petrochemical processing

Bringing you the benefits that come from decades of experience and a proven track record

Oxygen Enrichment of the FCC NOx Recovery Process

Fluid catalytic cracking (FCC) plant Fluid catalytic cracking (FCC) plants are used to convert heavy distillates into lighter ones like gasoline and diesel. The feedstock is primarily vacuum gas oil, often mixed with refinery residues.

The main products are:

  • Gas fraction (mainly C3/C4)
  • Liquid fraction
  • Coke (solid formation on the catalyst).

FCC units produce sulphur dioxide and nitrogen oxides (NOx) and these particulates are tightly regulated. This places refinery operators under pressure to manage NOx emissions and ensure they do not impair air quality.

We offer various solutions to enrich regeneration air with oxygen and boost capacity. These include LoTOx technologies to help control particulates, sulphur dioxide and NOx emissions from the FCC.

LoTOx technology is a patented innovation that uses ozone to selectively oxidize insoluble NOx to highly soluble species that can be easily removed in a wet scrubber. The benefits include increased capacity, greater flexibility in the choice of feeds, increased conversion rates and reduced emissions.

  • Gas/Liquid Reactions

Industrial gases like oxygen, hydrogen, carbon monoxide and carbon dioxide are widely used for synthetic processes in the chemical industry

Modular, multifunctional stirred reactor test plant (CSTR) for the investigation of a large number of homogeneous gas/liquid reactions.

We have designed a modular, multifunctional stirred reactor test plant (CSTR) for the investigation of a large number of homogeneous gas/liquid reactions.

The test plant shown in the picture is perfectly suited for verification of preliminary laboratory results as well as scale-up to medium or large sized technical plants.

Gaseous oxygen is used in many gas/liquid oxidations, for example, in production of hydroperoxides, the oxidative decarboxylations or oxidation of toluene derivatives. Two oxygen applications could be considered for oxidation processes, oxygen enrichment of oxidation air and total substitution of air by oxygen.

The benefits of these applications include:

  • Increased throughput and selectivity
  • Same conversion rate at lower temperatures
  • Savings in total operating costs.

Oxygen for Heterogeneous Oxidations

Improving plant capacity and flexibility

Oxidations performed in the heterogeneous gas phase of fixed or fluidised bed reactors are widely used for production of bulk chemicals.

Molecular oxygen is the predominant oxidative agent used in these reaction steps. Dependent on the applied process either; air (e. g. for production of maleic or phthalic anhydride), oxygen enriched air (e. g. for production of acrylonitrile) or pure oxygen (e. g. for production of vinylacetate) can be used as a gaseous oxidant.

Fluidized bed oxidations are often operated by means of oxidation air, because of its high nitrogen contest, it provides an effective fluidising gas stream for solid particles.

The addition of pure oxygen to the oxidation air or the direct oxygen injection into the reactor can reveal considerable benefits to the customer:

  • Higher plant capacity
  • Backup of air compression
  • Relief of waste gas treatment
  • Enhanced flexibility of plant operation.
  • Hydrogen Applications in Refineries

Demand for hydrogen will increase in the upcoming years as a result of stricter environmental legislation

Not only legislation but more extensive processing of residues and higher diesel demand compared with petrol will also increase hydrogen’s demand.

There are various hydrotreating processes in a refinery. To name a few:

  • Hydrodesulphurisation: sulphur compounds are hydrogenated to hydrogen sulphide H2S as feed for Claus plants
  • Hydroisomerisation: normal paraffins are converted into iso-paraffins to improve the product properties (e.g. RON)
  • Dearomatisation: aromatics are hydrogenated to cyclo paraffins or alkanes
  •  Hydrocracking: long-chain hydrocarbons are cracked to shorter chains in the gasoline range.

Hydrogen volumes consumed increasingly exceed those produced in a platformer and have to be supplemented by other sources.

Main processes for hydrogen on-site supply:

  • Steam reforming of methane or other hydrocarbons
  • Recovery from refinery off-gases
  • Recovery from syngas
  • Gasification of oil refining residues.
  • Oxygen Enrichment in Claus Plants
  • Reducing potential bottlenecks in refineries

claus plant As the sulphur content in crude oil rises, many refineries are increasingly relying on Claus plants to increase flexibility in handling feed gas composition variations. Claus plants convert concentrated hydrogen sulphide (H2S) fractions into elemental sulphur. They can also remove pollutants, particularly by decomposing ammonia.

However, environmental regulations continue to tighten, putting growing pressure on Claus sulphur recovery processes and this step can become a bottleneck within the refinery.

Boosting Efficiency

You can overcome this problem by enriching the combustion air in a Claus plant with oxygen. This increases the capacity significantly. Our innovative burner technology ensures excellent mixing of hydrogen sulphide and oxygen-enriched air over a wide load range.

Benefits of Oxygen Enrichment

  • Increased Claus plant capacity at low revamp capital cost
  • Increased productivity without changing the pressure drop
  • More effective treatment of feeds containing ammonia
  • Greater flexibility in handling feed gas composition variations
  • Less effort for tail-gas purification (reduced nitrogen flow)
  • Ease of installation with minimum disruption to plant operation.

Partial Oxidation For the conversion of residues

Partial Oxidation Plants are used to form hydrogen, carbon monoxide, carbon dioxide and water from the residues (liquids, highly viscous hydrocarbons) of the refining process.

The products can be used as synthesis gas, fuel gas or feed for hydrogen recovery. With tailored oxygen supply for Partial Oxidation (POX) we can offer you the following benefits:

  • Cleaner and better reuse of residues
  • Broader economic base of the refinery
  • Higher flexibility through a wider range of products
  • Handling of refinery feed compositions within a wide range