A preparation method of eicosapentaenoic acid (EPA) ethyl ester is provided and relates to the field of EPA ethyl ester processing technologies. The preparation method includes: performing degumming and deacidification on a sardine crude oil to obtain a semi-refined sardine oil, performing esterification on the semi-refined sardine oil to obtain an esterified sardine oil and then performing winterization on the esterified sardine oil to thereby obtain an semi-refined esterified sardine oil, performing bleaching and deodorization on the semi-refined esterified sardine oil, and performing multi-stage distillation treatment. Finally, the sardine oil is purified by liquid chromatography to obtain the high purity EPA ethyl ester. The preparation method can improve a utilization rate of the sardine oil and obtain the high-purity EPA ethyl ester.

A novel process can be used for purifying methyl methacrylate (MMA) contaminated with low-boiling components by distillation, where the process involves producing MMA by oxidative esterification, and a crude product containing methyl propionate (MP), methyl isobutyrate (MIB), and methacrolein (MAL) as low-boiling components. The process is compatible with MMA produced from C.sub.2-based methacrolein containing the low-boiling components specified.

A novel process can be used for purifying methyl methacrylate (MMA) contaminated with low-boiling components by distillation, where the process involves producing MMA by oxidative esterification, and a crude product containing methyl propionate (MP), methyl isobutyrate (MIB), and methacrolein (MAL) as low-boiling components. The process is compatible with MMA produced from C.sub.2-based methacrolein containing the low-boiling components specified.

A novel process can be used for purifying methyl methacrylate (MMA) contaminated with low-boiling components by distillation, where the process involves producing MMA by oxidative esterification, and a crude product containing methyl propionate (MP), methyl isobutyrate (MIB), and methacrolein (MAL) as low-boiling components. The process is compatible with MMA produced from C.sub.2-based methacrolein containing the low-boiling components specified.

A process discharges low boilers during production of dialkyl terephthalates or dialkyl phthalates having C8 to C11 alkyl radicals. The production is carried out using a C8 to C11 alcohol or a mixture of two or more C8 to C11 alcohols in one or more reactors. The low boilers formed during the reaction are separated off by an efficient process and thus cannot accumulate.

A process discharges low boilers during production of dialkyl terephthalates or dialkyl phthalates having C8 to C11 alkyl radicals. The production is carried out using a C8 to C11 alcohol or a mixture of two or more C8 to C11 alcohols in one or more reactors. The low boilers formed during the reaction are separated off by an efficient process and thus cannot accumulate.

A process discharges low boilers during production of dialkyl terephthalates or dialkyl phthalates having C8 to C11 alkyl radicals. The production is carried out using a C8 to C11 alcohol or a mixture of two or more C8 to C11 alcohols in one or more reactors. The low boilers formed during the reaction are separated off by an efficient process and thus cannot accumulate.

A process can be used for preparing methyl methacrylate by direct oxidative esterification of methacrolein. Methyl methacrylate is used in large amounts for preparing polymers and copolymers with other polymerizable compounds. In addition, methyl methacrylate is an important synthesis unit for a variety of specialty esters based on methacrylic acid (MAA) which can be prepared by transesterification with the appropriate alcohol. There is consequently a great interest in very simple, economic and environmentally friendly processes for preparing this starting material. A corresponding optimized workup of the reactor output from the oxidative esterification of methacrolein, through which unconverted methacrolein (MAL) can be recycled very efficiently, is useful. In addition, the process can be carried out in a manner which compared to known variants is markedly more energy- and water-saving.

A process can be used for preparing methyl methacrylate by direct oxidative esterification of methacrolein. Methyl methacrylate is used in large amounts for preparing polymers and copolymers with other polymerizable compounds. In addition, methyl methacrylate is an important synthesis unit for a variety of specialty esters based on methacrylic acid (MAA) which can be prepared by transesterification with the appropriate alcohol. There is consequently a great interest in very simple, economic and environmentally friendly processes for preparing this starting material. A corresponding optimized workup of the reactor output from the oxidative esterification of methacrolein, through which unconverted methacrolein (MAL) can be recycled very efficiently, is useful. In addition, the process can be carried out in a manner which compared to known variants is markedly more energy- and water-saving.

Herein is provided a process for producing renewable products, such as alkenes, from a feedstock of biological origin. The process includes subjecting a feedstock including fatty acid glycerides and optionally free fatty acids, wherein at least one hydrocarbon chain is unsaturated, to esterification reaction in the presence of an alcohol. The ester stream thereby obtained is then fractionated and a fraction including esters of unsaturated C18 fatty acids is subjected to metathesis conditions in the presence of an alkene to obtain metathesis products. Fractionation of the metathesis products includes recovery of at least renewable 1-decene, and unsaturated C10-C15 fatty acid esters.