Lignocellulosic resources uses for savings of fossil fuels

Lignocellulosic biomass makes up the main part of the biomass produced in the world (12.1011 ton per year); relatively speaking, saccharose and starch make up a lower part (108t). Wood (from secondary-growth species) and related biomaterial from primarygrowth species (palms, coconut, bamboo) make up nearly 80% of lignocellulosic biomass produced in the world. The remaining part mainly comes from co-products of food plants (straw and co-products from cereals and oleaginous plants, bagasse...) and also annual plants produced for fibre (cotton, flax, hemp). A part of these fibres is used for other various applications than energy: pulp, biomaterial, and bioproducts. The wide range of celluloses- lignin-hemicelluloses distribution and structure of these biopolymers sometimes limit their applications. The development of these applications is also limited by two factors: (1) the collection and the transport of the fibres are not well organized; (2) the fibres must be frequently left on the ground after harvesting in order to maintain the soil fertility. Lignocellulosic materials play a major role to save fossil fuels for three main reasons: (1) their elaboration and their use need a low quantity of energy, by comparison with other materials; (2) lignocellulosic materials capture carbon during plant growth and store it during the life cycle of the manufactured products; (3) savings of energy are also possible when the biomaterials are used on the spot instead of imported materials, without long transport distances. It is economically interesting to produce energy from lignocellulosic biomass only if a part of this biomass is used as far as possible for higher added value applications, i.e. plant materials. Co-products and by-products used for energy are then obtained at lower cost. Lignocellulosic materials and energy applications are directly linked due to carbon storage in biomass that is used for energy at the end of life cycle. (Résumé d'auteur

Literature review of physical and chemical pretreatment processes for lignocellulosic biomass

Different pretreatment technologies published in public literature are described in terms of the mechanisms involved, advantages and disadvantages, and economic assessment. Pretreatment technologies for lignocellulosic biomass include biological, mechanical, chemical methods and various combinations thereof. The choice of the optimum pretreatment process depends very much on the objective of the biomass pretreatment, its economic assessment and environmental impact. Only a small number of pretreatment methods has been reported as being potentially cost-effective thus far. These include steam explosion, liquid hot water, concentrated acid hydrolysis and dilute acid pretreatments

Pretreatment Processes of Biomass for Biorefineries: Current Status and Prospects

Producción CientíficaThis article seeks to be a handy document for the academy and the industry to get quickly up to speed on the current status and prospects of biomass pretreatment for biorefineries. It is divided into two biomass sources: vegetal and animal. Vegetal biomass is the material produced by plants on land or in water (algae), consuming sunlight, CO2, water, and soil nutrients. This includes residues or main products from, for example, intensive grass crops, forestry, and industrial and agricultural activities. Animal biomass is the residual biomass generated from the production of food from animals (e.g., manure and whey). This review does not mean to include every technology in the area, but it does evaluate physical pretreatments, microwave-assisted extraction, and water treatments for vegetal biomass. A general review is given for animal biomass based in physical, chemical, and biological pretreatments

Fifth International Conference on Renewable Resources and Biorefineries, 10-12 June 2009, Ghent, Belgium

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Lignocellulosic Biomass

Recently, there has been a growing awareness of the need to make better use of natural resources. Hence, the utilization of biomass has led to so-called biorefinery, consisting of the fractionation or separation of the different components of the lignocellulosic materials in order to achieve a total utilization of the same, and not only of the cellulosic fraction for paper production. The use of plant biomass as a basic raw material implies a shift from an economy based on the exploitation of non-renewable fossil fuels, with limited reserves or with regeneration cycles far below the rates of exploitation, to a bioeconomy based on the use of renewable organic natural resources, with balanced regeneration and extraction cycles. To make this change, profound readjustments in existing technologies are necessary, as well as the application of new approaches in research, development, and production."Biorefinery" is the term used to describe the technology for the fractionation of plant biomass into energy, chemicals, and consumer goods. The future generation of biorefinery will include treatments, leading to high-value-added compounds. The use of green chemistry technologies and principles in biorefineries, such as solvent and reagent recovery and the minimization of effluent and gas emissions, is essential to define an economically and environmentally sustainable process.In particular, the biorefinery of lignocellulosic materials to produce biofuels, chemicals and materials is presented as a solid alternative to the current petrochemical platform and a possible solution to the accumulation of greenhouse gases

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

Production of bioethanol from multiple waste streams of rice milling

This work describes the feasibility of using rice milling by-products as feedstock for bioethanol. Starch-rich residues (rice bran, broken, unripe and discolored rice) were individually fermented (20% w/v) through Consolidated Bioprocessing by two industrial engineered yeast secreting fungal amylases. Rice husk (20% w/v), mainly composed by lignocellulose, was pre-treated at 55 degrees C with alkaline peroxide, saccharified through optimized dosages of commercial enzymes (Cellic (R) CTec2) and fermented by the recombinant strains. Finally, a blend of all the rice by-products, formulated as a mixture (20% w/v) according to their proportions at milling plants, were co-processed to ethanol by optimized pre-treatment, saccharification and fermentation by amylolytic strains. Fermenting efficiency for each by-product was high (above 88% of the theoretical) and further confirmed on the blend of residues (nearly 52 g/L ethanol). These results demonstrated for the first time that the co-conversion of multiple waste streams is a promising option for second generation ethanol production