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

Chapter 44.5 BAT for sulphuric acidBAT is to apply the common BAT given in Section 1.5.BAT for storage is to apply BAT given in [5, European Commission, 2005].BAT is to use recoverable energy: co-generated steam, electrical power, hot water (see Section4.4.15).BAT is to apply a combination of the following techniques and to achieve the conversion ratesand emission levels given in Table 4.24:• double contact/double absorption (see Section 4.4.2)• single contact/single absorption (see Section 4.4.1)• addition of a 5 th catalyst bed (see Section 4.4.3)• using a caesium promoted catalyst in bed 4 or 5 (see Section 4.4.4)• change over from single to double absorption (see Section 4.4.5)• wet or combined wet/dry processes (see Sections 4.4.8 and 4.4.9)• regular screening and replacement of catalyst, especially of catalyst bed 1 (see Section4.4.12)• replace brick-arch converters by stainless steel converters (see Section 4.4.6)• improve raw gas cleaning (metallurgical plants) (see Section 4.4.12)• improve air filtration, e.g. by two stage filtration (sulphur burning) (see Section 4.4.12)• improve sulphur filtration, e.g. by applying polishing filters (sulphur burning) (see Section4.4.12)• maintaining heat exchanger efficiency (see Section 4.4.13)• tail gas scrubbing, provided that by-products can be recycled on-site (see Section, 4.4.19,4.4.20, 4.4.21 and 4.4.22).Conversion process typeSulphur burning, doublecontact/double absorptionOther double contact/doubleabsorption plantsExistinginstallationsConversion rate xDaily averagesSO 2 in mg/Nm 3 xx99.8 – 99.92 % 30 – 680New installations 99.9 – 99.92 % 30 – 34099.7 – 99.92 % 200 – 680Single contact/single absorption 100 – 450Other 15 – 170x these conversion rates relate to the conversion including the absorption tower, they do not include the effect of tailgas scrubbingxx these levels might include the effect of tail gas scrubbingTable 4.24: Conversion rates and SO 2 emission levels associated with BATBAT is to continuously monitor the SO 2 levels required to determine the SO 2 conversion rateand the SO 2 emission level.Large Volume Inorganic Chemicals – Ammonia, Acids and Fertilisers 211