Fossil fuels are one-time energy gift to the human race . Once they are gone, they are gone forever (or at least for millions of years far longer than human history). The average age of the gasoline in your car's fuel tank is about 70 million years. Yet we are using this precious resource as though it were unlimited. Worse, we have based our economic welfare on cheap, abundant fossil fuels. And worst is the lack of preparation for moving over to renewable energy sources in a manner that will minimize the unprecedented economic and social disruption due to the impending depletion of this resource. Many governments cannot afford to acknowledge this imminent disaster for fear of triggering economic problems including lack of credit worthiness in a world economy and civil unrest.
Fossil fuel use has tremendous impact on the world ecology and global climate. From oil spills to contaminated ground water, using fossil fuels has caused great harm to the environment and humans. One of the net combustion products from burning this type of fuel is to release stored carbon into the Earth's atmosphere. The carbon dioxide gas then acts as a blanket, trapping heat in the atmosphere and causing temperatures to rise. This worldwide effect is called global warming and has significant consequences for humans.
Diesel fuel is derived from light virgin gas oil that is produced from the distillation of crude oil. Low Sulfur Diesel is produced in the refineries with a hydro-desulfphurisation unit and has a sulfur content of 350 ppm. High levels of sulfur are undesirable as during combustion these are converted into volatile sulfur oxides, which lead to increased engine wear. They also contribute directly to acid rain and form solid sulphates, which add to the particulate matter in the exhaust gas.
Ultra low sulfur diesel is produced in much the same way as normal diesel but requires the fuel to go through an extra series of processing steps which are typically accomplished using a two-stage high severity hydro desulphurisation unit. This unit comprises a cobalt-molybdenum catalyst in the first stage and nickel molybdenum catalyst in the second stage. Hydrogenation of diesel over the Co-Mo catalyst removes mostly sulfur associated with aliphatic hydrocarbons. A more active Ni-Mo catalyst facilitates hydrogenation of aromatic sulfur as well as saturation of aromatic hydrocarbons. This results in a higher cetane number and affects the physical properties of the resulting product, changing things like the cloud point and viscosity of the final diesel fuel product.
Diesel cars are better than petrol cars with reference to carbon dioxide, the global warming gas.
There is less energy in a gallon of biodiesel than there is in No.2 diesel fuel. This is one of the many reasons that blends of B5 and B20 are most commonly seen on the market. Blending biodiesel with petro based diesel fuel tends to mitigate the effect of the lower calorific value of biodiesel while the user still gains many of the benefits accrued from using biodiesel.
Unfortunately it is a common experience to see and smell a black cloud of smoke rising from behind a diesel powered vehicle. Fossil-fuel based diesel exhaust contains potent carcinogens and diesel particulates increase the risk of asthma, lung disease as well as cancer.
Nearly a half-million people in the Dallas-Fort Worth region live with diseases that are aggravated by air pollution, according to the American Lung Association. In the Dallas/Fort Worth Metroplex there are 63,758 children with asthma, 208,835 adults with asthma, 137,717 people with chronic bronchitis, and 36,099 people with emphysema.