Standard cubic foot

Fig. 7. H-Coal process using Illinois No. 6 coal (a) in syncmde mode, and (b) in low sulfur fuel oil mode. To convert to Btu, multiply by 6.48 x lO ". To convert m to bbl, multiply by 6.29. To convert m to standard cubic feet (SCF), multiply by 35.3...

Permeation rate Standard cubic feet/miniite kmol/s... 

FIG. 22-76 Constant -cost lines as a function of permeability and selectivity for CO2/CH4, Cellulose-acetate membrane mscf is one thousand standard cubic feet, CouHesy VP R. Grace.)... 

MWCs Metal Emissions The NSPS includes a PM emission limit of 0.015 grains per dry standard cubic feet (gr/dscf) at 7 percent oxygen dry/volume and an opacity hmit of 10 percent (6 minute aver-... 

From Table 1 and solids rate, estimate duct size and flow in SCFM (standard cubic feet per minute). 

Pipeline engineers use the flow value stated as standard cubic feet per day. This is an artificial weight flow because flowing conditions are referred to a standard pressure and temperature. The balance of the flow specification is then stated in tenns of specific gravity. 

A common method of stating flow is standard cubic feet per minute where the flowing conditions are referred to an arbitrary set of standard conditions. Unfortunately, standard conditions are anything but standard. Of the many used, two are more common. The ASME standard uses 68°F and 14.7 psia. The relative humidity is given as 36%. The other standard that is used by the gas transmission industry and the API Mechanical Equipment Standards is 60°F at 14.7 psia. As can be seen from this short discussion, a flow value must be carefully evaluated before it can be used in a compressor calculation. 

Air Flow Typical gas flow rates for a single cyclone unit are 0.5 to 12 standard cubic meters per second (smVsec) (1,060 to 25,400 standard cubic feet per minute (scfm)). Flows at the high end of this range and higher (up to approximately 50 smVsec or 106,000 scfm) use multiple cyclones in parallel (Cooper, 1994). There are single cyclone units employed for specialized applications which have flow rates of up to approximately 30 smVsec (63,500 scfm) and as low as 0.0005 smVsec (1.1 scfm) (Wark, 1981 Andriola, 1999). 

Standard cubic feet per minute (sefm)). Custom baghouses are designed for speeifie applieations and are built to the speeifieations preseribed by the eustomer. These units are generally mueh larger than standard units, i.e., from 50 to over 500 smVsee (100,000 to over 1,000,000 sefm). 

Air Flow. Typical gas flow rates for dry wire-pipe ESPs are 0.5 to 50 standard cubic meters per second (smVsec) (1,000 to 100,000 standard cubic feet per minute (scftn)). 

The air pollution control solutions that are available to control these emissions are normally dictated by the volume of air that is to be processed. The volume of air flow, measured in cubic feet per minute, is designated as ACFM for Actual Cubic Feet per Minute of SCFM where "S" stands for standard cubic feet per minute, at 70°F, sea level, and one atmosphere. 

From the standard cubic feet per minute estimate, the linear velocity is as follows ... 

In this equation all percentages are on a volume basis. The term XSA refers to the excess air over the stoichiometric requirement. The volumes of the air and gas must be measured at the same temperature and pressure. For consistency, it is best to first convert to actual conditions (i.e., from actual cubic feet (ACF) to standard cubic feet (SCF). The following formula can be used for this conversion ... 

The definitions above are an abbreviated version of those used in a veiy complex and financially significant exercise with the ultimate goal of estimating resei ves and generating production forecasts in the petroleum industry. Deterministic estimates are derived largely from pore volume calculations to determine volumes of either oil nr gas in-place (OIP, GIP). This volume when multiplied by a recovery factor gives a recoverable quantity of oil or natural gas liquids—commonly oil in standard barrels or natural gas in standard cubic feet at surface conditions. Many prefer to use barrels of oil equivalency (BOE) or total hydrocarbons tor the sum of natural gas, natural gas liquids (NGL), and oil. For comparison purposes 6,000 cubic feet of gas is considered to be equivalent to one standard barrel on a British thermal unit (Btu) basis (42 U.S. gallons). 

Establish the normal, maximum, and minimum gas flow for the system where the unit will operate. This is usually in standard cubic feet per minute, per hour or per day. Note the catalog units carefully, and also that the reference standard temperature is usually 60°F for gas or vapor flow. 

Scfm is standard cubic feet per minute corrected to standard density conditions. For example, to determine the scfm of 10,000 acfm at 600°F and 6 in. WG for air ... 

Compressors are rated as to their maximum volumetric flowrate they can operate at, and the maximum pressure they can maintain. These ratings are usually specified as standard cubic feet per minute (scfm) and psig. The scfm of volumetric flow rate refers to the compressor intake. The pressure rating refers to the output pressure capability. 

A small amount of nickel in the FCC feed has a significant influence on the unit operation. In a clean gas oil operation, the hydrogen yield is about 40 standard cubic feet (scf) per barrel of feed (0.07 wi /r ). This is a manageable rate that most units can handle. If the nickel level increases to 1.5 ppm, the hydrogen yield increases up to 100 scf per barrel (0.17 wt%). Note that in a 50,000 barrel/day unit, this corresponds to a mere 16 pounds per day of nickel. Unless the catalyst addition rate is increased or the nickel in the feed is passivated (see Chapter 3), the feed rate or conversion may need to be reduced. The wet gas will become lean and may limit the pumping capacity of the wet gas compressor. 

In general, the rate of deactivation was much lower at the lower fresh gas feed rate than at the higher feed rates. For example, the rate of deactivation was 0.022%/mscf/lb during the period between 600 and 800 hrs stream time at the lower feed rate of 206 standard cubic feet per hour (scfh) whereas it was 0.143%/mscf/lb for the period between 100 and 400 hrs when the fresh feed rate was about 386 scfh. 

Bench-Scale Reactor. The bench-scale reactor is 0.81 in. i.d. and 48 in. long. The nominal feed gas rate for this unit is 30 standard cubic feet per hour (scfh) the feed gas is supplied from premixed, high-pressure gas cylinders. Except for reaction temperature, the bench-scale unit is substantially manually operated and controlled. The catalysts used in these studies were standard commercial methanation catalysts ground to a 16-20 mesh size which is compatible with the small reactor diameter. 

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