Optimum composition ratios of multicomponent mixtures of organic Rankine cycle for engine waste heat recovery

With the temperature glide in saturation states, the mixture working fluids have the advantages in thermal energy conversion. In this study, through the investigation in optimum mass fractions of multicomponent mixture working fluids, the economic performance enhancement of the organic Rankine cycle system is obtained for recovering waste heat from engine. The zero ozone-depletion-potential and dry working fluids of R236fa, R245fa, and R1336mzz(Z) are selected as the components of multicomponent mixtures in the system. The net power output, heat transfer calculation, and apparatus cost evaluation are employed to evaluate the power cost of the organic Rankine cycle system. Parameters of temperatures of waste heat sources and efficiencies of expanders are taken into account. The comparisons of economic performances for single-component working fluid and multicomponent mixtures with optimum mass fractions are proposed. The results show that R245fa, having a levelized cost of energy, LCOE, of 8.75 × 10⁻² $/kW-h, performs the best for single-component working fluids, better than R236fa by 1.6% and R1336mzz(Z) by 8.3%. All the two-component mixtures are superior to their single-component working fluids in economic performance. Among the three two-component mixture working fluids, R1336mzz(Z)/R236fa has the lowest LCOE_min, 8.57 × 10⁻² $/kW-h, followed by R236fa/R245fa and R245fa/R1336mzz(Z). In addition, R236fa/R245fa/R1336mzz(Z) mixture, which has a LCOE_min of 8.47 × 10⁻² $/kW-h, economically outperforms all other working fluids and has a lower LCOE_min than R236fa/R245fa by 1.7% and R245fa/R1336mzz(Z) by 2%.     

Prospect Evaluation of Low-GWP Refrigerants R1233zd(E) and R1336mzz(Z) Used in Solar-Driven Ejector-Vapor Compression Hybrid Refrigeration System

In this paper, the entrainment ratio, pump work, heat loads of heat exchangers and COPthermal were theoretically evaluated for a solar-driven ejector-vapor compression hybrid refrigeration system with R1233 zd(E) and R1336 mzz(Z) as the working fluids. The evaluation of the utilization potentials of R1233 zd(E) and R1336 mzz(Z) was presented by comparing the system performance with that of R245 fa, a commonly used refrigerant in the ejector system. The results indicated that the systems with R1233 zd(E) and R1336 mzz(Z) had a higher entrainment ratio and lower pump work. The pump works when using R1233 zd(E) and R1336 mzz(Z) can be up to 14.59% and 38.05% lower than those of R245 fa, respectively. Meanwhile, the system showed the highest COP_(thermal) utilizing R1233 zd(E) followed by that of R245 fa, with the R1336 mzz(Z) system having the lowest value. The differences between R1233 zd(E) and R1336 mzz(Z) systems, R1233 zd(E) and R245 fa systems were 4.33% and 2.0%, respectively. This paper was expected to provide a good reference for the utilizing prospect of R1233 zd(E) and R1336 mzz(Z) in ejector refrigeration systems.     

Thermal stability of propylene carbonate and ethylene carbonate–propylene carbonate-based electrolytes for use in Li cells

The thermal stability of mixed-solvent electrolytes used in lithium cells was investigated by differential scanning calorimetry (DSC) through the use of airtight containers. The electrolytes used were propylene carbonate (PC) and ethylene carbonate (EC)+PC, in which was dissolved 1 M LiPF₆, 1 M LiBF₄, 1 M LiClO₄, 1 M LiSO₃CF₃, 1 M LiN(SO₂CF₃)₂, or 1.23 M LiN(SO₂CF₃)(SO₂C₄F₉). The influence of lithium metal or the Li_0.5CoO₂ addition on the thermal behavior of these electrolytes was also investigated. The peak temperature of PC-based electrolytes increased following the order of LiPF₆<LiClO₄<LiBF₄<LiN(SO₂CF₃)₂<LiSO₃CF₃<LiN(SO₂CF₃)(SO₂C₄F₉). The order of peak temperature of EC–PC-based electrolytes shows a similar tendency to that of EC–PC-based electrolytes, with the exception of the LiN(SO₂CF₃)₂ electrolyte. The EC–PC-based electrolytes with Li metal show a more stable profile compared with the DSC curves of the PC-based electrolytes with the Li metal. The solid electrolyte interphase (SEI) covers the surface of the Li metal and prevents further reduction of the electrolytes. EC may form a better SEI compared with PC. The PC-based electrolytes of LiSO₃CF₃, LiN(SO₂CF₃)₂ and LiN(SO₂CF₃)(SO₂C₄F₉) with the coexistence of Li_0.49CoO₂ show a broad peak at around 200 °C, which may be caused by the reaction of the Li_0.49CoO₂ surface and electrolytes. The PC-based electrolytes of LiPF₆, LiClO₄ and LiBF₄ with Li_0.49CoO₂ show exothermic peaks at higher temperatures than 230 °C. The peak temperatures of the EC–PC-based electrolytes with the coexistence of Li_0.49CoO₂ are nearly the same temperature as the EC–PC-based electrolytes.     

Influence of temperature and steam on the products from the flash pyrolysis of Jordan oil shale

Oil shale samples from the Sultani deposit in the south of Jordan, were pyrolysed in a semi‐continuous fluidized bed reactor under nitrogen and nitrogen/steam atmosphere. The pyrolysis temperature between 400 and 650°C were investigated. Increasing the pyrolysis temperature from 400 to 520°C caused a large increase in the oil yield. Further increase of the pyrolysis temperature resulted in a decrease in oil yield and a large increase in the evolved gases. This increase in the hydrocarbon gas yield was attributed to oil thermal cracking reactions. The evolved gases were composed of H₂, CO, CO₂, and hydrocarbons from C₁ to C₄. The presence of steam improved the oil yield which may be a result of reducing the degree of decomposition. The derived oils were fractionated into chemical classes using mini‐column liquid chromatography. Copyright © 2002 John Wiley & Sons, Ltd.     

Thermal decomposition of titanium hydrides in electrochemically hydrogenated electron beam melting (EBM) and wrought Ti–6Al–4V alloys using in situ high-temperature X-Ray diffraction

Thermal decomposition of titanium hydrides in electrochemically hydrogenated electron beam melting (EBM) and wrought Ti–6Al–4V alloys containing 6 wt% β is compared. Differential scanning calorimetry (DSC) is used to identify phase transitions. High-temperature X-ray diffraction (HTXRD) is used to identify phases and determine their contents and crystallographic parameters. Both alloys are found to contain α_H (hcp) and β_H (bcc) solid solutions, as well as δ_a (fcc) and δ_b (fcc) hydrides after hydrogenation. δ_a is found to decompose between room temperature and 350 °C to α_H (in both alloys) plus either β_H and δ_b (wrought alloy) or δ_b only (EBM alloy). δ_b fully decomposes at either 450 °C (wrought alloy) or 600 °C (EBM alloy) to α_H plus H₂ desorption (which starts at 300 and 350 °C in the wrought and EBM alloys, respectively). In the case of the wrought alloy, β_H is also formed in this decomposition reaction due to faster diffusion of hydrogen. The non-continuous, finer needle-like morphology of the β-phase in the as-printed EBM alloy combined with its smaller lattice constants seem to inhibit hydrogen diffusion into the bulk alloy through the β-phase, thus triggering δ_a dissociation into δ_b (rather than to β_H+δ_b) and δ_b decomposition into α_H (rather than to α_H + β_H). Hydrogen incorporation in the α_H phase results in its expansion in the c direction in both alloys. HTXRD allows to conclude that both δ_a and δ_b hydrides decompose up to 600 °C. Hydrogen peaks measured at higher temperatures are due to hydrogen desorption from the hydride that is decomposed from the sample's bulk and/or hydrogen desorption from β_H and/or α_H during heating. These findings indicate that the EBM Ti–6Al–4V alloy might be more prone to hydrogen damage at elevated temperatures than its wrought counterpart when both have a similar β-phase content.     

Preparation and performance of bisimidazole cationic crosslinked addition-type polynorbornene-based anion exchange membrane

The late transition metal catalyst system (η³-allyl)Pd(PPh₃)Cl/Li[B(C₆F₅)₄]·2.5Et₂O (Li[FABA]) was used to catalyze 5-norbornene-2-methylenehexyl ether (NB-MHE) and 5-norbornene-2-methylene-(6-bromohexyl) ether (NB–O–Br) controllable addition copolymerization to obtain post-functionalized vinyl addition-type block copolymer aP(NB-O-Br-b-NB-MHE). 1,6-Bis(2-methylimidazole)hexane (Bis-MeIm) was used as a crosslinking agent to prepare a series of anion exchange membranes (AEMs) CL-aP(NB-O-Br-b-NB-MHE). The initial thermal decomposition temperature of the obtained addition-type polynorbornene-based AEM was about 250 °C. The AEM had moderate water uptake (WU) and swelling ratio (SR), and obvious micro-phase separation structure that could be observed from the AFM phase diagram. It could maintain high OH^? conductivity (85.07 mS cm^?1, 80 °C) and alkali resistance stability (soaking alkali for more than 500 h at 25 °C). In the single cell test of the H₂/O₂ fuel cell assembled by CL5-aP(NB-O-Br-b-NB-MHE), the peak power density was 177 mW cm^?2.     

Numerical simulation of the synergistic effects of unwanted combustion enhancement by the C3H2F3Br and C2HF5 blends

Owing to the restriction of using Halon 1301 (CF₃Br) for fire suppression, several alternatives to Halon 1301 have been developed, including C₂HF₅ (HFC-125), C₃H₂F₃Br (2-BTP), and C₆F₁₂O (Novec1230). However, in the Federal Aviation Administration (FAA) Aerosol Can Explosion Test (FAA-ACET), it was found that these alternatives did not suppress lean flames at sub-inert concentrations, but promoted combustion, eventually leading to overpressure. Therefore, they have not been successfully applied in aircraft cargo compartments. Herein, different blend ratios of C₃H₂F₃Br and C₂HF₅ were used to explore their inhibitory effects on combustion enhancement under lean combustion conditions. A chemical kinetic model was developed and validated using a one-dimensional free-propagation flame simulator. The laminar burning velocity predicted by the model was consistent with the experimental results. The adiabatic flame temperature and overall reaction rate were determined using thermodynamic equilibrium calculations and perfectly stirred reactor (PSR) simulations. By comparing the blend inhibitors with different blend ratios, it was found that the blend of C₃H₂F₃Br and C₂HF₅ at blend ratios of 25/75 and 50/50 effectively reduced the total heat release and system reactivity. In addition, the blend inhibitor not only weakened the fuel properties of C₂HF₅, but also further enhanced the bromine-catalysed radical recombination cycle. Notably, a new reaction occurred when C₃H₂F₃Br and C₂HF₅ were blended into the FAA-ACET chamber: Br + CHF₂CF₃ = HBr + CF₃-CF₂, indicating that the Br atoms promoted the decomposition of C₂HF₅.     

Improvement of heavy crude oil via catalytic cracking process for refining into valuable blending stocks

In this study, it was aimed to obtain the conversion of the heavy crude oil with 12.2° API gravity into the liquid fuel-like condensate fractions having different boiling points of gasoline (initial boiling point–180), kerosene (180–240°C), light diesel or distillate (240–290°C), and gas oil (290–360°C). A series of catalytic cracking runs were carried out on the pre-upgraded oil with using the molasses soil catalyst in different ratios of 0.0–10.0wt.%. The catalytic condensate and coke yields were found as 94.81wt.% and 2.42 wt.%, respectively, for the optimal catalyst ratio of 2.5wt.%. The optimal cracking condensate and its fractions were characterized via spectroscopic and analytical test methods. The results revealed that the catalytic condensate was more rich in view of n-paraffinic hydrocarbons with lower carbon number of C₁₀–C₁₂ found in diesel fuel.     

Enhancement of discharge performance of Li/CFx cell by thermal treatment of CFx cathode material

In this work we demonstrate that the thermal treatment of CF_x cathode material just below the decomposition temperature can enhance discharge performance of Li/CF_x cells. The performance enhancement becomes more effective when heating a mixture of CF_x and citric acid (CA) since CA serves as an extra carbon source. Discharge experiments show that the thermal treatment not only reduces initial voltage delay, but also raises discharge voltage. Whereas the measurement of powder impedance indicates the thermal treatment does not increase electronic conductivity of CF_x material. Based on these facts, we propose that the thermal treatment results in a limited decomposition of CF_x, which yields a subfluorinated carbon (CF_x−δ), instead of a highly conductive carbon. In the case of CF_x/AC mixture, the AC provides extra carbon that reacts with F₂ and fluorocarbon radicals generated by the thermal decomposition of CF_x to form subfluorinated carbon. The process of thermal treatment is studied by thermogravimetric analysis and X-ray diffraction, and the effect of treatment conditions such as heating temperature, heating time and CF_x/CA ratio on the discharge performance of CF_x cathode is discussed. As an example, a Li/CF_x cell using CF_x treated with CA at 500 °C under nitrogen for 2 h achieved theretical specific capacity when being discharged at C/5. Impedance analysis indicates that the enhanced performance is attributed to a significant reduction in the cell reaction resistance.     

The dehydrogenation kinetics and reversibility improvements of Mg(BH4)2 doped with Ti nano-particles under mild conditions

Magnesium borohydride, Mg(BH₄)₂, is ball-milled with Ti nano-particles. Such catalyzed Mg(BH₄)₂ releases more hydrogen than pristine Mg(BH₄)₂ does during isothermal dehydrogenation at 270, 280, and 290 °C. The catalyzed Mg(BH₄)₂ also exhibits better dehydrogenation kinetics than the pristine Mg(BH₄)₂. Based on kinetics model fitting, the activation energy (E_a) of the catalyzed Mg(BH₄)₂ is calculated to be lower than pristine Mg(BH₄)₂. During partial dehydrogenation, the catalyzed Mg(BH₄)₂ releases 4.23 wt % (wt%) H₂ for the second dehydrogenation at 270 °C, comparing to 4.05, and 3.75 wt% H₂ at 280, and 290 °C. The reversibility of 4.23 wt% capacity is also one of the highest for Mg(BH₄)₂ dehydrogenation under mild conditions such as 270 °C as reported. 4 cycles of Mg(BH₄)₂ dehydrogenation are conducted at 270 °C. The capacities degrade during 4 cycles and tend to be stable at about 3.0 wt% for the last two cycles. By analyzing the hydrogen de/absorption products of the catalyzed sample, Mg(BH₄)₂ is found to be regenerated after rehydrogenation according to Fourier Transform Infrared (FTIR) spectroscopy. Ti nano-particles can react with Mg(BH₄)₂ during ball-milling and de/rehydrogenation. The products include TiH_1.924, TiB, and TiB₂, which can improve the dehydrogenation properties of Mg(BH₄)₂ from a multiple aspect.     

The Experimental Study on Regenerative Heat Transfer in High Temperature Air Combustion

For the purpose of decomposing the processing gases CF4 from semiconductor manufacturers, ceramic honeycomb regenerative burner system is suggested by using the principle of HTAC. A simulated high temperature air combustion furnace has been used to determine the features of HTAC flames and the results of the decomposition of CF4. The preheat air temperature of it is above 900℃. The exhaust gas released into the atmosphere is lower than 150℃. Moreover, the efficiency of recovery of waste heat is higher than 80%, the NOx level in exhaust gas is less than 198 mg/m3 and the distribution of temperature in the furnace is nearly uniform. The factors influencing on heat transfer, temperature profile in chamber and NOX emission were discussed. Also some CF4 can be decomposed in this system.     

An experimental and modeling study of methyl propanoate pyrolysis at low pressure

Methyl propanoate (MP) pyrolysis in a laminar flow reactor was studied at low pressure (30 Torr) within the temperature range from 1000 to 1500 K. About 30 products were detected and identified in the pyrolysis process using the photoionization mass spectrometry, including H₂, CO, CO₂, CH₃OH, CH₂O, CH₂CO, C1 to C4 hydrocarbons and radicals (such as CH₃, C₂H₅ and C₃H₃). Their mole fraction profiles versus temperature were also measured. For the unimolecular dissociation reactions, the rate constants were calculated by high precision theoretical calculations. Based on the theoretical calculations and measured mole fraction profiles of pyrolysis species, a kinetic model of MP pyrolysis containing 98 species and 493 reactions was developed. The model simulates the primary decomposition process well with the calculated rate constants. According to the rate of production analysis, the decomposition pathways of MP and the formation channels of both oxygenated and hydrocarbon products were discussed. It is concluded that the main decomposition pathway is MP → CH₂COOCH₃ → CH₃CO + CH₂O → CO.     

Thermogravimetric and mass spectrometric analysis of powdered pine bark

Using thermal analysis and mass spectrometry, this study examined samples of powdered pine bark by subjecting them to: (a) complete combustion, (b) partial combustion, and (c) pyrolysis. For each of the examined samples, which heated at the rate of 30°C min^?1, temperature regions corresponded to moisture loss and the degassing process. Global and local maximum values of ionic currents representing H₂O, CO₂, CO, and additionally for hydrocarbons such as CH₄, C₂H₄, and C₂H₅ for pyrolysis were identified. Based on the recorded values of ionic currents of hydrocarbons in the helium atmosphere, C₂H₅ dominance was determined at T ≤ 415°C, and CH₄ dominance was determined at T > 415°C. Assuming first-order kinetics, thermogravimetric data were analyzed by the Arrhenius type model, and kinetic parameters were determined.     

Enhanced hydrogen production in catalytic pyrolysis of sewage sludge by red mud: Thermogravimetric kinetic analysis and pyrolysis characteristics

The catalytic mechanism of red mud (RM) on the pyrolysis of sewage sludge was investigated. The thermogravimetric data were used to study the kinetic characteristics by using a discrete distributed activation energy model (DAEM) to clarify the effects of three main components (Fe₂O₃, Al₂O₃, SiO₂) in the RM on the pyrolysis of organic matters in sewage sludge. The modeling results showed that the pyrolysis of organic matters, especially at the higher temperature stage, was promoted by Fe₂O₃ and Al₂O₃ in the RM. Adding Fe₂O₃ or the RM alone could reduce the mean activation energy of sewage sludge pyrolysis by 13.9 and 20.1 kJ mol^?1, respectively. The modeling results were validated by pyrolysis experiments of raw sludge with different additives at 600, 700, 800, and 900 °C. The experimental results showed that the addition of Al₂O₃, Fe₂O₃ or the RM could produce more gas than the addition of SiO₂, especially at high temperatures. Fe₂O₃ and Al₂O₃ acted as catalysts in the tar decomposition by in-situ catalyzing the cracking of CC and CH bonds to produce more gases. Especially, Fe₂O₃ and Al₂O₃ increased the H₂ yield from sewage sludge pyrolysis at 700, 800, and 900 °C by 268.5 and 50.7%, 111.1 and 56.0%, 10.9 and 10.3%, respectively. The char obtained from pyrolysis of sewage sludge with the RM possessed magnetic property, which has various potential applications. The research indicates that the RM is an efficient catalyst in the pyrolysis of sewage sludge.     

Electrical behaviour of composite plasma polymer/ metal films

Composite thin films were deposited by simultaneous plasma polymerization of C₂F₃Cl or CF₄ monomers and magnetron sputtering of gold in an rf glow discharge. The electrical resistivity was examined as a function of the gold volume fraction. The effect of annealing on the resistance is shown to be influenced by the measuring procedure (in situ or transfer through the ambient atmosphere) and by the nature of the polymer (C₂F₃Cl or CF₄). The changes in the film resistance after annealing are explained in terms of the microstructural rearrangement.     

Impact of fast and slow pyrolysis on the degradation of mixed plastic waste: Product yield analysis and their characterization

This work primarily investigated the pyrolysis of post-consumer mixed plastic wastes during slow pyrolysis (non-isothermal) in a batch reactor to assess the effect of different heating rates on the product yield and its composition. The effect of residence time during fast pyrolysis (Isothermal) in Pyro-GC was also investigated. Initially, TG analysis was performed to investigate the degradation temperature range at different heating rates of 5, 10, 20 and 40 °C/min. Two different heating rates of 10 and 20 °C/min were selected for examining the effect on products such as oil and gases (H₂, CO, CO₂ and C₁-C₆ hydrocarbons) during slow pyrolysis. The oil obtained at higher heating rate had higher density (0.743 kg/m³) while the amount of residue decreased with the increase in heating rate. Also, the effect of residence time during fast pyrolysis was investigated using Pyro-GC at 500 °C for the product formation. It was observed that an optimum residence time of 10sec was favourable for the higher production of lower hydrocarbons (C₁-C₃) and less production of heavier hydrocarbons (C₆). This work represents the combined analysis of fast and slow pyrolysis and their impact on the product yield. Also, the effect of heating rate on non-isothermal condition and the effect of the residence time of volatiles in isothermal condition was analysed and reported.     

Process knowledge inspired opportunistic approach for thermodynamically feasible and efficient design of hydrogen liquefaction process

Hydrogen (H₂) liquefaction process is one of the complex processes because of the highly non-linear interaction between design variables and objective function. Finding a feasible design for such a complex process is challenging. Knowledge of refrigerant selection, composition, cycle temperatures, and compression ratio is essential in finding this feasible design. This study presents a simple, yet efficient approach inspired by process knowledge, known as knowledge-based optimization (KBO), to selecting an optimal mixed refrigerant (MR) composition and studying the effect of each refrigerant on the performance of the H₂ liquefaction process. The infeasible design shows approach temperature (i.e., MITA) values as −33.5 °C, −4.0 °C, and −11.65 °C. The design variables' values are adjusted based on the KBO approach to keep the MITA value in the range of 1–2 °C. The share of each MR component in optimal case is 17% C₁, 5% C₂, 70% C₃, 8% N₂ in precooling, 9% C₁, 80% N₂, 11% H₂ in cooling and 85% H₂, 15% He in liquefaction cycle. Further, the KBO approach guides in selecting the lower and upper limit of each refrigerant based on their impact inside heat exchangers. Additionally, the heat flow behavior of H₂ streams is analyzed for adiabatic and isothermal ortho-to-para reactors. This study will help process engineers and engineering practitioners to develop an energy-efficient and cost-effective initial design for the H₂ liquefaction process.     

Comparison of hydrogen consumption behavior of chromium and manganese promoted copper-based catalysts

CuO/ZnO/Al₂O₃/MgO–Cr and -Mn catalysts are synthesized using nitrate route via co-precipitation method. The precursors are characterized by XRD. The decomposition behavior of the precursors is analyzed by Air-TGA. The catalysts calcined at 250, 300, 350 and 450 °C are characterized by XRD and BET. CuO particle size reduction and surface area of the catalysts are investigated. Increasing the calcination temperature from 350 °C to 450 °C crystallite size increases about 3 nm, and BET surface area decreases about 30 m²/g. The reduction characteristics of the catalysts are analyzed via TPR and H₂-TGA, and H₂ consumption values of Cr and Mn containing catalysts is found as 40% and 60%, respectively. Peak temperatures of Mn containing catalysts (290–325 °C) are lower than peak temperatures of Cr containing catalysts (300–360 °C) as confirmed by H₂-TGA and H₂-DTG. The optimum H₂ consumption value of 52% is obtained with CuO/ZnO/Al₂O₃/MgO–Mn catalyst calcined at 350 °C.     

A new lithium salt with dihydroxybenzene and lithium tetrafluoroborate for lithium battery electrolytes

A new unsymmetrical lithium salt containing F⁻, C₆H₄O₂²⁻ [dianion of 1,2-benzenediol], lithium difluoro(1,2-benzene-diolato(2-)-o,o′)borate (LDFBDB) is synthesized and characterized. Its thermal decomposition in nitrogen begins at 170 °C. The cyclic voltammetry study shows that the LDFBDB solution in propylene carbonate (PC) is stable up to 3.7 V versus Li⁺/Li. It is soluble in common organic solvents. The ionic dissociation properties of LDFBDB are examined by conductivity measurements in PC, PC+ ethyl methyl carbonate (EMC), PC + dimethyl ether (DME), PC + ethylene carbonate (EC) + EMC solutions. The conductivity values of the 0.564 mol dm⁻³ LDFBDB electrolyte in PC + DME solution is 3.90 mS cm⁻¹. All these properties of the new lithium salt including the thermal characteristics, electrochemical stabilities, solubilities, ionic dissociation properties are studied and compared with those of its derivatives, lithium difluoro(3-fluoro-1,2-benzene-diolato(2-)-o,o′)borate (FLDFBDB), lithium [3-fluoro-1,2-benzenediolato(2-)-o,o′ oxalato]borate (FLBDOB), and lithium bis(oxalate)borate (LBOB).     

Screening alternatives for producing paraffinic phase change materials for thermal energy storage in buildings

Screening alternatives for producing paraffinic phase change materials (PCMs) from natural gas‐based products was investigated. Based on the quality and cost of these PCMs, two sources were identified: (i) hydrogenated gas‐to‐liquid (GTL) products such as heavy detergent feedstocks; and (ii) linear alpha olefins. Fractionation of a typical hydrogenated GTL mixture, containing C₁₄ – C₁₈ alkene and alkane hydrocarbons, has been experimentally conducted to produce five paraffinic PCMs with melting points between 3 and 28 °C. ChemCAD simulation has been proved to be a valid tool for predicting the behaviour of the GTL fractionation, including optimum experimental conditions and compositions of products. Also, hydrogenation of technical 1‐octadecene was experimentally carried out in order to evaluate the quality of PCM produced from one of the available technical alpha‐olefins. All PCMs produced in this work were analysed by gas chromatography equipped with flame ionization detector to determine their compositions and by differential scanning calorimetry to determine their latent heats. The results showed that the PCM with a melting temperature in the range 22 to 25 °C can be technically produced through hydrogenation of commercial 1‐octadecene showing a higher latent heat compared to the PCM produced from fractionation of hydrogenated GTL mixture. Copyright © 2017 John Wiley & Sons, Ltd.