Hydrochemical modeling of migration of dissolved oil products in groundwater

Изложена методика прогнозирования распространения нефтепродуктов группы BTEX (бензол, толуол, этилбензол, ксилолы) в подземных водах на основе гидрохимического моделирования с учетом изменения окислительно-восстановительных и кислотно-щелочных свойств раствора в процессе биодеградации нефтепродуктов. Представлена геохимическая модель биологического разложения нефтепродуктов комплекса BTEX на основе модифицированной кинетики Моно с учетом реакций между акцепторами, продуктами реакции биодеградации и неорганическими компонентами раствора. Приведены примеры геохимического моделирования, демонстрирующие важность учета процессов, связанных с изменением гидрогеохимической обстановки в подземных водах при разложении углеводородов. Разработанная модель может быть использована для выполнения геохимических прогнозов распространения легких нефтепродуктов в подземных водах, проведения работ в рамках оценки воздействия на природную среду, разработки систем инженерной защиты подземных вод от загрязнения нефтепродуктами. A method for predicting the spread of BTEX group oil products (benzene, toluene, ethylbenzene, xylenes) in groundwater based on hydrochemical modeling with account of changes in the redox, acidity or alkalinity of the solution during the biodegradation of oil products is stated. A geochemical model of the biological decomposition of oil products of BTEX group based on modified Mono kinetics with account of the reactions between acceptors, biodegradation products and inorganic components of the solution is presented. Examples of geochemical modeling are given that demonstrate the importance of taking into account the processes associated with the changes in the hydrogeochemical environment in groundwater during the decomposition of hydrocarbons. The developed model can be used to carry out geochemical predictions of the spread of light-end oil products in groundwater, to carry out works within the framework of estimating the environmental impact, and to develop systems for engineering protection of groundwater from oil pollution.

Selected Aspects of Hydrogen Production via Catalytic Decomposition of Hydrocarbons

Owing to the high hydrogen content, hydrocarbons are considered as an alternative source for hydrogen energy purposes. Complete decomposition of hydrocarbons results in the formation of gaseous hydrogen and solid carbonaceous by-product. The process is complicated by the methane formation reaction when the released hydrogen interacts with the formed carbon deposits. The present study is focused on the effects of the reaction mixture composition. Variations in the inlet hydrogen and methane concentrations were found to influence the carbon product’s morphology and the hydrogen production efficiency. The catalyst containing NiO (82 wt%), CuO (13 wt%), and Al2O3 (5 wt%) was prepared via a mechanochemical activating procedure. Kinetics of the catalytic process of hydrocarbons decomposition was studied using a reactor equipped with McBain balances. The effects of the process parameters were explored in a tubular quartz reactor with chromatographic analysis of the outlet gaseous products. In the latter case, the catalyst was loaded piecemeal. The texture and morphology of the produced carbon deposits were investigated by nitrogen adsorption and electron microscopy techniques.

Hydrocarbon decomposition kinetics on the Ir(111) surface

The kinetics of the thermal decomposition of hydrocarbons on the Ir(111) surface is determined using kinetic Monte Carlo (kMC) and rate equations simulations, both based on the density functional theory (DFT) calculated energy barriers of the involved reaction processes.