinsic properties, renewability, and abundance. In this review, we present nanocellulose-based materials from sourcing, synthesis, and surface modification of nanocellulose, to materials formation and applications. Nanocellulose can be sourced from biomass, plants, or bacteria, relying on fairly simple, scalable, and efficient isolation techniques. Mechanical, chemical, and enzymatic treatments, or a combination of these, can be used to extract nanocellulose from natural sources. The properties of nanocellulose are dependent on the source, the isolation technique, and potential subsequent surface transformations. Nanocellulose surface modification techniques are typically used to introduce e...

/pdf/nanocellulose-a-versatile-green-platform-from-biosources-to-2lbk2f63rt.pdf

Nanocellulose, a Versatile Green Platform: From Biosources to Materials and Their Applications

Intuitively, the rate of heat release from an unwanted fire is a major indication of the threat of the fire to life and property. This is indeed true, and a reliable measurement of a fire’s heat release rate was a goal of fire researchers at NBS and other fire laboratories at least as early as the 1960s. Historically, heat release measurements of burning materials were based on the temperature rise of ambient air as it passed over the burning object. Because the fraction of heat released by radiant emission varies with the type of material being burned, and because not all the radiant energy contributes to temperature rise of the air, there were large errors in the measurements. Attempts to account for the heat that was not captured by the air required siting numerous thermal sensors about the fire to intercept and detect the additional heat. This approach proved to be tedious, expensive, and susceptible to large errors, particularly when the burning “object” was large, such as a full-sized room filled with flammable furnishings and surface finishes. A novel alternative technique for determining heat release rate was developed at NBS during the 1970s. It had distinct advantages over the customary approach, but its widespread acceptance was hampered by uneasiness in the fire science community concerning potential errors if the technique were used in less-than-ideal circumstances. In 1980 Clayton Huggett, a fire scientist at NBS, published the seminal paper [1] that convinced the fire science community that the new technique was scientifically sound and sufficiently accurate for fire research and testing. The technique is now used worldwide and forms the basis for several national and international standards. The underlying principle of the new heat release rate technique was “discovered” in the early 1970s. Faced with the challenge of measuring the heat release of combustible wall linings during full-scale room fire tests, William Parker, Huggett’s colleague at NBS, investigated an alternative approach based on a simple fact of physics: in addition to the release of heat, the combustion process consumes oxygen. As part of his work on the ASTM E 84 tunnel test, Parker [2] explored the possibility of using a measurement of the reduction of oxygen in fire exhaust gases as an indicator of the amount of heat released by the burning test specimens. Indeed, for well-defined materials with known chemical composition, heat release and oxygen consumption can both be calculated from thermodynamic data. The problem with applying this approach to fires is that in most cases the chemical compositions of modern materials/ composites/mixes that are likely to be involved in real fires are not known. In the process of examining data for complete combustion (combustion under stoichiometric or excess air conditions) of the polymeric materials with which he was working, Parker found that, although the heat released per unit mass of material consumed (i.e., the specific heat of combustion), varied greatly, the amount of heat released per unit volume of oxygen consumed was fairly constant, i.e., within 15 % of the value for methane, 16.4 MJ/m of oxygen consumed. This fortunate circumstance—that the heat release rate per unit volume of oxygen consumed is approximately the same for a range of materials used to construct buildings and furnishings—meant that the heat release rate of materials commonly found in fires could be estimated by capturing all of the products of combustion in an exhaust hood and measuring the flow rate of oxygen in that exhaust flow. The technique was dubbed oxygen consumption calorimetry, notwithstanding the absence of any actual calorimetric (heat) measurements. Later in the decade, Huggett [1] performed a detailed analysis of the critical assumption of constant proportionality of oxygen consumption to heat release. Parker’s assumption was based on enthalpy calculations for the complete combustion of chemical compounds to carbon dioxide, water, and other fully oxidized compounds. Indeed, a literature review by Huggett revealed that Parker’s findings were actually a rediscovery and extension of the work of W. M. Thornton [3], published in 1917, which found that the heat released per unit amount of oxygen consumed during the complete combustion of a large number of organic gases and liquids was fairly constant. Nevertheless, since in real fires and fire experiments the oxygen supply is sometimes limited, incomplete combustion and partially oxidized products can be produced. Huggett’s paper examined in detail the assumption of constant heat release per amount of oxygen consumed under real fire conditions and assessed its effect on the accuracy of heat release rate determinations for fires. Instead of expressing results on a unit volume basis, as Parker did, Huggett expressed results in the more convenient and less ambiguous unit mass of oxygen

Estimation of Rate of Heat Release by Means of Oxygen Consumption Measurements

Modeling of lignocellulosic biomass pyrolysis processes can be used to determine their key operating and design parameters. This requires significant amount of information about pyrolysis kinetic parameters, in particular the activation energy. Thermogravimetric analysis (TGA) is the most commonly used tool to obtain experimental kinetic data, and isoconversional kinetic analysis is the most effective way for processing TGA data to calculate effective activation energies for lignocellulosic biomass pyrolysis. This paper reviews the overall procedure of processing TGA data for isoconversional kinetic analysis of lignocellulosic biomass pyrolysis by using the Friedman isoconversional method. This includes the removal of “error” data points and dehydration stage from original TGA data, transformation of TGA data to conversion data, differentiation of conversion data and smoothing of derivative conversion data, interpolation of conversion and derivative conversion data, isoconversional calculations, and reconstruction of kinetic process. The detailed isoconversional kinetic analysis of TGA data obtained from the pyrolysis of corn stalk at five heating rates were presented. The results have shown that the effective activation energies of corn stalk pyrolysis vary from 148 to 473 kJ mol−1 when the conversion ranges from 0.05 to 0.85.

/pdf/processing-thermogravimetric-analysis-data-for-1brt22wocb.pdf

Processing thermogravimetric analysis data for isoconversional kinetic analysis of lignocellulosic biomass pyrolysis: Case study of corn stalk

Experimental methods in chemical engineering: Thermogravimetric analysis—TGA

Chapter 27 describes the history and development of techniques for measuring heat release rate (HRR). This chapter outlines features and details of today’s preferred instrument for measuring bench-scale HRR—the cone calorimeter. Other cone calorimeter measuring functions are

The Cone Calorimeter

Characterization of the thermal decomposition of two kinds of plywood with a cone calorimeter – FTIR apparatus

Characterization of the burning behavior and gaseous emissions of pine needles in a cone calorimeter – FTIR apparatus

Characterization of the radiative exchanges when using a cone calorimeter for the study of the plywood pyrolysis

Efectis France, route de l'Orme des Merisiers, 91193 Saint Aubin Cedex, France Efectis UK‐Ireland, Jordanstown Campus Block 27, Shore Road, Newtownabbey BT 37 0QB, UK Ulster University, FIRESERT, Jordanstown Campus Block 27, Shore Road, Newtownabbey BT 37 0QB, UK Correspondence Eric Guillaume, Efectis France, route de l'Orme des Merisiers, 91193 Saint Aubin Cedex, France. Email: eric.guillaume@efectis.com

https://www.onlinelibrary.wiley.com/doi/pdf/10.1002/fam.2635

Study of fire behaviour of facade mock-ups equipped with aluminium composite material-based claddings, using intermediate-scale test method

https://pure.ulster.ac.uk/ws/files/11570709/JAAP_2015_173_Revision_1_V0.pdf

Talal Fateh

Papers

Characterization of the thermal decomposition of two kinds of plywood with a cone calorimeter – FTIR apparatus

Characterization of the burning behavior and gaseous emissions of pine needles in a cone calorimeter – FTIR apparatus

Characterization of the radiative exchanges when using a cone calorimeter for the study of the plywood pyrolysis

Study of fire behaviour of facade mock-ups equipped with aluminium composite material-based claddings, using intermediate-scale test method

Experimental and modelling studies on the kinetics and mechanisms of thermal degradation of polymethyl methacrylate in nitrogen and air