Fast pyrolysis utilizes biomass to produce a product that is used both as an energy source and a feedstock for chemical production. Considerable efforts have been made to convert wood biomass to liquid fuels and chemicals since the oil crisis in mid-1970s. This review focuses on the recent developments in the wood pyrolysis and reports the characteristics of the resulting bio-oils, which are the main products of fast wood pyrolysis. Virtually any form of biomass can be considered for fast pyrolysis. Most work has been performed on wood, because of its consistency and comparability between tests. However, nearly 100 types of biomass have been tested, ranging from agricultural wastes such as straw, olive pits, and nut shells to energy crops such as miscanthus and sorghum. Forestry wastes such as bark and thinnings and other solid wastes, including sewage sludge and leather wastes, have also been studied. In this review, the main (although not exclusive) emphasis has been given to wood. The literature on woo...

Pyrolysis of Wood/Biomass for Bio-oil: A Critical Review

Biodiesel is a renewable transportation fuel consisting of fatty acid methyl esters (FAME), generally produced by transesterification of vegetable oils and animal fats. In this review, the fatty acid (FA) profiles of 12 common biodiesel feedstocks were summarized. Considerable compositional variability exists across the range of feedstocks. For example, coconut, palm and tallow contain high amounts of saturated FA; while corn, rapeseed, safflower, soy, and sunflower are dominated by unsaturated FA. Much less information is available regarding the FA profiles of algal lipids that could serve as biodiesel feedstocks. However, some algal species contain considerably higher levels of poly-unsaturated FA than is typically found in vegetable oils. Differences in chemical and physical properties among biodiesel fuels can be explained largely by the fuels’ FA profiles. Two features that are especially influential are the size distribution and the degree of unsaturation within the FA structures. For the 12 biodiesel types reviewed here, it was shown that several fuel properties – including viscosity, specific gravity, cetane number, iodine value, and low temperature performance metrics – are highly correlated with the average unsaturation of the FAME profiles. Due to opposing effects of certain FAME structural features, it is not possible to define a single composition that is optimum with respect to all important fuel properties. However, to ensure satisfactory in-use performance with respect to low temperature operability and oxidative stability, biodiesel should contain relatively low concentrations of both long-chain saturated FAME and poly-unsaturated FAME.

Review of biodiesel composition, properties, and specifications

A review of the production of activated carbons from agricultural residues is presented. The effects of various process parameters on the pyrolysis stage are reviewed. Influences of activating conditions, physical and chemical, on the active carbon properties are discussed. Under certain process conditions several active carbons with BET surface areas, ranging between 250 and 2410 m 2 /g and pore volumes of 0.022 and 91.4 cm 3 /g, have been produced. A comparison in characteristics and uses of activated carbons from agricultural residues with those issued from tires, and commercial carbons, have been made. A review is carried out of the reaction kinetic modelling, applied to pyrolysis of agricultural wastes and activation of their pyrolytic char.

Agricultural residues as precursors for activated carbon production—A review

Porous carbons have several advantageous properties with respect to their use in energy applications that require constrained space such as in electrode materials for supercapacitors and as solid state hydrogen stores. The attractive properties of porous carbons include, ready abundance, chemical and thermal stability, ease of processability and low framework density. Activated carbons, which are perhaps the most explored class of porous carbons, have been traditionally employed as catalyst supports or adsorbents, but lately they are increasingly being used or find potential applications in the fabrication of supercapacitors and as hydrogen storage materials. This manuscript presents the state-of-the-art with respect to the preparation of activated carbons, with emphasis on the more interesting recent developments that allow better control or maximization of porosity, the use of cheap and readily available precursors and tailoring of morphology. This review will show that the renewed interest in the synthesis of activated carbons is matched by intensive investigations into their use in supercapacitors, where they remain the electrode materials of choice. We will also show that activated carbons have been extensively studied as hydrogen storage materials and remain a strong candidate in the search for porous materials that may enable the so-called Hydrogen Economy, wherein hydrogen is used as an energy carrier. The use of activated carbons as energy materials has in the recent past and is currently experiencing rapid growth, and this review aims to present the more significant advances.

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Energy storage applications of activated carbons: supercapacitors and hydrogen storage

The world is confronted with the twin crises of fossil fuel depletion and environmental degradation. The indiscriminate extraction and consumption of fossil fuels have led to a reduction in petroleum reserves. Alternative fuels, energy conservation and management, energy efficiency and environmental protection have become important in recent years. The increasing import bill has necessitated the search for liquid fuels as an alternative to diesel, which is being used in large quantities in transport, agriculture, industrial, commercial and domestic sectors. Biodiesel obtained from vegetable oils has been considered a promising option. In this paper, an attempt has been made to review the work done on biodiesel production and utilization, resources available, process(es) developed/being developed, performance in existing engines, environmental considerations, the economic aspect, and advantages in and barriers to the use of biodiesel.

Prospects of biodiesel production from vegetable oils in India

Thermal regeneration of activated carbon saturated with p-nitrophenol

Conversion of tomato-peel waste into solid fuel by hydrothermal carbonization: Influence of the processing variables

A study was made of the reaction of transesterification of Cynara cardunculus L. oil by means of methanol, using sodium hydroxide, potassium hydroxide, and sodium methoxide as catalysts. The objective of the work was to characterize the methyl esters for use as biodiesels in internal combustion motors. The operation variables used were methanol concentration (5−21 wt %), catalyst concentration (0.1−1 wt %), and temperature (25−60 °C). The evolution of the process was followed by gas chromatography, determining the concentration of the methyl esters at different reaction times. The biodiesel was characterized by determining its density, viscosity, high heating value, cetane index, cloud and pour points, Ramsbottom carbon residue, characteristics of distillation, and flash and combustion points according to ISO norms. The biodiesel with the best properties was obtained using 15% methanol, sodium methoxide as catalyst (1%), and 60 °C temperature. This biodiesel has very similar properties to those of diesel ...

Preparation and Properties of Biodiesel from Cynara cardunculus L. Oil

The purpose of this study was to optimise the combustion process of different residues in a 11.6 kW mural boiler for domestic heating. The fuels used were pellets from three biomass residues (tomato, olive stone and cardoon (Cynara cardunculus L.)) and the forest pellet recommended by the boiler manufacturer. Previously, the fuels were characterised by means of the higher heating value, proximate and ultimate analyses. The influence of the residue type, fuel mass flow, draught and residue mixture on the combustion parameters was studied. A TESTO 300 M-I analyzer was used to determine the principal parameters of the combustion process (CO2, CO and O2 contents, fumes temperature, not-burnt gaseous and sensitive heat losses in the fumes, volumetric flow rate and velocity of the fumes, air excess coefficient, efficiency). The behaviour of the three residues is similar to that of the forest pellet. The boiler efficiencies obtained with the maximum fuel mass flow (100%) and minimum draught (0%) were 90%, 90.5%, 89.7% and 91.6% for tomato, forest, olive stone and cardoon pellets, respectively. The optimum residue mixture was tomato (75%) and forest (25%) with a boiler efficiency of 92.4% for a mass flow and draught of 75% and 0%, respectively.

E. Sabio

Papers

Thermal regeneration of activated carbon saturated with p-nitrophenol

Conversion of tomato-peel waste into solid fuel by hydrothermal carbonization: Influence of the processing variables

Preparation and Properties of Biodiesel from Cynara cardunculus L. Oil

Combustion optimisation of biomass residue pellets for domestic heating with a mural boiler

Volatile compounds present in six types of dry-cured ham from south European countries