Utilization of pyrolytic oil and hydrogen enriched syngas from single feedstock (delonix regia) through pyrolysis process and its influence on performance and emission characteristics in CI engine

The main objective of the present investigation is to conduct the performance, combustion and emission analysis of CI engine operated using hydrogen enriched syngas (pyrolytic gas) and biodiesel (pyrolytic oil) as dual fuel mode condition. Both the pyrolytic oil and syngas is obtained from single feedstock delonix regia fruit pod through pyrolysis process and then pyrolytic oil is converted into biodiesel through esterification. Initially biomass is subjected to thermal degradation at various pyrolysis temperature ranges like 350–600 °C. During the pyrolysis process syngas, pyrolytic oil and char are produced. The syngas is directly used in the CI engine and pyrolytic oil is converted into biodiesel and then used in the CI engine. The pyrolytic oil and syngas is subjected to FTIR and GC/TCD analysis respectively. The syngas analysis confirms the presence of various gases like H₂, CH₄, CO₂, CO and C₂H₄ in different proportions. The various proportions of the syngas is mainly depending upon the reactor temperature and moisture content in the biomass. The syngas composition varies with increase in the temperature and at 400 °C, higher amount of hydrogen is present and its composition are H₂ 28.2%, CO is 21.9%, CH₄ is 39.1% and other gases in smaller amounts. The biodiesel of B20 and syngas of 8lpm produced from the same feedstock are considered as test sample fuels in the CI engine under dual fuel mode operation to study the performance and emission characteristics. The study reveals that BTE has slight increase than diesel of 1.5% at maximum load. On the another hand emission like CO, HC and smoke are reduced by 15%,25% and 32% respectively at full load condition, whereas NO_x emission is increased at all loads in the range of 10–15%. Therefore B20+syngas of 8lpm can be used as an alternative fuel in CI engine without any modification and major products from pyrolysis process with waste biomass is fully used as fuel in the CI engine.     

Thermal degradation of corn starch based biodegradable plastic plates and determination of kinetic parameters by isoconversional methods using thermogravimetric analyzer

Oil shortage and awareness of environment pollution leads to the extensive use of biodegradable starch-based materials against synthetic plastics. The accumulated wastes of these plastics takes more time for natural recycling and the process is complex. Therefore the best option of recycling would be to convert these polymers into a source of energy by pyrolysis. So to understand the pyrolytic behaviour, kinetics of such waste plastics is studied by using thermogravimetric analysis at different heating rates of 10 °C, 20 °C, 40 °C, 60 °C, 80 °C and 100 °C in nitrogen atmosphere followed by characterization of the pyrolysis products. The kinetic parameters are obtained for two major stages of decomposition in two different temperature ranges 250–620 °C and 620–855 °C by iso-conversional methods such as Friedman, Coats-Redfern, FWO and Kissinger methods. The regression coefficient data (>0.9) of kinetic plots obtained for different methods best fits to the kinetic equation. Empirical formula of the compound is determined by ultimate analysis is CH_2.214S_0.0018O_0.6910. Proximate analysis gives the idea of volatile component which is74.33%. The range of average value of activation energy is 120.7013 kJ/mol to 140.7707 kJ/mol for the biodegradable plastic plate with different conversion (0.1–0.6) and (0.1–0.3) respectively at two different temperatures. The pyrolysis products obtained using a semi-batch reactor are characterized to know their composition and other properties.     

热解样品分析中重量的变化及其影响

热解除油是目前室内岩心分析中样品除油的主要方法之一，但由于热解温度较高，会对样品中粘土矿物的结构水和层间水产生较大的影响。本文结合粘土矿物的吸水特性，通过对大量的实验测定结果分析后认为：经过热解处理后的样品，在测定过程中受粘土矿物（主要是伊利石和蒙脱石）层间水变化的影响，会引起样品重量及样品孔隙空间体积的变化，从而对物性分析中孔隙度测定结果产生较大的影响。     

Autothermal two-stage gasification of low-density waste-derived fuels

In order to increase the efficiency of waste utilization in thermal conversion processes, pre-treatment is advantageous. With the Herhof Stabilat^® process, residual domestic waste is upgraded to waste-derived fuel by means of biological drying and mechanical separation of inerts and metals. The dried and homogenized waste-derived Stabilat^® fuel has a relatively high calorific value and contains high volatile matter which makes it suitable for gasification. As a result of extensive mechanical treatment, the Stabilat^® produced is of a fluffy appearance with a low density. A two-stage gasifier, based on a parallel-arranged bubbling fluidized bed and a fixed bed reactor, has been developed to convert Stabilat^® into hydrogen-rich product gas. This paper focuses on the design and construction of the configured laboratory-scale gasifier and experience with its operation. The processing of low-density fluffy waste-derived fuel using small-scale equipment demands special technical solutions for the core components as well as for the peripheral equipment. These are discussed here. The operating results of Stabilat^® gasification are also presented.     

多用途放射性废物焚烧系统工程验证试验

对建立的多用途放射性废物焚烧系统，进行了工程验证试验。试验主要包括固体废物（包括树脂）和废油焚烧及烟气净化时系统的性能测定、非放示踪试验、72h连续运行考验等。经过共计500多小时的试验，验证了工艺流程、主要设备结构、仪表测控及系统安全等设计的可行性和可靠性；系统运行平稳，设备及仪表工作正常。本系统可一炉多用，其处理能力、减容系数、焚烧灰中残炭率以及系统总去污系数等指标，均达到了设计要求。     

Depollution of atmospheric emissions of wood pyrolysis furnaces

The wood carbonization in Tunisia consists essentially of traditional activity using charcoaling stacks and pits characterized by high atmospheric pollution and poor energy conversion. Indeed, 70% of the initial mass of anhydrous wood are found in the vapor as aerosols, polluting and toxic gases and complex condensable organic compounds that can cause a substantial pollution of air, ground and water. Several processes of treatment and energy valorization of such effluents were proposed, but the incineration remains at present the most promising technique of depollution. The results show that the incineration, at about 1000°C, of wood carbonization smokes allows the destruction of 99% of the mass of pollutants except CO₂ and the reduction of polluting gas emission. The possible valorization of the smoke’s energy in the exit of the incinerator enhances the thermal efficiency of the process.     

Sulfur distribution in coke and sulfur removal during pyrolysis

In order to investigate the mechanisms of coke desulfurization by blowing additional gas into coking chamber during pyrolysis process, some experiments were conducted to study the effects of some factors on the distribution of sulfur in coke. These factors include pyrolysis temperatures, the kinds of the blowing gases and the diameters of coking chamber. It was found that sulfur was mainly released at the range of 300–600 °C. Under this temperature range, the sulfur content in coke can be reduced by 0.05–0.06% by blowing N₂, CO or CH₄, and by 0.14% by blowing H₂ at a space velocity of 1.2 mm/s compared with the absolute sulfur content of 0.92% in the case without gas feeding. Obviously, H₂ is more effective on sulfur removal than N₂, CO or CH₄. The total, organic and inorganic sulfur contents in coke increase with increasing the diameter of coking chamber under identical pyrolysis conditions. Both organic and inorganic sulfur contents in coke increase regularly from the center to brim at identical height of a coke column for all the cases. In addition, the organic and inorganic sulfur contents at the cranny surface are higher than those in interior at the same sampling position. X-ray photoelectron spectroscopy (XPS) analyses suggest that the main contributions to the increase of inorganic and organic sulfur contents are due to the formation of negative bivalent sulfur and thiophenic compounds, respectively.     

Characterization of CuInS2 thin films for solar cells prepared by spray pyrolysis

We have made a study of the chemical composition, the electrical, the optical and the structural properties of polycrystalline CuInS₂ thin films prepared by spray pyrolysis to be used for thin film solar cells. These films were deposited starting from aqueous solutions with different chemical compositions ([Cu]/[In] and [S]/[Cu] ratios) and at different substrate temperatures. In all cases, the material is p-type with grains preferentially oriented in the (112) direction of the sphalerite structure. The electro-optical properties show a very strong dependence on the [Cu]/[In] ratio in the solution. Films with copper excess have smaller resistivity and better crystallinity than those which are stoichiometric or have indium excess. The results obtained in this work show the possibility of having CuInS₂ thin films with a wide range of resistivity, a fact that could be important for making solar cells based on this material.     

Improved sooting tendency measurements for aromatic hydrocarbons and their implications for naphthalene formation pathways

Sooting tendencies have been determined for aromatic hydrocarbons using a new definition: the maximum soot volume fraction fv,max measured in a coflow methane/air nonpremixed flame whose fuel is doped with 400 ppm of the test hydrocarbon. These fv,max were converted into apparatus-independent yield sooting indices (YSIs) by the equation YSI=C×fv,max+D, where C and D are apparatus-specific parameters chosen so that YSI-benzene = 30 and YSI-1,2-dihydronaphthalene = 100. The dopants were added to the fuel mixture with a syringe pump and fv,max was measured with laser-induced incandescence. YSI was determined for 6 cycloaliphatics and for 62 aromatics, which included 28 alkylbenzenes, 10 alkenylbenzenes, 10 alkynylbenzenes, 25 multiply substituted benzenes, 6 two-ring aromatics, and 6 substituted benzenes with heteroatoms in the side chains. The YSIs correlate well with literature values of threshold sooting index (TSI), which is a more traditional sooting tendency based on the height of pure-fuelled flames at the smoke point. This agreement indicates that fv,max and smoke height are equivalent measures of sooting tendency and that YSI is largely apparatus-independent. However, the YSIs have a total uncertainty of ±3%, which is substantially better than the TSIs, and the number of aromatic YSIs reported here is more than double the number of aromatic TSIs in the literature. The YSIs depend strongly on molecular structure; thus they provide information about the chemical kinetic reaction mechanisms responsible for fuel decomposition and hydrocarbon growth from a broad cross section of one-ring aromatics. Important naphthalene formation pathways appear to include acetylene addition to ethynylphenyl, propargyl addition to benzyl, and methyl addition to indenyl. This last pathway is particularly significant because it converts indene quantitatively to naphthalene and because the side chains in many alkenylbenzenes and alkynylbenzenes cyclize to form five-membered rings.     

A MODEL OF A PYROLYSIS GASIFIER FOR PREDICTION COMPOSITIONS AND FLOU RATE OF PRODUCED GAS

A model of pyrolysis gasifier, which is mainly composed of a pyrolysis, a cracking and a combustion chamber, it developed to predict its performance parameters and to simulate its operation. Toe model consists of a pyrolysis-cracking sub-model, a secondary gasification sub-model and a combustion sub- model, of which the pyrolysis-cracking sub-model is modified to predict components of tbe pyrolysis gas. Then, It with the other two sub-models can predict components, heating value and flow rate of the produced gas, thermal efficiency and total energy efficiency of the gasifier as ell. Crank-Nicolson Scheme (half implicit difference formulation) in which the time step is not confined by stability and the cutting error is small, is applied to solving the model whose differential equations are nonlinear and have no analytic solution. Theo, the nonlinear difference algebraic equations are solved by interalions, which requires less storage of computer. Underrelaxation is applied to avoiding divergence of Causs-Seidel interations. Finally, the simulated results are input to Software Lotus 1-2-3, by which the results are printed and graphed so as to compare with the experimental ooes, and it shots acceptable agreement, thus validate the model.