ENVIRONMENTAL EFFECTS OF REFINERY

 ENVIORMENTAL EFFECTS OF REFINERY

Crude oil consists of millions of components with the major component being hydrocarbons, along with traces of other compounds, such as Nitrogen, Sulphur, Oxygen and Metals etc. We will be stressing upon the presence of Sulfur element, which is a hazardous material. When the fossil fuels are burnt, oxides of sulfur such as SO2, and SO3, (SOx) are released in significant quantities. These gases are extremely toxic and cause irreversible damage to the environment and living beings on the earth. The presence of sulfur in the atmosphere is dangerous because it promotes formation of smog. Cold, humid air in light windy conditions facilitates fog formation. When sulfur dioxide is present in the lower regions of the atmosphere; it gets trapped within the fog and reacts with it to give sulfuric acid, which forms Smog. This smog then condenses as acid rain, which causes serious soil degradation and destruction of flora.

Automobile repair workshops release waste products such as engine oil, transmission oil, brake fluid, damaged tyres, battery electrolytes, wire carbide, spent batteries and cells into their surrounding areas. Their improper disposal leads to the discharge of toxic emissions during abrasion and contributes to metal contamination of the areas around the auto-repair workshops. Heavy metals pose higher risk for living organisms rather than metals present in higher concentration . Scrap batteries and solder, waste engine oil, brake fluid and other fluid generated by their activities in the workshop are not properly disposed off. They are usually released on to the surrounding soil. Since the activity of artisans in auto-repair workshops is one of the major routes for entry of heavy metals into the environment to cause contamination of soil and drinking wells and crops, monitoring the available pools of metals in contaminated soils becomes relevant. Accumulation of heavy metals in the soil possibly controls the soil microbial functions triggering toxicity and contamination of the food chain. Lateral migration of heavy metals towards drinking water wells dug in these reclaimed auto-repair workshop areas causes discharge of heavy metals via soil into wells thereby exposing the residents to unsafe water for drinking and other domestic usage

SO2 also contaminates the exhaust oxygen sensor, which interferes with precise feedback controlling the air to fuel ratio. Alliance and Association of International Automobile Manufacturers (AIAM) have reported that emissions of HC, CO, and NOx were reduced by more than 20% in low and ultralow emissions vehicles when the sulfur content in gasoline decreased from 100 to 30 ppm.

Although CNG is a fossil fuel, it has several benefits over other fossil fuels. It is an inherently “cleaner” fuel resulting in lower engine emissions, is in abundant supply in North America, currently has a low price, and results in lower GWP. A primary impact of the vehicle comparability issue is the additional fuel and fuel storage required for CNG vehicles to attain the 595-km range .

High-sulfur coal when burnt in air releases sulfur predominantly in the form of SO2. Combustion of high sulfur lignites is one of the fundamental reasons for problem with sulfur dioxide emissions. The sulfur dioxide in the air combines with rainwater to form sulfurous acid (acid rain). Polluted air causes erosion whereby an originally smooth concrete surface can be weathered away leaving only a coarse exposed aggregate highly susceptible to deterioration. Sulfur dioxide is one of the air pollutants that evolves mostly from fossil fuels used in transport vehicles, industrial furnaces, and thermal power plants . Different methods of desulfurization have been developed based on physical, microbial, and chemical principles. There are nearly 15 different processes, which can be applied to remove sulfur dioxide from the flue gases produced by coal combustion. These processes can in general be classified into two main groups: wet processes and dry processes.

There are four primary methods used to control tailpipe emissions: increasing engine efficiency, treatment of emissions emitted, increasing vehicle efficiency, or increasing driving efficiency. This paper is concerned only with innovations related to the former two types of technologies, namely those that increase engine efficiency and those that involve post-combustion devices. The latter two types of control methods depend on non-technological aspects (e.g., driving techniques, levels of congestion) or on material improvements (e.g., light-weighting, aerodynamic design). Consequently, these issues are not considered here in this paper. A number of factors are likely to affect the rate and direction of innovation with respect to automotive emissions control, including general macroeconomic conditions (size and openness of an economy, integration in international trade) and general propensity to patent (strength of intellectual property rights regimes, scientific and research capacity). However, such factors affect patents in total and not specifically those associated with emissions control technologies. 

In response to environmental regulations introduced by several countries in the 1970s car manufacturers generally based their compliance strategies on the use of catalytic converters. In the early 1980s, some car manufacturers applied three-way catalyst in a closed-loop emissions control system using sophisticated electronic devices for controlling engine functions, while others relied solely on the use of three-way catalyst without these electronic devices (e.g., Bresnahan and Yao 1985). The U.S. established Tier I standards for HC and NOX emissions in 1994, followed by Tier II standards in 2004.9 Relative to the initial levels in the early 1970s, standards have become significantly more stringent. For example, compared to pre-regulation levels, the 2004 standards represent a reduction of 97% for HC, 94% for NOX, and 95% for CO. Additional standards for particulate matter (PM) were implemented in 1994, and are currently set at 0.08 g/mile. Japanese automobile regulations are also embedded in the 1992 Motor Vehicle NOX law, which specified performance standards for NOX emissions from in-use vehicles. More recently, in cooperation with the Japan Automobile Manufacturers Association (JAMA) and the Petroleum Association of Japan (PAJ), the Japan Clean Air Program (JCAP) was established in 1996 with the aim to improve air quality. For diesel engines, the CO standard first coincided with the standard for gasoline engines in the period 1986-1999 and became more stringent in 2002.11 The HC and NOX standards for diesel have generally been less strict than the corresponding standards for gasoline engines.12 Furthermore, PM standards for diesel came into effect after 1994 and gradually changed from 0.23 g/km to 0.0135 g/km in 2005 – about a 94% reduction.

Gasoline- and diesel-fueled automobiles have made important progress in improving fuel economy and reducing emissions. Near-term improvements of gasoline vehicles, combined with low-sulfur RFG, make it difficult for any fuel to displace gasoline. A further difficulty is the need to build a new infrastructure to produce and deliver the alternative fuel. No alternative fuel is likely to be successful unless there are substantial petroleum price increases or more stringent regulations concerning emissions and fuel economy standards, along with new regulations concerning GHG emissions. Biofuels offer the benefits of lower GHG emissions, sustainability, and domestic fuel production. The herbaceous and woody biomass based C2H5OH options are more attractive than producing the biofuels from food products. The latter crops require additional maintenance, and feasible fuel production requires a high demand for their co-products. The C2H5OH from herbaceous or woody biomass could replace much of the gasoline required for the light-duty fleet while supplying electricity as a co-product. While it is more expensive than gasoline, bioethanol would be attractive if the price of gasoline doubled, if significant reductions in GHG emissions were required, or with tightening of fuel economy regulations for gasoline vehicles.