2004 Rashid Fertil IFA Operational experience of the benfield CO2 removal system
FERTIL has been operating an Ammonia/Urea Complex since the end of 1983. The Ammonia Plant is based on Haldor Topsoe Technology license and incorporates a Benfield carbon dioxide removal section, employing hot potassium carbonate solution, licensed by UOP of USA. The name plate capacity of the Ammonia Plant was 1,000 MTPD, which was enhanced to 1,050 MTPD by incorporating a cryogenic purge gas recovery unit in 1988. The plant capacity has been progressively increased over the years and the plant currently operates at 130% of the name plate capacity consistently. This has been achieved without undertaking any formal debottlenecking. However, various in-house studies were carried out and minor modifications implemented to achieve the present rate of production. This paper describes the operating experience of the Benfield CO2 removal section, detailing the problems faced in it and subsequent corrective actions taken to: Alleviate the problem of Regenerator Tower carryover. Solve the problems of foaming and high level of hydrogen content in the acid gas. Replace the conventional DEA activator with ACT-1, which has resulted in increased throughput, reduced CO2 slip and reduced heat consumption. The elimination of DEA from solution resulted in solving the problem of amine degradation, dark colour, foaming, vanadium reduction and high consumption of potassium nitrite, etc.