1,089 research outputs found
Stagnating liquid biofuel developments in Russia: Present status and future perspectives
It is widely acknowledged that Russia possesses enormous biomass resources (Hoogwijk et al., 2005). Its vast areas devoted to agricultural production and plentiful timber resources suggest good prospects for the development of liquid biofuel production. However, no significant advances in this direction have been reported till now. None of the numerous investment projects announced at the heydays of biofuel excitement in Russia (2006-2008) are at the moment commercially operating. There are no specialised plants for the production of bioethanol and biodiesel in Russia. Little is known of the reasons for this discrepancy between biofuel potential and actual development. In investigating this discrepancy, this article analyses national developments and investigates local dynamics through a case-study in the Omsk region. It is found that the reasons for this discrepancy are not related to technological incapabilities, but are to be found in the low policy and institutional priority given to non-fossil fuel exploitation and lack of market opportunities. Sprouts of second generation liquid biofuel technologies can be identified within the state system, but it remains to be seen how strong and how long these will be supported by the Russian stat
125th anniversary review: fuel alcohol: current production and future challenges
Global research and industrial development of liquid transportation biofuels are moving at a rapid pace. This is mainly due to the significant roles played by biofuels in decarbonising our future energy needs, since they act to mitigate the deleterious impacts of greenhouse gas emissions to the atmosphere that are contributors of climate change. Governmental obligations and international directives that mandate the blending of biofuels in petrol and diesel are also acting as great stimuli to this expanding industrial sector. Currently, the predominant liquid biofuel is bioethanol (fuel alcohol) and its worldwide production is dominated by maize-based and sugar cane-based processes in North and South America, respectively. In Europe, fuel alcohol production employs primarily wheat and sugar beet. Potable distilled spirit production and fuel alcohol processes share many similarities in terms of starch bioconversion, fermentation, distillation and co-product utilisation, but there are some key differences. For example, in certain bioethanol fermentations, it is now possible to yield consistently high ethanol concentrations of ~20% (v/v). Emerging fuel alcohol processes exploit lignocellulosic feedstocks and scientific and technological constraints involved in depolymerising these materials and efficiently fermenting the hydrolysate sugars are being overcome. These so-called secondgeneration fuel alcohol processes are much more environmentally and ethically acceptable compared with exploitation of starch and sugar resources, especially when considering utilisation of residual agricultural biomass and biowastes. This review covers both first and second-generation bioethanol processes with a focus on current challenges and future opportunities of lignocellulose-to-ethanol as this technology moves from demonstration pilot-plants to full-scale industrial facilities
Toward a sustainable biorefinery using high-gravity technology
The realization of process solutions for a sustainable bioeconomy depends on the efficient processing of biomass. High-gravity technology is one important alternative to realizing such solutions. The aims of this work were to expand the knowledge-base on lignocellulosic bioconversion processes at high solids content, to advance the current technologies for production of second-generation liquid biofuels, to evaluate the environmental impact of the proposed process by using life cycle assessment (LCA), and to develop and present a technically, economically, and environmentally sound process at high gravity, i.e., a process operating at the highest possible concentrations of raw material. The results and opinions presented here are the result of a Nordic collaborative study within the framework of the HG Biofuels project. Processes with bioethanol or biobutanol as target products were studied using wheat straw and spruce as interesting Nordic raw materials. During the project, the main scientific, economic, and technical challenges of such a process were identified. Integrated solutions to these challenges were proposed and tested experimentally, using wheat straw and spruce wood at a dry matter content of 30% (w/w) as model substrates. The LCA performed revealed the environmental impact of each of the process steps, highlighting the importance of the enzyme dose used for the hydrolysis of the plant biomass, as well as the importance of the fermentation yield
Alternative energy carriers for the transportation sector:Report prepared in framework of Øresund Ecomobility project
Evaluation of hydrophobic micro-zeolite-mixed matrix membrane and integrated with acetone–butanol–ethanol fermentation for enhanced butanol production
Opportunities, recent trends and challenges of integrated biorefinery: Part II
Availability of cost-competitive biomass conversion technologies plays crucial role for successful realization of biorefinery for sustainable production of fuels and organic chemicals from biomass. The present article provides an outline of opportunities and socio-techno-economic challenges of various biomass processing technologies. The biomass processing technologies were classified into three broad categories: thermochemical, chemical and biochemical. This review article presents an overview of two potential thermochemical conversion processes, gasification and fast pyrolysis, for direct conversion of lignocellulosic biomass. The article further provides a brief review of chemical conversion of triglycerides by transesterification with methanol for production of biodiesel. The highly productive microalgae as an abundant source of triglycerides for biodiesel and various other fuels products were also reviewed. The present article also provides an outline of various steps involved in biochemical conversion of carbohydrates to alcoholic bio-fuels, bio-ethanol and bio-butanols and conversion of nature׳s most abundant aromatic polymer, lignin, to value-added fuels and chemicals. Furthermore, an overview of production of hydrocarbon fuels through various biomass processing technologies such as hydrodeoxygenation of triglycerides, biosynthetic pathways and aqueous phase catalysis in hydrocarbon biorefinery were highlighted. The present article additionally provides economic comparisons of various biomass conversion technologies
Biofuels from algae: technology options, energy balance and GHG emissions: Insights from a literature review
During the last decade(s), algal biomass received increasing interest as a potential source of advanced biofuels production resulting in a considerable attention from research, industry and policy makers. In fact, algae are expected to offer several advantages compared to land-based biomass crops, including: better photosynthetic efficiency; higher oil yield; growth on non-fertile land; tolerance to a variety of water sources (i.e. fresh, brackish, saline) and CO2 re-using potential. The algal growth can be also integrated in wastewater (WW) treatment systems to combine the nutrient streams removal with biofuels production. In addition, a wide range of marketable co-products can be extracted from algae (e.g. chemicals, pharmaceuticals, nutritionals) along with the production of biofuels, under a biorefinery system. Considering the potential benefits, several European-funded pilot projects, under science-business partnerships, have been dedicated to the development of algae technologies in the biofuels and bioenergy sectors. Despite the extensive research and investments in the last decade(s), no large-scale, commercial algae-to-biofuels facilities were implemented yet. In fact, in the current algae cultivation sites, the produced biomass is currently exploited for production of food and feed, combined with the extraction of high added-value products, such as proteins, nutritional supplements and chemicals.
We report on the current-status of technology options for the potential exploitation of algae (of both macro- and microalgae species) in the biofuels and bioenergy sectors. We presents a comprehensive review of recent advances on promising algal biofuel production pathways, in terms of technological development, opportunities and limitations to their overall effectiveness.
Furthermore, we analyse the main features, assumptions, modelling approaches and results of the algal biofuel pathways considered in the LCA literature. We highlight and interpret the energy and greenhouse gas (GHG) emissions balances resulting from examined LCA studies, in view of the key parameters mainly affecting the results. A comparison of the performance associated to the proposed algal biofuels pathways with that found for conventional fossil derived fuels is also reported.JRC.F.8-Sustainable Transpor
Biobutanol as Fuel for Direct Alcohol Fuel Cells-Investigation of Sn-Modified Pt Catalyst for Butanol Electro-oxidation
Direct alcohol fuel cells (DAFCs) mostly use low molecular weight alcohols such as methanol and ethanol as fuels. However, short-chain alcohol molecules have a relative high membrane crossover rate in DAFCs and a low energy density. Long chain alcohols such as butanol have a higher energy density, as well as a lower membrane crossover rate compared to methanol and ethanol. Although a significant number of studies have been dedicated to low molecular weight alcohols in DAFCs, very few studies are available for longer chain alcohols such as butanol. A significant development in the production of biobutanol and its proposed application as an alternative fuel to gasoline in the past decade makes butanol an interesting candidate fuel for fuel cells. Different butanol isomers were compared in this study on various Pt and PtSn bimetallic catalysts for their electro-oxidation activities in acidic media. Clear distinctive behaviors were observed for each of the different butanol isomers using cyclic voltammetry (CV), indicating a difference in activity and the mechanism of oxidation. The voltammograms of both n-butanol and iso-butanol showed similar characteristic features, indicating a similar reaction mechanism, whereas 2-butanol showed completely different features; for example, it did not show any indication of poisoning. Ter-butanol was found to be inactive for oxidation on Pt. In situ FTIR and CV analysis showed that OHads was essential for the oxidation of primary butanol isomers which only forms at high potentials on Pt. In order to enhance the water oxidation and produce OHads at lower potentials, Pt was modified by the oxophilic metal Sn and the bimetallic PtSn was studied for the oxidation of butanol isomers. A significant enhancement in the oxidation of the 1° butanol isomers was observed on addition of Sn to the Pt, resulting in an oxidation peak at a potential ?520 mV lower than that found on pure Pt. The higher activity of PtSn was attributed to the bifunctional mechanism on PtSn catalyst. The positive influence of Sn was also confirmed in the PtSn nanoparticle catalyst prepared by the modification of commercial Pt/C nanoparticle and a higher activity was observed for PtSn (3:1) composition. The temperature-dependent data showed that the activation energy for butanol oxidation reaction over PtSn/C is lower than that over Pt/C
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