36 resultados para Biometano,upgrading,biogas

em Aston University Research Archive


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Customer Base Analysis is perhaps the first stage of analysis in customer value, aiming to predict purchase frequency and customer lifecycle. An important part of the customer purchase frequency and its retention has to do with the service upgrade. Many models have tried to predict purchase frequency as well as upgrading. The comparison of these models seems important to provide academics with a picture of the current situation. The purpose of this research is to evaluate how models can predict service upgrade among a customer database of an online DVD rental company and suggest an alternative based on data mining techniques and data on historical transactions.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Fast pyrolysis liquid or bio-oil has been used in engines with limited success. It requires a pilot fuel and/or an additive for successful combustion and there are problems with materials and liquid properties. It is immiscible with all conventional hydrocarbon fuels. Biodiesel, a product of esterification of vegetable oil with an alcohol, is widely used as a renewable liquid fuel as an additive to diesel at up to 20%. There are however limits to its use in conventional engines due to poor low temperature performance and variability in quality from a variety of vegetable oil qualities and variety of esterification processes. Within the European Project Bioliquids-CHP - a joint project between the European Commission and Russia - a study was undertaken to develop small scale CHP units based on engines and microturbines fuelled with bioliquids from fast pyrolysis and methyl esters of vegetable oil. Blends of bio-oil and biodiesel were evaluated and tested to overcome some of the disadvantages of using either fuel by itself. An alcohol was used as the co-solvent in the form of ethanol, 1-butanol or 2-propanol. Visual inspection of the blend homogeneity after 48 h was used as an indicator of the product stability and the results were plotted in a three phase chart for each alcohol used. An accelerated stability test was performed on selected samples in order to predict its long term stability. We concluded that the type and quantity of alcohol is critical for the blend formation and stability. Using 1-butanol gave the widest selection of stable blends, followed by blends with 2-propanol and finally ethanol, thus 1-butanol blends accepted the largest proportion of bio-oil in the mixture. © 2013 Elsevier Ltd. All rights reserved.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Reproducible preparation of a number of modified clay and clay~like materials by both conventional and microwave-assisted chemistry, and their subsequent characterisation, has been achieved, These materials are designed as hydrocracking catalysts for the upgrading of liquids obtained by the processing of coal. Contact with both coal derived liquids and heavy petroleum resids has demonstrated that these catalysts are superior to established proprietary catalysts in terms of both initial activity and deactivation resistance, Of particular activity were a chromium-pillared montmorillonite and a tin intercalated laponite, Layered Double Hydroxides (LDH's) have exhibited encouraging thermal stability. Development of novel methods for hydrocracking coal derived liquids, using a commercial microwave oven, modified reaction vessels and coal model compounds has been attempted. Whilst safe and reliable operation of a high pressure microwave "bomb" apparatus employing hydrogen, has been achieved, no hydrotreatment reactions occurred,

Relevância:

20.00% 20.00%

Publicador:

Resumo:

A comprehensive examination is made of the characteristics and quality requirements of bio-oil from fast pyrolysis of biomass. This considers all aspects of the special characteristics of bio-oil – how they are created and the solutions available to help meet requirements for utilisation. Particular attention is paid to chemical and catalytic upgrading including synthesis gas and hydrogen production which has seen a wide range of new research activities and also more limited attention to chemicals recovery. An appreciation of the potential for bio-oil to meet a broad spectrum of applications in renewable energy has led to a significantly increased R&D activity that has focused on addressing liquid quality issues both for direct use for heat and power and indirect use for biofuels and green chemicals. This increased activity is evident in North America, Europe and Asia with many new entrants as well as expansion of existing activities. The only disappointment is the more limited industrial development and also deployment of fast pyrolysis processes that are necessary to provide the basic bio-oil raw material.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

A hot filtration unit downstream of a 1kg/h fluidised bed fast pyrolysis reactor was designed and built. The filter unit operates at 450oC and consists of 1 exchangeable filter candle with reverse pulse cleaning system. Hot filtration experiments up to 7 hours were performed with beech wood as feedstock. It was possible to produce fast pyrolysis oils with a solid content below 0.01 wt%. The additional residence time of the pyrolysis vapours and secondary vapour cracking on the filter cake caused an increase of non-condensable gases at the expense of organic liquid yield. The oils produced with hot filtration showed superior quality properties regarding viscosity than standard pyrolysis oils. The oils were analysed by rotational viscosimetry and gel permeation chromatography before and after accelerated aging. During filtration the separated particulates accumulate on the candle surface and build up the filter cake. The filter cake leads to an increase in pressure drop between the raw gas and the clean gas side of the filter candle. At a certain pressure drop the filter cake has to be removed by reverse pulse cleaning to regenerate the pressure drop. The experiments showed that successful pressure drop recovery was possible during the initial filtration cycles, thereafter further cycles showed minor pressure drop recovery and therefore a steady increase in differential pressure. Filtration with pre-coating the candle to form an additional layer between the filter candle and cake resulted in total removal of the dust cake.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This paper provides an updated review on fast pyrolysis of biomass for production of a liquid usually referred to as bio-oil. The technology of fast pyrolysis is described including the major reaction systems. The primary liquid product is characterised by reference to the many properties that impact on its use. These properties have caused increasingly extensive research to be undertaken to address properties that need modification and this area is reviewed in terms of physical, catalytic and chemical upgrading. Of particular note is the increasing diversity of methods and catalysts and particularly the complexity and sophistication of multi-functional catalyst systems. It is also important to see more companies involved in this technology area and increased take-up of evolving upgrading processes. © 2011 Elsevier Ltd.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This paper explores the role of indigenous and foreign innovation efforts in technological upgrading in developing countries, taking into account sectoral specificities in technical change. Using a Chinese firm-level panel dataset covering 2001–05, the paper decomposes productivity growth into technical change and efficiency improvement and examines the impact of indigenous and foreign innovation efforts on these changes. Indigenous firms are found to be the leading force on the technological frontier in the low- and medium-technology industries, while foreign-invested firms enjoy a clear lead in the high-technology sector. Collective indigenous R&D activities at the industry level are found to be the major driver of technology upgrading of indigenous firms that push out the technology frontier. While foreign investment appears to contribute to static industry capabilities, R&D activities of foreign-invested firms have exerted a significant negative effect on the technical change of local firms over the sample period.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This paper explores the drivers of technology upgrading in emerging economies using a recent Chinese firm-level panel dataset over the 2001-2005 period. It extends the Directed Technical Change theory by considering differences in technology intensities across industries within a country; examines the drivers of technical change, efficiency improvement and TFP growth in Chinese manufacturing firms; and explores the roles of indigenous innovations and foreign technology. It finds that FDI contributes to static industry capabilities by advanced technologies embedded in imported machineries, but not to dynamic technological capabilities of indigenous firms in developing countries. Collective indigenous R&D activities at industry level are the major driver of technology upgrading of indigenous firms that push up the technology frontier. Policy implications are discussed.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The aim of this work is to improve some of the less desirable properties of bio-oil via the catalytic fast pyrolysis of sugarcane bagasse using a novel supported molybdenum carbide (20 wt.% MoC/AlO ) catalyst. Proximate and elemental analysis of the bagasse were carried out to determine the moisture, ash, carbon, hydrogen, nitrogen and oxygen content. The ground pellets were classified in sieves to a size range of 0.25-1 mm and were pyrolysed in a 300 g h fluidised bed reactor at 500 C. MoC/AlO replaced the sand in the fluidised bed reactor in different proportions (0 wt.%, 12 wt.%, 25 wt.% and 50 wt.%) to investigate the effect of this catalyst on the pyrolysis products. Bio-oil yield results showed that ground sugarcane bagasse pellets gave high organic yields in the bio-oil of 60.5 wt.% on dry feed with a total liquid yield of 73.1 wt.% on dry feed without catalyst. Increasing the catalyst proportions in the fluidised bed reduced bio-oil yields, significantly reduced sugars (as a-levoglucosan) concentration and increased furanics and phenolics concentration in the bio-oil. It was observed that the higher the concentration of the 20 wt.% MoC/AlO catalyst in the fluidised bed the lower the viscosity of the bio-oil. © 2013 Elsevier B.V. All rights reserved.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

A comprehensive examination is made of the characteristics and quality requirements of bio-oil from fast pyrolysis of biomass. An appreciation of the potential for bio-oil to meet a broad spectrum of applications in renewable energy has led to a significantly increased R&D activity that has focused on addressing liquid quality issues both for direct use for heat and power and indirect use for biofuels and green chemicals. This increased activity is evident in North America, Europe, and Asia with many new entrants as well as expansion of existing activities. The only disappointment is the more limited industrial development and also deployment of fast pyrolysis processes that are necessary to provide the basic bio-oil raw material. © 2012 American Institute of Chemical Engineers (AIChE).

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Biomass is the term given to naturally-produced organic matter resulting from photosynthesis, and represents the most abundant organic polymers on Earth. Consequently, there has been great interest in the potential exploitation of lignocellulosic biomass as a renewable feedstock for energy, materials and chemicals production. The energy sector has largely focused on the direct thermochemical processing of lignocellulose via pyrolysis/gasification for heat generation, and the co-production of bio-oils and bio-gas which may be upgraded to produce drop-in transportation fuels. This mini-review describes recent advances in the design and application of solid acid catalysts for the energy efficient upgrading of pyrolysis biofuels.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Propylsulfonic acid derivatised SBA-15 catalysts have been prepared by post modification of SBA-15 with mercaptopropyltrimethoxysilane (MPTMS) for the upgrading of a model pyrolysis bio-oil via acetic acid esterification with benzyl alcohol in toluene. Acetic acid conversion and the rate of benzyl acetate production was proportional to the PrSO3H surface coverage, reaching a maximum for a saturation adlayer. Turnover frequencies for esterification increase with sulfonic acid surface density, suggesting a cooperative effect of adjacent PrSO3H groups. Maximal acetic acid conversion was attained under acid-rich conditions with aromatic alcohols, outperforming Amberlyst or USY zeolites, with additional excellent water tolerance.

Relevância:

20.00% 20.00%

Publicador: