Synthesis And Performance Evaluation Of1,3,5-tris（2-hydroxyethyl）-hexahydro-s-Triazinane Liquid H₂S Scavenger

Triazine hydrogen sulfide scavenger has a very promising future as a kind ofliquid hydrogen sulfide scavenger with a direct injection method for itsconvenient-preparation, low-cost, occupied small space, direct injection into theoffshore oil pipeline, and high-efficiency.Various H2S removal processes at presentaren’t available for offshore oil-drilling due to limited space and cost. Developingtriazine direct-injected H2S scavenger has being received more and more attention.But the domestic research is still less.In this thesis,1,3,5-tris(2-hydroxyethyl)-hexahydro-s-triazinane as a kind oftriazine hydrogen sulfide scavenger was synthesized by using formaldehyde andethanolamine. The structure was confirmed by FT-IR, GC-MS, GC,1H NMR and13CNMR. These characterization methods can reflect optimal synthetic condition oftriazine was that:1:1mol ratio of reagent,0℃ice water bath, the formaldehyde wasadded as a dropping rate of1.5mL/min, ethanol was added as an anti-polymerizationagent.Stability of triazine H2S scavenger in different condition was investigated by1HNMR. The triazine was more stable when triazine concentration increased, solutionpH value was higher, the temperature was lower and the reaction time was shorter.Water solution was more likely to lead to the hydrolysis of the triazine than alcoholsolution.The most significant factors affecting the stability were solvent type andtempreture, the secondary were triazine concentration and solution pH value, and thelast was reaction time.Methods for evaluation of the H2S removal of triazine were designed includingstatic and dynamic H2S removal. The static H2S removal efficiency was higher whenthe temperature was higher, triazine concentration increased, the reaction time waslonger, and the injection rate of triazine was faster. Water solution was better thanalcohol solution.0.22-0.30mg H2S was removed by1.0mL2.0V%-10V%triazinein water solution while H2S volume was600-1000ppm.The static H2S removalefficiency reached90.0%above with the condition adjusted appropriate as follows:10-70℃, pH=6.86-9.18, the reaction time was2-4h. Dynamic H2S removal efficiency and capability was higher when triazineconcentration increased and reaction time was longer. N2gas flow rate was confirmedby field test suitably. The volume of triazine only affected H2S removal capabilityinstead of efficiency, and was decided to add in accordance with the actual situation.0.960-1.06g H2S was removed by30-70mL0.10V%-10V%traizine in watersolution while740-760cm3H2S was produced.The dynamic H2S removal efficiencyreached90.0%above with the condition adjusted appropriate as follows: roomtempreture,20-50mL/min N2gas flow rate, the reaction time was11-31h.