TAILIEUCHUNG - Chapter 4: Hydroformylation

In today`s industry, hydroformylation is the largest volume homogeneous catalytic process employing organometallic catalysts [1]. The simplest representation of this process (Scheme ) is the reaction of a terminal alkene with CO and to afford linear and branched aldehydes. n-Butyraldehyde is produced for manufacturing 2-ethylhexanol used on large scale as an additive in plastics industry. Therefore the straight chain product of propene hydroformylation (linear aldehyde) is more valuable than iso-butyraldehyde, although the branched isomer, as well, has a smaller but constant market. . | Chapter 4 Hydroformylation Introduction In today s industry hydroformylation is the largest volume homogeneous catalytic process employing organometallic catalysts 1 . The simplest representation of this process Scheme is the reaction of a terminal alkene with CO and H2 to afford linear and branched aldehydes. Scheme n-Butyraldehyde is produced for manufacturing 2-ethylhexanol used on large scale as an additive in plastics industry. Therefore the straight chain product of propene hydroformylation linear aldehyde is more valuable than iso-butyraldehyde although the branched isomer as well has a smaller but constant market. The selectivity of a catalyst towards the production of linear aldehyde is usually expressed as the n i or 1 b ratio. It is mentioned though that there are reactions in which the branched product is the more valuable one as is the case of the hydroformylation of styrene. There is no need to treat here the basic chemistry of hydroformylation in much detail since these days it is covered by inorganic chemistry or catalysis courses at universities 2 3 moreover there are numerous recent books devoted partly or entirely to hydroformylation references 1-8 represent only a selection and many other would deserve mentioning. For this reason the details not directly relevant to aqueous organometallic chemistry will be kept to a minimum. 149 150 Chapter 4 Following O. Roelen s original discovery in 1938 hydroformylation the oxo-process employed cobalt carbonyls as catalyst which later became modified with tertiary phosphines . with PnBu3 Shell 1964 . The modified cobalt catalyst allowed reactions run at lower temperature and pressure but still suffered from rather low n i selectivity. The next fundamental step in developing a less expensive and more selective way of industrial hydroformylation was the introduction of rhodium-phosphine catalysts in the mid-nineteen seventies which allowed milder conditions and brought about high selectivity .

TÀI LIỆU LIÊN QUAN
TỪ KHÓA LIÊN QUAN
TAILIEUCHUNG - Chia sẻ tài liệu không giới hạn
Địa chỉ : 444 Hoang Hoa Tham, Hanoi, Viet Nam
Website : tailieuchung.com
Email : tailieuchung20@gmail.com
Tailieuchung.com là thư viện tài liệu trực tuyến, nơi chia sẽ trao đổi hàng triệu tài liệu như luận văn đồ án, sách, giáo trình, đề thi.
Chúng tôi không chịu trách nhiệm liên quan đến các vấn đề bản quyền nội dung tài liệu được thành viên tự nguyện đăng tải lên, nếu phát hiện thấy tài liệu xấu hoặc tài liệu có bản quyền xin hãy email cho chúng tôi.
Đã phát hiện trình chặn quảng cáo AdBlock
Trang web này phụ thuộc vào doanh thu từ số lần hiển thị quảng cáo để tồn tại. Vui lòng tắt trình chặn quảng cáo của bạn hoặc tạm dừng tính năng chặn quảng cáo cho trang web này.