What is Petcoke ?

Cocking is a thermal cracking course of characterized by lengthy residence time and the production of petroleum coke (Petcoke), a heavy carbon residue. Petcoke is produced by thermal cracking of vacuum residue that’s produced from crude oil.

In a petroleum refinery, atmospheric and vacuum distillation processes remove from the crude the oil the elements that boil as much as about 500oC. The distillation process separates the lighter part of the crude oil into fractions which are then processed into helpful refined products similar to LPG, petrol, kerosene, diesel, and many others. The a part of the crude oil which doesn’t boil off throughout the distillation process even below vacuum is understood as the vacuum reside. The vacuum residue consists of heavy, viscous, complicated hydrocarbon molecules.

The coking course of converts the vacuum residue into gasoline, liquid and solid merchandise. In delayed coking, the heavy feedstock is heated in a tube nonetheless and pumped as quickly as attainable to insulated drums where it the large molecules are cracked into smaller molecules and residue, producing gas, liquid merchandise and coke. The term ‘delayed’ comes from the delay between heating and coking. As coke buiilds up within the drum, the lighter merchandise of cracking are recovered as overhead vapours and are taken to a fractionator for separation into varied products.

Petcoke yield is mainly dependent on the carbon content of the feedstock, while the structural high quality of the Petcoke is influenced chiefly by the kind of feed, i.e., virgin crude or cracked merchandise. Fuel grade Petcoke is produced from vacuum residues which have excessive sulfur contents. Excessive sulphur Petcoke is used as gas whereas low sulphur Petocoke is utilized in producing anodes.

Gas grade Petcoke usually replaces iignite and coal.

How does Petcoke compare with Lignite ?

Lignite is a pure product and a fossil gasoline Lignite is discovered at and round Panandro, Rajpardi and Bhavnagar in Gujarat Lignite is the primary stage of conversion of wooden and biomass product into coal. It has very excessive moisture content about 30-40%. The volitile conteint can be very high, about 30-forty%. Mounted carbon is less not like Anthracite and Petcoke. Sulphur content is 3.Zero-5.Zero%. Calorific vlaue of lignite may be very low, about 2800-3800 kcal / kg where as calorific worth of Petcoke is 8200-8500 kcal / kg. So, on heat equal basis, 2.5 to three kg of lignite is changed by 1 kg of Petcoke. It means that whereas for a similar heat equal simply kg of Petcoke with about seventy five gm of Sulphur is injected into the furnace. Hence, the generation of SO2 with lignite is 1.Four instances larger as in comparison with Petcoke. When Petcoke is used as a gasoline, limestone is normally injected into the furnace to absorb SO2 from the flue gasoline as soonas it’s genrated. Some users provide wet lime scrubbers to absorb SO2 from the flue gas. Limestone injection is never carried out during lignite firing. Thsu the emission of SO2 is much lesse with Petcoke as in comparison with lignite.

How does Petcoke compare with Coal ?

Specs of Petroleum Coke (Petcoke)

RIL is manufacturing three grades of Petcoke, Grade A, Grade B and Grade C Whose specs are given beneath.

Property

As Received

Unit

Petcoke Grade A

Petcoke Grade B

Petcoke Grade C

Typical Traits

Assured

Limits

Whole Moisture

Air Dried Foundation

Ash

Volatile Matter

Mounted Carbon

Gross Calorific Worth

Sulphur

HGI

Kcal/kg

%

• 7.Zero, max.
• 7.5, max.
• 35, min.
• 8.0, max.
• 1.Zero, max.
• 8 min.
• 87, min.
• 8200, min.
• Eight.5, max.
• Four.0, max.

0.6-zero.8

9-11

89

• 8300-8500
• 6.Zero-7.Zero Grade A
• 7.Zero-7.5 Grade B
• 7.5-eight.5 Grade C
• 38-forty five for Grade A & Grade B

Petcoke can be used as a substitute of coal / lignite. It can be used in mix type together with coal / lignite or one hundred% in AFBC / CFBC boilers.

AFBC Boilers are able to absorbing SO, and prohibit BO, emissions ot the specified levels by limestone injection system.

Ash content in Petcoke is far lower than coal / lignite. Hence particulate emissions are always decrease as compared to coal.