There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

https://www.massey.ac.nz/~ychisti/Biodiesel.pdf

Biodiesel from microalgae.

Fast pyrolysis utilizes biomass to produce a product that is used both as an energy source and a feedstock for chemical production. Considerable efforts have been made to convert wood biomass to liquid fuels and chemicals since the oil crisis in mid-1970s. This review focuses on the recent developments in the wood pyrolysis and reports the characteristics of the resulting bio-oils, which are the main products of fast wood pyrolysis. Virtually any form of biomass can be considered for fast pyrolysis. Most work has been performed on wood, because of its consistency and comparability between tests. However, nearly 100 types of biomass have been tested, ranging from agricultural wastes such as straw, olive pits, and nut shells to energy crops such as miscanthus and sorghum. Forestry wastes such as bark and thinnings and other solid wastes, including sewage sludge and leather wastes, have also been studied. In this review, the main (although not exclusive) emphasis has been given to wood. The literature on woo...

Pyrolysis of Wood/Biomass for Bio-oil: A Critical Review

Sustainable economic and industrial growth requires safe, sustainable resources of energy. For the future re-arrangement of a sustainable economy to biological raw materials, completely new approaches in research and development, production, and economy are necessary. The ‘first-generation’ biofuels appear unsustainable because of the potential stress that their production places on food commodities. For organic chemicals and materials these needs to follow a biorefinery model under environmentally sustainable conditions. Where these operate at present, their product range is largely limited to simple materials (i.e. cellulose, ethanol, and biofuels). Second generation biorefineries need to build on the need for sustainable chemical products through modern and proven green chemical technologies such as bioprocessing including pyrolysis, Fisher Tropsch, and other catalytic processes in order to make more complex molecules and materials on which a future sustainable society will be based. This review focus on cost effective technologies and the processes to convert biomass into useful liquid biofuels and bioproducts, with particular focus on some biorefinery concepts based on different feedstocks aiming at the integral utilization of these feedstocks for the production of value added chemicals.

http://staff.cimap.res.in/PublicationFiles/Renew_Sustain_Energ_Rev_14_578.pdf

Production of first and second generation biofuels: A comprehensive review

Ti-HMS substrates were synthesized by using dodecylamine as structure-directing agents. A series of HPW/Ti-HMS catalysts with different Si/Ti ratios, promoted by Ni was prepared using Keggin-type heteropolyacids (H 3 PW 12 O 40 ) as active phase precursors. These catalysts were compared with corresponding NiW/HMS catalysts prepared from the traditional precursors (ammonium metatungstate). Prepared supports and catalysts were characterized by small- and wide-angle XRD, N 2 physisorption, FT-IR, Raman, DRIFT, TEM, and SEM. Catalytic activity was assessed for hydrodesulfurization (HDS) and hydrodenitrogenation (HDN) of coker light gas oil (CLGO) derived from Athabasca bitumen, in a trickle bed reactor at a temperature, pressure, and LHSV of 370 °C, 8.8 MPa, and 2.0 h −1 , respectively. The W catalysts prepared from heteropolyacids showed better performance for hydrotreating than their counterparts prepared from traditionally used W ammonium salts. The incorporation of Ti into HMS afforded catalysts that were more active than the Ti-free counterpart, due to the larger number of coordinately unsaturated sites (CUS) of the metal sulfide on Ti-loaded catalysts. Under steady-state conditions, the NiPW/Ti-HMS (20) catalyst with a Si/Ti ratio of 20 was the most active among the catalysts studied due to more uniform distribution of active species.

Hydrotreating of coker light gas oil on Ti-HMS supported heteropolytungstic acid catalysts

Canadian pine cones (pine cone type I and pine cone type II) and deoiled canola meal were utilized as precursors for preparation of powdered activated carbons (PACs) using thermo-chemical process. Physicochemical properties of the biomass and obtained adsorbents were evaluated. Prepared PACs were investigated for the adsorptive removal of acyclovir (ACV) from aqueous solutions. Pine cone type I PAC was found to have well developed pores and surface area. It was found to be suitable for removal of ACV from aqueous solution. Response surface methodology was used for the optimization of ACV adsorption on PAC prepared from pine cone type I and the development of predictive model. A second-order polynomial equation fitted data well which indicated that the process variables such as temperature, pH and especially adsorbent dose had large impact on the ACV adsorption process. The optimum conditions for ACV removal were found to be 39 °C, pH 8 and 2 g/L of pine cone type I PAC dose. At these conditions, the removal of ACV was 90.3 %, which was close to the maximum predicted value of 92.5 %.

Adsorption optimization of acyclovir on prepared activated carbon

Comparison of nitrogen adsorption and transmission electron microscopy analyses for structural characterization of carbon nanotubes

Design and Preparation of Ni-Co Bimetallic Nanocatalyst for Carbon Dioxide Reforming of Methane

Elemental mercury in the atmospheric environment has been identified as a significant environmental issue. The primary reason is the increased anthropogenic emissions of this metal into the global atmospheric environment in recent years. This paper provides a review for elemental mercury uptake in a flue gas stream. The objectives are to provide a summary of the carbon materials and effective parameters involved in an elemental mercury emission flue gas stream control system for industry. Activated carbon injection systems into emission stacks of coal fired power plant have been credited with providing a significant elemental mercury emission control technology. Various chemicals including sulfur, halogens and others species have been identified as key capture agents for elemental mercury emission control on an activated carbon. With the successes of the past several years, there is in place an excellent frame work in the literature to build an activated carbon injection control system to further increase the efficiency of uptake for elemental mercury from mixed gas streams.

Ajay K. Dalai

Papers

Hydrotreating of coker light gas oil on Ti-HMS supported heteropolytungstic acid catalysts

Adsorption optimization of acyclovir on prepared activated carbon

Comparison of nitrogen adsorption and transmission electron microscopy analyses for structural characterization of carbon nanotubes

Design and Preparation of Ni-Co Bimetallic Nanocatalyst for Carbon Dioxide Reforming of Methane

Elemental Mercury Capture Using Activated Carbon: A Review