A kinetic study of pyrolysis process of Parthenium hysterophorous is carried out by using thermogravimetric analysis (TGA) equipment. The present study investigates the thermal degradation and determination of the kinetic parameters such as activation E and the frequency factor A using model-free methods given by Flynn Wall and Ozawa (FWO), Kissinger-Akahira-Sonuse (KAS) and Kissinger, and model-fitting (Coats Redfern). The results derived from thermal decomposition process demarcate decomposition of Parthenium hysterophorous among the three main stages, such as dehydration, active and passive pyrolysis. It is shown through DTG thermograms that the increase in the heating rate caused temperature peaks at maximum weight loss rate to shift towards higher temperature regime. The results are compared with Coats Redfern (Integral method) and experimental results have shown that values of kinetic parameters obtained from model-free methods are in good agreement. Whereas the results obtained through Coats Redfern model at different heating rates are not promising, however, the diffusion models provided the good fitting with the experimental data.

Abstract-The purview of paper pivoted around the pyrolysis decomposition of forest waste (pine needle litter) by thermogravimetric analysis (TGA). Experiments were carried out in the presence of Nitrogen atmosphere. The experimental data was compared with those obtained by numerical solution of distributed activation energy model (DAEM). Asymptotic expansion is adopted to evaluate the pre-exponential factor, mean activation energy and variance. The correction factor Bi has been invoked to describe accurately the differential thermogravitmeric curves of thermal decomposition of pine needles.

Abstract:The forests of Chir pine (Pinus Roxburgii) encompass 97.4 thousand acres or 16.15 % of the total forest land of Uttrakhand, a state in India. According to Forest Department of India, Dehradun, a massive forest fire in 1995 engulfed 14.7 thousand acres of valuable forest area through 2,272 forest fire incidents in Uttrakhand, which resulted in the loss of crores of rupees and created various long-lasting ecological consequences. The fires damaged the fertile top layer of the soil and left a layer of pine needle litter that prevented rain water from being absorbed by the soil and contributed to early depletion of the groundwater cycle and stopped grass growth, thus depriving livestock of important food. So the question of what to do with these pine needles is an important one for forest and livestock. Regarding this problem, the German organization, Deutsche Gesellschaft für Internationale Zusammenarbeit, has been studying ways to use pine needles as a feedstock for downdraft gasifiers. If successful, the gasifier would provide incentive to collect the pine needles during dry months and improve the condition of the soil by allowing water to permeate top soils. Using chemical analysis, flue gas analysis, and combustion analysis, our paper analyzes the potential of pine needles as a substrate for gasification. We also argue that using pine needles in this way would alleviate carbon dioxide emissions due to forest fire. Average carbon dioxide emissions in forests that have an abundance of pine needles is 15.46%, but reduced to 12.8% when pine needles are used in a gasifier plant.Key words: Chemical analysis, Flue gas analysis, Combustion analysis, India rural people face severe consequences from the overuse of biomass: exposure to smoke from traditional cook stoves and open fires causes more than 1.5 premature deaths annually, with women and young children the most affected. Furthermore, people lose time and money by collecting and purchasing wood and the environment suffers from depletion of natural forests [3]. Materials and MethodsPine needles for gasification were collected from the seven sites in Uttrakhand and tested for chemical and physical properties. Chemical tests were performed at The Energy and Resource Institute (TERI) and Jawaharlal Nehru University (JNU) laboratories. Field work on gasifiers was conducted at the Chanderpur Works Private Limited (Yamunanagar) and TERI (Gurgaon) in Haryana. The schedule of parallel testing of 60 hrs and 40 hrs in Yamunanagar and Gurgaon was adopted for those sites, respectively. The industrial-based Kirloskar Green CNG Engine, SL 90 TA series, and the modified Kirloskar RV 3 series, generator sets have been used.

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Mitigating global climate change via emission control and taxation is promising for strengthening the economic benefits of bioenergy generation and utilization. This study examines the cost effectiveness of pine needles as an alternative fuel for off-grid electricity generation in India. We first examined the changes of prices in coal for electricity generation due to CO 2 emission reductions and taxes using experimental data of gasification plants. The time value of money and depreciation scale were used to find out the real levellized cost of electricity generation of gasification plants. Then, the costs of electricity generation fuelled by pine needles and coal were estimated using the cost analysis method. Our results indicate that pine needles would have more competitive edge than coal if emission had taxed at about an emission tax INR 525.15 Mg -1 of CO 2 (US$ 8.4), or higher would be needed for pine needles at a yield of 202.176 dry Mg hm -2 yr. The price of coal used for electricity generation would have significantly increased if global CO 2 emission had abridged by 20% or more. However, pine needles were found a much better fuel source with an increasing yield of 5.05 Mg hm -2 yr (with respect to power generation) and 2.335 Mg hm -2 yr (with respect to feedstock production).

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The Distributed Activation Energy Model (DAEM) or Multiple Reaction Model (MRM) applies either to the total amount of volatiles released or to the amount of an individual volatile constituent like carbon monoxide or tar (Howard, 1981). It is also called the Distributed Rate Model, and uses Vand's treatment of independent parallel processes (Vand, 1943) in modelling the resistance of metallic films. The detailed study includes the total amount of volatiles released during the pyrolysis process (Howard, 1981;Donskoi and McElwain, 1999). Originally, the coal devolatilization, however, was considered first to develop the Distributed Activation Energy Model (Pitt, 1962), yet the DAEM also applies to the pyrolysis of other materials, including biomass, residual oils, resin char (Teng and Hsieh, 1999), and kerogen (Lakshmanan and White, 1994). Calculations of solutions to this model involve evaluations of double integrals, which vary rapidly and hence create significant numerical difficulties. In order to tackle the integral complication, asymptotic expansion has been adopted for the accurate approximation to our problem. The solution for the DAEM model is given by Eq. (1): (1) where:-the time varying absolute temperature of the biomass R -the universal gas constant E -the activation energy k 0 -the pre-exponential or frequency factor β (β >0) -the scale parameter of initial distribution function respectivelyThe aim of this paper is to use asymptotic methods to make accurate approximations to the integrals and thereby evaluate the influence of relevant parameters on the biomass pyrolysis. Asymptotic expansionThe relationship between the DAEM and the single first order reaction model have been explored by Niksa and Lau (1993), which is based on the approach of holding the activation energy fixed, and defining an effective or nominal rate constant (Niksa and Lau, 1993). They also gave an analytical approximations to the DAEM for the exponentially and the linearly varying temperature profiles. The basis of approach lies on exploiting the rapid changes occurring in the double exponential term in Eq. (1). The procedure adopted by Niksa and Lau (1993) provides accurate approximations to the DAEM for all the relevant parameters for the kinetic mechanism of biomass pyrolysis. The modification done by them is simply refinement of the concept applied by Suuberg (1983), who used unit step function approximation to Double exponential term (DExp) (Howard, 1981;Vand, 1943;Pitt, 1962). In the subsequent sections, a more accurate approximation to DExp has been developed, which is implemented in the two different types of distribution cases (Narrow and Wide distribution). Acta Technologica Agriculturae 3 Nitra, Slovaca Universitas Agriculturae Nitriae, 2017, pp. 78-84 ApproximAtions to the non-isothermAl DistributeD ActivAtion energy moDel for biomAss pyrolysis using the rAyleigh Distribution This paper deals with the influence of some parameters relevant to biomass pyrolysis on the numerical solutions of the nonisothermal n th ...

This paper deals with pyrolysis decomposition of Cedrus deodara leaves with the help of thermogravimetric analysis (TGA). Experiments are performed in the presence of inert atmosphere of nitrogen. Experiments are conducted at three different heating rates of 5 °C∙min-1, 10 °C∙min-1 and 15 °C∙min-1 within temperature range of 35 °C to 700 °C. Arrhenius parameters such as activation energy and frequency factor are estimated by Flynn Wall and Ozawa (FWO), Kissinger-Akahira-Sonuse (KAS) and Kissinger. The activation energy and frequency factor calculated by using Kissinger method are 67.63 kJ∙mol-1 and 15.06 . 104 min-1 respectively; whereas the averaged values of the same parameters through FWO and KAS methods are 89.59 kJ∙mol-1 and 84.748 kJ∙mol-1, 17.27 . 108 min-1 and 62.13 . 107 min-1 respectively. Results obtained through Kissinger method represent the actual values of kinetic parameters. Conversely, FWO and KAS methods reflect the apparent values of kinetic parameters, as they are highly influenced by the overlapping of competitive reactions occur during pyrolysis.