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Abstract

Liquid organic peroxides have been broadly employed in the process industries such as tert-butyl peroxy-2-ethyl hexanoate (TBPO). This study investigated the thermokinetic parameters of TBPO, a typical liquid organic peroxide, by isothermal kinetic algorithms and non-isothermal kinetic algorithms with thermal activity monitor III, and differential scanning calorimetry, respectively. An attempt has been made to determine the thermokinetic parameters by simulation software, such as exothermic onset temperature (T0), maximum temperature (Tmax), decomposition (ΔHd), activation energy (Ea), self-accelerating decomposition temperature, and isothermal time to maximum rate (TMRiso). A liquid thermal explosion model was established for a reactor containing liquid organic peroxide of interest. From experimental results, liquid organic peroxides’ optimal conditions for avoiding a violent runaway reaction of storage and transportation were created.

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Journal of Thermal Analysis and Calorimetry
Authors:
Sheng-Hung Wu
,
Chu-Chin Hsieh
,
Chung-Cheng Chiang
,
Jao-Jia Horng
,
Wei-Ping Pan
, and
Chi-Min Shu

Abstract

Volatile organic compounds (VOCs) and greenhouse gases are the main factors involved in pollution control and global warming. Various treatment methods involving incineration, adsorption, etc., have been employed to reduce VOCs and greenhouse gases concentration in the operating environment and atmosphere. Activated carbon, zeolite, silica gel, and alumina have been broadly used to adsorb pollutants in various industrial applications. Based on the promising effect of adsorption, we analyzed and identified the thermal phenomena of home-made zeolite using various instruments. The endothermic reaction under 100 °C of home-made zeolite was identified as steam adsorption, which is an important discovery. The optimal adsorption temperatures of home-made zeolite have been determined at 200–550 °C.

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Journal of Thermal Analysis and Calorimetry
Authors:
Sheng-Hung Wu
,
Hung-Cheng Chou
,
Ryh-Nan Pan
,
Yi-Hao Huang
,
Jao-Jia Horng
,
Jen-Hao Chi
, and
Chi-Min Shu

Abstract

Organic peroxides (OPs) and inorganic peroxides (IPs) are usually employed as an initiator for polymerization, a source of free radicals, a hardener, and a linking agent in low density polyethylene (LDPE), polyvinyl chloride (PVC), controlled-rheology polypropylene (CR-PP), and styrene industries. Worldwide, due to their unstably reactive natures, OPs and IPs have caused many serious thermal explosions and runaway reaction incidents. This study was conducted to elucidate its essentially hazardous characteristics. To analyze the runaway behavior of OPs and IPs in the traditional process, thermokinetic parameters including heat of decomposition (ΔH d ), exothermic onset temperature (T 0), self-accelerating decomposition temperature (SADT), time to maximum rate (TMR), critical temperature (T c ), etc., were measured by calorimetric approaches involving differential scanning calorimetry (DSC), vent sizing package 2 (VSP2), and calculation method. Safety and health handling information of hazardous materials and toxic substances is noted in material safety data sheets (MSDS) and was applied to analyze in process safety management (PSM) in the chemical industries, but MSDS are not providing important handling indicators concerning the SADT, TMR, T c , etc. In view of loss prevention, more useful indicators must be provided in the sheets or guide book.

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Fire and explosion hazard evaluation for the acetone aqueous solutions

Using weighting analysis of influence factors by grey system theory and 20-L-apparatus flammability investigations

Journal of Thermal Analysis and Calorimetry
Authors:
Yi-Ming Chang
,
Mei-Li You
,
Chien-Hung Lin
,
Siou-Yuan Wu
,
Jo-Ming Tseng
,
Chun-Ping Lin
,
Yaw-Long Wang
, and
Chi-Min Shu

Abstract

The prevention of fire and explosion is recognized as an imperative necessity that is a first priority in all operating management details of the chemical process industries. Based on significant research and original emphasis on loss control and disaster prevention, this study investigated the flammability characteristics, comprising the lower/upper explosion limit (LEL and UEL), maximum explosion overpressure (P max), maximum rate of explosion pressure rise [(dP dt −1)max], gas or vapor deflagration index (K g), and explosion class (St class) of four acetone aqueous solutions [water vapor (steam)/acetone: 75/25, 50/50, 25/75, and 0/100 vol.%], and discussed the effect of inert steam (H2O(g)) on them. Interactive influences of various loading fuel concentrations and initial testing conditions of 150, 200 °C, and 101, 202 kPa on flammability characteristics were revealed via a 20-L-apparatus. Weighting analysis of the above influence factors was explored by employing the GM(h,N) grey system theory for rating their fire and explosion hazard degrees both specifically and quantitatively. The results indicated that the most important influence factor was the initial pressure that the manager or engineer in such a steam/acetone mixing system should consider to be well-controlled first. The second influence factor in GM(1,N) and GM(0,N) model was the initial temperature and steam/acetone mixing concentration, but the third influence factor was individual contrariwise. This study established a complete flammability hazard evaluation approach that is combined with an experimentally and theoretically feasible way for fire/explosion prevention and protection. The outcomes would be useful for positive decisions for safety assessment for the relevant practical plants or processes.

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