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Abstract A great attention is subjected to the environmentally friendly natural gas. Compared to other fossil fuels, natural gas is a cleaner burning due to the lower emission of carbon dioxides into the air. Removal of associated hydrocarbons from natural gas streams plays an important role to sell and to achieve the pipeline specification of natural gas. To satisfy the specification of pipelines, the hydrocarbon dew point and water dew point of natural gas must be controlled below the pipeline operating conditions to prevent many problems: two-phase flow and hydrate formation in the system. The main purpose of this paper is to simulate the gas plant process to study the effect of natural gas composition and changing in differential pressure of Joule–Thomson expansion valve on the obtained values of hydrocarbon, water dew points, and cricondentherm temperature. The results of process simulation using Aspen HYSYS have shown that the control of hydrocarbon dew point, water dew point, and cricondentherm of natural gas is achieved through increasing the Joule-Thomson valve differential pressure. There is an inverse relation between increasing Joule-Thomson valve differential pressure (∆p) and hydrocarbon dew point, water dew point, and cricondentherm to meet the specification of gas pipeline transmission. Increasing differential pressure (∆p) from 14 bar to 24 bar causes a decrease in hydrocarbon dew point, water dew point from −1 to −26°C and from 0 to −18°C, respectively. Cricondentherm is also decreased from 4 to −12°C by increasing differential pressure (∆p) from 14 to 24 bars. The operating conditions at differential pressure below 14 bar is not advisable because cricondentherm temperature does not meet the specification of gas pipeline transmission and hence lead to many problems. Careful adjustment of the operating conditions of gas processing plant is very important by making such simulations to choose the optimum operating conditions which meet gas pipeline transmission.

Abstract The winter closure is an annual action taken every year by the Egyptian authorities by closing water flows in series of channels for maintenance of water channels where levels in water channels are forced to reduce. However, Kafr El Sheikh and El Behaira, located in North Egypt, were affected by pollutant during winter closure due to the drainage of industrial wastes causing high pollution load of ammonia (mainly) and other pollutants. This paper focuses on testing agricultural wastes and natural materials to decrease ammonia in water at the inlet of water treatment stations that may reach 30 mg/l which happened during the winter closure. Nine adsorbents were investigated for ammonia removal: sugarcane peels, activated diatom, activated carbon, activated zeolite, rice straw, white foam, ilmenite, red brick, and a mixture of ilmenite with sugarcane. The sugarcane peels were the optimum treatment solution with a removal efficiency of 58% at an initial concentration of 38 mg/l, ~ 0.7 g of the adsorbent mass, and pH ranges from 10 to 12 after 1 h of contact time. At the same time, ilmenite reached an efficiency of 62% at an initial concentration of 21 mg/l, ~ 1.7 g of ilmenite, and pH 7 after 1 h of contact time. In addition, the reaction kinetics and adsorption isotherms were investigated for the selected adsorbent sugarcane peels, and the results showed that it matched the first-order kinetics with a regression coefficient (R 2) of 0.99 and Langmuir adsorption isotherm (R 2) of 0.96. Graphical Abstract