Synthetic ammonia(NH3) refers to ammonia that has been synthesized from natural gas or gasified coal. The feed gas firstly goes through steam reforming to produce synthesis gas, which contains mainly Hydrogen(H2), carbon monoxide(CO) and carbon dioxide(CO2). After purification the hydrogen is then reacted with process air (as source of nitrogen) to produce ammonia. Six process steps are required to produce synthetic ammonia using the catalytic steam reforming method (also called as Harber-Bosch Process): 1) feed gas desulfurization, 2) catalytic steam reforming, 3) CO shift, 4) CO2 removal, 5) methanation, and 6) ammonia synthesis.
Approximately 80 percent of the ammonia produced is used as fertilizer, either directly as ammonia or indirectly after synthesis as urea, ammonium nitrate, etc.
Critical Control of Process Gas
By measuring carbon monoxide(CO), carbon dioxide(CO2) and Hydrogen (H2) after primary steam reformer to monitor the reaction and condition of the catalyst.
Detect residual carbon monoxide(CO), carbon dioxide(CO2) to monitor respectively the process of CO shift and CO2 Removal.
Measure ammonia (NH3) on acid gas scrubber and urea synthesis prilling tower to ensure environmental compliance.
Challenge of Instrumentation
The most used technologies for Syngas analysis are infrared combined with thermal conductivity, or a standalone GC. The infrared method is sensitive to the presence of water vapor in the syngas, and requires periodic calibration. The GC method is not continuous analysis with comparatively slow response, and operated only in a limited temperature range less than 100 °C and greater than -50°C. GC requires periodic calibration and maintenance.
Measuring the extremely soluble and adsorptive NH3 either in process or emission prefers non-contact analyzer, and a very robust heat traced sampling system is obliged.
Syngas analysis is satisfied by an affordable analyzer, which combined most reliable TDL technology with thermal conductivity, truly continuous real-time analysis and interference free. FPI provides the world’s most flexible NH3 solutions for process NH3 control, NH3 slip control and NH3 emission monitoring. The diverse NH3 analyzers, in the form of cross-duct, extractive and open path, effectively solved the difficulties to work in high dust, moisture contained flue gas, or fuel with high sulfur content.
Acid gas scrubber
NOTES: Listed are typical data FPI experienced and backed by field references. Alternate gases and ranges may be available or customizable on request.