Botryococcus braunii is a colonial, unicellular green alga which synthesizes and accumulates special kind of hydrocarbons, extracellularly and in the colonies, up to over 50% of its total dry biomass. It became clear about fifty years ago that this unique alga had ever flourished in geological ages in many places of the world and formed many kinds of oilshales, Torbanite in Australia for instance. Coorongite, which is considered to be the peat stage of Torbanite, was found in South Australia in the earlier period of this century. And many disputes and speculations occured around the “fool's oil” drived from Coorongite. No oil fields were discovered after all with big investment. And now this organism is highlighted as a “oil plant” for a renewable fuel in the future. Berkeley strain was found to be most suitable for mass-cultivation among the many strains of Botryococcus braunii. The productivity of biomass and hydrocarbon were highest, and the hydrocarbon gave 60% of gasoline fraction of octane number ab-out 95. The growth characteristics and the features of the hydrocarbon were investigated. And the feasibility of production of the renewable fuel by mass-cultivation of this alga was discussed.
This report is described with the current status of research and development of pilot plant. The object of the R&D is to develop the technology to produce hydrogen from coal on a large scale and economically. The Research Association for Hydrogen-from-Coal Process Development (HYCOL) has been receiving commission from the New Energy and Industrial Technology Development Organization (NEDO) and has been established. The key technology of this gasification process has the following features: Oxygen-blownone-chamber and twostep spiral flow gasification system: This enables treatment of coal at a high temperature, leading to the higher gasi-fication efficiency and thus wider coal type utilization. (2) Dry coal feed system: This increases heat efficiency as well as product gas yield. (3) Multi-burner system: This can gasify a large amount of coal in a small but easy to scale-up gasifier. Slag self-coating refractory with water-cooled tubes: This can achieve long life of furnace wall and high reliability.
Although China is not yet a highly industrialized country, China has experienced severe atmospheric pollution due to coal combustion and discharged ca. 16 million ton of sulfur dioxide/year. Coal combustion is the primary contributor to atmospheric pollution, especially so in big cities. Concentration of total suspended particulate matter is usually higher in northern cities than in southern cities and higher in winter than in summer. pH of rainfall in cities, Chongqing and Guiyang, located at south of the Yangtze River is less than 5.6. However, no acid rain has been found in Beijing and Tianjin. Although the formation of acid rain can thus be thought of as dependent on the presence of enough sulfur dioxide, other factors such as alkalinity of airborne particulate matter and atmospheric concentration of gaseous ammonia also play important role. While, in Lanzhou and Beijing where petroleum in-dustry was developed and/or traffic volume was rapidly increased photochemical smog has appeared.
Since Victorian brown coal contains about 60wt.% moisture, it is necessary to remove the water from the coal before liquefaction. The effects of mois-ture content on liquefaction of the coal dewatered in a recycling solvent (DW-coal) were studied using an autoclave with iron oxide/sulfur catalyst under the following conditions: temperature of 430°C, initial hydrogen pressure of 6MPa and hold time of 1h. When moisture content of the coal decreased, distillate (b.p.<420°C) yield and H2 gas consumption increased, and heavy product (b.p.>420°C) and naphtha (b.p.<180°C) yields decreased. Gaseous product yields and reaction pressure also de-pended on the moisture content of the coal. Specifically CO/CO2 ratio was strongly affected by the moisture content, which indicated that CO shift reaction occurred and affected the H2 gas consumption. The coal dried with a tubular dryer (TD-coal) was liquefied under the same con-ditions as the DW-coal to compare the coals in reactivity. The reactivity of the TD-coal was lower than that of the DW-coal. According to these results, it is shown that the dewatering in the solvent is profitable for brown coal liquefaction.
The two-stage hydrotreatment of Morwell coal liquid vacuum residue (CLVR) were examined using an autoclave and a commercial Ni-Mo/Al2O3 catalyst under the conditions of 390°C-2h and 430°C-2h, before and after the solvent fractionation with THF or the pretreatment with HCl/THF. The THF soluble fraction of CLVR was further treated using a cation-exchange resin or an activated alumina column chromatography. The pretreatment of whole CLVR with HCl/THF was more effective in the recovery and maintaining the catalytic activity of nitrogen removal than the THF extraction through the selective removal of specific nitrogen-containing compounds. The catalytic activity for the aluminatreated CLVR-THFS was maintained at the higher level in nitrogen removal than that for cation-exchange treated one, although the recovery was much higher in the latter than the former treatment. Based on the above results, the mechanism of catalyst deactivation is discussed.
Behavior of fuel droplets across propagating spray flames has been examined experimentally by using 16mm high-speed schlieren photomicrography and predicted analytically by considering the interaction between droplets and surrounding gas flows. The results show that most droplets smaller than 20μm in diameter vanish during passing across a propagating spray flame, but droplets larger than 40μm in diameter gradually diminish after they passed through the flame. The droplets ahead of the flame, at the start, are found to move slowly in the same direction with the flame propagation and to be accelerated in the region approaching to the spray flame by the increase of velocity of surrounding gas flows. The rate of acceleration is shown to increase as the droplet diameter decreases. Most phenomena predicted analytically are confirmed to agree to the observed ones.
Coal liquids have received much attention recently as useful raw materials since they contain polycyclic aromatic compounds and heterocyclic compounds. Supercritical gas extraction is expected as one of the successful separation techniques to separate and purify them. In design of such a separation process, physical properties of coal-derived components, i.e., sublimation pressures, solid molar volumes, critical temperatures, critical pressures, critical molar volumes, the Pitzer's acentric factors, and the Stiel's polar factors are needed. The authors surveyed these properties from literature and handbooks. If no experimental critical properties are reported, they are estimated by the Lydersen's group-contribution method. Solubility parameters that are useful to evaluate molecular interaction are also compiled.