tailieunhanh - The Basics of Oil Spill Cleanup - Chapter 3

Các loại dầu và tài sản của họ Dầu mỏ là một thuật ngữ chung mô tả một loạt các chất tự nhiên có nguồn gốc thực vật, động vật, khoáng sản, cũng như một loạt các hợp chất tổng hợp. Các loại dầu được tạo thành từ hàng trăm các hợp chất và hàng ngàn những cái nhỏ. Khi thành phần của họ khác nhau, mỗi loại sản phẩm dầu hoặc xăng dầu có một số đặc điểm độc đáo hoặc tài sản. Các tính chất này ảnh hưởng đến cách cư xử khi nó là tràn dầu và xác. | CHAPTER 3 Types of Oil and their Properties Oil is a general term that describes a wide variety of natural substances of plant animal or mineral origin as well as a range of synthetic compounds. The many different types of oil are made up of hundreds of major compounds and thousands of minor ones. As their composition varies each type of oil or petroleum product has certain unique characteristics or properties. These properties influence how the oil behaves when it is spilled and determine the effects of the oil on living organisms in the environment. These properties also influence the efficiency of cleanup operations. This book deals specifically with crude oils and petroleum products derived from crude oils. The chemical composition and physical properties of these oils are described in this chapter. THE COMPOSITION OF OIL Crude oils are mixtures of hydrocarbon compounds ranging from smaller volatile compounds to very large non-volatile compounds. This mixture of compounds varies according to the geological formation of the area in which the oil is found and strongly influences the properties of the oil. For example crude oils that consist primarily of large compounds are viscous and dense. Petroleum products such as gasoline or diesel fuel are mixtures of fewer compounds and thus their properties are more specific and less variable. Hydrocarbon compounds are composed of hydrogen and carbon which are therefore the main elements in oils. Oils also contain varying amounts of sulphur nitrogen oxygen and sometimes mineral salts as well as trace metals such as nickel vanadium and chromium. In general the hydrocarbons found in oils are characterized by their structure. The hydrocarbon structures found in oil are the saturates olefins aromatics and polar compounds some examples of which are shown in Figure 5. 2000 by CRC Press LLC Group_Sub-group Saturates Alkanes Example Compound butane hexane Cyclo-alkanes cyclohexane tetrahydronapthal ene Waxes I arge al kane