Ammonia, 3. Production Plants

Abstract

The article contains sections titled: 1. Complete Ammonia Production Plants 1.1. Steam Reforming Ammonia Plants 1.1.1. The Basic Concept of Single‐Train Plants 1.1.2. Further Developments 1.1.3. Minimum Energy Requirement for Steam Reforming Processes 1.1.4. Commercial Steam Reforming Ammonia Processes 1.1.4.1. Advanced Conventional Processes 1.1.4.2. Processes with Reduced Primary Reformer Firing 1.1.4.3. Processes Without a Fired Primary Reformer (Exchanger Reformer) 1.1.4.4. Processes Without a Secondary Reformer (Nitrogen from Air Separation) 1.2. Ammonia Plants based on Partial Oxidation 1.2.1. Ammonia Plants Based on Heavy Hydrocarbons 1.2.2. Ammonia Plants Using Coal as Feedstock 1.3. Waste‐Heat Boilers 1.4. Single‐Train Capacity – Mega Ammonia Plants 2. Modernization of Older Plants (Revamping) 3. Material Considerations for Equipment Fabrication

Plasma-driven catalysis: green ammonia synthesis with intermittent electricity

“…Conventional ammonia production processes are extensively discussed in ref. [10][11][12][13]. We also elaborate on scale-down and intermittency issues, 6 providing a rationale for research on novel technologies.…”

“…Since then, the Haber-Bosch process and catalysts have undergone only gradual changes. 11,12 Hydrogen and nitrogen react in a H 2 : N 2 molar ratio of 2 : 1 to 3 : 1 over a multiple-promoted iron catalyst at 400-500°C and 100-450 bar. 16 The Haber-Bosch process has outcompeted other nitrogen fixation processes, such as NO x production using electrical arcs (the Birkeland-Eyde process) 17,18 and the cyanamide process (the Frank-Caro process).…”

“…The ammonia production process starts with hydrogen production, usually through stream methane reforming (SMR), with >70% of the ammonia currently produced (eqn (2)). 11,12,21 Other processes for hydrogen production include coal or biomass gasification and electrolysis. 14,20 In the primary reforming section (the tubular reformer), natural gas and water react at 400-800°C.…”

“…The residual CH 4 concentration is below 0.5 vol%. 12 CH 4 þ H 2 O Ð CO þ 3H 2 with ΔH°r ¼ 206 kJ mol À1 ð2Þ…”

“…23 The residual CO concentration after the low-temperature-shift reactor is below 0.3 vol%. 12 Gas cleaning is required before ammonia synthesis. Firstly, the CO 2 is scrubbed out using a caustic scrub, either based on amines like MEA or MDEA, or alkali hydroxides like potash.…”