In most chemical and petrochemical industries, carbon and hydrogen elements are combined and arranged to form the determined structure of a desirable organic chemical compound. Chemical plants still use natural gas and naphtha as a source for carbon and hydrogen. The chemical structure of natural gas is of methane and it as to be broken up to simple compound so that they can be rearranged and reacted to form another required organic compounds. To do this a systematic and wonderful procedure was still in practice. Let see how to produce a synthesis gas containing carbon monoxide, hydrogen, and discuss the operation of the individual equipments developed and designed by an extensive research.
In brief, synthesis gas production sequence would be like
Naphtha/ Natural Gas Supply → Desulphurisation Section → Reforming Section → CO2 Conversion removal → Synthesis gas
Naphtha / Natural Gas Supply
In case of Naphtha, huge floating tanks are used for storage and supply the liquid form to the process plant. Generally, at 40kg/cm2g and 40oC it is pumped from storage to process section.
Predesulphurization first stage in synthesis gas production
Sulphur content of the raw naphtha is high when compared to natural gas. Single stage sulphur treatment is enough for the natural gas where naphtha two stages are used for removing sulphur. For synthesis gas production, predesulphurization section is the first stage to reduce the sulphur content less than 10 ppm. The raw naphtha coming from the storage tank yard is first passed through the raw naphtha deaerator/surge drum, where oxygen is stripped off by flow of natural gas. This is done to prevent the gum formation in subsequent equipments like catalyst reactors. Level controller adjusts the flow of raw naphtha from storage tanks to the deaerator to control the level in the lower part of the deaerator /surge drum tower. The stripped out gas from stripper is sent to the off gas header through venting valve which controls the pressure in stripping column.
The deaerated raw naphtha is transferred by means of the raw naphtha pump and is mixed with a recycle gas having a high content of hydrogen, coming from the recycle compressor and with make-up from the purge gas recovery unit or recycle gas header. The mixture is then heated in the feed effluent exchanger and superheated in a fired heater to 380 oC and led to the hydrogenator (a fixed bed reactor). The inlet temperature to hydrogenator is controlled by temperature controller that adjusts the flow of fuel naphtha to the stripping column by controlling in cascade which controls its pressure valve.
In hydrogenator fixed bed reactor, the major percentage of the sulphur compounds converted by hydrogenated into H2S. The outlet from the hydrogenator leaves to further decrease its temperature through the feed effluent exchanger and then finally through the effluent cooler. Unreacted hydrogen gas is separated in the effluent separator and returned to recycle compressor and added to hydrogen rich gas line. Water formed in the process is removed continuously from the bottom sump of the effluent separator.
Naphtha stripper separated the H2S and naphtha and feed is heated stripper feed preheater. The operating pressure and temperature of the ideal naphtha-stripping column would be 10kg/cm2g and 125 oC. A reboiler supplies heat continuously by high-pressure saturated steam at 25.5 kg/cm2g. The vapour from the top of stripper is condensed in a condenser and condensed liquid naphtha is separated in the overhead separator. The H2S gas from separator flows to the off-gas header through a pressure control valve, which controls the pressure in the stripper. A stream of reflux is drawn out from the separator outlet liquid stream.
Purified naphtha is passed to stripper feed preheater from the bottom of the stripper. This is sent to final desulphurization section.
In the ammonia functionality, nitrogen is in addition to hydrogen in a stoichiometric rate of 1:3 to give ammonia with no by-products. Ammonia itself is used as a manure. About 85% of ammonia usage is used for the production of manure. Air contains 79 % (volume) of nitrogen. So, nitrogen required for the response can be acquired from air. Now the problems can be discovered in removing the hydrogen required for the response from its resource. Hydrogen generation strategy is the major resource of variation between the various ammonia generation tracks.
Most of the changes in the engineering regarding the ammonia manufacturing over the last four generations were worried with the hydrogen generation phase. Hydrogen can be created by water changing, partially oxidation and water electrolysis. The variety on the planet ammonia generation is according to water changing. The significant hydrogen resources are normal gas, naphtha and fossil fuel. Most of the water changing vegetation use normal gas as feast share. All-natural gas contains less toxins, high hydrogen to as well as rate and less amount of greater hydrocarbons. So normal gas is excellent when in contrast to other feast shares.
The opportunity of this venture is to evaluate different techniques available for hydrogen removing from its resource and to find an reasonable way to generate functionality gas (which will type ammonia) from normal gas. In this various techniques of functionality gas generation are mentioned and the best way to created functionality gas is discovered out. The specific style of the some procedure gadgets is also done in this work. This features the PSA system for air removing, tubular loaded bed reactor for methane water changing.