Developing a kinetic model to analyze the multi-step reaction of biomass pyrolysis is pivotal to elucidate the mechanism of the pyrolysis. For this purpose, a model-fitting method such as multi-distribution the Distributed Activation Energy Model (DAEM) is one of the most reliable methods. DAEM with 4 different distribution functions of Gaussian, Logarithmic, Gumbel, and Cauchy was utilized to characterize the pyrolysis of cellulose and lignin during Thermogravimetric Analysis/Differential Scanning Calorimetry (TGA/DSC) instrumentation. By comparing Derivative Thermogravimetry (DTG) and DSC profiles, determination of pseudo-components can be done more accurately. A kinetics analysis on the pyrolysis of cellulose with a single Gaussian distribution DAEM yielded a single activation energy of 178 kJ mol −1 with a narrow standard deviation. This result was justified by a single and dominant endothermic peak followed by minor exothermic peaks in the DSC result. For lignin pyrolysis, the presence of multiple peaks is characterized by four pseudo-components in DAEM with activation energies of 157, 174, 194, and 200 kJ mol −1 . These pseudo-components were confirmed by the DSC result which indicated the occurrences of two exothermic peaks with two lesser exothermic or possibly endothermic peaks at the same temperature range. These findings imply the importance of DSC to support a kinetics study of thermogravimetric pyrolysis.

Municipal solid waste (MSW) processing is still problematic in Indonesia. From the hierarchy of waste management, it is clear that energy recovery from waste could be an option after prevention and the 5R (rethink, refuse, reduce, reuse, recycle) processes. The Presidential Regulation No 35/2018 mandated the acceleration of waste-to-energy (WtE) plant adoption in Indonesia. The present study aimed to demonstrate a techno-economic evaluation of a commercial WtE plant in Indonesia by processing 1000 tons of waste/day to produce ca. 19.7 MW of electricity. The WtE electricity price is set at USD 13.35 cent/kWh, which is already higher than the average household price at USD 9.76 cent/kWh. The capital investment is estimated at USD 102.2 million. The annual operational cost is estimated at USD 12.1 million and the annual revenue at USD 41.6 million. At this value, the internal rate of return (IRR) for the WtE plant is 25.32% with a payout time (PoT) of 3.47 years. In addition, this study also takes into account electricity price sales, tipping fee, and pretreatment cost of waste. The result of a sensitivity analysis showed that the electricity price was the most sensitive factor. This study reveals that it is important to maintain a regulated electricity price to ensure the sustainability of the WtE plant in Indonesia.

Turpentine is a non-wood forest product derived from pine trees. Turpentine oil can be produced from the distillation of pine tree sap (family Pinaceae). The main component of turpentine is α-pinene, and turpentine isomerization may produce various derivative products. The objective of the present study was to investigate the isomerization products of turpentine oil with two acid catalysts: hydrochloric and acetic acid. Here, the influence of acid concentration was investigated by using various concentrations of hydrochloric and acetic acid concentrations between 0.4 to 1 M. Further, the combination of acetic acid and hydrochloric acid as catalyst was also investigated by varying the molar ratio of HCl:Acetic Acid=1 : 0.5 and 1:1. The experiments were carried out in a batch reactor equipped with heater, condenser, and stirrer. The reaction temperatures were maintained at 150°C and reaction time of 6 h. The resulting products from turpentine isomerization were analyzed using GC-MS. The results showed that the largest isomerization product obtained with HCl and combination of HCl:H.Acetic was trans sabinene hydrate. Additional products that could be detected varied among α-terpinolene, α-terpineol, α-terpinene, γ-terpinene and δ-carene. The experimental data showed that α-pinene conversion as high as 62, 63 and 57% were obtained by using HCl concentrations of 0.4, 0.7 and 1 M, respectively. In addition, the use of HCl:H.Acetic=1 :0.5 and 1:1 gave final conversion of 63 and 61%. The modeling results showed the kinetic model for pinene conversion for both catalysts was d X d t = 0.5222 ⋅ ( 1 − X ) 2.5210 C HCl − 0.2233 ⋅ ( 1 − X ) 4.5300 C HAc

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Petrochemical industries have faced growing pressure to decrease their carbon emission from direct and indirect sources. This work aims to demonstrate a carbon tax’s introduction to a feasibility study on the heat exchanger (HE) replacement project at PT Kaltim Methanol Industri, Indonesia. The project was aimed to avoid methanol release as much as 48.88 MT/year. The release of methanol can also be associated with CO2 emission with an emission factor of 0.6 ton CO2e/ton methanol. Here, we investigated the influence of inclusion and exclusion of carbon tax to monetize the CO2 release. From the project investment point of view, carbon tax inclusion is expected to increase the cost-saving. Introduction of the carbon tax as high as 10 USD/ton CO2e with 5% annual increase gives IRR value of 7.06% with Payout Time (PoT) of ca. 11 years. The IRR value without carbon tax scenario is 6.68 % with the same range of PoT. Hence, the inclusion of carbon tax may increase the feasibility of the project. This work has demonstrated the positive role of the carbon tax to increase the feasibility of a project which inlines with the national initiatives to curb the CO2 emission from chemical industries. It is also worth noting that introduction of carbon tax should be accompanied by a reorganization of government incentives, including several financial policies to create a conducive atmosphere for investors in Indonesia.