Michio Ikura

Emulsification of pyrolysis derived bio-oil in diesel fuel

Abstract Bio-oil produced by fast pyrolysis is very viscous, highly acidic and does not ignite easily as it contains a substantial amount of structural water. To circumvent these problems pyrolytic bio-oil was emulsified in No. 2 diesel fuel. In the current investigation, very heavy fractions of bio-oil were removed from bio-oil by centrifugation prior to emulsification. Emulsions so produced can be very stable depending on processing conditions. A series of emulsification runs was carried out to determine the relationship between process conditions, emulsion stability and processing costs. Of five process variables examined (temperature, residence time, bio-oil concentration, surfactant concentration and power input per unit volume) only the last three had significant effects on emulsion stability. The tests showed there were optimal operating conditions that produced stable emulsions. The formation of stable emulsions required surfactant concentration ranging from 0.8 to 1.5 wt % of total, depending on bio-oil concentration and power input. The costs of producing stable emulsions using Hypermers (commercial surfactants) were unacceptably high, ranging from 5.2 cents/L for 10% emulsion to 8.9 cents/L for 30% emulsion. However, when the cost of a newly developed proprietary CANMET surfactant was assumed, they could be reduced to 2.6 cents/L for 10% emulsion, 3.4 cents/L for 20% emulsions and 4.1 cents/L for 30% emulsions, respectively. Fuel properties such as heating values, cetane number, viscosity and corrosivity were characterized. The heating value of centrifuged bio-oil was about one third of that of No. 2 diesel, reducing the heating values of emulsions accordingly. A cetane number of pyrolytic bio-oil was 5.6. Emulsion viscosities, particularly in the 10–20% bio-oil concentration range, are substantially lower than the viscosity of bio-oil itself, making these products very easy to handle. The viscosity of emulsion fuels was best described by Einsteins equation for dilute solid dispersions. The corrosivity of emulsion fuels defined by the weight loss of steel is about half of the bio-oil alone.

Characterization and potential applications of pyrolytic char from ablative pyrolysis of used tires

Pyrolysis has the potential of transforming used tires into useful recyclable products. Pyrolytic char is one of the most important products of tire pyrolysis. The process economy depends strongly on its commercial value. A 2-year study was undertaken to examine the chemistry and commercial applications of pyrolytic char obtained from the commercialized process called Continuous Ablative Regenerator (CAR) system (Enervision Inc., Halifax, Canada). The pyrolysis temperature was 550°C, residence time 0.6 s, under N2 flow and using ∼1 cm tire shreds. A small-scale unit, 0.25 ton day−1, was used in the study. The process is unique in design and features several operating parameters, which favor optimum tire pyrolysis (e.g. no heat transfer medium, fast pyrolysis and rapid product quenching). The physical properties (porosity, particle and aggregate size, surface area), chemical properties (elemental analysis, ash content and composition) and aqueous adsorption properties (for metals, phenols and methylene blue) of the pyrolytic char were examined. As well, laboratory-scale production of activated carbon from tire pyrolysis char was examined as a means of upgrading. The activated carbon was characterized in the same manner as the char. Results revealed that the char must be post- carbonized (600°C) to remove unwanted odor and trace oils. The resulting carbonized char has excellent adsorption capacity for phenol and metals (i.e. lead) from solution. It is believed that the high sulfur content in the char (2%) and the inherent composition of tire char is responsible for these properties. Activation using steam (900°C, 3 h) produced an activated carbon with good surface area (302 m2 g−1), excellent adsorption for phenol and methylene blue, but showed no improvement for metal removal. Norit SA3 and commercial charcoal were used for comparison. Further studies will be conducted to examine the char performance for Hg removal from air and water and its use in wastewater treatment and as a stack gas scrubber medium.

Short contact time thermal cracking of carbonaceous wastes to alpha olefins

A continuous short contact time thermal cracker was constructed and operated to investigate the production of alpha olefins in the C9–C16 range. Alpha olefins in this range are normally used as chemical feedstocks for lubricants, surfactants, alcohols and other valuable commodities. The CETC unit was operated at 100 g h−1 between 495 and 570°C using paraffin wax, waste wax from a gold refinery, waste plastic-derived oil and topped waste plastic-derived (wax enriched) oil. The effect of operating temperature, heavy ends recycle rate and feed types on the production of alpha olefins was examined in detail. It was found that the concentration of heavy paraffins with carbon numbers greater than C16 in the heavy ends recycle stream is a good indicator for estimating the concentration of alpha olefins in the C9–C16 range. It was shown that feed type is the most critical factor in determining high alpha olefins yield in this range. Following is the order of suitability for producing alpha olefins in the C9–C16 range: paraffin wax>plastic-derived oil (topped)>plastic-derived oil (as received)>waste wax.

A continuous warming computer-controlled calorimeter using a pyroelectric thermometer

A computer-controlled adiabatic calorimeter for use in the continuous warming mode was designed, constructed, and tested. Since its intended use was in measuring the singularities in specific heats near critical solution temperatures, a thermometric sensor capable of yielding accurate values of T at very slow temperature scan rates was required. A pyroelectric thermometer was selected for the purpose. The pyroelectric thermometer is reviewed and its design and testing are described. Details of the design of the calorimeter, the platinum resistance thermometer, and the computerized data acquisition and control system are presented. Preliminary measurements of the specific heats of methanol, benzene, triethyl-amine, and the singularity of the specific heat of the triethylamine-water system are discussed.

Coprocessing of Petroleum Derived Vacuum Bottoms and a Lignite using Catalyst Precursors

Publisher Summary This chapter explores the coprocessing of petroleum-derived vacuum bottoms and lignite using catalyst precursors. Petroleum-derived vacuum bottoms are known to give lower distillate yields than bitumen-derived vacuum bottoms under the same process conditions. The use of appropriate catalysts is a way to increase distillate yields. There are a number of ways to utilize catalysts in coprocessing using petroleum-derived vacuum bottoms to enhance the process efficiency. Comparison of the organometallic compounds runs and the metal salt runs indicates that ferric acetylacetonate and ferrocene give higher coal and pitch conversions than FeSO 4 or NiSO 4 . This is reflected in a slightly higher distillate yield in the ferric acetylacetonate run and a substantially higher distillate yield in the ferrocene run. Distillate elemental analyses for these runs are essentially the same as those for the metal salts. Slightly higher nitrogen and sulfur contents in the distillates from these runs stem from higher concentrations of nitrogen and sulfur in the feed slurry. Lower unconverted coal and coke yields and increased distillate yields without buildup of asphaltenes and preasphaltenes indicates that the organometallics are more efficient catalyst precursors than the metal salts.