Client name: Zebec Biogas Ltd
Profile: TÜV SÜD National Engineering Laboratory was approached to optimise the design of an air biofilter for an anaerobic digestion plant producing renewable energy from food and animal waste. Having provided the client with the optimal solution, they successfully built and commissioned a biogas plant and the design blueprint was adopted thereafter to construct a second plant on the same site.
Business challenge: Getting the optimal design of the air biofilter is vital to ensure the overall efficiency and performance of a biogas plant. The biofilter treats the exhaust air by eliminating odours and toxic gases before the gas is discharged into the atmosphere. To do this, air is channelled through the biofilter unit, based on an array of perforated pipes beneath a bed of woodchips, soil and filtration media. Achieving optimum design can be extremely challenging and depends on multiple factors including flow distribution, pipe sizing and fan duty.
Our approach: TÜV SÜD National Engineering Laboratory worked with the client to ascertain the exact working requirements of the anaerobic digestion plant in order to define the performance criteria for the air biofilter unit.
TÜV SÜD National Engineering Laboratory’s expertise in fluid mechanics was then used in conjunction with pipe-flow software to review a range of different pipe configurations.
A number of design options were developed. In each design, the degree of maldistribution of air and the required fan duty were calculated to determine the overall capital outlay requirements and operating costs.
Our solution: In order to ensure optimum performance of the air biofilter, TÜV SÜD National Engineering Laboratory derived a design that maximised the uniform distribution of air flow from pipe exit holes, whilst minimising associated pipe work, pressure drop and fan duty. The final solution ensured that the biofilter piping delivered a uniformly distributed airflow through the filtration bed. If flow distribution had not been balanced, the filtration media would have been displaced thus rendering the whole unit ineffective.
Business benefits: The client was able to make an informed investment decision based on the optimum design solution developed by TÜV SÜD National Engineering Laboratory. This design maximised biogas production capacity whilst minimising capital and operating costs. It also maximised pollution reduction efficiency and provided the end client confidence that their environmental obligations relating to the release of odours and harmful pollutants would be fulfilled. Following successful construction and commissioning of the first biogas plant, the TÜV SÜD National Engineering Laboratory design solution was adopted for a second unit located on the same site.