NEW OIL-DEPTH TECHNOLOGIES

Processing of heavy ends (vacuum distillates, wax concentrates) with high content of normal paraffin into diesel fuel (antiknock gasoline, waxy diesel fuel) and base oils.

CHANGED REQUIREMENTS TO DIESEL FUELS

In 1997-2001, diesel fuel requirements have been changed in the Russian Federation and the developed countries of Western Europe and North America. New limitations were created for aromatic hydrocarbons, benzene, and oxygen-containing compounds. Aromatic hydrocarbons and oxygen-containing compounds are used for increasing the octane level in gasoline.

The current fuel quality requirements make it necessary to create an ideal concentration of isoparaffin in diesel fuel. This requirement applies to gasoline as well as diesel fuel. In gasoline, many-branched iso-paraffins have a high octane number. In diesel fuel, mono-branched isoparaffin have a high cetane rating and their setting point temperature is considerably lower than that of the normal paraffins. Isoparaffins are one of the major components of high quality base oils, because they combine a low setting point temperature with a high viscosity index.

In the near-term, oil refineries in the Russian Federation will have to change diesel fuel and base oil production technologies to make their products competitive.

BENEFITS OF THE OFFERED TECHNOLOGY

The offered technology allows production of gasoline cut, diesel oil cut, and base oil end from pre-hydrofined heavy ends during one technological stage.

The major goal of the offered process is hydroisomerization of normal paraffins. Therefore, all produced cuts predominantly contain iso-paraffins. The feedstock could contain up to 25% of monoaromatic or polyaromatic hydrocarbons. In the offered process polyaromatic hydrocarbons get almost completely hydrogenated while fractional conversion of monoaromatic hydrocarbons can make up from 30 to 70%, depending on the process option.

OPTIONS OF THE OFFERED PROCESS

Process options	Catalyst	Product output, % of the mass.	Gasoline cut output, % of the mass.	Diesel oil cut output, % of the mass.	Base oil cut output, % of the mass.
1	К-1	88-90*	72-74	15-17	1-2
2	К-2	92-94	42-45	35-37	15-17
3	К-3	94-95	15-17	25-27	54-56

*) rest - paraffins С3-С4

COMPOSITON OF PRODUCED MATERIALS (FEEDSTOCK: N-PARAFFINS-75%, AROMATICS-25%)

Components	Gasoline cut, % of the mass.	Diesel oil cut, % of the mass.	Base oil cut, % of the mass.
n-paraffins	16-18	34-36	20-23
isoparaffins	64-67	46-48	72-75
naphthenes	7-10	3-8	4-5
aromatics	10-13	10-12	1-2
product properties	ММ octane numbur - 80-82	cetane - 45-47 Т of set point= -15-20 0С	Т of set point= -10-15 0С

MAJOR BENEFITS OF THE OFFERED PROCESSES ARE:

1. Possibility of processing of heavy ends with a high content of n-paraffins and Тк.к = 420-450⁰С, into products with standardized content of isoparaffins during one technological stage.
2. The produced materials contain gasoline and diesel oil cut that could be fractionated into marketable gasoline and diesel fuels complying with the latest standards.
3. We can vary the ratio of gasoline diesel and base oil cut in the products depending on the catalyst utilized in the process.
4. We can ensure production of all needed catalysts in the Russian Federation within a short period of time.
5. The flexible process allows adaptation of existing refineries to the new technology.

SHORT DESCRIPTION OF THE OFFERED PROCESS

The offered process includes two major stages:

First stage: Catalytic Hydrofining
The goal of catalytic hydrofining is fragmentation of sulfur- and nitrogen-containing organic compounds to remove sulfur and nitrogen from the feedstock. After this stage, the sulfur content in the feedstock is up to 0.1 - 0.2% and nitrogen up to 0.1% of the feedstock mass. The first stage is a standard stage of hydrofining of hydrocarbon material.

Second stage: Catalytic hydroisomaerization
The goal of catalytic hydroisomaerization of the first stage product is conversion of the aromatic and n-paraffin hydrocarbons into alkyl-substituted naphthenic and isoparaffin hydrocrbons. The chemical reactions that simultaneously take place in the catalysts offered by the Scientific Research Center "Zeosit" of the Russian Academy of Science are:

• Isomerisation of normal paraffins;
• Cracking of the long-chain normal paraffins;
• Alkylation of aromatic compounds by cracking products;
• Hydrogenation of alkylaromatic compounds with formation of alkylnaphthenic hydrocarbons;
• Hydroisomerization of olefins.

DIAGRAM OF THE OFFERED PROCESS