Processing methods, characteristics and adsorption behavior of tire derived carbons: a review.

The remediation of carbon dioxide emitted into the atmosphere has become the topic of the day due to the enormous contribution of CO 2 to the devastating global warming. The Boudouard reaction, in which solid carbon (char) reacts with CO 2 to produce carbon monoxide (CO 2 (g)+C(s)↔CO (g)), is a straightforward route for the CO 2 emission mitigation. Through this reaction, the CO 2 coming from variety of combustion plants, including exhaust/flue gas and synthesis gas, can be upgraded to the fuel gas, CO. This work presents a review on the CO 2 gasification of char, from coal, biomass, municipal solid wastes, sewage sludge or any co-utilized blend of them, to produce CO through the Boudouard reaction. An outline of the most effective parameters on the char gasification rate is presented. The parameters which affect the char reactivity are reviewed as those related to the char and its structural features (surface area and porosity, active sites, mineral content, structural evolution of char during gasification, pyrolysis condition and carbon source) and operation parameters (use of catalyst, gasification temperature, gasification pressure and CO 2 partial pressure, char particle size and gasification heat source). The kinetics of the char gasification reaction is studied and several theoretical or semi-empirical kinetic models used to interpret the reaction rate data and calculation of kinetic parameters, specifically activation energy, are reviewed and discussed.

Conversion of the greenhouse gas CO2 to the fuel gas CO via the Boudouard reaction: A review

The increased worldwide demand for energy, particularly from petroleum-derived fuels has led to the search for a long-term solution of a reliable source of clean energy. Lignocellulosic biomasses appear to hold the key for a continuous supply of renewable fuels without compromising with the increasing energy needs. However, the major possible solutions to the current energy crisis include ethanol, bio-oils and synthesis gas (syngas) produced from lignocellulosic biomass. Recently, a great deal of research has been made in the fields of biomass conversion through biochemical, hydrothermal or thermochemical pathways to biofuels. However, a broad-spectrum assessment of the above pathways is rare in literature in terms of technology used, biofuel yields, potential challenges and possible outcomes. This review paper discusses different routes for biofuel production, particularly ethanol, bio-oil and syngas with the bio-oil upgrading techniques. This review highlights ethanol fermentation and available biomass pretreatment as the biochemical mode, not limiting to the pros and cons of the pretreatments. Supercritical water gasification (hydrothermal pathway) of biomass for syngas production followed by gas-to-liquid technologies (syngas fermentation and Fischer–Tropsch catalysis) has been discussed. In addition, thermochemical pathway dealing with biomass gasification for syngas and pyrolysis for bio-oils has been presented with compositional analysis of bio-oils and their upgrading technologies. The review focuses on various engineering limitations encountered during biomass conversion and bioprocessing with the potential solutions which do not restrict them to different biofuel production pathways.

Pathways of lignocellulosic biomass conversion to renewable fuels

The proper use of alternative fuels and materials in the cement industry is essential for the planning and promotion of different methods that can decrease the environmental impacts, lower the consumption of energy and material resources, and reduce the economic costs of this industry. Because of the great potential for the cement industry to save energy and reduce greenhouse gas emissions (GHG), many new research advances associated with the promising approach of introducing waste materials as alternative fuels or sustainable raw materials into the cement manufacturing process have been developed in recent years. Therefore, the main objective of this paper is to provide a literature review of these approaches based on previously published research studies. The analysis is specially focused on the technical, economic, and environmental effects of the uses of five solid wastes, namely, municipal solid waste (MSW), meat and bone animal meal (MBM), sewage sludge (SS), biomass, and end-of-life tyres (ELT), in the cement industry.

Uses of alternative fuels and raw materials in the cement industry as sustainable waste management options

The 7·106 t of waste tires that are generated yearly represent for a potential source of fuels considering its composition, rich in C and H, and its chemical features. Waste tires can be recycled through several processes aiming for either material, energy, or chemical product recovery. In this work we review the current status of these valorization pathways, with a particular focus on pyrolysis, its main products and their characteristics. Despite the extended reviews on the pyrolysis of tires, scarce material is available regarding the possibilities that scrap tires pyrolysis oil (STPO) offers and its limitations. STPO is both the most economically and energetically attractive product, and its composition (as obtained by different authors) is analyzed in this work, finding that the main barriers to solve for its direct implementation are (i) high sulfur content, (ii) high content of aromatics and (iii) high proportion of heavy molecules (>350 °C). From an industrial perspective, a sequential 2-stage hydrotreating–hydrocracking strategy has been proposed for STPO upgrading in order to simultaneously overcoming all these limitations and produce high quality fuels.

Opportunities and barriers for producing high quality fuels from the pyrolysis of scrap tires

Steam gasification of tyre waste, poplar, and refuse-derived fuel: a comparative analysis.

http://www.tygre.eu/cms/mi-top-download/category/5-proceedings?download=4%3Aecomondo-2010

Steam gasification of waste tyre: influence of process temperature on yield and product composition.

The disposal of waste tires represents a relevant problem within the waste management strategy of the European community: more than 300 000 000 tires are estimated to reach their end of life each year in the 27 member states of the European Union and comparable amounts are found in North America, Latin America, Asia, and the Middle East. The global total is ∼1 000 000 000 and rising each year. (Source: European Tyre Recycling Association (ETRA), 2006.) It is well-known that scrap tires possess high volatiles and low ash contents, together with a heating value that is higher than coal and biomass. These properties make them an ideal material for alternative thermal processes, such as pyrolysis and gasification, which can be finalized both to energy and material recovery. Within this frame, the present work is related to experimental tests and has obtained results of a combined process of scrap tire steam gasification and syngas catalytic reforming, with the aim of exploring the possible utilization of syng...

Optimizing H2 production from waste tires via combined steam gasification and catalytic reforming

The synthesis of beta silicon carbide (β-SiC) powders by carbothermal reduction of silica with carbon in a high temperature tube furnace was investigated. As carbon source, fine carbon-containing char from biomass gasification was used, in order to verify the feasibility of producing a high added value material starting from waste residue, and to promote the gasification processes as alternative route of energy production by the proper by-products exploitation. Starting mixture was prepared by mechanically mixing silica and char in the weight ratio of SiO2:C of 1.514; the mixture then reacted in a tube furnace at temperature of 1,550 °C at different residence times (1, 1.5, 2 and 2.5 h), at a constant flow rate of 0.8 dm3 min−1 of argon. The reaction products were characterised with XRD, FTIR spectroscopy and transmission electron microscopy (TEM). The process turned out to be capable of producing high quality SiC powders, suitable for making ceramic materials and composites; the product shows an uniform spherical shape, a very fine particle size (within the range of 30–100 nm) and a purity degree varying from 70% to 95%, depending on the residence time.

Synthesis of beta silicon carbide powders from biomass gasification residue

Refuse derived fuels (RDF) characterization and pyrolysis behaviour, carried out by means of thermogravimetric analysis, infrared and mass spectroscopy, are presented. Thermal degradation of RDF takes place through three main mass loss stages; the analyses of evolved gas allow us to discriminate the contributions of the different fractions (paper, LDPE, wood, rubber, etc.) to the global decomposition. Furthermore thermogravimetry (TG) was used for the determination of kinetic parameters, using the differential method. In order to set up the conditions of production of a good quality pyrolysis gas, the operating conditions of RDF in a pyrolysis reactor have been simulated. Data show that the volatile fraction grows with the temperature, together with the relative conversion, and that light volatile fraction (hydrogen, ethyne, etc.) gets richer, at the expense of superior homologous hydrocarbons.

Antonio Russo

Papers

Steam gasification of tyre waste, poplar, and refuse-derived fuel: a comparative analysis.

Steam gasification of waste tyre: influence of process temperature on yield and product composition.

Optimizing H2 production from waste tires via combined steam gasification and catalytic reforming

Synthesis of beta silicon carbide powders from biomass gasification residue

REFUSE DERIVED FUELS PYROLYSIS Influence of process temperature on yield and products composition