Recent advances in the science and technology of ultra low sulfur diesel (ULSD) production

The general principles of green chemistry guide the design of environmentally benign products and processes. It is known that the efficient utilization of carbon resources and carbon recycling are of great importance for the sustainable development of our society, and there are many related challenging scientific issues to be solved. Herein we attempt a holistic view on carbon resource processing, utilization, and recycling, and we call this “green carbon science”. We will discuss the definition and the four key principles of green carbon science and highlight some related fields including petroleum refining, the production of liquid fuels and chemicals from coal and methane, and transformations of CO2 and biomass into fuels and chemicals.

Green Carbon Science: Scientific Basis for Integrating Carbon Resource Processing, Utilization, and Recycling

In a typical temperature-programmed desorption (TPD) experiment on a supported metal catalyst, a small amount of catalyst (10–200 mg) is contained in a reactor that can be heated by a furnace. An inert gas, usually helium at atmospheric pressure, flows over the catalyst. Following pretreatment to obtain a reduced catalyst, a gas is adsorbed on the surface, usually by pulse injections of the adsorbate into the carrier gas upstream from the reactor. After the excess gas is flushed out, the catalyst is heated to create a linear rise in temperature with time. A small thermocouple inserted in the catalyst measures the temperature and a detector downstream measures the change in the inert gas stream. The ideal detector is a mass spectrometer which measures the composition of the effluent stream as a function of catalyst temperature. Because of the high carrier-gas flow rate, the detector response is proportional to the rate of desorption if diffusion and readsorption are not limiting.

Temperature-Programmed Desorption and Reaction: Applications to Supported Catalysts

New π-complexation-based sorbents were studied for desulfurization of diesel, gasoline, and jet fuels. The sorbents were obtained by ion exchanging faujasite type zeolites with Cu + , Ni 2+ or Zn 2+ cations using different techniques, including liquid phase ion exchange (LPIE). Hydrolysis of the cations in aqueous solutions should be avoided in order to increase the ion exchange level when aqueous solutions are used. Cation hydrolysis limitation could be avoided when vapor phase (VPIE) and solid-state (SSIE) ion exchange techniques are used instead. The deep-desulfurization (sulfur levels of Ni(II)-Y(SSIE) > Ni(II)-X(LPIE) > Zn(II)-X(LPIE) > Zn(II)-Y(LPIE). Molecular orbital calculations indicate the sorbents performance decreases as follows: Cu + > Ni 2+ > Zn 2+ . This agrees well with the experimental results. The best sorbent, Cu(I)-Y(VPIE), has breakthrough adsorption capacities of 0.395 and 0.278 mmol S/g of sorbent for commercial jet fuel (364.1 ppmw S) and diesel (297.2 ppmw S), respectively.

Desulfurization of transportation fuels by π-complexation sorbents: Cu(I)-, Ni(II)-, and Zn(II)-zeolites

Increased demand for liquid transportation fuels coupled with gradual depletion of oil reserves and volatile petroleum prices have recently renewed interest in coal-to-liquids (CTL) technologies. Large recoverable global coal reserves can provide liquid fuels and significantly reduce dependence on oil imports. Direct coal liquefaction (DCL) converts solid coal (H/C ratio ≈ 0.8) to liquid fuels (H/C ratio ≈ 2) by adding hydrogen at high temperature and pressures in the presence or absence of catalyst. This review provides a comprehensive literature survey of the coal structure, chemistry and catalysis involved in direct liquefaction of coal. This report also touches briefly on the historical development and current status of DCL technologies. Key issues, challenges involved in DCL process and directions for the future research are also addressed.

Clean liquid fuels from direct coal liquefaction: chemistry, catalysis, technological status and challenges

Study of the formation and removal of carbonaceous deposits on platinum - ruthenium alumina supported bimetallic catalysts

A straight run gas oil has been hydrotreated with a commercial CoMo/Al2O3 catalyst, under variable conditions of severity, in order to yield processed products containing a variable amount of residual sulfur. These products have been characterized by simulated distillation, gas chromatography with sulfur-selective detection (GC−SCD), and thin-layer chromatography. The sulfur compounds have been grouped into distinct representative families. The rate constants for the reaction of desulfurization of the considered groups and the apparent rate order with respect to some individual sulfur compounds have been determined. The following hydrocarbon groups have been determined in the hydrotreated products by analytical thin-layer chromatography−densitometry:  alkanes, cycloalkanes, total aromatics, and polyaromatic compounds (PACs). The straight run gas oil has been submitted to fractionation by preparative thin-layer chromatography, and the resulting fractions of alkanes, cycloalkanes, and aromatics have been ch...

Evolution of Sulfur Compounds and Hydrocarbons Classes in Diesel Fuels during Hydrodesulfurization. Combined Use of Thin-Layer Chromatography and GC−Sulfur-Selective Chemiluminescence Detection

On the chemical effects on catalysts in the direct liquefaction of coal

As part of a program for the evaluation of coal liquefaction, supported by the French government and the European Community between 1980 and 1990, our Institute has developed a synthetic catalyst. We first consider the approach that led us to the selection of iron-based solids in the form of dispersed disposable catalysts, as a convenient solution to the improvement of coal liquefaction efficiency. This choice implies the catalysts possess some specific properties which are detailed in the light of experimental and operational evidences. Several methods for the production of highly divided solids have been tested experimentally. The most promising phases were obtained through hydrolysis of volatile iron compounds in a hydrogen-oxygen flame

R. Bacaud

Papers

Study of the formation and removal of carbonaceous deposits on platinum - ruthenium alumina supported bimetallic catalysts

Evolution of Sulfur Compounds and Hydrocarbons Classes in Diesel Fuels during Hydrodesulfurization. Combined Use of Thin-Layer Chromatography and GC−Sulfur-Selective Chemiluminescence Detection

On the chemical effects on catalysts in the direct liquefaction of coal

Development of a new iron catalyst for the direct liquefaction of coal

Catalytic hydroliquefaction of coal: about the methodology in batch experiments