Dear Sir, Thank you very much for your reply. This is well understood. But my question was whether due to less aromatic content in oil (less than 2%) the oil in this case is unstable and its gassing tendency is negative and is not absorbing hydrogen produced. Is it a case od OD? But CH4 is absent also cellulose involvement is not there. H2 is increasing nearly at the rate of 35ppm per day. Should we take shutdown but what to look for? Sreelatha.G