The effect of catalyst temperature zoning on hydrotreating a coal-derived liquid

1985 ◽  
Vol 11 (3) ◽  
pp. 241-250
Author(s):  
J.R. Beazer ◽  
B.L. Crynes
1986 ◽  
Vol 18 (7-8) ◽  
pp. 413-420 ◽  
Author(s):  
P. C. Chiang ◽  
J. H. You

In this investigation it was found that the waste sludge obtained from a municipal sewage treatment plant could be reclaimed as an adsorbent for removal of organic vapours, i.e. toluene, methyl-ethyl-ketone and 1-1-2-trichloroethylene, through use of a pyrolysis technique. In order to find the optimum manufacturing process, several tests were performed under various conditions in which the addition of a catalyst, temperature control, and residence time in the furnace, were considered as the three major factors. Both the reclaimed adsorbent and commercially available activated carbon were evaluated to determine their adsorption capacity at various influent concentrations of organic vapours.


Catalysts ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 663
Author(s):  
Luigi di Bitonto ◽  
Valeria D’Ambrosio ◽  
Carlo Pastore

In this work, the transesterification of methyl estolides (ME) extracted from the lipid component present in the sewage scum was investigated. Methyl 10-(R)-hydroxystearate (Me-10-HSA) and Fatty Acid Methyl Esters (FAMEs) were obtained in a single step. A three-level and four factorial Box–Behnken experimental design were used to study the effects of methanol amounts, catalyst, temperature, and reaction time on the transesterification reaction using aluminum chloride hexahydrate (AlCl3·6H2O) or hydrochloric acid (HCl) as catalysts. AlCl3·6H2O was found quite active as well as conventional homogeneous acid catalysts as HCl. In both cases, a complete conversion of ME into Me-10-HSA and FAMEs was observed. The products were isolated, quantified, and fully characterized. At the end of the process, Me-10-HSA (32.3%wt) was purified through a chromatographic separation and analyzed by NMR. The high enantiomeric excess (ee > 92%) of the R-enantiomer isomer opens a new scenario for the valorization of sewage scum.


Author(s):  
Tao Deng ◽  
Ke Zhao ◽  
Haoyuan Yu

In the process of sufficiently considering fuel economy of plug-in hybrid electric vehicle (PHEV), the working time of engine will be reduced accordingly. The increased frequency that the three-way catalytic converter (TWCC) works in abnormal operating temperature will lead to the increasing of emissions. This paper proposes the equivalent consumption minimization strategy (ECMS) to ensure the catalyst temperature of PHEV can work in highly efficient areas, and the influence of catalyst temperature on fuel economy and emissions is considered. The simulation results show that the fixed equivalent factor of ECMS has great limitations for the underutilized battery power and the poor fuel economy. In order to further reduce fuel consumption and keep the emission unchanged, an equivalent factor map based on initial state of charge (SOC) and vehicle mileage is established by the genetic algorithm. Furthermore, an Adaptive changing equivalent factor is achieved by using the following strategy of SOC trajectory. Ultimately, adaptive equivalent consumption minimization strategy (A-ECMS) considering catalyst temperature is proposed. The simulation results show that compared with ordinary ECMS, HC, CO, and NOX are reduced by 14.6%, 20.3%, and 25.8%, respectively, which effectively reduces emissions. But the fuel consumption is increased by only 2.3%. To show that the proposed method can be used in actual driving conditions, it is tested on the World Light Vehicle Test Procedure (WLTC).


2017 ◽  
Vol 17 (14) ◽  
pp. 8739-8755 ◽  
Author(s):  
Jenni Alanen ◽  
Pauli Simonen ◽  
Sanna Saarikoski ◽  
Hilkka Timonen ◽  
Oskari Kangasniemi ◽  
...  

Abstract. Natural gas usage in the traffic and energy production sectors is a growing trend worldwide; thus, an assessment of its effects on air quality, human health and climate is required. Engine exhaust is a source of primary particulate emissions and secondary aerosol precursors, which both contribute to air quality and can cause adverse health effects. Technologies, such as cleaner engines or fuels, that produce less primary and secondary aerosols could potentially significantly decrease atmospheric particle concentrations and their adverse effects. In this study, we used a potential aerosol mass (PAM) chamber to investigate the secondary aerosol formation potential of natural gas engine exhaust. The PAM chamber was used with a constant UV-light voltage, which resulted in relatively long equivalent atmospheric ages of 11 days at most. The studied retro-fitted natural gas engine exhaust was observed to form secondary aerosol. The mass of the total aged particles, i.e., particle mass measured downstream of the PAM chamber, was 6–268 times as high as the mass of the emitted primary exhaust particles. The secondary organic aerosol (SOA) formation potential was measured to be 9–20 mg kgfuel−1. The total aged particles mainly consisted of organic matter, nitrate, sulfate and ammonium, with the fractions depending on exhaust after-treatment and the engine parameters used. Also, the volatility, composition and concentration of the total aged particles were found to depend on the engine operating mode, catalyst temperature and catalyst type. For example, a high catalyst temperature promoted the formation of sulfate particles, whereas a low catalyst temperature promoted nitrate formation. However, in particular, the concentration of nitrate needed a long time to stabilize – more than half an hour – which complicated the conclusions but also indicates the sensitivity of nitrate measurements on experimental parameters such as emission source and system temperatures. Sulfate was measured to have the highest evaporation temperature, and nitrate had the lowest. The evaporation temperature of ammonium depended on the fractions of nitrate and sulfate in the particles. The average volatility of the total aged particles was measured to be lower than that of primary particles, indicating better stability of the aged natural gas engine-emitted aerosol in the atmosphere. According to the results of this study, the exhaust of a natural gas engine equipped with a catalyst forms secondary aerosol when the atmospheric ages in a PAM chamber are several days long. The secondary aerosol matter has different physical characteristics from those of primary particulate emissions.


2016 ◽  
Vol 11 (2) ◽  
pp. 111 ◽  
Author(s):  
Khoirina Dwi Nugrahaningtyas ◽  
Eko Cahyono ◽  
Dian Maruto Widjonarko

This research deals with the study of the paraffin cracking reaction with termal reaction, active natural zeolite (ZAA) and NiMo / active natural zeolite (ZAA) catalyst. Temperature variation was done in order to study the optimum temperature of paraffin cracking reactions. Paraffin cracking reaction carried out at temperatures of 200 - 400 °C and a hydrogen flow rate of 30 mL / min. Cracking products obtained, and then analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry(GCMS). Catalyst activity (%) was defined as the amount of lighter fractions/the amount of feed (paraffin) (%). The results showed that the catalyst NiMo/ZAA has the highest activity (31.33 %) at the cracking reaction temperature of 300 ºC


1998 ◽  
Vol 519 ◽  
Author(s):  
Christof Roscher ◽  
Ralf Buestrich ◽  
Peter Dannberg ◽  
Oliver Rösch ◽  
Michael Popall

AbstractNew fluorinated inorganic-organic hybrid polymers (ORMOCER*s) for integrated optics were synthesized via hydrolysis and condensation (sol-gel processing) of functionalized pentafluorophenylalkoxysi lanes followed by organic crosslinking reactions. Process parameters (catalyst, temperature and ratio of educts) were optimized to achieve low transmission losses at the most important wavelengths for telecommunication in the NIR range: 1310 nm and 1550 nm.The result is a photopatternable transparent ORMOCER (negative resist behavior) with excellent low losses: 0.20 dB/cm at 1310 nm and 0.30 dB/cm at 1550 nm.Besides their high transparency the fluorinated ORMOCERs show a variety of other properties enabling their use as waveguide materials within the production of optoelectronic devices and related thin film technology: good wetting and adhesion on various substrates (e.g. glass, silicon and several polymers), low processing temperatures (postbake below 160 °C), high thermal stability (decomposition > 250°C) and a tunable refractive index.


1995 ◽  
Author(s):  
Alain Atanasyan ◽  
Karlheinz Croissant ◽  
Mariano Sans ◽  
Werner Hosp

Author(s):  
Peter Larsson ◽  
Paul Ravenhill ◽  
Lars-Uno Larsson ◽  
Per Tunestål

NOx pollution from Diesel engines causes over 10 000 premature deaths annually and the trend is increasing. In order to decrease this growing global problem, exhaust after-treatment systems for Diesel engines have to be improved. The most common SCR systems in the market place inject an aqueous Urea solution, DEF that evaporates prior the catalytic surface of the SCR-catalyst. Due to a catalytic reaction within the catalyst, NOx is converted nominally into Nitrogen and Water. Currently, the evaporative process is enhanced by aggressive mixer plates and long flow paths; these, negatively, create extra exhaust back pressure and cool the exhaust gases decreasing engine and catalyst efficiency. To achieve future emission legislation targets SCR efficiency has to be improved especially under low catalyst temperature conditions, plus Ammonia slip has to be avoided as it is now legislated against. Swedish Biomimetic’s novel μMist® platform technology, inspired by the Bombardier Beetle, injects a hot, effervescent, finely atomised, highly dispersed spray plume of DEF into the exhaust stream. This is achieved by raising the temperature of the DEF, in a closed volume, above its saturated vapour pressure. The DEF is then rapidly released creating effervescent atomisation. This study investigates a back to back study of the evaporating and mixing behaviour of the μMist® injector and a class leading DEF injector. The test conditions are with and without a mixer plate and the use of two different flow path designs. Spray distribution across the face of the catalyst is assessed by measuring NOx conversion whilst Ammonia slip is also measured post catalyst. This report describes how the novel μMist® injector significantly increases NOx conversion and catalyst surface usage whilst considerably reducing Ammonia slip.


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