Process Technology: An Introduction - Haan A.B. 2015

1 The chemical industry
1.1 Introduction

The industry that applies the knowledge of chemical behavior is generally called the chemical process industry. Chemical reactions and separation of compounds are used to obtain products with desired properties. In reality the chemical industry is a set of related industries with many diverse functions and products. Some of these different areas, divided into three general classes of products, are listed in Fig. 1.1:

· (1) industrial chemicals and monomers such as acids, alkalis, salts, chlorine, ammonia, ethylene, propylene, caprolactam, acrylonitrile, industrial gases and other organic chemicals;

· (2) polymers and end chemicals to be used in further manufacture, such as synthetic resins, plastics, fibers, elastomers, dyes and pigments;

· (3) finished chemical products for consumer applications, such as architectural paints, drugs, cosmetics, and soaps, or to be used as materials or supplies in other industries, such as industrial paints, adhesives, fertilizers, and explosives.

Fig. 1.1 emphasizes that certain raw materials are used to prepare key chemicals, monomers and intermediates that may be sold independently or used directly in additional steps to give various polymers and end chemicals. These in turn can be formulated and fabricated into chemical products, which can sometimes be modified into finished products. Hence the term chemicals and allied products accurately represents this diversity as well as the flow of materials and products from raw sources to finished formulations. Although the division is approximate, about 60% of the chemical industry manufactures industrial products that are further modified, whereas 40 % of their products are sold directly to the consumer. Clearly the chemical industry is part of the manufacturing industry, and within this it plays a central part, even though it is by no means the largest part of the manufacturing sector. Its key position arises from the fact that almost all the other parts of the manufacturing sector utilize its products.

The three major segments of the chemical industry depicted in Fig. 1.2 are related to commodities, fine chemicals, and specialty chemicals. The substances representing these segments exhibit an increasing complexity in molecular architecture. In the business sector, starting from fossil fuels and culminating in the application products, fine chemicals take a position with their special characteristics between the commodities or base chemicals such as toluene, acetic acid, acetone, methanol, etc. and specialty chemicals or desired products for various markets. Fine chemicals are sold on the basis of their chemical composition for use as intermediates in the production of other materials. They are often needed in relatively small quantities and high purity for only one or a few end uses. Product applications can be found in pharmaceutical (50 %), agrochemicals (20 %) flavors and fragrances (5 %), food additives (5 %), and various other industries (20 %). Specialty chemicals are purchased because of their effect rather than composition. There is some overlap in the definitions of fine and specialty chemicals. The European market in fine chemicals is estimated to be approximately € 50 billion in sales, compared to € 500 billion for the commodity segment. With respect to the financial turnover (sales) the specialty chemicals industry is as large as the bulk chemical industry.

Fig. 1.1: Chemical process industry.

Fig. 1.2: Business sector segmentation.