Large Volume Inorganic Chemicals - Ammonia ... - ammk-rks.net

Chapter 2BAT is to apply a combination of the following techniques and to achieve energy consumptionlevels given in Table 2.14:• extended preheating of the hydrocarbon feed (see Section 2.4.4)• preheating of combustion air (see Section 2.4.12)• installation of a second generation gas turbine (Section 2.4.4 and 2.4.8)• modifications of the furnace burners to assure an adequate distribution of gas turbineexhaust over the burners (see Section 2.4.4)• rearrangement of the convection coils and addition of additional surface (see Section2.4.4)• pre-reforming in combination with a suitable steam saving project (see Section 2.4.5)• improved CO 2 removal (see Section 2.4.11)• low temperature desulphurisation (see Section 2.4.13)• isothermal shift conversion (mainly for new installations, see Section 2.4.14)• use of smaller catalyst particles in ammonia converters (see Section 2.4.15)• low pressure ammonia synthesis catalyst (see Section 2.4.17)• use of a sulphur resistant catalyst for shift reaction of syngas from partial oxidation (seeSection 2.4.18)• liquid nitrogen wash for final purification of the synthesis gas (see Section 2.4.19)• indirect cooling of the ammonia synthesis reactor (see Section 2.4.20)• hydrogen recovery from the purge gas of the ammonia synthesis (see Section 2.4.21)• implementation of an advanced process control system (see Section 2.4.7).Plant conceptNet energy consumption xGJ(LHV)/tonne NH 3Conventional reforming processes, processes with reducedprimary reforming or heat exchange autothermal reforming27.6 – 31.8x For interpretation of the given energy consumption levels, see Section 2.3.1.1. As a consequence, thelevels might vary up to ± 1.5 GJ. Generally, the levels relate to steady state operation as would betypically experienced during a performance test directly following a revamp or an overhaul at intendedcapacity.Table 2.14: Energy consumption levels associated with BATBAT for partial oxidation is to recover sulphur from flue-gases, e.g. by applying a combinationof Claus unit and tail gas treatment and to achieve BAT associated emission levels andefficiencies given in [8, European Commission, 2002], see Section 2.4.9.BAT is to remove NH 3 from process condensates, e.g. by stripping.BAT is to recover NH 3 from purge and flash gases in closed loop.BAT is to handle startup/shutdown and other abnormal operating conditions according toSection 2.4.25.Large Volume Inorganic Chemicals – Ammonia, Acids and Fertilisers 93