Yara International

The present disclosure provides a computer-implemented method for controlling ammonium nitrate production, comprising mixing a stream of ammonia and a stream of nitric acid to form a biphasic composition, the biphasic composition comprising an aqueous solution and an exhaust gas, the aqueous solution comprising ammonium nitrate and the exhaust gas comprising water, ammonium nitrate and ammonia, condensing the exhaust gas to form a process condensate, measuring online variables of the process condensate, estimating the exhaust gas composition based on the measured online variables, estimating the value of at least one variable of the biphasic composition based on the estimated exhaust gas composition, and adjusting at least one process parameter such that the estimated value is within a desired range, preferably at a desired value.

The present disclosure discloses a catalytic system comprising: a Pt-containing, Pd-containing, and/or Rh-containing catalyst; and a recovery system downstream of the catalyst; wherein the recovery system comprises at least one oxide of formula A'<1-x>A"<x>BO<3>, with A' being selected from lanthanoids, preferably A' being selected from La, Sm and Gd; A" being selected from alkaline earth metals, preferably A" being Sr or Ca; B being selected from 3d-5d elements, preferably B being selected from Cr, Mn, Fe, and Co; and wherein x = 0 to 1. The present disclosure further relates to the use of said oxides for recovering volatile Pt, Pd and/or Rh and to a method for recovering volatile Pt, Pd and/or Rh.

The present disclosure relates to method to remove water during production of a ternary molten salt mixture, comprising at least calcium nitrate and potassium nitrate where the calcium nitrate in the form of a hydrated calcium nitrate or a hydrated calcium nitrate / potassium nitrate double salt. Foaming can be reduced by controlling the interaction between water evolving from the calcium nitrate and the potassium nitrate, more particularly to impurities present in the potassium nitrate.

The present disclosure provides a process for regenerating a dryer of a syngas dryer assembly comprising one or more dryers in an ammonia plant (100), the process comprising steps of: (i) contacting a charge of desulphurized natural gas (1) and steam (2), with air, oxygen-enriched air or oxygen, in a conversion section resulting in a synthesis gas comprising hydrogen, CO and CO<2>, the conversion section comprising at least one furnace; (ii) subjecting the synthesis gas obtained in step (i) to shift conversion, carbon dioxide removal and methanation, thereby obtaining a stream of treated syngas (7') and further passing the treated syngas (7') through a first syngas compressor (8) to obtain a compressed syngas (8'); (iii) introducing the compressed syngas (8') to a first dryer (9) of the syngas dryer assembly, located downstream of the first syngas compressor (8) to absorb water resulting in a dried make-up syngas, wherein the syngas dryer assembly further comprises a second dryer (14) positioned in parallel to the first dryer (9), wherein the second dryer is a saturated dryer requiring regeneration, wherein a part of the dried make-up syngas (9") is compressed in a second syngas compressor (10) to provide a compressed make-up syngas (10') that is further supplied to an ammonia synthesis loop (11) forming ammonia (11') and generating a purge gas (11") comprising hydrogen, ammonia, methane and argon; and (iv) introducing the purge gas (11") to a purge gas recovery unit (12), whereby ammonia and hydrogen are recovered and a reject gas (12') is generated, wherein a part of the reject gas (12a) is introduced to a third dryer (13) positioned in series to the second dryer (14) resulting in a dried reject gas (13'), wherein a part of the dried reject gas (13') is supplied to the second dryer (14), located downstream of the third dryer (13), thereby regenerating the second dryer (14) and resulting in a used reject gas (14'). The disclosure further provides a plant for producing ammonia, the use of a reject gas emerging from the purge gas recovery unit in the ammonia plant to perform the process of the disclosure and a method of revamping the ammonia plant.

The present disclosure provides a method for operating a urea plant comprising an urea synthesis section, wherein the synthesis section comprises at least one high-pressure process line, a flushing system fluidly connected to the at least one high-pressure process line, a first high pressure flushing pump configured to direct an aqueous solution to the flushing system, and at least one sensor for measuring a process variable, wherein the urea plant comprises a second high-pressure flushing pump configured to direct an aqueous solution to the at least one sensor for measuring a process variable, and wherein the method further comprises continuously directing an aqueous solution from the second high-pressure flushing pump to the flushing system. The present disclosure further provides an assembly comprising a flushing system, a first high pressure flushing pump fluidly connected to the flushing system, a second high-pressure flushing pump and at least one sensor for measuring a process variable in the synthesis section, wherein the second high-pressure flushing pump is fluidly connected to the flushing system and to the at least one sensor and configured to provide an aqueous solution to the flushing system and to the at least one sensor.

A computer-implemented method for asset identification and modeling, the method comprising: - receiving asset information data and asset operating data; - defining operating states of the asset and identifying faulty periods of the asset based on the received asset information and asset operating data; - selecting non-anomalous operating data of the asset; - training at least one model configured to detect asset anomalies based on the selected non-anomalous operating data; - validating the at least one model; - determining an asset anomaly based on the asset current operating data and on at least one of the validated at least one models.

The present disclosure relates to a process for production of nitric acid and a nitric acid production plant, particularly wherein a tail gas recycle stream is supplied to the converter. More in particular, in the process and plant of the present disclosure, at least part of the tail gas is treated in a tail gas treatment section and further heated in a heating section, thereby obtaining a heated tail gas stream, typically having the temperature in the range of 400-600°C. The temperature of this heated tail gas stream is reduced by mixing with a tail gas bypass stream bypassing the tail gas treatment section and/or heating section, resulting in the tail gas recycle stream that can be recirculated to the converter and having the correct temperature for the converter, typically having a temperature in the range of 150-300°C. The disclosure further provides the use of the nitric acid production plant for performing the method according to present disclosure and the method of revamping a nitric acid production plant.

The present disclosure provides a method for measuring the biuret content of an aqueous solution comprising urea, one or more ammonium salts, free ammonia, and biuret, the method comprises: passing a first aqueous solution comprising urea, one or more ammonium salts, free ammonia, and biuret, through an ion exchange column comprising acid groups with a pKa ranging from 3.0 to 5.0, thereby obtaining a second aqueous solution comprising urea, one or more ammonium salts, and biuret and depleted in ammonia; analyzing the second aqueous solution in a system comprising a high-performance liquid chromatography device, thereby measuring the biuret content of the second aqueous solution; and processing the biuret content of the second aqueous solution, thereby obtaining the biuret content of the first aqueous solution.

The present disclosure relates to a gas handling equipment of a chemical production plant, comprising a bottom with a lowest part, and being configured to receive a gas which comprises solid particles, wherein, during operation, the solid particles at least partially are carried over from the gas phase to a condensate phase, and comprising a drain arrangement located in the lowest part of the bottom of the gas handling equipment, which comprises a drain nozzle comprising an drain opening, and a drain pipe which is in liquid communication with the drain nozzle, the drain opening being configured to drain the condensate out of the gas handling equipment towards the drain pipe, and wherein one or more floating ball liquid traps are installed downstream the one or more drain arrangements, each floating ball trap being configured to evacuate the condensate out of one or more of the drain pipes when condensate is present in the drain pipe of the respective drain arrangement(s). The present disclosure further relates to a nitric acid production plant comprising an ammonia oxidizer, an absorption tower, and gas handling equipment. The present disclosure finally relates to a method for handling a gas in a gas handling equipment of a chemical production plant.

The present disclosure relates to a horizontally oriented gas handling equipment of a chemical production plant, comprising a bottom with a lowest part, and being configured to receive a gas which comprises solid particles, wherein, during operation, the solid particles at least partially are carried over from the gas phase to a condensate phase, and comprising a drain arrangement located in the lowest part of the bottom of the gas handling equipment, which comprises a drain nozzle comprising an drain opening, and a drain pipe which is in liquid communication with the drain nozzle, the drain opening being configured to drain the condensate out of the gas handling equipment towards the drain pipe, and wherein a collar which at least partially surrounds the drain opening and comprises one or more collar drain openings which are located in a side of the collar opposite to the flow direction of the incoming gas in the gas handling equipment, at least part of the solid particles of the condensate being stopped by the collar, thereby obtaining a remaining part of the condensate with a reduced amount of solid particles which will flow towards the one or more collar drain openings, and subsequently in the nozzle opening and finally in the drain pipe. The present disclosure further relates to a nitric acid production plant comprising an ammonia oxidizer, an absorption tower, and horizontally oriented gas handling equipment. The present disclosure finally relates to a method for handling a gas with solid particles in a horizontally oriented gas handling equipment of a chemical production plant.