Review of fast pyrolysis of biomass and product upgrading

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.

Indigenous and foreign innovation efforts and drivers of technological upgrading:evidence from China

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.

Indigenous and foreign innovation efforts and drivers of technological upgrading:evidence from China

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.

In situ catalytic upgrading of bio-oil using supported molybdenum carbide

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.

Upgrading biomass fast pyrolysis liquids

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).

Catalytic upgrading of bio-oils by esterification

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.

Mesoporous sulfonic acid silicas for pyrolysis bio-oil upgrading via acetic acid esterification

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.

Upgrading legacy long-haul WDM systems through unbalancing the proportion of 1s and 0s in the transmitted data

We present experimental results for wavelength-division multiplexed (WDM) transmission performance using unbalanced proportions of 1s and 0s in pseudo-random bit sequence (PRBS) data. This investigation simulates the effect of local, in time, data unbalancing which occurs in some coding systems such as forward error correction when extra bits are added to the WDM data stream. We show that such local unbalancing, which would practically give a time-dependent error-rate, can be employed to improve the legacy long-haul WDM system performance if the system is allowed to operate in the nonlinear power region. We use a recirculating loop to simulate a long-haul fibre system.

Does market upgrading benefit farmers? : market differentiation, contract farming, and professional cooperatives in China's pork processing industry

This study tested whether contract farming or farmers professional cooperatives (FPCs) improved the social benefit of pork production and income of breeding farmers in China. The main concern of this study is whether institutional arrangement like contract farming or FPCs actually improved the welfare of farmers as expected. To answer this question accurately, we estimated the differentiated market demand of pork products in order to quantify the benefit by transaction types. Our study finds that contract farming or FPCs improved the benefits of pork products, but farmer's income remained lower than that of traditional transaction types. This finding is new in terms of quantifying distribution of the economic values among sales outlets, agro-firms and farmers. It is more reliable because it explicitly captures impacts from both demand side and supply side by structural estimation. In practice, we need to keep it mind the bargaining power of small farmers will not improve instantly even when the contract farming or FPCs are introduced.

An overview of top-down vs. bottom-up models for informal settlement upgrading in South Africa

The paper explores informal settlement upgrading approaches in South Africa and presents a review of top-down vs. bottom-up models, using experience and lessons learned from the Durban metropolitan area. Reflections on past upgrading efforts suggest that top-down policies in South Africa have not been successful to date. By contrast, participatory techniques, such as planning activism, can be used to enhance community empowerment and a sense of local ownership. This paper reveals that although the notion of ‘bottom-up’, participatory methods for community improvement is often discussed in international development discourses, the tools, processes and new knowledge needed to ensure a successful upgrade are under-utilised. Participation and collaboration can mean various things for informal housing upgrading and often the involvement of local communities is limited to providing feedback in already agreed development decisions from local authorities and construction companies. The paper concludes by suggesting directions for ‘co-producing’ knowledge with communities through participatory, action-research methods and integrating these insights into upgrading mechanisms and policies for housing and infrastructure provision. The cumulative impacts emerging from these approaches could aggregate into local, regional, and national environmental, social and economic benefits able to successfully transform urban areas and ensure self-reliance for local populations.