Abstract:The biomass gasification process is widely accepted as a popular technology to produce fuel for the application in gas turbines and Organic Rankine Cycle (ORC). Chemical reactions of this process can be separated into three reaction zones: pyrolysis, combustion, and reduction. In this study, sensitivity analysis with respect to three input parameters (gasification temperature, equivalence ratio, and steam-to-biomass ratio) has been carried out to achieve energy self-sufficient conditions in a steam gasification process under the criteria that the carbon conversion efficiency must be more than 70%, and carbon dioxide gas is lower than 20%. Simulation models of the steam gasification process have been carried out by ASPEN Plus and validated with both experimental data and simulation results from Nikoo & Mahinpey (2008). Gasification temperature of 911 • C, equivalence ratio of 0.18, and a steam-to-biomass ratio of 1.78, are considered as an optimal operation point to achieve energy self-sufficient condition. This operating point gives the maximum of carbon conversion efficiency at 91.03%, and carbon dioxide gas at 15.18 volumetric percentages. In this study, life cycle assessment (LCA) is included to compare the environmental performance of conventional and energy self-sufficient gasification for steam biomass gasification.

Arsenic (As) and Mercury (Hg) are impurities unique to condensate produced from reservoir in the Gulf of Thailand and thus, the treatment process is critical to meet PTTEP's sale obligation. Mercury has been successfully removed by filtration, but no proven technology exists for arsenic removal until now. Normally, there are 3 condensate tankers to transfer offloading condensate to Petrochemical plant. In case any batch of condensate is rejected by customer. Trader is generally required at least 2 weeks to manage the tanker holding the high As condensate. Thus, the business impact of this project is cost saving from reducing the frequency of tanker demurrage. The major financial ramification is a key driver for exploring the alternative treatment techniques for As removal. Several techniques to remove As content in condensate have been explored and tested to find a suitable solution to this major challenge. Several technologies were tested in-house, and solid bed adsorption is found to be the most effective with approximately 90% removal efficiency. The scaled-up unit is developed for pilot test with operating conditions designed to simulate actual site conditions for further large-scale development. The Arsenic Removal Mobile Unit is designed for a capacity of 4,670 BPD located at the Condensate Tank Terminal prior to installation at offshore facilities. Basic engineering was performed in-house by PTTEP according to adsorbent specifications with modular fabrication for flexibility of installation and relocation. Detailed engineering and construction were performed by contractor under PTTEP supervision. The engineering and procurement of long lead equipment were performed by PTTEP. Furthermore, in parallel, the engineering team are also performed to provide a basis design facility, plan & schedule for installing a permanent arsenic removal unit at Offshore locations (Full-scale). This test result will prove the performance of selected adsorbent and how the adsorbent reacts with actual condensate in full scale. PTTEP is the only company who have been studied about arsenic removal technology from condensate. This initiative has been carried through from preliminary conception to prototype field trials for practical application with an ambitious end-goal of commercialization. The success of this project will provide confidence for large-scale ARU investment to support the condensate management strategy. The expected benefit gain is saving revenue loss of each relevant party. Once this unit is installed at offshore. It will unlock field potential and increase operating flexibility. For downstream industry, it will reduce the adverse impact on downstream petrochemical plants. The service life of catalyst can be prolonged and reduce a toxicity risk to personnel. The high arsenic contaminated in disposal water shall be resolved.