Biofuels compositions

Palm oil has been cracked at atmospheric pressure and a reaction temperature of 723 K to produce biofuel in a fixed-bed microreactor. The reaction was carried out over microporous HZSM-5 zeolite, mesoporous MCM-41, and composite micromesoporous zeolite as catalysts. The products obtained were gas, organic liquid product, water, and coke. The organic liquid product was composed of hydrocarbons corresponding to gasoline, kerosene, and diesel boiling point range. The maximiun conversion of palm oil, 99 wt.%, and gasoUne yield of 48 wt.% was... 

Based on this ability to manipulate the algal composition, these organisms can be used for the production of different types of biofuel. For example, those algae which are rich in hpids are better suited for the production of bio-oil or biodiesel those rich in starch can be used for alcoholic fermentations to afford ethanol and those rich in proteins and starch can be used for the production of biogas. 

Justin Stege (Diversa Corporation) discussed the molecular evolution of enzymes for particular pathways, with a focus on the modification of oil composition. Oleochemical applications for such enzymes include applications as biocatalysts for fatty acid modifications. In a program to integrate production and processing, such enzymes can be used to modify the fatty acid content of vegetable oils in planta. Results show that expressing such new enzymes in oilseed crops has resulted in altered oil composition, and that the features may be used to better design plant-based oils for use as biofuels and as improved renewable feedstocks. 

Figure 4 The conversion of fiiel-N to NO from grate frimace (200 kW ), fluidized bed combustor (50 kW ) and stove furnaces for different biofuels compared to the conversion of Vol-N to NO calculated under plug flow conditions for wood Air-to-fuel ratio 1,2, 0 concentration 10 v-%, temperature 800°C, residence time 3 s, HCN / Vol-N ratio 0.2. Volatiles composition according to Table 1.

The biofuel ash characteristics defined by the composition (major and minor components) and fusion temperatures were also different (Table 2). All radiata pine wood residue biofuels (RPB, RPO and RPA) showed higher SiOj contents but lower... 

In this context, the present work aims at examining comparatively (I) chemical compositions, heating values and surface properties of char samples obtained from slow pyrolysis of different lignocellulosic wastes, in relation to their potential as biofuel and/or for fiuther processing to produce activated carbons (2) pyrolysis kinetics of the selected wastes, necessary for the design of the reactors for char production. 

Investigations on the behaviour of volatile and ash components have been carried out. The solid pyrolysis residues of several fuels have been analysed for their main ash composition and their devolatilisation. Increasing reaction temperatures result in a higher devolatilisation for all fuels. E g. straw shows a devolatilisation of approx. 80 above 600 °C pyrolysis temperature. But already at low pyrolysis tenqreratures of 400 °C a rather high devolatilisation of about 70 % can be reached. Other biofuel show a similar behaviour on ash and water free basis. Focusing the devolatilisation efficiency high temperatures in the pyrolysis process give best results, but also pyrolysis at low temperatures yields in sufficient devolatilisation rates. 

Table 2 Approximate compositions and properties for selected transport fossil fuels and biofuels...

Pizzariello, A., Stredansky. M.. and Miertus, S. (2002) A glucose/hydrogen peroxide biofuel cell that uses oxidase and peroxidase as catalysts by composite bulk-modified bioelectrodes based on a solid binding matrix. Bioelectrochemistry, 56 (1-2), 99-105. 

Air pollutants derived from biofuels are the result of incomplete combustion (conditions for efficient combustion of these fuels are difficult to achieve in typical household-scale stoves) and are practically the same for any type of biomass. However, the amount and the characteristics of pollutants produced during the burning of biomass fuels depend on several factors, including the composition of original fuel, combustion conditions (temperature and air flow). 

In addition to these substantial differences, several barriers currently impede the market entry of renewable resources Predominantly today s chemical industry is orientated towards fossil raw materials and thus the existing processes are incompatible with the new resources. Currently, the use of renewable resources leads to disadvantages in price compared with crude oil. Further, the qualitative and quantitative availability of the natural products hampers a major breakthrough. The supply and the composition of the renewables often change with year and location. Additionally, some renewable resources with special properties, such as palm oil, cannot be cultivated everywhere because of unfavorable climatic conditions and must therefore be imported via long routes. Furthermore, the increasing competition between using crops for food and feed on the one hand and for biofuels on the other hand causes ethical problems. 

The gas leaving the gasification reactor is often called producer gas. The same name is also used if this gas is cleaned to match the requirements for combustion within e.g. an engine or a turbine for the provision of electricity (and heat). If the gas is conditioned to fulfil certain requirements concerning the composition and it is intended to use this gas for the synthesis of liquid or gaseous biofuels it is called synthesis gas (or in abbreviated form syngas ). 

Hydrophobic/hydrophilic membranes for recovery of biofuel and dehydration, respectively Composite polydimethylsiloxane membrane... 

Controllable PHA molecular weight The use of PHA monomer methyl esters as a biofuel or fuel additives Plants as PHA production machines PHA with special properties Novel PHA with unique properties Controllable PHA compositions... 

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