Bench-scale Pyrolysis Research Articles

Pyrolysis of sweet orange ( Citrus sinensis) dry peel

Three different products were obtained from the pyrolysis of dry peel sweet orange: bio-oil, char and non-condensable gases. The yield of each product was determined. The bio-oil was characterized by GC–MS to determine that can be used as a renewable source of valuable industrial chemicals or as a source of energy, high heating value was calculated by Channiwala and Parikh correlation based on Dulong's Formula. Thermogravimetric analysis at 1, 5, 10, 20, and 40 °C/min, shows three different overlapped steps resulting in an average mass loss of ∼80% within the temperature range of 114–569 °C. The bench scale pyrolysis experiments, produces average yields of 53.1, 21.1 and 25.8 wt.% for bio-oil, char and gases, respectively. Bio-oil characterization by GC–MS and FTIR identified limonene as its main component while other identified compounds included δ-limonene, alcohols, phenols, benzene, toluene, xylene and carboxylic acids.

Simultaneous determination of major characteristic parameters of naphtha by capillary gas chromatography

A method for determining major characteristic parameters of naphthas by capillary gas chromatography was developed to identify the individual hydrocarbons in naphtha and determine the hydrocarbon-type PNA value, the average molecular weight, the carbon-to-hydrogen ratio, the density and boiling point range of naphtha. The method can also be used to analyze other light fractions of petroleum such as natural gas liquid and by-products from petrochemical processing such as raffinate oil. The data obtained by the method had a good agreement with those by other methods. The method was not affected by surroundings conditions when determining boiling point range of light petroleum fractions and can provide with more detailed information. The recovery percentage was 100% when the method used to measure boiling distribution of light fraction. The method was utilized to predict the pyrolytic effect of different naphthas for ethylene production. The prediction had an agreement with the results that were obtained by pyrolysis of naphthas on the Bench Scale Pyrolysis Apparatus (BSPA) made by M.W. Kellogg Company.

Gasification behaviour of Australian coals at high temperature and pressure

This paper presents gasification conversion data generated for a suite of Australian coals reacting with oxygen/nitrogen mixtures at 2.0 MPa pressure and at temperatures up to 1773 K, as part of a wider investigation into the gasification behaviour of Australian coals. The effects of O:C ratio, residence time and coal type on conversion levels and product gas composition were investigated under conditions relevant to those present in entrained-flow gasification systems. At higher temperatures, coal conversion levels are, as expected, higher, whilst product gas compositions continue to reflect the relevant gas phase equilibrium conditions. These gas phase equilibrium concentrations show strong dependence on the amount of carbon in the gas phase (i.e. coal conversion). The increased conversion achieved at high temperatures allows the contribution of coal-specific properties such as char structure and reactivity to be investigated in more detail than previously possible. Furthermore, at higher conversion levels the effects of coal type on product gas composition are more apparent than at lower conversion levels. These high temperature, high pressure gasification conversion data have been reconciled with high pressure bench-scale pyrolysis and char reactivity measurements, highlighting the significance of coal-specific effects of key gasification parameters.

Use of pyrolysis GC/MS for predicting emission byproducts from the incineration of double-base propellant.

Gas chromatography/mass spectrometry was used to analyze the pyrolytic byproducts from an Army-unique propellant compound (AA2) that is composed of predominantly nitrocellulose and nitroglycerin. Compounds produced by AA2 pyrolysis were compared to compounds detected in the gaseous effluent from AA2 incineration. The light permanent gases and most of the higher molecular weight byproducts produced by AA2 incineration are replicated by laboratory pyrolysis on AA2. The reverse case also holds whereby 18 out of 24 high molecular weight AA2 pyrolytic byproducts are found in the incinerator emissions. Poor matching, however, was obtained between the two processes for the volatile, water-soluble species. None of these low molecular weight compounds produced under pyrolytic conditions were detected in the AA2 incinerator samples, likely indicating inefficient capture of these compounds from the effluent stream. Separate pyrolytic degradation of the individual components of AA2 provides evidence that nearly all of the incomplete combustion products detected during incineration originate not from the prevalent energetic ingredients but rather from the minor and trace additives in AA2. In addition, pyrolysis successfully identified the AA2 components capable of surviving the incineration process intact. This work illustrates the potential of bench-scale pyrolysis for predicting incineration behavior.

Fate of polyaromatic hydrocarbons in the pyrolysis of industrial waste oils

Four different waste oils have been pyrolyzed using an experimental bench scale pyrolysis unit at 600 °C under atmospheric pressure and the polyaromatic hydrocarbons (PAHs) have been analyzed in the valuable liquid fraction. After the appropriate digestion and extraction procedures, the individual PAHs were quantified in each case by HPLC–UV. Toxicity of the PAHs mixture obtained in the liquid fraction resulting from the pyrolysis of machine waste oil, automotive waste oil, hydraulic waste oil and cutting waste oil as well as the PAHs profile are compared and discussed.

Synthesis and Characterization of Tris(catecholato) Silicates, [(C6H4O2)3Si]2-with Different Counter Cations – First Pyrolysis Study and X-ray Structure of [{(CH3)2CH}2NH2]2[(C6H4O2)3Si] · 2CH3CN · H2O

The synthesis of hypervalent tris(catecholato)silicate ion, [(C6H4O2)3Si]2- with six different counter cations: (i) diethylammonium (I), (ii) triethylammonium (II), (iii) diisopropylammonium (III), (iv) morpholinium (IV), (v) piperazinium (V) and (vi) N-methylpiperazinium (VI) has been achieved (yield: ca.95%) by the reaction of catechol and tetraethoxysilane in presence of the corresponding amine. Single crystal X-ray structure of compound (III) has been determined. It crystallizes in orthorhombic system [space group P212121; a = 11.735(2), b = 13.708(3), c = 23.283(5) A; α = 90°, β = 90°, γ = 90°; Volume = 3745.4(11) A3; Density = 1.165 gcm−3; Z = 4; R = 0.0585; wR2(I) = 0.1610 and 3677 reflections] and the structure shows slightly distorted octahedral geometry around silicon. Results of TG, DT and EG analysis of compounds (I)–(VI) reveal the influence of the counter cation on thermal stability. Bench scale pyrolysis of (I) and (II) convert them to [(C6H4O2)2Si] n by the quantitative expulsion of ammoni...

Low-cost sorbents for demetalisation of waste oils via pyrolysis

The behaviour of several solid sorbents during the pyrolysis process of industrial waste oils in a bench-scale pyrolysis unit is studied. The concentrations of V, Ni, Pb, Cd, Cu and Cr in the waste oils and in the original sorbents as well as that obtained in the final valuable product liquid fraction are measured. Limestone, commercial active char, Samca char, activated Samca char and sepiolite were the solid sorbents used. 100% of the lead from the waste oils can be retained on limestone. The behaviour of both metals and sorbents and the influence of specific surface area as well as chemical nature of metals and sorbents are discussed. Final liquid fractions resulted in valuable industrial products.

Progress in continuing oil shale project studies

Research, development and engineering effort has been maintained on Condor, Duaringa, Lowmead, Nagoorin and Nagoorin South oil shales. Results have steadily and progressively accumulated, and the first extremely detailed pyrolysis and combustion kinetics data were generated for at least one oil shale from each deposit. Bench scale pyrolysis and combustion studies have also been completed since last reported.

High severity pyrolysis of shale and petroleum gas oil mixtures

Light gas oil and heavy gas oil from Paraho shale oil and their mixtures with a petroleum light gas oil were pyrolyzed in the presence of steam at 880-900/sup 0/C and contact times between 60 and 90 ms in a nonisothermal bench-scale pyrolysis reactor. Blending of petroleum LGO into the shale oil feeds provided product yields that were the weighted linear combination of the yields of the individual components of the blends. Partial denitrogenation and a pronounced decrease in the rate of coke deposition on the reactor walls were observed when petroleum gas oil was blended with the shale gas oils.

Feedstock characterization and prediction of product yields for industrial naphtha crackers on the basis of laboratory and bench-scale pyrolysis

A new severity function has been introduced in order to plot and evaluate the yield data from hydrocarbon pyrolysis. It is demonstrated that the new severity function can also be used for the presentation of product yields obtained from hydrocarbon mixtures and naphtha fractions. In order to characterize and evaluate available feedstocks for olefin production, yields for seven naphtha fractions were determined in a bench-scale reactor. It was established that the yields of ethylene and propylene obtained from the different naphtha fractions increase proportionally with the increase in the characterization factor. On the basis of pyrolysis experiments carried out in laboratory, bench-scale and pilot reactors and in a commercial furnace it is shown that by using the new severity function the yield data obtained in reactors of different sizes and operating under different conditions can be directly compared and uniformly evaluated. The feasibility of micro-scale pyrolysis-gas chromatography for predicting product yields and evaluating naphtha feedstocks is also discussed.