Petrochemicals are chemicals derived (or extracted) from petroleum products. These chemicals include: ethylene, used to make anesthetics, antifreeze, and detergents; propylene, used to produce acetone and phenol; benzene, used to make other chemicals and explosives; toluene, used as a solvent and in refined gasoline; and xylene is used as a solvent and cleaning agent.
Examples of petrochemicals are plastics, rubbers, fibres, paints, solvents, adhesives, fertilizers, detergents …and so on. In fact, petroleum products are mixtures of hydrocarbons, whereas the raw materials for petrochemicals are pure hydrocarbons separated and converted to desirable products.
Classification of Petrochemicals
1. Feedstocks (First-generation petrochemicals or Basic petrochemicals).
2. Intermediates (Second-generation petrochemicals).
3. Finished products or End - products (Third-generation petrochemicals).
Products similar to petrochemicals derived from non-petroleum sources are not strictly petrochemicals. For example, cellulose, natural rubber, natural resins, nylon 11, and ethanol of plant origin are strictly non-petrochemicals.
Coal distillation is also a source of varieties of coal chemicals, e.g., benzene, toluene, xylene, and naphthalene. In fact, before petroleum sources were known, coal chemicals were used to produce a variety of products. Many of the chemicals from non-petroleum sources are co-processed with petrochemicals to the finished product.
Non-hydrocarbons obtained from petroleum, e.g., hydrogen, carbon monoxide, carbon dioxide, sulfur, and carbon, are also loosely called petrochemicals. Hydrogen, nitrogen and oxides of carbon manufactured from steam reforming and partial oxidation of naphtha are also petrochemicals. These are used for production of ammonia, urea, melamine, fertilizer, etc.
Feedstocks (Basic petrochemicals)
Feedstocks are the raw hydrocarbons obtained from crude oil refining by distillation and thermal and catalytic processes. For instance, hydrocarbon gases and naphtha are available from atmospheric distillation of crude oil; similarly, benzene, toluene, and xylene, obtained by catalytic reforming and catalytic cracking processes, are the major raw materials for the manufacture of second-generation petrochemicals.
Benzene, toluene, xylene, and heavier aromatics are also generated as by-products from petrochemical plants. Thus, the feedstocks for petrochemical plants are either directly obtained from refineries or are further processed to generate them in the petrochemical plant itself.
Natural gas and refinery products are the major source of feedstocks for petrochemicals.
المادة المعروضة اعلاه هي مدخل الى المحاضرة المرفوعة بواسطة استاذ(ة) المادة . وقد تبدو لك غير متكاملة . حيث يضع استاذ المادة في بعض الاحيان فقط الجزء الاول من المحاضرة من اجل الاطلاع على ما ستقوم بتحميله لاحقا . في نظام التعليم الالكتروني نوفر هذه الخدمة لكي نبقيك على اطلاع حول محتوى الملف الذي ستقوم بتحميله .
الرجوع الى لوحة التحكم
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