US-12618015-B2 - Process for producing kerosene from renewable sources

US12618015B2US 12618015 B2US12618015 B2US 12618015B2US-12618015-B2

Abstract

A process for producing kerosene involves reacting a renewable feedstock in a hydroprocessing section under hydroprocessing conditions sufficient to cause a hydroprocessing reaction to produce a hydroprocessed effluent. The hydroprocessed effluent is separated to produce a hydroprocessed liquid stream and a separation system offgas stream. The hydroprocessed liquid stream is directed to a work-up section where gases are stripped to produce a stripped liquid product stream and a stripper offgas stream. A gas stream comprising the separation system offgas stream and/or the stripper offgas stream are directed to a gas-handling section to obtain a pressurized gas stream and a hydrocarbon fraction that is liquid at a pressure in a range from 0-1.5 MPaG and a temperature in a range from 0 to 50 C. The hydrocarbon fraction is recycled to the work-up section. A kerosene stream separated in the product recovery unit has a higher yield compared to conventional processes.

Inventors

Bastiaan Willem Van Hasselt
Roy Léon Bernard HENKET
Marjan SAMSON

Assignees

SHELL USA, INC.

Dates

Publication Date: 20260505
Application Date: 20220914
Priority Date: 20210928

Claims (12)

1 . A process for producing kerosene from a renewable feedstock, the process comprising the steps of: reacting a renewable feedstock in a hydroprocessing section under hydroprocessing conditions sufficient to cause a hydroprocessing reaction to produce a hydroprocessed effluent; separating the hydroprocessed effluent to produce at least one hydroprocessed liquid stream and at least one separation system offgas stream; directing one or more of the at least one hydroprocessed liquid stream to a work-up section, comprising a product stripper and a product recovery unit; stripping one or more of the at least one hydroprocessed liquid stream in the product stripper to remove gases from the one or more of the at least one hydroprocessed liquid stream to produce a stripped liquid product stream and a stripper offgas stream; directing a gas stream comprising gases selected from the group consisting of one or more of the at least one separation system offgas stream, the stripper offgas stream, and combinations thereof, to a gas-handling section to obtain a pressurized gas stream and a hydrocarbon fraction that is liquid at a pressure in a range from 0.5 to 15 barg (0-1.5 MPaG) and a temperature in a range from 0 to 50° C.; recycling the hydrocarbon fraction to the work-up section; and separating a kerosene stream from the stripped liquid product stream in the product recovery unit.
2 . The process of claim 1 , wherein the hydroprocessing reaction is selected from the group consisting of hydrogenation, hydrotreating, hydrocracking, hydroisomerization, selective cracking, and combinations thereof.
3 . The process of claim 1 , wherein the reacting step is comprised of at least two stages and wherein the step of separating the hydroprocessed effluent is conducted after each stage.
4 . The process of claim 1 , wherein the reacting step is a one stage step.
5 . The process of claim 1 , wherein the step of separating the hydroprocessed effluent comprises directing the effluent to one or more separator units, the separator unit selected from the group consisting of a hot high-pressure separator, a hot low-pressure separator, an intermediate high-pressure separator, an intermediate low-pressure separator, a cold high-pressure separator, a cold low-pressure separator, a stripper, an integrated stripper, and combinations thereof.
6 . The process of claim 1 , wherein the step of separating the hydroprocessed effluent further comprising a gas-treatment selected from the group consisting of membrane separation, amine adsorption, pressure swing adsorption, caustic wash, and combinations thereof.
7 . The process of claim 3 , wherein the step of separating the hydroprocessed effluent comprises directing the hydroprocessed effluent from each stage to the same or different separator units, the separator unit selected from the group consisting of a hot high-pressure separator, a hot low-pressure separator, an intermediate high-pressure separator, an intermediate low-pressure separator, a cold high-pressure separator, a cold low-pressure separator, a stripper, an integrated stripper, and combinations thereof.
8 . The process of claim 1 , wherein the kerosene separating step further comprises separating a higher boiling point stream, preferably a diesel stream.
9 . The process of claim 1 , wherein the kerosene separating step further comprises separating a lower boiling point stream, preferably a naphtha stream.
10 . The process of claim 1 , wherein the hydrocarbon fraction is recycled to the work-up section at a point selected from the group consisting of a feed of the product stripper, the stripped liquid product stream, a feed to the product recovery unit, the kerosene stream from the product recovery unit, and combinations thereof.
11 . The process of claim 1 , wherein the renewable feedstock is selected from the group consisting of one or more bio-renewable fats and oils, liquid derived from a biomass liquefaction process, liquid derived from a waste liquefaction process, and combinations thereof.
12 . The process of claim 1 , further comprising adding a petroleum-derived feedstock for co-processing with the renewable feedstock, preferably in an amount to produce a feed stream comprising from 30 to 99 wt. % renewable feedstock.

Description

CROSS REFERENCE TO RELATED APPLICATIONS This is a National stage application of International Application No. PCT/US2022/043465, filed 14 Sep. 2022, which claims priority of U.S. Provisional Application No. 63/245,017 filed 16 Sep. 2021 and European Application No. 21199562.6 filed 28 Sep. 2021 which is incorporated herein by reference in its entirety. FIELD OF THE INVENTION The present invention relates to the field of producing kerosene from renewable sources and, in particular, to a process for improving the yield of kerosene from renewable sources. BACKGROUND OF THE INVENTION The increased demand for energy resulting from worldwide economic growth and development has contributed to an increase in concentration of greenhouse gases in the atmosphere. This has been regarded as one of the most important challenges facing mankind in the 21st century. To mitigate the effects of greenhouse gases, efforts have been made to reduce the global carbon footprint. The capacity of the earth's system to absorb greenhouse gas emissions is already exhausted. Accordingly, there is a target to reach net-zero emissions by 2050. To realize these reductions, the world is transitioning away from solely conventional carbon-based fossil fuel energy carriers. A timely implementation of the energy transition requires multiple approaches in parallel. For example, energy conservation, improvements in energy efficiency and electrification may play a role, but also efforts to use renewable resources for the production of fuels and fuel components and/or chemical feedstocks. Typical jet fuels and liquid kerosene rocket fuels are prepared in a refinery from a crude mineral oil source. Typically, the crude mineral oil is separated by means of distillation into a distillate kerosene fraction boiling in the aviation fuel range or a more purified liquid kerosene rocket fuel. If required, these fractions are subjected to hydroprocessing to reduce sulfur, oxygen, and nitrogen levels. For the reasons mentioned above, there is a need to explore methods to increase environmentally-friendly fuel sources while meeting jet fuel specifications. Vegetable oils, oils obtained from algae, and animal fats are seen as new sources for low carbon fuel production. Also, deconstructed materials are seen as a potential source for low carbon renewable fuels materials, such as pyrolyzed recyclable materials or wood. Renewable materials may comprise materials such as triglycerides with very high molecular mass and high viscosity, which means that using them directly or as a mixture in fuel bases is problematic for modern engines. On the other hand, the hydrocarbon chains that constitute, for example, triglycerides are essentially linear and their length (in terms of number of carbon atoms) is compatible with the hydrocarbons used in/as fuels. Thus, it is attractive to transform triglyceride-comprising feeds in order to obtain good quality fuel components. As well, renewable feedstocks may comprise unsaturated compounds and/or oxygenates that are unsaturated compounds. Petroleum-derived jet fuels inherently contain both paraffinic and aromatic hydrocarbons. In general, paraffinic hydrocarbons offer the most desirable combustion cleanliness characteristics for jet fuels. Challenges in using paraffinic hydrocarbons from renewable sources include higher boiling point, due to chain length, and higher freeze point. Solutions to these challenges include cracking to reduce chain length and/or isomerization to increase branching to reduce the freeze-point. Aromatics generally have the least desirable combustion characteristics for aircraft turbine fuel. In aircraft turbines, certain aromatics, such as naphthalenes, tend to burn with a smokier flame and release a greater proportion of their chemical energy as undesirable thermal radiation than other more saturated hydrocarbons. The closest current option for reducing aviation emissions is blending synthesized paraffinic kerosene (“SPK”) from Fischer-Tropsch or hydroprocessed esters and fatty acids with conventional jet fuel. Up to 50% by volume of SPK is permitted by the alternative jet fuel specification ASTM D7566. If the resulting blend meets the specification, it can be certified and considered equivalent to conventional, petroleum-derived jet fuel. Typically, these synthesized paraffinic kerosenes contain a mixture of normal and branched paraffin according to ASTM D7566. Ginestra et al. (U.S. Pat. No. 11,021,666, 1 Jun. 2021) is directed to a method for upgrading a kerosene fuel to meet Jet A-1 or JP-8 specifications by blending a kerosene base fuel with a synthetic cyclo-paraffinic kerosene fuel. Brady et al. (U.S. Pat. No. 8,193,400, 5 Jun. 2012) relates to a process for producing a branched-paraffin-enriched diesel product by hydrogenating/hydrodeoxygenating a renewable feedstock, separating a gaseous stream comprising H2, H2O and carbon oxides from n-paraffins in a hot high-pressure hydrogen stripper, and isomeri