Our client was notified by the NGL pipeline that they were going to be penalized for excessive methane (C1) in the NGL’s that were being delivered into the pipeline from our client’s gas plant. The plant had been operating over a year with the methane in their NGL’s (EPBC) ranging up to 6 LV% when the specified limit was 0.5 LV%. The plant called us because they were having troubles getting on-spec as they could not get enough heat into the bottoms to drive off the methane and meet the spec without reducing the plant throughput.
RCE was given some plant data and proceeded to evaluate the data. It was immediately noticed that the residue compressors were recycling to maintain suction pressure. RCE recommended that they lower the residue compressor suction pressure which also lowered the demethanizer pressure. At the lower tower pressure and with the same bottoms temperature the methane content in the NGL’s dropped quickly from 0.94 LV% to 0.2 LV%, well below the pipeline spec.
Another example of how RCE adds value to our client’s operations.