Acid Rain

Introduction

Acid rain has become an environmental concern of global importance within the last decade. With the increasing environmental awareness of the "unhealthy" condition of our planet earth the concern about acid rain has not lessened.

In brief, acid rain is rain with pH values of less than 5.6. When dealing with acid rain one must study and understand the process of making Sulfuric acid. In this project we will take an in depth look into the production of sulfuric acid, some of its uses and the effects of it as a pollutant in our environment.

Sulfuric Acid Industry in Ontario

Among the many plants in Ontario where sulfuric acid is produced, there are three major plant locations that should be noted on account of their greater size. These are:

Inco. - Sudbury

Noranda Mines Ltd. - Welland

Sulfide - Ontario

There are a number of factors which govern the location of each manufacturing plant. Some of these factors that have to be considered when deciding the location of a Sulfuric Acid plant are:

a. Whether there is ready access to raw materials;

b. Whether the location is close to major transportation routes;

c. Whether there is a suitable work force in the area for plant construction and operation;

d. Whether there is sufficient energy resources readily available;

e. Whether or not the chemical plant can carry out its operation without any unacceptable damage to the environment.

Listed above are the basic deciding factors that govern the location of a plant. The following will explain in greater detail why these factors should be considered.

1) Raw Materials The plant needs to be close to the raw materials that are involved in the production of sulfuric acid such as sulfur, lead, copper, zinc sulfides, etc..

2) Transportation A manufacturer must consider proximity to transpor-tation routes and the location of both the source of raw materials and the market for the product. The raw materials have to be transported to the plant, and the final product must be transported to the customer or distributor. Economic pros and cons must also be thought about. For example, must sulfuric plants are located near the market because it costs more to transport sulfuric acid than the main raw materials, sulfur. Elaborate commission proof container are required for the transportation of sulfuric acid while sulfur can be much more easily transported by truck or railway car.

3) Human Resources For a sulfuric acid plant to operate, a large work force will obviously be required. The plant must employ chemists, technicians, administrators, computer operators, and people in sales and marketing. A large number of workers will also be required for the daily operation of the plant. A work force of this diversity is therefore likely to be found only near major centres of population.

4) Energy Demands Large amounts of energy will also be required for the production of many industrial chemicals. Thus, proximity to a plentiful supply of energy is often a determining factor in deciding the plant's location. 5) Environmental Concerns Most importantly, however, concerns about the environment must be carefully taken into consideration. The chemical reaction of changing sulfur and other substances to sulfuric acid results in the formation of other substances like sulfur dioxide. This causes acid rain. Therefore, there is a big problem about sulfuric plants causing damage to our environment as the plant is a source of sulfur emission leading to that of acid rain.

6) Water Supplies Still another factor is the closeness of the location of the plants to water supplies as many manufacturing plants use water for cooling purposes. In addition to these factors, these questions must also be answered: Is land available near the proposed site at a reasonable cost? Is the climate of the area suitable? Are the general living conditions in the area suitable for the people involved who will be relocating in the area? Is there any suggestions offered by governments to locate in a particular region?

The final decision on where the sulfuric acid plant really involves a careful examination and a compromise among all of the factors that have been discussed above.

Producing Sulfuric Acid

Sulfuric acid is produced by two principal processes-the chamber process and the contact process.

The contact process is the current process being used to produce sulfuric acid. In the contact process, a purified dry gas mixture containing 7-10% sulfur dioxide and 11-14% oxygen is passed through a preheater to a steel reactor containing a platinum or vanadium peroxide catalyst. The catalyst promotes the oxidation of sulfur dioxide to trioxide. This then reacts with water to produce sulfuric acid. In practice, sulfur trioxide reacts not with pure water but with recycled sulfuric acid.The reactions are:

2SO2 + O2> 2SO3

SO3 + H2O> H2SO4

The product of the contact plants is 98-100% acid. This can either be diluted to lower concentrations or made stronger with sulfur trioxide to yield oleums. For the process, the sources of sulfur dioxide may be produced from pure sulfur, from pyrite, recovered from smelter operations or by oxidation of hydrogen sulfide recovered from the purification of water gas, refinery gas, natural gas and other fuels.

Battery Acid Industry

Many industries depend on sulfuric acid. Among these industries is the battery acid industry.

The electric battery or cell produces power by means of a chemical reaction. A battery can be primary or secondary. All batteries, primary or secondary, work as a result of a chemical reaction. This reaction produces an electric current because the atoms of which chemical elements are made, are held together by electrical forces when they react to form compounds.

A battery cell consists of three basic parts; a positively charged electrode, called the cathode, a negatively charged electrode, called the anode, and a chemical substance, called an electrolyte, in which the electrodes are immersed. In either a wet or dry cell, sufficient liquid