Revisiting the Rist diagram for predicting operating conditions in blast furnaces with multiple injections

Background: The Rist diagram is useful for predicting changes in blast furnaces when the operating conditions are modified. In this paper, we revisit this methodology to provide a general model with additions and corrections. The reason for this is to study a new concept proposal that combines oxygen blast furnaces with Power to Gas technology. The latter produces synthetic methane by using renewable electricity and CO2 to partly replace the fossil input in the blast furnace. Carbon is thus continuously recycled in a closed loop and geological storage is avoided. Methods: The new model is validated with three data sets corresponding to (1) an air-blown blast furnace without auxiliary injections, (2) an air-blown blast furnace with pulverized coal injection and (3) an oxygen blast furnace with top gas recycling and pulverized coal injection. The error is below 8% in all cases. Results: Assuming a 280 tHM/h oxygen blast furnace that produces 1154 kgCO2/tHM, we can reduce the CO2 emissions between 6.1% and 7.4% by coupling a 150 MW Power to Gas plant. This produces 21.8 kg/tHM of synthetic methane that replaces 22.8 kg/tHM of coke or 30.2 kg/tHM of coal. The gross energy penalization of the CO2 avoidance is 27.1 MJ/kgCO2 when coke is replaced and 22.4 MJ/kgCO2 when coal is replaced. Considering the energy content of the saved fossil fuel, and the electricity no longer consumed in the air separation unit thanks to the O2 coming from the electrolyzer, the net energy penalizations are 23.1 MJ/kgCO2 and 17.9 MJ/kgCO2, respectively. Discussion: The proposed integration has energy penalizations greater than conventional amine carbon capture (typically 3.7 – 4.8 MJ/kgCO2), but in return it could reduce the economic costs thanks to diminishing the coke/coal consumption, reducing the electricity consumption in the air separation unit, and eliminating the requirement of geological storage.

A mathematical optimization model for secondary settler

The study of secondary settler modelling, which aims to establish the main model (one-dimensional-1D model), which is involved in some fundamental processes of the hydrodynamic behaviour of this liquid/solid separation unit and to engender variations of the sludge blanket height as a function of the operating parameters and maintaining of the municipal wastewater treatment plant of Setif. The objective of this research is focused on solid/liquid separation in the secondary settler by attempting a mathematical model that allows us to evaluate the sedimentation velocity as a function of the sludge settleability parameters.

Analisis dan Optimasi Pengaruh Suhu Gas Umpan Pada Kinerja Acid Gas Removal Unit

The Gas Gathering Station (GGS) in field X processes gas from 16 (sixteen) wells before being sent as selling gas to consumers. The sixteen wells have decreased in good pressure since 2011, thus affecting the performance of the Acid Gas Removal Unit (AGRU). The GGS consists of 4 (four) main units, namely the Manifold Production/ Test, the Separation Unit, the Acid Gas Removal Unit (AGRU), the Dehydration Unit (DHU). The AGRU facility in field X is designed to reduce the acid gas content of CO2 by 21 mol% with a feed gas capacity of 85 MMSCFD. A decrease in reservoir pressure caused an increase in the feed gas temperature and an increase in the water content of the well. Based on the reconstruction of the design conditions into the simulation model, the amine composition consisting of MDEA 0.3618 and MEA 0.088 wt fraction to obtain the percentage of CO2 in the 5% mol sales gas. The increase in feed gas temperature up to 146 F caused foaming due to condensation of heavy hydrocarbon fraction, so it was necessary to modify it by adding a chiller to cool the feed gas to become 60 F. Based on the simulation, the flow rate of gas entering AGRU could reach 83.7 MMSCFD. There was an increase in gas production of 38.1 MMSCFD and condensate of 1,376 BPD. Economically, the addition of a chiller modification project was feasible with the economical parameters of NPV US$ 132,000,000, IRR 348.19%, POT 0.31 year and PV ratio 19.06.

EFFECTIVENESS OF PROCESS INTENSIFICATION OF SMALL-SCALE BIODIESEL PLANTS: STUDIES ON PRODUCT REPRODUCIBILITY AND QUALITY

Process intensification is an innovation implemented in the design and development of processes and equipment, which can provide significant benefits for process efficiency, product selectivity and quality, energy efficiency, less waste, and process safety. Intensification of technological processes is classified into two main groups: intensification of equipment and processing methods. This study used the process and equipment intensification into a small-scale biodiesel plant system with 5 liters/batch capacity. The system consists of a reaction process unit integrated with a methanol recovery process unit and a separation unit integrated with a biodiesel purification unit. This study aims to test the reproducibility and quality of biodiesel products in small-scale factories using palm oil and soybean oil. The results showed that the small-scale biodiesel plant provided fairly good performance in the form of reproducibility, namely a consistent biodiesel yield in the range of 74.54%-77.8% and biodiesel quality that met the Indonesian National Standard. In the process using palm oil, the yield of biodiesel is 74.54%-76.5%, glycerol 6.9%-9.0%, and methanol recovery 7.5%-9.0%, with a physical viscosity of 2.89 mm2/s, density 0.86 g/mL, and acid value 0.45 mg KOH/g. As for the process using soybean oil, biodiesel yield is 77.4%-77.8%, glycerol 6%-6.5%, and methanol recovery 8.4%-8.9%, with a physical viscosity of 1.97 mm2/s, density 0.85 g/mL, and acid value 0.45 mg KOH/g. The biodiesel composition from palm oil is dominated by methyl oleate, methyl palmitate, and methyl stearate. In comparison, biodiesel composition from soybean oil is dominated by methyl palmitate, methyl linoleate, and methyl isostearate.