Ascertaining Optimum Pyrolysis Conditions for Biochar Production from Maple Sawdust

Sawdust is a bi-product from wood processing industries. In the recent time, pyrolysis of organic waste is an emerging technology where biochar can be produced and used for carbon sequestration. In that respect, the aim of the present work was to ascertaining optimum pyrolysis conditions in producing sawdust biochar (SBC) for the said uses. The raw material was collected from Belad furniture industry because of their specialization in furniture work and large volume availability. The proximate and ultimate analysis of 3.56% moisture, 1.49% ash content, 72.32% carbon and 0.19% surphur confirmed its good candidature for biochar production. The pyrolysis experiment was carried out by using six combination each of temperature (400, 450, 500, 550, 600 and 650°C), nitrogen flow rates (0.5, 1.0, 1.5, 2.0, 2.5 and 3.0L/mins) and residence times (10, 20, 30, 40, 50 and 60mins). Analysis of resulted biochar was done according to IBI standard. Results showed that the three factors decrease the yield of biochar at their increasing values. SBC yield being optimum at temperature of 400°C, 10 min residence time and 1.0L/min nitrogen flow rate.

Recent Perspectives in Biochar Production, Characterization and Applications

This chapter presents the most promising features and applications of biochar along with their optimal pyrolysis conditions. Biochars have a range of physicochemical properties depending on the feedstock and pyrolysis conditions, which greatly affect their wide applications. The biochar production and its characteristics, including the effect of feedstocks and different process-parameters on the properties and yield of biochar are thoroughly examined. The higher pyrolysis-temperature can give higher carbon-contents, pH, and surface-areas of biochars while volatiles and molar-ratios of O/C, H/C and N/C decrease with pyrolysis-temperature. Higher carbon-content and neutral-pH biochars have high affinity for organic pollutants due to high surface areas, making them attractive for adsorption and catalysis purposes. Biochars with higher-pH are preferred for soil application to correct soil-acidity. Thus, the pyrolysis temperature should be selected as per the final application of the biochar. Characterization of biochars of different feedstocks and pyrolysis conditions is reviewed and presented along with their proximate and ultimate analysis.

Microwave-Assisted Pyrolysis of Cashew Nut Shell

This research examines the characteristics of microwave assisted pyrolysis products of cashew nutshell waste (CNS). The pyrolysis process of CNS conducted with microwave heating of 400 W for 60 minutes. Pyrolysis product such as bio-gas, bio-oil and bio-char were identified using proximate and ultimate analysis, scanning electron microscope (SEM), thermogravimetric analysis (TGA/DTG), gas chromatograph-mass spectrometer (GC-MS) and Fourier Transform InfraRed (FTIR) Method. There is a significant increasing in volatile matter and fixed carbon of derived bio-char and the porous structure was observed in a range of macropore after pyrolysis. The TGA profile reveals CNS sample lost about 71.25% of mass before reached 750℃. The highest decomposition rate on the DTG profile was 0.57 mg/min and 0.56 mg/min as observed at about 261.2℃ and 340.3℃. Bio-oil yield has density of 1.036 gr/ml, viscosity of 19.5 cst after water removing, flash point of 138℃ and HHV of 21.7 MJ/kg. The GC-MS of the bio-oil shows about 53% phenol, 19% palmitic and oleic acid, 11% cyclobutene, 14% ethyl and methyl ester, and cyclopentene and cyclohexane in small amounts in accordance with FT-IR results.

Experimental Study of Absorbent Hygiene Product devolatilization in a bubbling fluidized bed

This paper aims to investigate the usage of waste from Absorbent Hygienic Products (AHP) as a fuel for gasification or pyrolysis, two attractive routes to obtain valuable products and dispose of this kind of waste. The study experimentally investigated the devolatilization of coarsely shred-ded materials from diapers, in a laboratory-scale bubbling fluidized bed made of sand, as a rep-resentative preparatory step of above-mentioned thermochemical conversions. Two versions of shredded materials were considered: as-manufactured diapers (AHPam, as a reference), and the cellulosic fraction of sterilized used diapers (AHPus). Results were presented, obtained from physic-chemical characterization of AHPam and AHPus (TGA, CHNS/O, proximate and ultimate analysis, XRF, ICP-AES, SEM-EDS) and their devolatilizations at 500-600-700-800°C, under two different atmospheres (air plus nitrogen, or pure nitrogen as a reference). Generally, temperature had most influenced syngas composition, with better performances under pure nitrogen. At 700-800 °C under pure nitrogen, the highest syngas quality and yield were obtained. For AHPam and AHPus, respectively: (i) H2 richness equaled 29.5 vol% and 23.7 vol%, while hydrocarbons poorness equaled 14.8 vol% and 7.4 vol% on dry, dilution-free basis; (ii) 53.7 Nl 100 gfuel-1 and 46.0 Nl 100 gfuel-1 were produced. Overall, AHP emerged as an interesting fuel for thermochemical conversions.

Lab-Scale Study of Temperature and Duration Effects on Carbonized Solid Fuels Properties Produced from Municipal Solid Waste Components

In work, data from carbonization of the eight main municipal solid waste components (carton, fabric, kitchen waste, paper, plastic, rubber, paper/aluminum/polyethylene (PAP/AL/PE) composite packaging pack, wood) carbonized at 300–500 °C for 20–60 min were used to build regression models to predict the biochar properties (proximate and ultimate analysis) for particular components. These models were then combined in general models that predict the properties of char made from mixed waste components depending on pyrolysis temperature, residence time, and share of municipal solid waste components. Next, the general models were compared with experimental data (two mixtures made from the above-mentioned components carbonized at the same conditions). The comparison showed that most of the proposed general models had a determination coefficient (R2) over 0.6, and the best prediction was found for the prediction of biochar mass yield (R2 = 0.9). All models were implemented into a spreadsheet to provide a simple tool to determine the potential of carbonization of municipal solid waste/refuse solid fuel based on a local mix of major components.

Influence of addition of KOH on the yield and characteristics of humic acids extracted from lignite using NaOH

In this study, humic acids (HAs) were extracted from Chinese lignite by adding KOH to a NaOH solution. The extraction yield of HAs was found to improve because of the synergistic effect imparted by the alkali mixture of sodium hydroxide (NaOH) and potassium hydroxide (KOH). The maximum yield was obtained at 150 min by adding the mixture of 0.750 M NaOH + 0.710 M KOH to Xianfeng lignite at 80 °C. The potassium (K), sodium (Na), nitrogen (N), oxygen (O), and iron (Fe) contents were determined by X-ray diffraction, scanning electron microscopy, and proximate and ultimate analysis. The oxygen-containing functional groups in HAs were identified by Fourier transform infrared spectroscopy. The addition of KOH resulted in higher oxygen/carbon and nitrogen/carbon ratios and oxygen-containing functional groups, as compared with that in NaOH alone. The extractants containing KOH could release HAs with a higher proportion of K, Fe, N contents, which is beneficial for HAs fertilizers prepared from the lignite. The release of the nutrients (K, Fe, N) which are essential for the crops is determined by the KOH dosages.