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There are many oil and gas fields in Indonesia which contain high CO2 that need to be treated. The Acid Gas Removal Unit (AGRU) is installed to remove the CO2. The AGRU will release the CO2 gas from the regeneration column. It still contains a high concentration of CO2 (higher than 80%). The accumulation of CO2 emission to the atmosphere will impact the environment. To promote environment-friendly technology, the process can be improved with conversion of CO2 into methanol. It will provide a relatively closed loop of the carbon cycle and as a renewable energy alternative. This study aims to provide packed bed reactor design which can be implemented in the small-scale methanol production plant utilizing high CO2 feed gas. The reactor temperature was varied from 200°C to 250°C and pressure were operated in the range of 40 Bar up to 75 Bar. These variations were used to analyze the effects of methanol production. The simulation results showed that peak methanol production rate was achieved at the temperature around 230°C. As the conclusion, the reactor showed better performance at the higher pressure and higher temperature although the reaction is exothermic including the recycling process can reduce the cost of hydrogen.

Methane Number (MN) is one of quality requirement of gas as fuel for gas engine, which indicates fuel capability to avoid knocking in the engine. Higher MN provides better quality of gas for gas engine. Natural gas with higher methane (CH4) and fewer higher hydrocarbon, tends to have higher MN score. This study aims to obtain heating methods of LNG to produce vapor that has appropriate MN as a fuel gas supply to gas engine. The simulation for LNG regasification prepared is an approach to the design of the existing regasification facility of the power plant in Bali. The temperature ranges for LNG heating simulation were obtained based on saturated temperatures of LNG phase envelopes. In the simulation. to obtain a certain MN value can be conducted by adjusting the temperatures at two different values i.e. above -110 ° and below - 80 °. To produce LNG vapor that has MN of 80 either through higher temperature of heating (HT heating) or lower temperature of heating (LT heating) requires more energy than direct heating without MN improvement. Heat loading for LT heating is higher than HT heating due to more temperature defference between LT and heating fluid temperatures. The ability of engine to produce power decreased with decreasing fuel gas MN. The power increment increases for lower MN gas if MN improvement is conducted.

Wastewater generated from the tofu industry usually still contains high organic pollutants that can contaminate the surface water. Therefore, it should be treated properly before it can be disposed to the environment. This study aims to evaluate the combination of coagulationflocculation and ultrafiltration methods in treating the wastewater from tofu industry. Based on the preliminary tests, the wastewater from tofu industry have pH, total dissolved solid (TDS), total suspended solid (TSS), turbidity and chemical oxygen demand (COD) of 3.4, 870 - 1080 mg/L, 370 mg/L, 446 FAU and 7954 mg/L, respectively. The coagulant and membrane used in this study were Poly aluminum chloride (PAC) and the ceramic membrane, respectively. Experimental results showed that the best pH for coagulation-flocculation process is at pH of 7.0, and this pH was then used for ultrafiltration process. The flux of the ultrafiltration membrane increased with increasing the trans membrane pressure due to increasing driving force. The observed parameters such as TSS and turbidity of wastewater decreased drastically after experiencing ultrafiltration process and met the National Environmental Quality Standard. However, the COD of water produced in the ultrafiltration process was still high and did not meet the National Environmental Quality Standard.

The tofu industry is generally a household-scale industry so that the efficiency of water used and wastewater treatment are mistreated. Wastewater from tofu industry is very hazardous when discharged directly into the aquatic environment as it contains high organic pollutants which is indicated by high concentrations of BOD (biological oxygen demand), COD (chemical oxygen demand), TSS (total suspended solid), TDS (total dissolved solid) and turbidity. The optimization of wastewater treatment process is needed to meet the quality standards set by the government and also needed to obtain more effective and efficient effluent treatment. The aim of this study is to evaluate the performance of combination coagulation-flocculation and ultrafiltration processes for tofu industry wastewater treatment. The process of pretreatment coagulation and flocculation using poly aluminum chloride (PAC) was conducted to extend the life of the ultrafiltration membrane and improve the performance of ultrafiltration membrane separation. The experimental results showed that TSS and turbidity decreased with precipitation time whereas COD did not significantly change. TDS after coagulation-flocculation has increased due to the addition of PAC. The TSS, TDS, COD and turbidity of wastewater were drastically reduced after experiencing ultrafiltration process. After the ultrafiltration process, the TSS, Turbidity, COD and TDS rejection were 98.8%, 98.1%, 71.0% and 50.6%, respectively.

Wastewater from tofu industry is one of water pollution sources that still require more effective treatment. This study aim to treat wastewater from tofu industry through a combination of coagulation-flocculation and ultrafiltration processes. Coagulation-flocculation is conducted prior to ultrafiltration process to minimize the effect of fouling on membrane and to improve the performance of ultrafiltration process. Poly aluminum chloride (PAC) was used as coagulant with doses of 100, 200, 300, 400 and 500 ppm. The wastewater feed have pH, total dissolved solid (TDS), total suspended solids (TSS), turbidity and chemical oxygen demand in the ranges of 3.8 - 4, 850 - 880 mg /L, 380 - 420 mg /L, 450-530 FAU and 5600 - 6600 mg /L, respectively. Experimental results showed that the effectiveness of coagulation increased with the addition of coagulant dose until the optimum dose is reached. After coagulation-flocculation process, COD, TSS, and turbidity decreased, whereas TDS increased. The optimum dose of the coagulationflocculation process was then used for a combination of coagulation-flocculation and ultrafiltration processes. The result of this combination process showed a decrease in COD, BOD, TSS, and turbidity.

Cryogenic Power Generation or commonly called Cryopower is the generation of electricity by utilizing cold energy which one is produced at the LNG (liquefied natural gas) Regasification Terminal. Cold energy utilization has been applied in several countries, especially in Japan. In Indonesia, the regasification terminal has been built few, but in the future according to the Government of Indonesia's plan, some natural gas/LNG power plants will be built to meet the national electricity needs. It requires gas infrastructure, one of which is the regasification terminal. The aim of this study is to evaluate the effects of LNG flowrate on working fluid and cooling water flowrates as well as power needed and produced in the combine direct expansion and Rankine cycle processes. The flowrates and power calculations were conducted using UNISIM R390.1. Simulation results showed that the working fluid and cooling water flowrates increase with increasing LNG flowrate. The increased in the working fluid and cooling water flowrates also increased the power needed by the pumps and power produced by the turbines. Overall, the net power produced from the combine cycle increased with increasing the LNG flowrate.