Case Studies

Energy Case Study

Posted in Machines and Reliability, Environmental, Process

Bioenergy: paying the price for cutting costs

Bioenergy is set to play an important role in meeting the UK’s 2050 greenhouse gas emissions targets – but some biomass operators are making expensive mistakes in their choice of materials and equipment.

Several clients have found out to their cost that it pays to invest in the best green energy technology.

Axiom has been involved with the failure of a number of “green” boilers, from woodchip to waste burning systems. Surprisingly, many fail because successful imported designs are modified to make them cheaper – a process that leaves them much more susceptible to corrosion and failure.

A large wood burning system in the North of England was built to an original design from Scandinavia which specified the use of stainless steel. However, the principal contractor looked at the costs and, with a typical project management approach, cut back on materials expenditure by using carbon steels.   

Within two years of commissioning, corrosion issues were found which made extensive repairs necessary, and required an expensive ongoing maintenance and repair programme for the life of the asset.

Similarly, but on a different site, a wood burning boiler was installed to provide heat and power to a small works. Corners were cut, materials degraded and costs “saved”.  Within a relatively short period, corrosion issues were evident and maintenance programmes had to be devised for ongoing repairs, meaning the initial cost savings were quickly exceeded by the higher than expected maintenance activities.   

This resulted in a net cost, rather than cost saving, to the owners.
We have seen similar short-sighted cost-savings applied to waste incineration plants. Cheaper, lower alloyed stainless steels are used to reduce initial costs. Just because these materials look the same, the unwary think they should perform the same. Sadly, they could not be more wrong.   

Under-specification of stainless steel grades results in underperformance of the component, increasing maintenance and repair costs, down time and adversely affecting throughput. Ultimately, no one wins.

Biofuels are not immune from the drive to save up-front costs, either. A major bioethanol plant dries its waste for use as cattle feed. The large rotary drier was up-scaled from a French agricultural design, but mechanical aspects such as fatigue loads and even shell thickness, were not reconsidered so failures occurred within a few months of commissioning.   

A purpose-designed modification was put together and installed, which, while not ideal, did resolve the short-term issues and gave the drier a useful, if not full, predicted service life.

One of the underlying issues is that many of the latest “green” technologies are being developed by people not used to a chemical industry type of environment. As such, they are not asking the right questions at the right time.   

Clients who have asked Axiom for support are benefitting from a wealth of knowledge and experience on many plants and in many industries, allowing safe but pragmatic designs to be developed in a cost-effective manner, using materials appropriate for the predicted operating conditions.

In most cases, if the right questions had been asked earlier in a project development, many of the subsequent issues would have been avoided. That said, Axiom is happy to get involved at any stage to support industries and developments.   It is never too late to ask the right question or to call for help.

Our advice? Always listen to the materials engineer, not the accountant.

Are you afraid of paying the price for trying to save money? Please feel free to contact us for a no obligation review.

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