Emissions naphtha

Compounds considered carcinogenic that may be present in air emissions include benzene, butadiene, 1,2-dichloroethane, and vinyl chloride. A typical naphtha cracker at a petrochemical complex may release annually about 2,500 metric tons of alkenes, such as propylenes and ethylene, in producing 500,000 metric tons of ethylene. Boilers, process heaters, flares, and other process equipment (which in some cases may include catalyst regenerators) are responsible for the emission of PM (particulate matter), carbon monoxide, nitrogen oxides (200 tpy), based on 500,000 tpy of ethylene capacity, and sulfur oxides (600 tpy). 

We examined all processes (from raw material extraction, production, and shipping) for succinic acid, 1,4-butanediol, and starch purchased as intermediate materials and examined Bionolle production plant, product distribution, and disposal after use for each of the two Bionolle t3q>es used in this study naphtha-derived neat Bionolle and starch-Bionolle compound. For disposal after use, only carbon emissions from Bionolle after biodegradation were taken into account. Disposal treatment was disregarded because the materials can be placed in landfills without treatment. Carbon from starch was disregarded, since we ignore CO2... 

In addition to high biodegradability, Bionolle is verified by this smdy to offer CO2 emission characteristics superior to conventional resins, despite the fact that raw materials (succinic acid and 1,4-butanediol) are derived from naphtha. Given the prospects for producing succinic acid and 1,4-butanediol from biomass and waste paper, Bionolle may eventually offer even greater environmental benefits when it... 

Isoprene occurs in the environment as emissions from vegetation, particularly from deciduous forests, and as a by-product in the production of ethylene by naphtha cracking. In the United States, the total emission rate of isoprene from deciduous forests has been estimated at 4.9 tonnes per year, with greatest emissions in the summer. The global annual emission of isoprene in 1988 was estimated to be 285 000 thousand tonnes. Isoprene is produced endogenously in humans. It has also been found in tobacco smoke, gasoline, turbine and automobile exhaust, and in emissions from wood pulping, biomass combustion and rubber abrasion (United States National Library of Medicine, 1997). 

Exposure to isoprene occurs in the production of the monomer and in the production of synthetic rubbers. Isoprene occurs in the environment due to emissions from vegetation and the production of ethylene by naphtha cracking. 

For ethylene, similar data could be constructed from either an average of ethylene producers in this geography or on-site naphtha crackers. In certain cases, databases exist for certain commonly used compounds. In other cases, data are unavailable and estimates have to be made. In case of plants that produce more than one product, the total emissions are allocated proportionally to their sales. 

In an oil refinery, oil is distilled into several fractions, including naphtha and gas oil. These fractions must be purified to diminish the contents of sulfur, nitrogen, and metals so that fewer air-polluting emissions of sulfur... 

Maleic anhydride is widely used in polyester resins, agricultural chemicals and lube additives. The growth rate of its production is currently 7-9 percent per year world-wide. In the U.S. the expected consumption by 1983 is 223,000 tons per year ( 5). Conventionally, the production of maleic anhydride via heterogeneous catalytic oxidation of benzene is performed in fixed bed reactors. Rapid increase in benzene prizes and tight benzene-emission control standards caused intense investigations in alternative feedstocks like n-butenes (6), butane ( 5) and the C,-fraction of naphtha crackers (7). As for these alternative feedstocks... 

The first group of fuels, natural gas, LPG, naphtha and fuel oil, are those which are typically used in furnace operations in the petrochemical industry. This illustrates that moving from fuel oil to natural gas can achieve significant reductions in the carbon emission of a site. However, it must be remembered that on a global (cradle to grave) basis this may overestimate the benefit as these figures ignore the carbon emission in production of the fuel. This can be quite substantial for natural gas when the raw gas in the field is contaminated with carbon dioxide many fields contain 30% (mass basis) or more carbon dioxide which is stripped from the raw gas in gas plant operations in order to produce gas of a quality that can be piped (typically <2% vol.) carbon dioxide. 

Carbon Emissions from Naphtha and LSWR Cracking... 

Table 9.5 gives the statistics for cracking naphtha (1 million tonnes of ethylene/year) for the OPEN and CLOSED systems. The first coluimi gives the mass of fuel and feed contributing to on-site emissions. The second column, the energy (HHV basis) for fuel and feed used. The third column gives the carbon dioxide emissions and when calculated on a unit basis this emission is attributed to the principal olefin products (ethylene and propylene). The fourth column gives the pertinent unit emissions when the carbon dioxide emission is distributed across all of the products. 

Figure 9.14 Sensitivity of ethylene production cost from naphtha to carbon emission cost - OPEN and CLOSED systems...

This table estimates the carbon dioxide emissions from propane dehydrogenation at about 0.9 t/t of propylene. This should be compared to the value for naphtha which is less than 0.4 t/t. This results from the lower thermodynamic efficiency of the process. However, again emission costs could be lowered by distributing some of the emissions to the hydrogen by-product. 

Dehydrogenation routes to propylene also increase the amount of carbon emissions relative to the production of propylene from naphtha. Increasing propylene output from FCC operations also increases emissions. Although this is the case for a standalone facility, it is not clear if a full cradle-to-grave analysis would ameliorate or exacerbate the emissions relative to naphtha cracking. 

Evaluated energy use and greenhouse gas (GHG) emissions impacts of central gaseous hydrogen (GH2) from natural gas (NG), central liquid hydrogen (LH2) from NG, station GH2 from NQ station LH2 from NG, solar photovoltaic (PV) GH2, solar PV LH2, station GH2 via electrolysis, station LH2 from electrolysis, gasoline, methanol, cellulosic ethanol, and naphtha from both cmde and NG. 

FIGURE 6-4 A portion of the flame emission speclrum for sodium, 800 ppm in naphtha isopropanol oxyhydrogen flame slit 0.02 mm. Note Chat the scale is expanded in the upper trace and flame conditions were changed to reveal greater detail for Na lines, but not for molecular bands. Note also that the lines at 589.00 and 589.59 nm are off scale in the upper trace. (Adapted from C. T. J. Alkemade and R. Herrmann, Fundamentdis oMna/yfrca/ Flams Specfroscopy, p. 229, New York Wiley. 1979, with permission.)... 

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