Risk based approach in the replacement of HP cigar type scrubbers
When in a HP scrubber the vapors from the synthesis are fully condensed the passivation air in combination with hydrogen and other flammables can form a gas mixture that may lead to deflagration.
As the latest design standard for HP scrubbers cannot always be implemented in existing plants, Stamicarbon can support their customers with a risk based approach for the replacement of existing scrubbers.
Topic
Based on the year 2000 design philosophy, a standard Stamicarbon grass roots urea plant incorporates a HP scrubber sphere design in conjunction with a catalytic combustion of hydrogen in the CO2 stream.
In this configuration the hydrogen converter reduces the probability of the presence of an explosive atmosphere within the HP scrubber whilst the sphere explosion dome volume mitigates the consequences of an internal deflagration.
Recently several operators of so called cigar type HP scrubbers have asked Stamicarbon to supply new (identical) cigar type HP scrubbers in Safurex®. Most of the early generation cigar type HP scrubber are however characterized by a very limited explosion dome volume and as such not complying with the latest Stamicarbon design standards, as they have developed over time.
Incorporation of the safest option, the sphere HP scrubber with an adequate explosion dome volume, is not always technically feasible or requires disproportional investments to adapt existing structural work (load limitations) and/or piping arrangements. This paper elaborates on the exploration of design solution alternatives in the background of a risk based approach.
About Harald Jorritsma
Mr. Harald Jorritsma obtained a bachelor degree in Mechanical Engineering at the university of professional education in Heerlen the Netherlands in 1984, followed by post graduate degree in business & marketing at the same institute in 1992. In 2006 a post graduate degree in safety engineering at the university of professional education in Utrecht was obtained.
He started his career in 1985 as a maintenance engineer responsible for urea and nitric acid plants within DSM. In 1992 he joined ExxonMobil where he held several positions; maintenance team leader, technical manager, process safety engineer and SHE manager of the PP packaging films plant in the Netherlands. As a process safety engineer he held an international position in which he supported films plants worldwide with regard to safety studies for both existing and new facilities. The last 6 years at Exxonmobil he was responsible for process safety in two LdPE plant locations in Belgium.
In 2014 he joined Stamicarbon as a HSE Engineer within the process control department. In this role he supports projects with respect to process design hazard studies. As a HSE engineer he is the content owner of HSE process design guidelines, policies and procedures. He advices on the impact of new HSE legislation on the scope and deliverables of Stamicarbon and/or of the Urea Technology group.