Slow oil shocks and the “weakening of the oil price–macroeconomy relationship”

Many papers have been documenting and analysing the asymmetry and the weakening of the oil price–macroeconomy relationship as off the early eighties. While there seems to be a consensus about the factors causing the asymmetry, namely adjustment costs which offset the benefits of low energy prices, the debate about the weakening of the relationship is not over yet. Moreover, the alternative oil price specifications which have been proposed by Mork (1989), Lee et al. (1995), and Hamilton (1996) to restore the stability of the relationship fail to Granger cause output or unemployment in post-1980 data. By using the concept of accelerations of the oil price, we show that the weakening of this relationship corresponds to the appearance of slow oil price increases, which have less impact on the economy. When filtering out these slow oil price variations from the sample, we manage to rehabilitate the causality running from the oil price to the macroeconomy and show that far from weakening, the oil price accelerations–GDP relationship has even been growing stronger since the early eighties.     

Is there a homogeneous causality pattern between oil prices and currencies of oil importers and exporters?

Although the link between oil prices and dollar exchange rates has been frequently analyzed, a clear distinction between prices and nominal exchange rate dynamics and a clarification of the issue of causality has not been provided. In addition, previous studies have mostly neglected nonlinearities which for example may stem from exogenous oil price shocks. Using monthly data for various oil-exporting and oil-importing countries, this study contributes to the clarification of those issues. We discriminate between long-run and time-varying short-run dynamics, using a Markov-switching vector error correction model. In terms of causality, the results differ between the economies under observation but suggest that the most important causality runs from exchange rates to oil prices, with a depreciation of the dollar triggering an increase in oil prices. On the other hand, changes in nominal oil prices are responsible for ambiguous real exchange rate effects mostly through the price differential and partly also through a direct influence on the nominal exchange rate. Overall, the fact that the adjustment pattern frequently differs between regimes underlines the fact that the relationships are subject to changes over time, suggesting that nonlinearities are an important issue when analyzing oil prices and exchange rates.     

Examining crude oil price – Exchange rate nexus for India during the period of extreme oil price volatility

This study probes crude oil price – exchange rate nexus for India using daily data for the time span July 2, 2007–November 28, 2008. Generalized autoregressive conditional heteroskedasticity (GARCH) and exponential GARCH (EGARCH) models have been employed to examine the impact of oil price shocks on nominal exchange rate. The study reveals that an increase in the oil price return leads to the depreciation of Indian currency vis-à-vis US dollar. The study also establishes that positive and negative oil price shocks have similar effects, in terms of magnitude, on exchange rate volatility and oil price shocks have permanent effect on exchange rate volatility.     

How do oil price shocks affect the output volatility of the U.S. energy mining industry? The roles of structural oil price shocks

This paper focuses on how explicit structural shocks that characterize the endogenous character of international oil price change affect the output volatility of the U.S. crude oil and natural gas mining industries. To this end, we employ a modified structural vector autoregressive model (SVAR) to decompose real oil-price changes into four components: U.S. supply shocks, non-U.S. supply shocks, aggregate demand shocks, and oil-specific demand shocks mainly driven by precautionary demand. The results indicate that output volatility of the U.S. crude oil and natural gas mining industry has significantly negative responses to U.S. supply shocks, aggregate demand shocks, and oil-specific demand shocks, while lacks significant response to non-U.S. supply shocks. Variance decomposition and historical decomposition confirm that U.S. supply shocks occupy most explaining variations in output volatility among the four structural oil shocks. Moreover, the oil-specific demand shocks explain more variation than that of aggregate demand shocks for the crude oil mining industry, but the opposite is true for the natural gas mining industry.     

What is behind the increase in oil prices? Analyzing oil consumption and supply relationship with oil price

The continuing increases in oil prices have renewed the argument over the real culprits behind these movements. The growth in demand for oil in international markets, especially from the United States and China, is often identified as the main source of consumption pressure on prices, and thus the upward trend in oil prices. This paper uses unit root tests with two endogenous breaks to analyze the characteristics of oil prices, production, and consumption for several countries. By taking into account structural breaks, we find that many countries’ oil consumption and oil prices are stationary, while other countries are not. We also perform causality tests to determine the direction of any possible relationship between oil price and oil consumption and production. Our statistical analysis reveals that production variables cause oil prices, while oil prices tend to cause consumption. As a result, we claim that the blame for the recent fluctuations in oil prices is more appropriately associated with supply factors, not consumption influences.     

Technical aspects of production and analysis of biodiesel from used cooking oil—A review

The increasing awareness of the depletion of fossil fuel resources and the environmental benefits of biodiesel fuel has made it more attractive in recent times. The cost of biodiesel, however, is the major hurdle to its commercialization in comparison to petroleum-based diesel fuel. The high cost is primarily due to the raw material, mostly neat vegetable oil. Used cooking oil is one of the economical sources for biodiesel production. However, the products formed during frying, can affect the transesterification reaction and the biodiesel properties. This paper attempts to review various technological methods of biodiesel production from used cooking oil. The analytical methods for high quality biodiesel fuel from used cooking oil like GC, TLC, HPLC, GPC and TGA have also been summarized in this paper. In addition, the specifications provided by different countries are presented. The fuel properties of biodiesel fuel from used cooking oil were also reviewed and compared with those of conventional diesel fuel.     

Optimization of biodiesel production from Pungamia oil by Taguchi’s technique

In biodiesel production process, not all fatty acid chains are turned into alkyl esters (biodiesel). This phenomenon reduces the biodiesel quality and yield significantly. Therefore, optimization of biodiesel production process is very much essential to attain maximum yield. In this work, biodiesel production from raw Pungamia oil was optimized by using Taguchi’s method. The L9 orthogonal array was used to optimize the maximum yield of biodiesel production. The parameters like stirrer speed, concentration of NaOH catalyst, and reaction time for producing maximum yield of methyl esters from raw Pungamia oil is reported. In this analysis, signal-to-noise ratio (S/N ratio) and the analysis of variance (ANOVA) are employed to identify and quantify the maximum yield. The analysis revealed that 550 rpm stirrer speed, 15 g of NaOH catalyst, and 80 min reaction time are the optimum parameters for methyl esters of biodiesel production from raw Pungamia oil.     

Application of different EOR techniques for the energy and recovery of Ashal’cha oil field

In this research, utilizing the reservoir and produced oil data, different enhanced oil recovery (EOR) techniques known as in-situ combustion, CO₂ flooding, and steam flooding were applied for Ashal’cha oil field in Republic of Tatarstan, Russia. For this purpose, In-Situ Combustion Predictive Model (ICPM), CO₂ Miscible Flood Predictive Model (CO₂PM) and Steam-flood Predictive Model (SFPM) are used. In addition to oil recovery, economic analysis of the discussed EOR applications was also conducted. By using the oil price forecast for 10 years, each EOR method is analyzed using their expenses and outcomes separately. Comparison among the EOR applications regarding the oil production, and economic feasibility was also given. Taking the reservoir and produced oil characteristics, oil production rate and economical payout time into account, it was observed that in-situ combustion is the most feasible and practical EOR method for Ashal’cha oil field.     

Optimization of biodiesel production from grape seed oil using Taguchi's orthogonal array​

The physicochemical properties of biodiesel are very similar to those of petroleum diesel fuel. The main focus of this study is the production of the biodiesel from grape seed oil. This study shows the optimization of the operation parameters, specifically regarding catalyst concentration, the reaction time, the molar ratio (i.e., methanol-to-oil ratio), and the reaction temperature for the production of biodiesel. The effect of operation factors on performance parameters is analyzed using Taguchi’s orthogonal array. The results depict that 96.90% was the optimum biodiesel yield at a molar ratio 6:1 with a catalyst concentration of 1% by weight and a reaction time of 60 min at 60°C and 4.34 cSt was the optimum biodiesel viscosity at a molar ratio of 6:1 with a catalyst concentration of 0.5% by weight and a reaction time of 75 min at 45°C. The most effective parameter was observed to be catalyst concentration, which conferred 76.39%, and 53.74% of the total influence on the biodiesel yield (Y₁) and viscosity (Y₂), respectively.     

Application of β-MnO2 nanorods as catalyst in single step production of biodiesel from palm oil

Fatty acid methyl ester, which is known as biodiesel obtained from vegetable oils, has been considered as a promising remedy for fossil fuel depletion and environmental degradation. In the present research, fatty acid methyl ester is produced by transesterification of palm oil using β-MnO₂ nano rods. The catalyst was synthesized and characterized by X-ray powder diffraction, Fourier Transform Infrared, and scanning electron microscope analysis. Catalyst activity towards transesterification of palm oil was examined. The reaction parameters were optimized by the classical method and were found to be 60°C, 0.5% catalyst, and methanol to oil molar ratio of 9:1. Kinetic and thermodynamic studies were also performed.     

Comparative analysis of various techniques to improve the performance of novel wheat germ oil – an experimental study

The current study aims to explore the opportunities of using the high viscous biofuel namely Wheat Germ oil (WGO) in a twin cylinder CI engine. High viscous fuels suffer from improper atomization leading to poor combustion and higher smoke emission. To address this problem, various techniques namely transesterification, fuel ionization and hydrogen induction were studied. WGO was converted to its ester which reduced the viscosity. Fuel ionization increases the vibrational frequency of the molecules, weakens the bonds and converted to ions, which increases the dispersion rate during injection and improves the combustion subsequently. Hydrogen is having faster flame speed and higher calorific value aids in combustion enhancement at its knock limited levels.The twin cylinder tractor engine selected for this experiment runs at a constant speed of 1500 rpm. The engine was run using diesel to achieve the preferred warm-up condition in order to use WGO, which hada cold starting problem. Tests were conducted with wheat germ biodiesel (WGBD), WGO with permanent magnet (PM), electromagnet (EM) and the combination of PM and EM-based fuel ionization system and finally WGO with hydrogen induction rates of 2%, 4.3%, 6.7% and 10.3% at maximum engine load condition. It is observed that all the techniques improved the performance of WGO. Among the techniques tested, hydrogen induction displayed better results in terms of performance and emission characteristics with a slight penalty in NO emission.     

Potentiality of “orujillo” (olive oil solid waste) to produce hydrogen by means of pyrolysis

The extraction of olive oil generates great amounts of solid waste and wastewater. The objective of this work is to evaluate the potentiality of slow pyrolysis of the solid oil waste, known as “orujillo”, to produce hydrogen rich gases. The effect of temperature and of different treatments of pyrolysis vapors on the yield and composition of the gases has been experimentally studied. “Orujillo” was pyrolyzed at 500 °C and 700 °C, and the pyrolysis vapors produced were directly fed to a second reactor where they were treated at 800 °C in different ways: just thermally, thermally treated through a refractory alumina bed and thermo-catalytically treated through a three layer bed (alumina + SiC mixed with Ni catalyst + alumina). The catalyst used was a commercial prereduced nickel-catalyst which contains 44 wt% Ni over calcium aluminate support (CaO/Al₂O₃). Concerning the effect of temperature, it has been proved that the raise in temperature leads to a decrease in the liquid yields and an increase in the gas yields, as well as to an increase in H₂ and a decrease in CO₂ content of the gases. With respect to the vapors treatments it has been observed that as a general rule any of the treatments reduces liquid and increases gas yields, and concerning gas composition, H₂ content increases, CO slightly increases and CO₂ decreases. These effects are more pronounced when the Ni-catalyst is used. With the Ni-catalyst about 50 wt% gas yield is obtained, with ≈ 50 vol% H₂ both at 500 and at 700 °C.     

Asymmetric effects of oil prices and exchange rates on China’s industrial prices

This paper explores the impacts of positive and negative changes in crude oil price and exchange rate variables on raw material procurement prices and product ex-factory prices of China’s industrial enterprises. We run the nonlinear autoregressive distributed lag (NARDL) model for the full sample from January 2000 to June 2019, and find the existence of the cointegrating relationships and the asymmetries of the long-run effects from positive and negative changes in oil price and exchange rate variables. Then, we run the OLS and quantile regressions for the two subsamples. Through the analysis of the estimates in different quantities in the latter model, we obtain rich and novel findings. The main findings include the inconsistency between the practice of oil price and exchange rate transmissions in China and the usual theoretical explanations, and the active roles of China’s oil product mechanism and exchange rate policy reforms in mitigating transmission distortions. In addition, we also find other asymmetries such as the asymmetric effects in different locations of dependent variable’s conditional distribution, and the different effects on raw material prices and product ex-factory prices from the same independent variables.     

Does oil price affect the value of firms? Evidence from Tunisian listed firms

A new debate on the potential impact of oil price changes on the value of firms was initiated in this paper. Using a stochastic frontier approach, an attempt was made to derive the optimal value Q* of firms and calculate the Q value observed. Then the shortfall (Q*–Q) which represents the inefficiency term was explained. Starting from 19 industrial Tunisian firms listed on the Tunis Stock Exchange between 2007 and 2011, the fact that variation of oil prices can largely explain distortions in the value of firms was empirically demonstrated.     

Impacts of nano-metal oxides on hydrogen production in anaerobic digestion of palm oil mill effluent – A novel approach

In the present study, hydrogen production from palm oil mill effluent (POME) was investigated with the incorporation of nanoparticles (NPs) comprising of nickel (NiO) and cobalt oxides (CoO). The NPs of NiO and CoO were prepared using hydrothermal method and were further applied to analyse, their effect on hydrogen production. The results demonstrated that, a maxima volumetric hydrogen production rate of 21 ml H₂/L-POME/h with the hydrogen yield of 0.563 L H₂/g-COD_removed was obtained with 1.5 mg/L concentration of NiO NPs. On the other hand, the addition of CoO NPs produced maximum volumetric hydrogen production rate of 18 ml H₂/L-POME/h with a hydrogen yield of 0.487 L H₂/g-COD_removed with 1.0 mg/L of CoO NPs. Results showed that addition of optimal concentration of NiO and CoO NPs to the POME enhances the hydrogen yield by 1.51 and 1.67 fold respectively. Besides, this addition of NiO and CoO enhanced the COD removal efficiency by 15 and 10% respectively as compared to an un-additive NPs POME. The toxicity of NPs was also tested using bacterial viability test, which revealed that application of 3.0 mg/L of NiO and CoO NPs to modified Luria-Bertani (LB) medium had 63% and 83% reduction in bacterial cell growth. The results concluded that supplementation of NiO and CoO NPs under an optimal range to the wastewater can improve the hydrogen productivity.     

Thermal and rheological characteristics of CuO–Base oil nanofluid flow inside a circular tube

In the present experimental investigation, stable CuO–Base oil nanofluids with different particle weight fractions of 0.2% to 2% are prepared. Then, these fluids are used for heat transfer measurements as well as rheological behavior investigation. Density, thermal conductivities, viscosities and specific heat capacities of base fluid and all nanofluids at different temperatures are measured and the effect of nanoparticles concentration on fluid properties is investigated. Also, heat transfer characteristics of CuO–Base oil nanofluids laminar flow in a smooth tube under constant heat flux are studied experimentally. Experimental results clearly indicate that addition of nanoparticles into the base fluid enhances the thermal conductivity of the fluid and the enhancement increases with increasing of particle concentration. For the particle concentrations tested, nanofluids exhibit Newtonian behavior. It is observed that the dynamic viscosity substantially increases with the increase in nanoparticle concentration and this increase is more pronounced at the lower temperatures of the nanofluid. The specific heat capacity of nanofluids is significantly less than that of base fluid and it is decreased with the increase in nanofluid concentration. The results show that for a specific nanoparticle concentration, there is an increase in heat transfer coefficient of nanofluid flow compared to pure oil flow. A maximum increase of 12.7% in Heat Transfer coefficient was observed for 2 wt.% nanofluid at the highest Reynolds number studied in this investigation. Furthermore, heat transfer coefficients obtained using experimental fluid properties are compared to those obtained using the existing theoretical models for fluid properties.     

The economic viability of gas-to-liquids technology and the crude oil–natural gas price relationship

This paper explores the viability of a gas-to-liquids (GTL) technology and examines how GTL penetration could shape the evolution of the crude oil–natural gas price ratio. Much research has established the cointegrated relationship between crude oil and natural gas prices in the U.S. The persistently low U.S. natural gas prices in recent years seem to mark a shift in this relationship, and have led some in industry to begin considering investments in GTL capacity in the US. In order to look forward over decades when the underlying economic drivers may be outside of historical experience, we use a computable general equilibrium model of the global economy to evaluate the economic viability of GTL and its impact on the evolution of the crude oil–natural gas price ratio. Our results are negative for the potential role of GTL. In order to produce any meaningful penetration of GTL, we find it necessary to evaluate scenarios that seem extreme. With any carbon cap GTL is not viable. Moreover, even without a carbon cap of any kind, extremely optimistic assumptions about (i) the cost and efficiency of GTL technology and about (ii) the available resource base of natural gas and the cost of extraction, before the technology penetrates and it impacts the evolution of the crude oil–natural gas price ratio.     

Combustion,emission and engine performance characteristics of used cooking oil biodiesel—A review

As the environment degrades at an alarming rate, there have been steady calls by most governments following international energy policies for the use of biofuels. One of the biofuels whose use is rapidly expanding is biodiesel. One of the economical sources for biodiesel production which doubles in the reduction of liquid waste and the subsequent burden of sewage treatment is used cooking oil (UCO). However, the products formed during frying, such as free fatty acid and some polymerized triglycerides, can affect the transesterification reaction and the biodiesel properties. This paper attempts to collect and analyze published works mainly in scientific journals about the engine performance, combustion and emissions characteristics of UCO biodiesel on diesel engine. Overall, the engine performance of the UCO biodiesel and its blends was only marginally poorer compared to diesel. From the standpoint of emissions, NOx emissions were slightly higher while un-burnt hydrocarbon (UBHC) emissions were lower for UCO biodiesel when compares to diesel fuel. There were no noticeable differences between UCO biodiesel and fresh oil biodiesel as their engine performances, combustion and emissions characteristics bear a close resemblance. This is probably more closely related to the oxygenated nature of biodiesel which is almost constant for every biodiesel (biodiesel has some level of oxygen bound to its chemical structure) and also to its higher viscosity and lower calorific value, which have a major bearing on spray formation and initial combustion.     

Who benefits from local oil and gas employment? Labor market composition in the oil and gas industry in Texas and the rest of the United States

This paper examines local labor market outcomes from an oil and gas boom. We examine two main outcomes; the probability of employment and the log wages of workers employed outside the oil and gas industry for Texas and the rest of the United States across gender, race, and ethnicity. We find that men and women gain employment in the oil and gas industry during booms, but such gains are much larger for men and are largest for black and Hispanic men. We also find positive income spillovers for workers in other industries that are similar in magnitude across demographic groups.     

Optimization of the operating conditions for steam reforming of slow pyrolysis oil over an activated biochar-supported Ni–Co catalyst

Highly performing activated biochar-based catalysts were produced for steam reforming of slow pyrolysis oil. The raw biochar obtained from the slow pyrolysis step was physically activated with CO₂ at 700 °C and 1.0 MPa and then employed as support. Preliminary tests on steam reforming of acetic acid at 600 °C showed that using activated biochar-supported catalysts containing 10 wt % Ni and 7 wt % Co led to a conversion above 90% with a relatively slow deactivation rate. When a representative organic model compounds mixture was used as feed, relatively fast deactivation of the catalyst was observed, probably due to the adsorption of heavy organic compounds, which could subsequently react to form not easily desorbable reaction intermediates. However, the dual Ni–Co catalysts exhibited a good performance during the steam reforming of a real slow pyrolysis oil at 750 °C, showing long stability and a constant carbon conversion of 65%.