When choosing filters for emissions technology, OEMs and owners need to consider a number of factors, but the primary criteria should be compliance
When it comes to choosing the right filter for emissions systems, be that exhaust gas cleaning systems (EGCS) or exhaust gas recirculation (EGR) systems, filter manufacturer Boll & Kirch says OEMs and shipowners need to consider a number of factors, but their number one priority should be compliance.
At Riviera Maritime Media’s Getting it right: selecting the right filters for emissions technology webinar, part of Marine Propulsion Webinar Week in June, Boll & Kirch Filterbau business development manager, business unit for filtration technology Thomas Mann provided an update on filter technology, with the latest developments for full-flow lube oil automatic filtration and innovative concepts to combine engine protection and oil care for diesel engines. Using ceramic technology, Boll & Kirch offers tailored filtration solutions for scrubbers that will remove large volumes of contaminants and particulate matter and that provide compliance with IMO regulation for treated washwater discharge. The company has over 300 washwater treatment plants in operation.
What criteria should be considered when selecting a filter for emissions technology? “There is always a cheaper solution,” said Mr Mann, but he asked, “would it survive past the warranty time?”
Delegates were able to weigh in on the question during one of the quick polls taken during the webinar. In a poll, they were asked: When selecting a water treatment system, we prioritise...: 86% of those responding chose higher cost, but lower operational expenditure. The remainder (14%) preferred lower cost, but higher operational expenditure.
Other factors to consider include environmental footprint, operator ability, performance, handling and product support. Mr Mann suggested the main criteria for a filter-based system should be compliance.
“No operator wants to be in the news for violations or for being fined for violations. Due to the very high public awareness in these matters, you need equipment that complies reliably and safely with IMO discharge regulations now and with future amendments,” he said. He noted that IMO does not require type-approval for washwater systems, unlike other equipment covered in MARPOL, Annex VI.
Compliance was the number one concern of delegates, with 72% of those responding to a poll choosing performance and compliance with discharge regulations when asked: When opting for a washwater treatment system, what is the number one priority? Environmental footprint was chosen by 6% and 12% picked price or ease of operation.
Mr Mann highlighted the ceramic membrane as the filter for emissions technology, citing the very narrow and homogenous pore size distribution, high filtration area, high flux rate and lack of rotating parts. He also noted that a high degree of automation is required that mitigates crew workload.
Operational aspects to consider include consumables. “Some systems require chemicals for the treatment process; are these cleaning chemicals available worldwide? Are they environmentally sound?” he asked. He also noted that any residue has to be assessed – what is the volume of residue produced and how will it be disposed of?
He added that using a well-known and reliable business partner, rather than a supplier, is preferable. “No treatment technology is plug and play, you always have to do minor things related to systems, but it should never be plug and play,” he said.
“There is always a cheaper solution, but will it survive past the warranty time?”
A poll asked: Who would you prefer to contract for retrofitting water treatment technology? Over half picked the scrubber maker (52%); 24% chose the water treatment technology provider and 24% the shipyard.
There are fluctuations around the current regulations and the impact of any amendments or the imposition of local regulations. In a poll, delegates were asked: Do you expect more and/or stricter discharge regulations for open-loop EGCS in the near future? The majority (85%) replied yes.
Joining Mr Mann on the panel, PureteQ chief executive Anders Skibdal said PureteQ does not make exhaust gas cleaning systems. The company buys them and integrates the EGCS and EGR system. “We design this process, and we deliver the equipment.”
In choosing the best fit, he emphasised it is not simply a question of relating the energy output of the engine to the scrubber. “The scrubber is designed for the operational pattern, the load and the time of operation,” he said, “That is what will decide the basic footprint of your system.”
As far as upgrades, Mr Skibdal noted there are huge differences in power consumption among the various models. He also noted there can be a huge variance in the amount of slops produced – from 2.4 kg per tonne of fuel to 28 kg per tonne of fuel – and this influences the cost of disposal. This can be very high in the US, he noted.
Another factor he shared from his experience is the wide range of operating costs. In general, a low capex would result in higher opex and vice versa. This is worth bearing in mind. “The cost of operating a water treatment system would be anywhere between €0.50 (US$0.61) to €2.5 (US$3.0) per MW,” he said.
The final poll asked the question: Will there be a future need for water treatment systems in light of the current climate focus (e-fuels)? Overwhelmingly, 94% of respondents agreed with the statement.