To provide low CTE and low puffing needle coke more stably while dealing with changes in the properties of a feedstock. The low CTE and low puffing needle coke is obtained by mixing and coking a needle coke main feedstock of a coal tar-based heavy oil or petroleum-based heavy oil having a weak hydrogen donating property with a PDQI value expressed by equation (1) of less than 5.0, with a secondary feedstock having a strong hydrogen donating property with a PDQI value expressed by equation (1) of 5.0 or more, and calcining the obtained raw coke. [Equation (1)] PDQI=H %×10×(HNβ/H), wherein H % is a hydrogen amount (% by weight) obtained by elemental analysis, and HNβ/H is a ratio of β naphthenic hydrogen to total hydrogen measured by .sup.1H-NMR.

The invention relates to pyrolysis tar upgrading processes, and in particular for decreasing reactor pressure drop when the upgrading includes converting pyrolysis tar in a reactor. The invention also relates to upgraded pyrolysis tar, and the use of upgraded pyrolysis tar, e.g., as a fuel oil blending component.

This invention relates to a process for determining the suitability of pyrolysis tar, such as steam cracker tar, for upgrading using hydroprocessing without excessive fouling of the hydroprocessing reactor. A pyrolysis tar is sampled, the sample is analyzed to determine one or more characteristics of the tar related to tar reactivity, and the analysis is used to determine conditions under which the tar can be blended, pre-treated, and/or hydroprocessed.

This invention relates to a process for determining the suitability of pyrolysis tar, such as steam cracker tar, for upgrading using hydroprocessing without excessive fouling of the hydroprocessing reactor. A pyrolysis tar is sampled, the sample is analyzed to determine one or more characteristics of the tar related to tar reactivity, and the analysis is used to determine conditions under which the tar can be blended, pre-treated, and/or hydroprocessed.

This invention relates to a process for determining the suitability of pyrolysis tar, such as steam cracker tar, for upgrading using hydroprocessing without excessive fouling of the hydroprocessing reactor. A pyrolysis tar is sampled, the sample is analyzed to determine one or more characteristics of the tar related to tar reactivity, and the analysis is used to determine conditions under which the tar can be blended, pre-treated, and/or hydroprocessed.

The present disclosure refers to a process and a process plant for extraction of metals from a hydrocarbon mixture obtained from a gasification or pyrolysis process, comprising the steps of combining said hydrocarbon mixture with an aqueous acid forming a mixture, mixing said mixture, separating said mixture in a contaminated aqueous phase and a purified hydrocarbon phase, with the associated benefit of said aqueous acid being able to release metals bound in such gasification and pyrolysis processes.

This invention relates to a process for determining the suitability of pyrolysis tar, such as steam cracker tar, for upgrading using hydroprocessing without excessive fouling of the hydroprocessing reactor. A pyrolysis tar is sampled, the sample is analyzed to determine one or more characteristics of the tar related to tar reactivity, and the analysis is used to determine conditions under which the tar can be blended, pre-treated, and/or hydroprocessed.

A process control method for the on-line operation in real time of a low-rank-coal pyrolysis process producing a coal-char product, a pyrolysis gas, and a complex multi-component coal-tar-oil. The control method is based on measuring the concentration of selected compounds in the three products, a solid phase, a gas phase and a liquid phase condensed from the gas-phase, using a combination of spectrometric technology including scanning in the infrared, visible, ultraviolet and microwave spectral regions, and analyzing the data based on application of a modified Chi-Square data manipulation fitting technique developed for the specific products and process. This process control method provides a basis for accurate on-line control of the process operating parameters and allows optimization of the coal-char quality as well as the quality and yield of the extracted coal-tar-oil with unique chemical composition derived from low-rank coal in a pyrolysis process. The subject invention is based on the selection of 2-6 key compounds contained in each product to be measured and used as control point, calibration of the process operating conditions to the key compound composition and monitoring the changes in concentration on-line in real time.

A process for producing mesophase pitch from high-temperature coal tar comprises: removing salts and quinoline insoluble fraction from a high-temperature coal tar to obtain a decant oil; using the decant oil as a hydrogenation feedstock, or pre-distilling the decant oil to obtain a residue with a boiling point higher than 230 and formulating the residue into a hydrogenation feedstock; catalytic hydrorefining the hydrogenation feedstock to obtain a hydrofined oil; distilling the hydrofined oil to obtain hydrogenated pitch; and subjecting the hydrogenated pitch to the thermal polymerization to obtain the mesophase pitch. The process has features such as an easily controllable degree of hydrogenation, complete removal of impurities, good raw material flowability, not tending to form the carbon deposition and the coking during the process, and not tending to jam the reactor. The product has a high content of mesophase pitch, a low softening point and a low impurity content.

The present disclosure refers to a process and a process plant for extraction of metals from a hydrocarbon mixture obtained from a gasification or pyrolysis process, comprising the steps of combining said hydrocarbon mixture with an aqueous acid forming a mixture, mixing said mixture, separating said mixture in a contaminated aqueous phase and a purified hydrocarbon phase, with the associated benefit of said aqueous acid being able to release metals bound in such gasification and pyrolysis processes.